WorldWideScience

Sample records for abrupt climate-driven ecosystem

  1. Causes and projections of abrupt climate-driven ecosystem shifts in the North Atlantic

    DEFF Research Database (Denmark)

    Beaugrand, G.; Edwards, M.; Brander, Keith

    2008-01-01

    Warming of the global climate is now unequivocal and its impact on Earth' functional units has become more apparent. Here, we show that marine ecosystems are not equally sensitive to climate change and reveal a critical thermal boundary where a small increase in temperature triggers abrupt...... ecosystem shifts seen across multiple trophic levels. This large-scale boundary is located in regions where abrupt ecosystem shifts have been reported in the North Atlantic sector and thereby allows us to link these shifts by a global common phenomenon. We show that these changes alter the biodiversity...... and carrying capacity of ecosystems and may, combined with fishing, precipitate the reduction of some stocks of Atlantic cod already severely impacted by exploitation. These findings offer a way to anticipate major ecosystem changes and to propose adaptive strategies for marine exploited resources such as cod...

  2. Abrupt climate-independent fire regime changes

    Science.gov (United States)

    Pausas, Juli G.; Keeley, Jon E.

    2014-01-01

    Wildfires have played a determining role in distribution, composition and structure of many ecosystems worldwide and climatic changes are widely considered to be a major driver of future fire regime changes. However, forecasting future climatic change induced impacts on fire regimes will require a clearer understanding of other drivers of abrupt fire regime changes. Here, we focus on evidence from different environmental and temporal settings of fire regimes changes that are not directly attributed to climatic changes. We review key cases of these abrupt fire regime changes at different spatial and temporal scales, including those directly driven (i) by fauna, (ii) by invasive plant species, and (iii) by socio-economic and policy changes. All these drivers might generate non-linear effects of landscape changes in fuel structure; that is, they generate fuel changes that can cross thresholds of landscape continuity, and thus drastically change fire activity. Although climatic changes might contribute to some of these changes, there are also many instances that are not primarily linked to climatic shifts. Understanding the mechanism driving fire regime changes should contribute to our ability to better assess future fire regimes.

  3. Abrupt climate change:Debate or action

    Institute of Scientific and Technical Information of China (English)

    CHENG Hai

    2004-01-01

    Global abrupt climate changes have been documented by various climate records, including ice cores,ocean sediment cores, lake sediment cores, cave deposits,loess deposits and pollen records. The climate system prefers to be in one of two stable states, i.e. interstadial or stadial conditions, but not in between. The transition between two states has an abrupt character. Abrupt climate changes are,in general, synchronous in the northern hemisphere and tropical regions. The timescale for abrupt climate changes can be as short as a decade. As the impacts may be potentially serious, we need to take actions such as reducing CO2emissions to the atmosphere.

  4. The resilience of postglacial hunter-gatherers to abrupt climate change.

    Science.gov (United States)

    Blockley, Simon; Candy, Ian; Matthews, Ian; Langdon, Pete; Langdon, Cath; Palmer, Adrian; Lincoln, Paul; Abrook, Ashley; Taylor, Barry; Conneller, Chantal; Bayliss, Alex; MacLeod, Alison; Deeprose, Laura; Darvill, Chris; Kearney, Rebecca; Beavan, Nancy; Staff, Richard; Bamforth, Michael; Taylor, Maisie; Milner, Nicky

    2018-05-01

    Understanding the resilience of early societies to climate change is an essential part of exploring the environmental sensitivity of human populations. There is significant interest in the role of abrupt climate events as a driver of early Holocene human activity, but there are very few well-dated records directly compared with local climate archives. Here, we present evidence from the internationally important Mesolithic site of Star Carr showing occupation during the early Holocene, which is directly compared with a high-resolution palaeoclimate record from neighbouring lake beds. We show that-once established-there was intensive human activity at the site for several hundred years when the community was subject to multiple, severe, abrupt climate events that impacted air temperatures, the landscape and the ecosystem of the region. However, these results show that occupation and activity at the site persisted regardless of the environmental stresses experienced by this society. The Star Carr population displayed a high level of resilience to climate change, suggesting that postglacial populations were not necessarily held hostage to the flickering switch of climate change. Instead, we show that local, intrinsic changes in the wetland environment were more significant in determining human activity than the large-scale abrupt early Holocene climate events.

  5. Paleoclimate from ice cores : abrupt climate change and the prolonged Holocene

    International Nuclear Information System (INIS)

    White, J.W.C.

    2001-01-01

    Ice cores provide valuable information about the Earth's past climates and past environments. They can also help in predicting future climates and the nature of climate change. Recent findings in ice cores have shown large and abrupt climate changes in the past. This paper addressed abrupt climate changes and the peculiar nature of the Holocene. An abrupt climate change is a shift of 5 degrees C in mean annual temperature in less than 50 years. This is considered to be the most threatening aspect of potential future climate change since it leaves very little time for adaptation by humans or any other part of the Earth's ecosystem. This paper also discussed the arrival of the next glacial period. In the past 50 years, scientists have recognized the importance of the Earth's orbit around the sun in pacing the occurrence of large ice sheets. The timing of orbital forcing suggests that the Earth is overdue for the next major glaciation. The reason for this anomaly was discussed. Abrupt climate shifts seem to be caused by mode changes in sensitive points in the climate system, such as the North Atlantic Deep Water Formation and its impact on sea ice cover in the North Atlantic. These changes have been observed in ice cores in Greenland but they are not restricted to Greenland. Evidence from Antarctic ice cores suggest that abrupt climate change may also occur in the Southern Hemisphere. The Vostok ice core in Antarctica indicates that the 11,000 year long interglacial period that we are in right now is longer than the previous four interglacial periods. The Holocene epoch is unique because both methane and carbon dioxide rise in the last 6,000 years, an atypical response from these greenhouse gases during an interglacial period. It was suggested that the rise in methane can be attributed to human activities. 13 refs., 2 figs

  6. Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

    Science.gov (United States)

    Buermann, Wolfgang; Beaulieu, Claudie; Parida, Bikash; Medvigy, David; Collatz, George J.; Sheffield, Justin; Sarmiento, Jorge L.

    2016-03-01

    The world's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, have uncovered an abrupt, substantial ( ˜ 1 PgC yr-1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been ˜ 30 % larger than observed (or ˜ 12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production significantly increased in the late 1980s (more so than heterotrophic respiration), consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

  7. Climate Stability: Pathway to understand abrupt glacial climate shifts

    Science.gov (United States)

    Zhang, X.; Knorr, G.; Barker, S.; Lohmann, G.

    2017-12-01

    Glacial climate is marked by abrupt, millennial-scale climate changes known as Dansgaard-Oeschger (DO) cycles that have been linked to variations in the Atlantic meridional overturning circulation (AMOC). The most pronounced stadial coolings, Heinrich Stadials (HSs), are associated with massive iceberg discharges to the North Atlantic. This motivates scientists to consider that the North Atlantic freshwater perturbations is a common trigger of the associated abrupt transitions between weak and strong AMOC states. However, recent studies suggest that the Heinrich ice-surging events are triggered by ocean subsurface warming associated with an AMOC slow-down. Furthermore, the duration of ice-rafting events does not systematically coincide with the beginning and end of the pronounced cold conditions during HSs. In this context, we show that both, changes in atmospheric CO2 and ice sheet configuration can provide important control on the stability of the AMOC, using a coupled atmosphere-ocean model. Our simulations reveal that gradual changes in Northern Hemisphere ice sheet height and atmospheric CO2 can act as a trigger of abrupt glacial/deglacial climate changes. The simulated global climate responses—including abrupt warming in the North Atlantic, a northward shift of the tropical rain belts, and Southern Hemisphere cooling related to the bipolar seesaw—are generally consistent with empirical evidence. We further find that under a delicate configuration of atmospheric CO2 and ice sheet height the AMOC can be characterized by a self-oscillation (resonance) feature (Hopf Bifucation) with a 1000-year cycle that is comparable with observed small DO events during the MIS 3. This provides an alternative explanation for millennial-scale DO variability during glacial periods.

  8. The adaptation rate of terrestrial ecosystems as a critical factor in global climate dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Fuessler, J S; Gassmann, F [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A conceptual climate model describing regional two-way atmosphere-vegetation interaction has been extended by a simple qualitative scheme of ecosystem adaptation to drought stress. The results of this explorative study indicate that the role of terrestrial vegetation under different forcing scenarios depends crucially on the rate of the ecosystems adaptation to drought stress. The faster the adaptation of important ecosystems such as forests the better global climate is protected from abrupt climate changes. (author) 1 fig., 3 refs.

  9. A Data-Driven Assessment of the Sensitivity of Global Ecosystems to Climate Anomalies

    Science.gov (United States)

    Miralles, D. G.; Papagiannopoulou, C.; Demuzere, M.; Decubber, S.; Waegeman, W.; Verhoest, N.; Dorigo, W.

    2017-12-01

    Vegetation is a central player in the climate system, constraining atmospheric conditions through a series of feedbacks. This fundamental role highlights the importance of understanding regional drivers of ecological sensitivity and the response of vegetation to climatic changes. While nutrient availability and short-term disturbances can be crucial for vegetation at various spatiotemporal scales, natural vegetation dynamics are overall driven by climate. At monthly scales, the interactions between vegetation and climate become complex: some vegetation types react preferentially to specific climatic changes, with different levels of intensity, resilience and lagged response. For our current Earth System Models (ESMs) being able to capture this complexity is crucial but extremely challenging. This adds uncertainty to our projections of future climate and the fate of global ecosystems. Here, following a Granger causality framework based on a non-linear random forest predictive model, we exploit the current wealth of satellite data records to uncover the main climatic drivers of monthly vegetation variability globally. Results based on three decades of satellite data indicate that water availability is the most dominant factor driving vegetation in over 60% of the vegetated land. This overall dependency of ecosystems on water availability is larger than previously reported, partly owed to the ability of our machine-learning framework to disentangle the co-linearites between climatic drivers, and to quantify non-linear impacts of climate on vegetation. Our observation-based results are then used to benchmark ESMs on their representation of vegetation sensitivity to climate and climatic extremes. Our findings indicate that the sensitivity of vegetation to climatic anomalies is ill-reproduced by some widely-used ESMs.

  10. Modelling marine community responses to climate-driven species redistribution to guide monitoring and adaptive ecosystem-based management

    NARCIS (Netherlands)

    Marzloff, Martin Pierre; Melbourne-Thomas, Jessica; Hamon, Katell G.; Hoshino, Eriko; Jennings, Sarah; Putten, Van Ingrid E.; Pecl, Gretta T.

    2016-01-01

    As a consequence of global climate-driven changes, marine ecosystems are experiencing polewards redistributions of species – or range shifts – across taxa and throughout latitudes worldwide. Research on these range shifts largely focuses on understanding and predicting changes in the distribution of

  11. The Vulnerability of Forest Ecosystems of Armenia to the Global Climate Change

    Science.gov (United States)

    Khachatryan, S.

    2009-05-01

    Climate changes characterized as global warming can lead to irreversible effects on regional and global scales, such as drought, pest attacks, diseases, excessive forest fires, and climate driven extinction of numerous animal and plant species. We assess the issues that the development of forestry in Armenia faces, where the climate change is causing the landscape zone borders in the territory to shift. This will have a significant impact on the most vulnerable tree species in Armenia. An increase in climate aridity and intensification of desertification can be expected under the projected escalated temperatures and reduced precipitation. For example, we can consider average annual temperature of the Ijevan meteorological station (located in forestry region) for the period of 1936-2008. We analyze the vulnerability of forest ecosystems in Armenia to climatic and anthropogenic factors for the period of 1936-2008. Temperature and precipitation data from 25 meteorological stations in the territory of Armenia is studied for the period of 1936-2008. The dynamic of average temperature annual anomalies are revealed. The deviations of temperature and precipitation from the norms (average for 1961-1990) are evaluated for the period of study. We discuss the reasons for the abrupt increase in temperature and decrease in precipitation. Based on the dataset, the possible near future impact of global climate change on the Armenian forest ecosystems is discussed, and measures on the adaptation to the adverse consequences that climate change has on forests are offered.

  12. Abrupt warming of the Red Sea

    KAUST Repository

    Raitsos, D. E.

    2011-07-19

    Coral reef ecosystems, often referred to as “marine rainforests,” concentrate the most diverse life in the oceans. Red Sea reef dwellers are adapted in a very warm environment, fact that makes them vulnerable to further and rapid warming. The detection and understanding of abrupt temperature changes is an important task, as ecosystems have more chances to adapt in a slowly rather than in a rapid changing environment. Using satellite derived sea surface and ground based air temperatures, it is shown that the Red Sea is going through an intense warming initiated in the mid-90s, with evidence for an abrupt increase after 1994 (0.7°C difference pre and post the shift). The air temperature is found to be a key parameter that influences the Red Sea marine temperature. The comparisons with Northern Hemisphere temperatures revealed that the observed warming is part of global climate change trends. The hitherto results also raise additional questions regarding other broader climatic impacts over the area.

  13. Abrupt warming of the Red Sea

    Science.gov (United States)

    Raitsos, D. E.; Hoteit, I.; Prihartato, P. K.; Chronis, T.; Triantafyllou, G.; Abualnaja, Y.

    2011-07-01

    Coral reef ecosystems, often referred to as “marine rainforests,” concentrate the most diverse life in the oceans. Red Sea reef dwellers are adapted in a very warm environment, fact that makes them vulnerable to further and rapid warming. The detection and understanding of abrupt temperature changes is an important task, as ecosystems have more chances to adapt in a slowly rather than in a rapid changing environment. Using satellite derived sea surface and ground based air temperatures, it is shown that the Red Sea is going through an intense warming initiated in the mid-90s, with evidence for an abrupt increase after 1994 (0.7°C difference pre and post the shift). The air temperature is found to be a key parameter that influences the Red Sea marine temperature. The comparisons with Northern Hemisphere temperatures revealed that the observed warming is part of global climate change trends. The hitherto results also raise additional questions regarding other broader climatic impacts over the area.

  14. Abrupt climate change in the computer: Is it real?

    OpenAIRE

    Stocker, Thomas F.; Marchal, Olivier

    2000-01-01

    Models suggest that dramatic changes in the ocean circulation are responsible for abrupt climate changes during the last ice age and may possibly alter the relative climate stability of the last 10,000 years.

  15. Climate, carbon cycling, and deep-ocean ecosystems.

    Science.gov (United States)

    Smith, K L; Ruhl, H A; Bett, B J; Billett, D S M; Lampitt, R S; Kaufmann, R S

    2009-11-17

    Climate variation affects surface ocean processes and the production of organic carbon, which ultimately comprises the primary food supply to the deep-sea ecosystems that occupy approximately 60% of the Earth's surface. Warming trends in atmospheric and upper ocean temperatures, attributed to anthropogenic influence, have occurred over the past four decades. Changes in upper ocean temperature influence stratification and can affect the availability of nutrients for phytoplankton production. Global warming has been predicted to intensify stratification and reduce vertical mixing. Research also suggests that such reduced mixing will enhance variability in primary production and carbon export flux to the deep sea. The dependence of deep-sea communities on surface water production has raised important questions about how climate change will affect carbon cycling and deep-ocean ecosystem function. Recently, unprecedented time-series studies conducted over the past two decades in the North Pacific and the North Atlantic at >4,000-m depth have revealed unexpectedly large changes in deep-ocean ecosystems significantly correlated to climate-driven changes in the surface ocean that can impact the global carbon cycle. Climate-driven variation affects oceanic communities from surface waters to the much-overlooked deep sea and will have impacts on the global carbon cycle. Data from these two widely separated areas of the deep ocean provide compelling evidence that changes in climate can readily influence deep-sea processes. However, the limited geographic coverage of these existing time-series studies stresses the importance of developing a more global effort to monitor deep-sea ecosystems under modern conditions of rapidly changing climate.

  16. Effects of land cover and regional climate variations on long-term spatiotemporal changes in sagebrush ecosystems

    Science.gov (United States)

    Xian, George Z.; Homer, Collin G.; Aldridge, Cameron L.

    2012-01-01

    This research investigated the effects of climate and land cover change on variation in sagebrush ecosystems. We combined information of multi-year sagebrush distribution derived from multitemporal remote sensing imagery and climate data to study the variation patterns of sagebrush ecosystems under different potential disturbances. We found that less than 40% of sagebrush ecosystem changes involved abrupt changes directly caused by landscape transformations and over 60% of the variations involved gradual changes directly related to climatic perturbations. The primary increases in bare ground and declines in sagebrush vegetation abundance were significantly correlated with the 1996-2006 decreasing trend in annual precipitation.

  17. Climate-driven changes in the ecological stoichiometry of aquatic ecosystems

    NARCIS (Netherlands)

    van de Waal, D.B.; Verschoor, A.M.; Verspagen, J.M.H.; van Donk, E.; Huisman, J.

    2010-01-01

    Advances in ecological stoichiometry, a rapidly expanding research field investigating the elemental composition of organisms and their environment, have shed new light on the impacts of climate change on freshwater and marine ecosystems. Current changes in the Earth's climate alter the availability

  18. Future of African terrestrial biodiversity and ecosystems under anthropogenic climate change

    Science.gov (United States)

    Midgley, Guy F.; Bond, William J.

    2015-09-01

    Projections of ecosystem and biodiversity change for Africa under climate change diverge widely. More than other continents, Africa has disturbance-driven ecosystems that diversified under low Neogene CO2 levels, in which flammable fire-dependent C4 grasses suppress trees, and mega-herbivore action alters vegetation significantly. An important consequence is metastability of vegetation state, with rapid vegetation switches occurring, some driven by anthropogenic CO2-stimulated release of trees from disturbance control. These have conflicting implications for biodiversity and carbon sequestration relevant for policymakers and land managers. Biodiversity and ecosystem change projections need to account for both disturbance control and direct climate control of vegetation structure and function.

  19. Detection and attribution of abrupt climate changes in the last one hundred years

    International Nuclear Information System (INIS)

    Zhang Wen; Wan Shiquan

    2008-01-01

    Based on physical backgrounds, the four time series of the Guliya (Tibetan plateau) ice core (GIC) δ 18 O, and three natural factors, i.e. the rotation rate of earth, sunspots, and El Nino–Southern Oscillation (ENSO) signals, are decomposed into two hierarchies, i.e. more and less than 10-year hierarchies respectively, and then the running t-test is used to reanalyse the data before and after filtering with the purpose of investigating the contribution of natural factors to the abrupt climate changes in the last one hundred years. The results show that the GIC δ 18 O evolved with a quasi-period of 7–9 years, and the abrupt climate changes in the early 1960s and in the period from the end of the 1970s to the beginning of the 1980s resulted from the joint effect of the two hierarchies, in other words, the two interdecadal abrupt changes of climate in the last one hundred years were global. The interannual variations of ENSO and sunspots were the important triggering factors for the abrupt climate changes in the last one hundred years. At the same time, the method of Information Transfer (IT) is employed to estimate the contributions of ENSO signals and sunspots activities to the abrupt climate changes, and it is found that the contribution of the interannual variation of ENSO signals is relatively large

  20. Climate Change Impacts on Ecosystem Services in High Mountain Areas: A Literature Review

    Directory of Open Access Journals (Sweden)

    Ignacio Palomo

    2017-05-01

    Full Text Available High mountain areas are experiencing some of the earliest and greatest impacts of climate change. However, knowledge on how climate change impacts multiple ecosystem services that benefit different stakeholder groups remains scattered in the literature. This article presents a review of the literature on climate change impacts on ecosystem services benefiting local communities and tourists in high mountain areas. Results show a lack of studies focused on the global South, especially where there are tropical glaciers, which are likely to be the first to disappear. Climate change impacts can be classified as impacts on food and feed, water availability, natural hazards regulation, spirituality and cultural identity, aesthetics, and recreation. In turn, climate change impacts on infrastructure and accessibility also affect ecosystem services. Several of these impacts are a direct threat to the lives of mountain peoples, their livelihoods and their culture. Mountain tourism is experiencing abrupt changes too. The magnitude of impacts make it necessary to strengthen measures to adapt to climate change in high mountain areas.

  1. Spontaneous abrupt climate change due to an atmospheric blocking–sea-ice–ocean feedback in an unforced climate model simulation

    NARCIS (Netherlands)

    Drijfhout, S.S.; Gleeson, E.; Dijkstra, H.A.|info:eu-repo/dai/nl/073504467; Livina, V.

    2013-01-01

    Abrupt climate change is abundant in geological records, but climate models rarely have been able to simulate such events in response to realistic forcing. Here we report on a spontaneous abrupt cooling event, lasting for more than a century, with a temperature anomaly similar to that of the Little

  2. Climate-driven changes in water level

    DEFF Research Database (Denmark)

    Hansen, Rikke Bjerring; Olsen, Jesper; Jeppesen, Erik

    2013-01-01

    level rose. Moreover, Nymphaeaceae trichosclereids were abundant during the period of algal enrichment. Cladoceran taxa associated with floating leaved plants or benthic habitats responded in a complex way to changes in water level, but the cladoceran assemblages generally reflected deep lake conditions...... hydrology driven by precipitation. The isotopic, sedimentary and plant macrofossil records suggested that the lake level started to decrease around 8400 cal. yr BP, the decrease accelerating during 8350-8260 before an abrupt increase during 8260-8210. This pattern shows that the climate anomaly started...... rates of cladoceran subfossils and algal pigments, possibly due to increased turbidity and reduced nutrient input during this drier period. Pigment analysis also showed added importance of diatoms and cryptophytes during this climate anomaly, while cyanobacteria became more important when the water...

  3. CLIMOOR. Climate driven changes in the functioning of heath and moorland ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Beier, C. [ed.; Tietema, A.; Riis Nielsen, T.; Emmett, B.; Estiarte, M.; Penuelas, J.; Llorens Guash, L.; Williams, D.; Gordon, C.; Pugh, B.; Roda, F.; Gundersen, P.; Gorissen, A.

    2000-01-01

    Emission of green house gases, partly generated from human activities, reduces the loss of heat from the earth thereby potentially causing climate change. This change in climate has been predicted to result in a 1-3 deg. C increase in temperature with more vigorous rainstorms and prolonged drought periods in the coming 100 years. The consequence of such climatic changes for the terrestrial ecosystems are largely unknown. In order to improve our understanding of the ecosystem response to climate change and thereby to improve the basis for the international negotiations and political decisions to avoid or minimise climate change and its effects, a European research project CLIMOOR has been initiated. The project is a cross European research project involving 6 research groups from Denmark, the Netherlands, UK and Spain and is funded by EU and the participating institutions. The project investigates the potential effects of warming and drought on heath and moorland ecosystems at four European sites. The ecosystems are manipulated at field scale by reducing the heat loss at night by IR-reflective curtains and by removing the precipitation during a 2 month period in the summer. The effects of these manipulations on the plants and the soil are studied. This report describes the technique used to apply the climate change at field scale and presents some preliminary results after the first growing season. EU and the participating institutions fund CLIMOOR. (au)

  4. The Role of the Tropics in Abrupt Climate Changes

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, Alexey [Yale University

    2013-12-07

    Topics addressed include: abrupt climate changes and ocean circulation in the tropics; what controls the ocean thermal structure in the tropics; a permanent El Niño in paleoclimates; the energetics of the tropical ocean.

  5. A Collaborative Proposal: Simulating and Understanding Abrupt Climate-Ecosystem Changes During Holocene with NCAR-CCSM3.

    Energy Technology Data Exchange (ETDEWEB)

    Zhengyu Liu, Bette Otto-Bliesner

    2013-02-01

    We have made significant progress in our proposed work in the last 4 years (3 years plus 1 year of no cost extension). In anticipation of the next phase of study, we have spent time on the abrupt changes since the last glacial maximum. First, we have performed further model-data comparison based on our baseline TRACE-21 simulation and made important progress towards the understanding of several major climate transitions. Second, we have made a significant effort in processing the model output of TRACE-21 and have put this output on a website for access by the community. Third, we have completed many additional sensitivity experiments. In addition, we have organized synthesis workshops to facilitate and promote transient model-data comparison for the international community. Finally, we have identified new areas of interest for Holocene climate changes.

  6. Ecosystem resilience to abrupt late Quaternary change in continental southern Siberia

    Science.gov (United States)

    Harding, Poppy; Mackay, Anson; Bezrukova, Elena; Shchetnikov, Alexander

    2017-04-01

    Quaternary climate variability is dominated by long term orbital forcing along with abrupt sub-Milankovitch events on the scales of millennia to centuries, driven by internal feedback mechanisms, volcanic forcing and fluctuating solar activity. Although these are well documented in the North Atlantic region, their expression is poorly understood in Siberia, particularly in relation to abrupt climatic events. Siberia has the world's highest level of continentality offering an opportunity to study changes remote from oceanic influences and improving understanding of interactions between the Siberian High and other atmospheric systems including the Aleutian Low, Arctic oscillation and Icelandic Low1 and ENSO2. Understanding of palaeoenvironmental change in Siberia is essential due to the region's high sensitivity to climatic change, with warming rates considerably higher than the global average over the past 50 years3, triggering significant environmental changes, including permafrost degradation, shifts in the forest-steppe biome, increases in forest fires and warming of seasonally ice-covered lakes. Additionally, the region provides essential palaeoenvironmental context for early hominins, for example at globally important sites such as Denisova cave4, and megafauna extinctions5. This presentation outlines ongoing work at Lake Baunt, SE Siberia including: key quaternary climate forcings, the site and its regional context, the key methods and preliminary results. These include a dated record back to ˜30ka BP (based on multiple 14C dates and Bayesian age modelling), multiproxy indicators of palaeoproductivity (e.g. biogenic silica and diatom analyses) and lake mixing regimes (inferred from diatom analyses). Together these highlight several key Quaternary fluctuations potentially correlated to events recorded in Greenland Ice Cores (GS2, GS2.1, GI1, GS1), and these are considered against key Quaternary records including those from nearby Lake Baikal and Hulu Cave in

  7. Climate change: The 2015 Paris Agreement thresholds and Mediterranean basin ecosystems.

    Science.gov (United States)

    Guiot, Joel; Cramer, Wolfgang

    2016-10-28

    The United Nations Framework Convention on Climate Change Paris Agreement of December 2015 aims to maintain the global average warming well below 2°C above the preindustrial level. In the Mediterranean basin, recent pollen-based reconstructions of climate and ecosystem variability over the past 10,000 years provide insights regarding the implications of warming thresholds for biodiversity and land-use potential. We compare scenarios of climate-driven future change in land ecosystems with reconstructed ecosystem dynamics during the past 10,000 years. Only a 1.5°C warming scenario permits ecosystems to remain within the Holocene variability. At or above 2°C of warming, climatic change will generate Mediterranean land ecosystem changes that are unmatched in the Holocene, a period characterized by recurring precipitation deficits rather than temperature anomalies. Copyright © 2016, American Association for the Advancement of Science.

  8. Atmospheric CO2 and abrupt climate change on submillennial timescales

    Science.gov (United States)

    Ahn, Jinho; Brook, Edward

    2010-05-01

    How atmospheric CO2 varies and is controlled on various time scales and under various boundary conditions is important for understanding how the carbon cycle and climate change are linked. Ancient air preserved in ice cores provides important information on past variations in atmospheric CO2. In particular, concentration records for intervals of abrupt climate change may improve understanding of mechanisms that govern atmospheric CO2. We present new multi-decadal CO2 records that cover Greenland stadial 9 (between Dansgaard-Oeschger (DO) events 8 and 9) and the abrupt cooling event at 8.2 ka. The CO2 records come from Antarctic ice cores but are well synchronized with Greenland ice core records using new high-resolution CH4 records,precisely defining the timing of CO2 change with respect to abrupt climate events in Greenland. Previous work showed that during stadial 9 (40~38 ka), CO2 rose by about 15~20 ppm over around 2,000 years, and at the same time temperatures in Antarctica increased. Dust proxies indicate a decrease in dust flux over the same period. With more detailed data and better age controls we now find that approximately half of the CO2 increase during stadial 9 occurred abruptly, over the course of decades to a century at ~39.6 ka. The step increase of CO2 is synchronous with a similar step increase of Antarctic isotopic temperature and a small abrupt change in CH4, and lags after the onset of decrease in dust flux by ~400 years. New atmospheric CO2 records at the well-known ~8.2 ka cooling event were obtained from Siple Dome ice core, Antarctica. Our preliminary CO2 data span 900 years and include 19 data points within the 8.2 ka cooling event, which persisted for ~160 years (Thomas et al., Quarternary Sci. Rev., 2007). We find that CO2 increased by 2~4 ppm during that cooling event. Further analyses will improve the resolution and better constrain the CO2 variability during other times in the early Holocene to determine if the variations observed

  9. Science to Support Management of Receiving Waters in an Event-Driven Ecosystem: From Land to River to Sea

    Directory of Open Access Journals (Sweden)

    Stuart E. Bunn

    2013-06-01

    Full Text Available Managing receiving-water quality, ecosystem health and ecosystem service delivery is challenging in regions where extreme rainfall and runoff events occur episodically, confounding and often intensifying land-degradation impacts. We synthesize the approaches used in river, reservoir and coastal water management in the event-driven subtropics of Australia, and the scientific research underpinning them. Land-use change has placed the receiving waters of Moreton Bay, an internationally-significant coastal wetland, at risk of ecological degradation through increased nutrient and sediment loads. The event-driven climate exacerbates this issue, as the waterways and ultimately Moreton Bay receive large inputs of nutrients and sediment during events, well above those received throughout stable climatic periods. Research on the water quality and ecology of the region’s rivers and coastal waters has underpinned the development of a world-renowned monitoring program and, in combination with catchment-source tracing methods and modeling, has revealed the key mechanisms and management strategies by which receiving-water quality, ecosystem health and ecosystem services can be maintained and improved. These approaches provide a useful framework for management of water bodies in other regions driven by episodic events, or where novel stressors are involved (e.g., climate change, urbanization, to support sustained ecosystem service delivery and restoration of aquatic ecosystems.

  10. A double-integration hypothesis to explain ocean ecosystem response to climate forcing

    Science.gov (United States)

    Di Lorenzo, Emanuele; Ohman, Mark D.

    2013-01-01

    Long-term time series of marine ecological indicators often are characterized by large-amplitude state transitions that can persist for decades. Understanding the significance of these variations depends critically on the underlying hypotheses characterizing expected natural variability. Using a linear autoregressive model in combination with long-term zooplankton observations off the California coast, we show that cumulative integrations of white-noise atmospheric forcing can generate marine population responses that are characterized by strong transitions and prolonged apparent state changes. This model provides a baseline hypothesis for explaining ecosystem variability and for interpreting the significance of abrupt responses and climate change signatures in marine ecosystems. PMID:23341628

  11. Spontaneous abrupt climate change due to an atmospheric blocking-sea-ice-ocean feedback in an unforced climate model simulation.

    Science.gov (United States)

    Drijfhout, Sybren; Gleeson, Emily; Dijkstra, Henk A; Livina, Valerie

    2013-12-03

    Abrupt climate change is abundant in geological records, but climate models rarely have been able to simulate such events in response to realistic forcing. Here we report on a spontaneous abrupt cooling event, lasting for more than a century, with a temperature anomaly similar to that of the Little Ice Age. The event was simulated in the preindustrial control run of a high-resolution climate model, without imposing external perturbations. Initial cooling started with a period of enhanced atmospheric blocking over the eastern subpolar gyre. In response, a southward progression of the sea-ice margin occurred, and the sea-level pressure anomaly was locked to the sea-ice margin through thermal forcing. The cold-core high steered more cold air to the area, reinforcing the sea-ice concentration anomaly east of Greenland. The sea-ice surplus was carried southward by ocean currents around the tip of Greenland. South of 70 °N, sea ice already started melting and the associated freshwater anomaly was carried to the Labrador Sea, shutting off deep convection. There, surface waters were exposed longer to atmospheric cooling and sea surface temperature dropped, causing an even larger thermally forced high above the Labrador Sea. In consequence, east of Greenland, anomalous winds changed from north to south, terminating the event with similar abruptness to its onset. Our results imply that only climate models that possess sufficient resolution to correctly represent atmospheric blocking, in combination with a sensitive sea-ice model, are able to simulate this kind of abrupt climate change.

  12. Precise interpolar phasing of abrupt climate change during the last ice age

    Science.gov (United States)

    ,; Buizert, Christo; Adrian, Betty M.; Ahn, Jinho; Albert, Mary; Alley, Richard B.; Baggenstos, Daniel; Bauska, Thomas K.; Bay, Ryan C.; Bencivengo, Brian B.; Bentley, Charles R.; Brook, Edward J.; Chellman, Nathan J.; Clow, Gary D.; Cole-Dai, Jihong; Conway, Howard; Cravens, Eric; Cuffey, Kurt M.; Dunbar, Nelia W.; Edwards, Jon S.; Fegyveresi, John M.; Ferris, Dave G.; Fitzpatrick, Joan J.; Fudge, T. J.; Gibson, Chris J.; Gkinis, Vasileios; Goetz, Joshua J.; Gregory, Stephanie; Hargreaves, Geoffrey Mill; Iverson, Nels; Johnson, Jay A.; Jones, Tyler R.; Kalk, Michael L.; Kippenhan, Matthew J.; Koffman, Bess G.; Kreutz, Karl; Kuhl, Tanner W.; Lebar, Donald A.; Lee, James E.; Marcott, Shaun A.; Markle, Bradley R.; Maselli, Olivia J.; McConnell, Joseph R.; McGwire, Kenneth C.; Mitchell, Logan E.; Mortensen, Nicolai B.; Neff, Peter D.; Nishiizumi, Kunihiko; Nunn, Richard M.; Orsi, Anais J.; Pasteris, Daniel R.; Pedro, Joel B.; Pettit, Erin C.; Price, P. Buford; Priscu, John C.; Rhodes, Rachael H.; Rosen, Julia L.; Schauer, Andrew J.; Schoenemann, Spruce W.; Sendelbach, Paul J.; Severinghaus, Jeffrey P.; Shturmakov, Alexander J.; Sigl, Michael; Slawny, Kristina R.; Souney, Joseph M.; Sowers, Todd A.; Spencer, Matthew K.; Steig, Eric J.; Taylor, Kendrick C.; Twickler, Mark S.; Vaughn, Bruce H.; Voigt, Donald E.; Waddington, Edwin D.; Welten, Kees C.; Wendricks, Anthony W.; White, James W. C.; Winstrup, Mai; Wong, Gifford J.; Woodruff, Thomas E.

    2015-01-01

    The last glacial period exhibited abrupt Dansgaard–Oeschger climatic oscillations, evidence of which is preserved in a variety of Northern Hemisphere palaeoclimate archives1. Ice cores show that Antarctica cooled during the warm phases of the Greenland Dansgaard–Oeschger cycle and vice versa2, 3, suggesting an interhemispheric redistribution of heat through a mechanism called the bipolar seesaw4, 5, 6. Variations in the Atlantic meridional overturning circulation (AMOC) strength are thought to have been important, but much uncertainty remains regarding the dynamics and trigger of these abrupt events7, 8, 9. Key information is contained in the relative phasing of hemispheric climate variations, yet the large, poorly constrained difference between gas age and ice age and the relatively low resolution of methane records from Antarctic ice cores have so far precluded methane-based synchronization at the required sub-centennial precision2, 3,10. Here we use a recently drilled high-accumulation Antarctic ice core to show that, on average, abrupt Greenland warming leads the corresponding Antarctic cooling onset by 218 ± 92 years (2σ) for Dansgaard–Oeschger events, including the Bølling event; Greenland cooling leads the corresponding onset of Antarctic warming by 208 ± 96 years. Our results demonstrate a north-to-south directionality of the abrupt climatic signal, which is propagated to the Southern Hemisphere high latitudes by oceanic rather than atmospheric processes. The similar interpolar phasing of warming and cooling transitions suggests that the transfer time of the climatic signal is independent of the AMOC background state. Our findings confirm a central role for ocean circulation in the bipolar seesaw and provide clear criteria for assessing hypotheses and model simulations of Dansgaard–Oeschger dynamics.

  13. Soil ecosystem functioning under climate change: plant species and community effects

    Energy Technology Data Exchange (ETDEWEB)

    Kardol, Paul [ORNL; Cregger, Melissa [ORNL; Campany, Courtney E [ORNL; Classen, Aimee T [ORNL

    2010-01-01

    Feedbacks of terrestrial ecosystems to climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the microbial communities that feed on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old-field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and water availability. Specifically, we collected soils at the plot level (plant community soils), and beneath dominant plant species (plant-specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning. Our study resulted in two main findings: 1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activities, and soil nematodes. Multiple climate change factors can interact to shape ecosystems, but in this case, those interactions were largely driven by changes in water availability. 2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning and this impact was not obvious when looking at plant community soils. Climate change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant-specific soils, but also within plant-specific soils. In sum, these results indicate that accurate assessments of climate change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate change-induced shifts in plant community composition will likely modify or counteract the direct

  14. Climate Regulation Services of Natural and Managed Ecosystems of the Americas

    Science.gov (United States)

    Anderson-Teixeira, K. J.; Snyder, P. K.; Twine, T. E.; Costa, M. H.; Cuadra, S.; DeLucia, E. H.

    2011-12-01

    Terrestrial ecosystems regulate climate through both biogeochemical mechanisms (greenhouse gas regulation) and biophysical mechanisms (regulation of water and energy). Land management therefore provides some of the most effective strategies for climate change mitigation. However, most policies aimed at climate protection through land management, including UNFCCC mechanisms and bioenergy sustainability standards, account only for biogeochemical climate services. By ignoring biophysical climate regulation services that in some cases offset the biogeochemical regulation services, these policies run the risk of failing to advance the best climate solutions. Quantifying the combined value of biogeochemical and biophysical climate regulation services remains an important challenge. Here, we use a combination of data synthesis and modeling to quantify how biogeochemical and biophysical effects combine to shape the climate regulation value (CRV) of 18 natural and managed ecosystem types across the Western Hemisphere. Natural ecosystems generally had higher CRVs than agroecosystems, largely driven by differences in biogeochemical services. Biophysical contributions ranged from minimal to dominant. They were highly variable in space and across ecosystem types, and their relative importance varied strongly with the spatio-temporal scale of analysis. Our findings pertain to current efforts to protect climate through land management. Specifically, they reinforce the importance of protecting tropical forests and recent findings that the climatic effects of bioenergy production may be somewhat more positive than previously estimated. Given that biophysical effects in some cases dominate, ensuring effective climate protection through land management requires consideration of combined biogeochemical and biophysical climate regulation services. While quantification of ecosystem climate services is necessarily complex, our CRV index serves as one potential approach to measure the

  15. Climate-driven changes in functional biogeography of Arctic marine fish communities.

    Science.gov (United States)

    Frainer, André; Primicerio, Raul; Kortsch, Susanne; Aune, Magnus; Dolgov, Andrey V; Fossheim, Maria; Aschan, Michaela M

    2017-11-14

    Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions. Copyright © 2017 the Author(s). Published by PNAS.

  16. The impacts of past climate change on terrestrial and aquatic ecosystems

    International Nuclear Information System (INIS)

    Bradshaw, R.H.W.; Anderson, N.J.

    2001-01-01

    The last two million years of global history have been dominated by the impacts of rapid climate change. This influence is not immediately obvious to most biologists whose observations rarely extend beyond a period of a few years, but becomes apparent when interpreting long-term data sets whether they be population studies or palaeoecological data. It is appropriate therefore to consider how terrestrial and aquatic ecosystems have responded to climate change during the Quaternary when speculating about response to future climatic developments. In this chapter we discuss and illustrate the complex interactions between climate and anthropogenic influence on terrestrial and aquatic ecosystems during the Holocene. Climate influences ecosystems both directly (e.g. physiological responses or lake thermal stratification) and indirectly (e.g. via fire frequency or catchment hydrology). Lake sediments can be used to study both past climatic change directly and the effects of past climatic variability. In this chapter we present summary examples of the influence of past climate change on terrestrial and aquatic ecosystems as well showing how lake sediment records can provide proxy records of past climate change. The geological record from the last 18 000 years documents large changes in terrestrial and aquatic ecosystems that are primarily driven by climatic change, but are modified by internal ecosystem processes. These changes are comparable in magnitude and rapidity to those predicted for the near future. Species at their distributional limits are particularly sensitive to climate change and contractions of range can be sudden in response to extreme climatic events such as the storm of December 1999 that damaged Picea trees far more than tree species that lay within their natural range limits. Palaeoecological records provide compelling evidence for direct climate forcing of aquatic and terrestrial ecosystems but importantly also permit comparative analyses of impacts

  17. Role of CO2 and Southern Ocean winds in glacial abrupt climate change

    Directory of Open Access Journals (Sweden)

    M. Montoya

    2012-06-01

    Full Text Available The study of Greenland ice cores revealed two decades ago the abrupt character of glacial millennial-scale climate variability. Several triggering mechanisms have been proposed and confronted against growing proxy-data evidence. Although the implication of North Atlantic deep water (NADW formation reorganisations in glacial abrupt climate change seems robust nowadays, the final cause of these reorganisations remains unclear. Here, the role of CO2 and Southern Ocean winds is investigated using a coupled model of intermediate complexity in an experimental setup designed such that the climate system resides close to a threshold found in previous studies. An initial abrupt surface air temperature (SAT increase over the North Atlantic by 4 K in less than a decade, followed by a more gradual warming greater than 10 K on centennial timescales, is simulated in response to increasing atmospheric CO2 levels and/or enhancing southern westerlies. The simulated peak warming shows a similar pattern and amplitude over Greenland as registered in ice core records of Dansgaard-Oeschger (D/O events. This is accompanied by a strong Atlantic meridional overturning circulation (AMOC intensification. The AMOC strengthening is found to be caused by a northward shift of NADW formation sites into the Nordic Seas as a result of a northward retreat of the sea-ice front in response to higher temperatures. This leads to enhanced heat loss to the atmosphere as well as reduced freshwater fluxes via reduced sea-ice import into the region. In this way, a new mechanism that is consistent with proxy data is identified by which abrupt climate change can be promoted.

  18. Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift.

    Science.gov (United States)

    Ling, S D; Johnson, C R; Frusher, S D; Ridgway, K R

    2009-12-29

    A key consideration in assessing impacts of climate change is the possibility of synergistic effects with other human-induced stressors. In the ocean realm, climate change and overfishing pose two of the greatest challenges to the structure and functioning of marine ecosystems. In eastern Tasmania, temperate coastal waters are warming at approximately four times the global ocean warming average, representing the fastest rate of warming in the Southern Hemisphere. This has driven range extension of the ecologically important long-spined sea urchin (Centrostephanus rodgersii), which has now commenced catastrophic overgrazing of productive Tasmanian kelp beds leading to loss of biodiversity and important rocky reef ecosystem services. Coincident with the overgrazing is heavy fishing of reef-based predators including the spiny lobster Jasus edwardsii. By conducting experiments inside and outside Marine Protected Areas we show that fishing, by removing large predatory lobsters, has reduced the resilience of kelp beds against the climate-driven threat of the sea urchin and thus increased risk of catastrophic shift to widespread sea urchin barrens. This shows that interactions between multiple human-induced stressors can exacerbate nonlinear responses of ecosystems to climate change and limit the adaptive capacity of these systems. Management actions focused on reducing the risk of catastrophic phase shift in ecosystems are particularly urgent in the face of ongoing warming and unprecedented levels of predator removal from the world's oceans.

  19. Nonlinear ecosystem services response to groundwater availability under climate extremes

    Science.gov (United States)

    Qiu, J.; Zipper, S. C.; Motew, M.; Booth, E.; Kucharik, C. J.; Steven, L. I.

    2017-12-01

    Depletion of groundwater has been accelerating at regional to global scales. Besides serving domestic, industrial and agricultural needs, in situ groundwater is also a key control on biological, physical and chemical processes across the critical zone, all of which underpin supply of ecosystem services essential for humanity. While there is a rich history of research on groundwater effects on subsurface and surface processes, understanding interactions, nonlinearity and feedbacks between groundwater and ecosystem services remain limited, and almost absent in the ecosystem service literature. Moreover, how climate extremes may alter groundwater effects on services is underexplored. In this research, we used a process-based ecosystem model (Agro-IBIS) to quantify groundwater effects on eight ecosystem services related to food, water and biogeochemical processes in an urbanizing agricultural watershed in the Midwest, USA. We asked: (1) Which ecosystem services are more susceptible to shallow groundwater influences? (2) Do effects of groundwater on ecosystem services vary under contrasting climate conditions (i.e., dry, wet and average)? (3) Where on the landscape are groundwater effects on ecosystem services most pronounced? (4) How do groundwater effects depend on water table depth? Overall, groundwater significantly impacted all services studied, with the largest effects on food production, water quality and quantity, and flood regulation services. Climate also mediated groundwater effects with the strongest effects occurring under dry climatic conditions. There was substantial spatial heterogeneity in groundwater effects across the landscape that is driven in part by spatial variations in water table depth. Most ecosystem services responded nonlinearly to groundwater availability, with most apparent groundwater effects occurring when the water table is shallower than a critical depth of 2.5-m. Our findings provide compelling evidence that groundwater plays a vital

  20. Predicting Chronic Climate-Driven Disturbances and Their Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, Nate G.; Michaletz, Sean T.; Bennett, Katrina E.; Solander, Kurt C.; Xu, Chonggang; Maxwell, Reed M.; Middleton, Richard S.

    2018-01-01

    Society increasingly demands the stable provision of ecosystem resources to support our population. Resource risks from climate-driven disturbances--including drought, heat, insect outbreaks, and wildfire--are rising as a chronic state of disequilibrium results from increasing temperatures and a greater frequency of extreme events. This confluence of increased demand and risk may soon reach critical thresholds. We explain here why extreme chronic disequilibrium of ecosystem function is likely to increase dramatically across the globe, creating no-analog conditions that challenge adaptation. We also present novel mechanistic theory that combines models for disturbance mortality and metabolic scaling to link size-dependent plant mortality to changes in ecosystem stocks and fluxes. Efforts must anticipate and model chronic ecosystem disequilibrium to properly prepare for resilience planning.

  1. Multiple equilibria in a stochastic implementation of DICE with abrupt climate change

    International Nuclear Information System (INIS)

    Lempert, Robert J.; Sanstad, Alan H.; Schlesinger, Michael E.

    2006-01-01

    Integrated assessment modeling of global climate change has focused primarily on gradually occurring changes in the climate system. However, atmospheric and earth scientists have become increasingly concerned that the climate system may be subject to abrupt, discontinuous changes on short time scales, and that anthropogenic greenhouse-gas emissions could trigger such shifts. Incorporating this type of climate dynamics into economic or integrated assessment models can result in model non-convexity and multiple equilibria, and thus complicate policy analysis relative to models with unique, globally optimal policies. Using a version of the Nordhaus DICE model amended in previous research by Keller et al. (2004) [Keller, Klaus, Benjamin M. Bolker, David F. Bradford, 2004. Uncertain climate thresholds and optimal economic growth. Journal of environmental economics and management 48 (1), 723-741], in conjunction with a stochastic global optimization algorithm, we generate 'level sets' of solutions, which helps identify multiple equilibria resulting from the potential abrupt cessation of the North Atlantic Thermohaline Circulation. We discuss the implications of this model geometry for formulating greenhouse-gas abatement policy under uncertainty and suggest that this general approach may be useful for addressing a wide range of model non-convexities including those related to endogenous technological change

  2. Solar ultraviolet radiation and ozone depletion-driven climate change: effects on terrestrial ecosystems.

    Science.gov (United States)

    Bornman, J F; Barnes, P W; Robinson, S A; Ballaré, C L; Flint, S D; Caldwell, M M

    2015-01-01

    In this assessment we summarise advances in our knowledge of how UV-B radiation (280-315 nm), together with other climate change factors, influence terrestrial organisms and ecosystems. We identify key uncertainties and knowledge gaps that limit our ability to fully evaluate the interactive effects of ozone depletion and climate change on these systems. We also evaluate the biological consequences of the way in which stratospheric ozone depletion has contributed to climate change in the Southern Hemisphere. Since the last assessment, several new findings or insights have emerged or been strengthened. These include: (1) the increasing recognition that UV-B radiation has specific regulatory roles in plant growth and development that in turn can have beneficial consequences for plant productivity via effects on plant hardiness, enhanced plant resistance to herbivores and pathogens, and improved quality of agricultural products with subsequent implications for food security; (2) UV-B radiation together with UV-A (315-400 nm) and visible (400-700 nm) radiation are significant drivers of decomposition of plant litter in globally important arid and semi-arid ecosystems, such as grasslands and deserts. This occurs through the process of photodegradation, which has implications for nutrient cycling and carbon storage, although considerable uncertainty exists in quantifying its regional and global biogeochemical significance; (3) UV radiation can contribute to climate change via its stimulation of volatile organic compounds from plants, plant litter and soils, although the magnitude, rates and spatial patterns of these emissions remain highly uncertain at present. UV-induced release of carbon from plant litter and soils may also contribute to global warming; and (4) depletion of ozone in the Southern Hemisphere modifies climate directly via effects on seasonal weather patterns (precipitation and wind) and these in turn have been linked to changes in the growth of plants

  3. Balancing trade-offs between ecosystem services in Germany’s forests under climate change

    Science.gov (United States)

    Gutsch, Martin; Lasch-Born, Petra; Kollas, Chris; Suckow, Felicitas; Reyer, Christopher P. O.

    2018-04-01

    Germany’s forests provide a variety of ecosystem services. Sustainable forest management aims to optimize the provision of these services at regional level. However, climate change will impact forest ecosystems and subsequently ecosystem services. The objective of this study is to quantify the effects of two alternative management scenarios and climate impacts on forest variables indicative of ecosystem services related to timber, habitat, water, and carbon. The ecosystem services are represented through nine model output variables (timber harvest, above and belowground biomass, net ecosystem production, soil carbon, percolation, nitrogen leaching, deadwood, tree dimension, broadleaf tree proportion) from the process-based forest model 4C. We simulated forest growth, carbon and water cycling until 2045 with 4C set-up for the whole German forest area based on National Forest Inventory data and driven by three management strategies (nature protection, biomass production and a baseline management) and an ensemble of regional climate scenarios (RCP2.6, RCP 4.5, RCP 8.5). We provide results as relative changes compared to the baseline management and observed climate. Forest management measures have the strongest effects on ecosystem services inducing positive or negative changes of up to 40% depending on the ecosystem service in question, whereas climate change only slightly alters ecosystem services averaged over the whole forest area. The ecosystem services ‘carbon’ and ‘timber’ benefit from climate change, while ‘water’ and ‘habitat’ lose. We detect clear trade-offs between ‘timber’ and all other ecosystem services, as well as synergies between ‘habitat’ and ‘carbon’. When evaluating all ecosystem services simultaneously, our results reveal certain interrelations between climate and management scenarios. North-eastern and western forest regions are more suitable to provide timber (while minimizing the negative impacts on remaining

  4. Invertebrates, ecosystem services and climate change.

    Science.gov (United States)

    Prather, Chelse M; Pelini, Shannon L; Laws, Angela; Rivest, Emily; Woltz, Megan; Bloch, Christopher P; Del Toro, Israel; Ho, Chuan-Kai; Kominoski, John; Newbold, T A Scott; Parsons, Sheena; Joern, A

    2013-05-01

    The sustainability of ecosystem services depends on a firm understanding of both how organisms provide these services to humans and how these organisms will be altered with a changing climate. Unquestionably a dominant feature of most ecosystems, invertebrates affect many ecosystem services and are also highly responsive to climate change. However, there is still a basic lack of understanding of the direct and indirect paths by which invertebrates influence ecosystem services, as well as how climate change will affect those ecosystem services by altering invertebrate populations. This indicates a lack of communication and collaboration among scientists researching ecosystem services and climate change effects on invertebrates, and land managers and researchers from other disciplines, which becomes obvious when systematically reviewing the literature relevant to invertebrates, ecosystem services, and climate change. To address this issue, we review how invertebrates respond to climate change. We then review how invertebrates both positively and negatively influence ecosystem services. Lastly, we provide some critical future directions for research needs, and suggest ways in which managers, scientists and other researchers may collaborate to tackle the complex issue of sustaining invertebrate-mediated services under a changing climate. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.

  5. Early Holocene hydroclimate of Baffin Bay: Understanding the interplay between abrupt climate change events and ice sheet fluctuations

    Science.gov (United States)

    Corcoran, M. C.; Thomas, E. K.; Castañeda, I. S.; Briner, J. P.

    2017-12-01

    Understanding the causes of ice sheet fluctuations resulting in sea level rise is essential in today's warming climate. In high-latitude ice-sheet-proximal environments such as Baffin Bay, studying both the cause and the rate of ice sheet variability during past abrupt climate change events aids in predictions. Past climate reconstructions are used to understand ice sheet responses to changes in temperature and precipitation. The 9,300 and 8,200 yr BP events are examples of abrupt climate change events in the Baffin Bay region during which there were multiple re-advances of the Greenland and Laurentide ice sheets. High-resolution (decadal-scale) hydroclimate variability near the ice sheet margins during these abrupt climate change events is still unknown. We will generate a decadal-scale record of early Holocene temperature and precipitation using leaf wax hydrogen isotopes, δ2Hwax, from a lake sediment archive on Baffin Island, western Baffin Bay, to better understand abrupt climate change in this region. Shifts in temperature and moisture source result in changes in environmental water δ2H, which in turn is reflected in δ2Hwax, allowing for past hydroclimate to be determined from these compound-specific isotopes. The combination of terrestrial and aquatic δ2Hwax is used to determine soil evaporation and is ultimately used to reconstruct moisture variability. We will compare our results with a previous analysis of δ2Hwax and branched glycerol dialkyl glycerol tetraethers, a temperature and pH proxy, in lake sediment from western Greenland, eastern Baffin Bay, which indicates that cool and dry climate occurred in response to freshwater forcing events in the Labrador Sea. Reconstructing and comparing records on both the western and eastern sides of Baffin Bay during the early Holocene will allow for a spatial understanding of temperature and moisture balance changes during abrupt climate events, aiding in ice sheet modeling and predictions of future sea level

  6. The Dependencies of Ecosystem Pattern, Structure, and Dynamics on Climate, Climate Variability, and Climate Change

    Science.gov (United States)

    Flanagan, S.; Hurtt, G. C.; Fisk, J. P.; Rourke, O.

    2012-12-01

    A robust understanding of the sensitivity of the pattern, structure, and dynamics of ecosystems to climate, climate variability, and climate change is needed to predict ecosystem responses to current and projected climate change. We present results of a study designed to first quantify the sensitivity of ecosystems to climate through the use of climate and ecosystem data, and then use the results to test the sensitivity of the climate data in a state-of the art ecosystem model. A database of available ecosystem characteristics such as mean canopy height, above ground biomass, and basal area was constructed from sources like the National Biomass and Carbon Dataset (NBCD). The ecosystem characteristics were then paired by latitude and longitude with the corresponding climate characteristics temperature, precipitation, photosynthetically active radiation (PAR) and dew point that were retrieved from the North American Regional Reanalysis (NARR). The average yearly and seasonal means of the climate data, and their associated maximum and minimum values, over the 1979-2010 time frame provided by NARR were constructed and paired with the ecosystem data. The compiled results provide natural patterns of vegetation structure and distribution with regard to climate data. An advanced ecosystem model, the Ecosystem Demography model (ED), was then modified to allow yearly alterations to its mechanistic climate lookup table and used to predict the sensitivities of ecosystem pattern, structure, and dynamics to climate data. The combined ecosystem structure and climate data results were compared to ED's output to check the validity of the model. After verification, climate change scenarios such as those used in the last IPCC were run and future forest structure changes due to climate sensitivities were identified. The results of this study can be used to both quantify and test key relationships for next generation models. The sensitivity of ecosystem characteristics to climate data

  7. Privacy driven internet ecosystem

    OpenAIRE

    Trinh, Tuan Anh; Gyarmati, Laszlo

    2012-01-01

    The dominant business model of today's Internet is built upon advertisements; users can access Internet services while the providers show ads to them. Although significant efforts have been made to model and analyze the economic aspects of this ecosystem, the heart of the current status quo, namely privacy, has not received the attention of the research community yet. Accordingly, we propose an economic model of the privacy driven Internet ecosystem where privacy is handled as an asset that c...

  8. Impacts of climate change on biodiversity, ecosystems, and ecosystem services: technical input to the 2013 National Climate Assessment

    Science.gov (United States)

    Staudinger, Michelle D.; Grimm, Nancy B.; Staudt, Amanda; Carter, Shawn L.; Stuart, F. Stuart; Kareiva, Peter; Ruckelshaus, Mary; Stein, Bruce A.

    2012-01-01

    Ecosystems, and the biodiversity and services they support, are intrinsically dependent on climate. During the twentieth century, climate change has had documented impacts on ecological systems, and impacts are expected to increase as climate change continues and perhaps even accelerates. This technical input to the National Climate Assessment synthesizes our scientific understanding of the way climate change is affecting biodiversity, ecosystems, ecosystem services, and what strategies might be employed to decrease current and future risks. Building on past assessments of how climate change and other stressors are affecting ecosystems in the United States and around the world, we approach the subject from several different perspectives. First, we review the observed and projected impacts on biodiversity, with a focus on genes, species, and assemblages of species. Next, we examine how climate change is affecting ecosystem structural elements—such as biomass, architecture, and heterogeneity—and functions—specifically, as related to the fluxes of energy and matter. People experience climate change impacts on biodiversity and ecosystems as changes in ecosystem services; people depend on ecosystems for resources that are harvested, their role in regulating the movement of materials and disturbances, and their recreational, cultural, and aesthetic value. Thus, we review newly emerging research to determine how human activities and a changing climate are likely to alter the delivery of these ecosystem services. This technical input also examines two cross-cutting topics. First, we recognize that climate change is happening against the backdrop of a wide range of other environmental and anthropogenic stressors, many of which have caused dramatic ecosystem degradation already. This broader range of stressors interacts with climate change, and complicates our abilities to predict and manage the impacts on biodiversity, ecosystems, and the services they support. The

  9. Linear trend and abrupt changes of climate indices in the arid region of northwestern China

    Science.gov (United States)

    Wang, Huaijun; Pan, Yingping; Chen, Yaning; Ye, Zhengwei

    2017-11-01

    In recent years, climate extreme events have caused increasing direct economic and social losses in the arid region of northwestern China. Based on daily temperature and precipitation data from 1960 to 2010, this paper discussed the linear trend and abrupt changes of climate indices. The general evolution was obtained by the empirical orthogonal function (EOF), the Mann-Kendall test, and the distribution-free cumulative sum chart (CUSUM) test. The results are as follows: (1) climate showed a warming trend at annual and seasonal scale, with all temperature indices exhibiting statistically significant changes. The warm indices have increased, with 1.37%days/decade of warm days (TX90p), 0.17 °C/decade of warmest days (TXx) and 1.97 days/decade of warm spell duration indicator (WSDI), respectively. The cold indices have decreased, with - 1.89%days/decade, 0.65 °C/decade and - 0.66 days/decade for cold nights (TN10p), coldest nights (TNn) and cold spell duration indicator (CSDI), respectively. The precipitation indices have also increased significantly, coupled with the changes of magnitude (max 1-day precipitation amount (RX1day)), frequency (rain day (R0.1)), and duration (consecutive dry days (CDD)). (2) Abrupt changes of the annual regional precipitation indices and the minimum temperature indices were observed around 1986, and that of the maximum temperature indices were observed in 1996. (3) The EOF1 indicated the overall coherent distribution for the whole study area, and its principal component (PC1) was also observed, showing a significant linear trend with an abrupt change, which were in accordance with the regional observation results. EOF2 and EOF3 show contrasts between the southern and northern study areas, and between the eastern and western study areas, respectively, whereas no significant tendency was observed for their PCs. Hence, the climate indices have changed significantly, with linear trends and abrupt changes noted for all climate indices

  10. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    Directory of Open Access Journals (Sweden)

    Adam E Vorsino

    Full Text Available Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75 as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1. This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  11. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates

    Science.gov (United States)

    Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam; Koob, Gregory A.

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  12. Integrating plant ecological responses to climate extremes from individual to ecosystem levels.

    Science.gov (United States)

    Felton, Andrew J; Smith, Melinda D

    2017-06-19

    Climate extremes will elicit responses from the individual to the ecosystem level. However, only recently have ecologists begun to synthetically assess responses to climate extremes across multiple levels of ecological organization. We review the literature to examine how plant responses vary and interact across levels of organization, focusing on how individual, population and community responses may inform ecosystem-level responses in herbaceous and forest plant communities. We report a high degree of variability at the individual level, and a consequential inconsistency in the translation of individual or population responses to directional changes in community- or ecosystem-level processes. The scaling of individual or population responses to community or ecosystem responses is often predicated upon the functional identity of the species in the community, in particular, the dominant species. Furthermore, the reported stability in plant community composition and functioning with respect to extremes is often driven by processes that operate at the community level, such as species niche partitioning and compensatory responses during or after the event. Future research efforts would benefit from assessing ecological responses across multiple levels of organization, as this will provide both a holistic and mechanistic understanding of ecosystem responses to increasing climatic variability.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).

  13. Fire Regime and Ecosystem Effects of Climate-driven Changes in Rocky Mountains Hydrology

    Science.gov (United States)

    Westerling, A. L.; Das, T.; Lubetkin, K.; Romme, W.; Ryan, M. G.; Smithwick, E. A.; Turner, M.

    2009-12-01

    Western US Forest managers face more wildfires than ever before, and it is increasingly imperative to anticipate the consequences of this trend. Large fires in the northern Rocky Mountains have increased in association with warmer temperatures, earlier snowmelt, and longer fire seasons (1), and this trend is likely to continue with global warming (2). Increased wildfire occurrence is already a concern shared by managers from many federal land-management agencies (3). However, new analyses for the western US suggest that future climate could diverge even more rapidly from past climate than previously suggested. Current model projections suggest end-of-century hydroclimatic conditions like those of 1988 (the year of the well-known Yellowstone Fires) may represent close to the average year rather than an extreme year. The consequences of a shift of this magnitude for the fire regime, post-fire succession and carbon (C) balance of western forest ecosystems are well beyond what scientists have explored to date, and may fundamentally change the potential of western forests to sequester atmospheric C. We link hydroclimatic extremes (spring and summer temperature and cumulative water-year moisture deficit) to extreme fire years in northern Rockies forests, using large forest fire histories and 1/8-degree gridded historical hydrologic simulations (1950 - 2005) (4) forced with historical gridded temperature and precipitation (5). The frequency of extremes in hydroclimate associated with historic severe fire years in the northern Rocky Mountains is compared to those projected under a range of climate change projections, using global climate model runs for the A2 and B1 emissions pathways for three global climate models (NCAR PCM1, GFDL CM2.1, CNRM CM3). Coarse-scale climatic variables are downscaled to a 1/8 degree grid and used to force hydrologic simulations (6, 7). We will present preliminary results using these hydrologic simulations to model spatially explicit annual

  14. Developing and implementing climate change adaptation options in forest ecosystems: a case study in southwestern Oregon, USA

    Science.gov (United States)

    Jessica E. Halofsky; David L. Peterson; Kerry L. Metlen; Gwyneth M. Myer; Alaric V. Sample

    2016-01-01

    Climate change will likely have significant effects on forest ecosystems worldwide. In Mediterranean regions, such as that in southwestern Oregon, USA, changes will likely be driven mainly by wildfire and drought. To minimize the negative effects of climate change, resource managers require tools and information to assess climate change vulnerabilities and to develop...

  15. A Business Ecosystem Driven Market Analysis

    DEFF Research Database (Denmark)

    Ma, Zheng; Billanes, Joy Dalmacio; Jørgensen, Bo Nørregaard

    2017-01-01

    Due to the huge globally emerging market of the bright green buildings, this paper aims to develop a business-ecosystem driven market analysis approach for the investigation of the bright green building market. This paper develops a five-steps business-ecosystem driven market analysis (definition...... of the business domain, stakeholder listing, integration of the value chain, relationship mapping, and ego innovation ecosystem mapping.). This paper finds the global-local matters influence the market structure, which the technologies for building energy technology are developed and employed globally......, and the market demand is comparatively localized. The market players can be both local and international stakeholders who involve and collaborate for the building projects. This paper also finds that the building extensibility should be considered into the building design due to the gap between current market...

  16. Postglacial Human resilience and susceptibility to abrupt climate change new insights from Star Carr

    Science.gov (United States)

    Blockley, Simon; Abrook, Ashley; Bayliss, Alex; Candy, Ian; Conneller, Chantal; Darvill, Chris; Deeprose, Laura; Kearney, Rebecca; Langdon, Pete; Langdon Langdon, Cath; Lincoln, Paul; Macleod, Alison; Matthews, Ian; Palmer, Adrian; Schreve, Danielle; Taylor, Barry; Milner, Nicky

    2017-04-01

    We know little about the lives of the early humans who lived during the early Postglacial period (the Lateglacial and Early Holocene), a time characterised by abrupt climate change after 16,000, which includes a series of abrupt climatic transitions linked to the reorganisation of the global environment after the glacial maximum and the last major global warming event at the onset of the Holocene. The hunter-gatherers who lived during the early Postglacial have been characterised as highly mobile, dispersed and living within small groups, and there is much debate as to how they adapted to climatic and environmental change: did they move in response to climatic transitions (and if so what was the climatic threshold), or instead adapt their lifeways to the new environmental conditions? A key area for examining these ideas is the British Isles as it sits on the Atlantic fringe of Northwest Europe with a climate that is highly responsive to the wider climate forcing experienced in the northern Hemisphere. Furthermore, in this period, Britain is directly linked to continental Europe due to lowered global sea levels allowing for the ease of human migration in and out of this region. In general the British record has been seen as being dominated by abandonment and reoccupation in the Postglacial during periods of climatic transition with hunter-gatherer mobility being closely linked to the prevailing environment. Recent discoveries at the Early Mesolithic site of Star Carr and surrounding area, linked to local and regional climate records, based on isotopic, chironomid and pollen proxy data and dated at high chronological resolution, offer a new picture. Postglacial human occupation of the area commences at the Pleistocene/Holocene transition but is short lived and appears to end close to the Pre-Boreal Oscillation, However, this is followed by a period where hunter-gatherers occupy Star Carr and settle and invest time and effort into building huts and large scale wooden

  17. Greenness and Carbon Stocks of Mangroves: A climate-driven Effect

    Science.gov (United States)

    Lule, A. V.; Colditz, R. R.; Herrera-Silveira, J.; Guevara, M.; Rodriguez-Zuniga, M. T.; Cruz, I.; Ressl, R.; Vargas, R.

    2017-12-01

    Mangroves cover less than 1% of the earth's surface and are one o­­­f the most productive ecosystems of the world. They are highly vulnerable to climate variability due to their sensitivity to environmental changes; therefore, there are scientific and societal needs to designed frameworks to assess mangrove's vulnerability. We study the relationship between climate drivers, canopy greenness and carbon stocks to quantify a potential climate-driven effect on mangrove carbon dynamics. We identify greenness trends and their relationships with climate drivers and carbon stocks throughout 15 years (2001-2015) across mangrove forests of Mexico. We defined several categories for mangroves: a) Arid mangroves with superficial water input (ARsw); b) Humid mangroves with interior or underground water input (HUiw); and c) Humid mangroves with superficial water input (HUsw). We found a positive significant trend of greenness for ARsw and HUsw categories (pmangrove's categories (pmangrove categories showed higher greenness values during winter; which is likely driven by temperature with a lag of -3 to -5 months (r2 > 0.69). Precipitation and temperature drive canopy greenness only across HUsw. Regarding carbon stocks, the HUiw shows the lower amount of aboveground carbon (AGC; 12.7 Mg C ha-1) and the higher belowground carbon (BGC; 219 Mg C ha-1). The HUsw shows the higher amount of AGC (169.5 Mg C ha-1) and the ARsw the lower of BGC (92.4 Mg C ha-1). Climate drivers are better related with canopy greenness and AGC for both humid mangrove categories (r2 > 0.48), while the relationship of BGC and canopy greenness is lower for all categories (r2 mangrove's ecosystem function and environmental services, as well as their potential vulnerability to climate variability.

  18. Simultaneous abrupt shifts in hydrology and fish assemblage structure in a floodplain lake in the central Amazon.

    Science.gov (United States)

    Röpke, Cristhiana P; Amadio, Sidinéia; Zuanon, Jansen; Ferreira, Efrem J G; Deus, Cláudia Pereira de; Pires, Tiago H S; Winemiller, Kirk O

    2017-01-10

    Combined effects of climate change and deforestation have altered precipitation patterns in the Amazon. This has led to changes in the frequency of extreme events of flood and drought in recent decades and in the magnitude of the annual flood pulse, a phenomenon that influences virtually all aspects of river-floodplain ecosystem dynamics. Analysis of long-term data revealed abrupt and synchronous changes in hydrology and fish assemblage structure of a floodplain lake near the confluence of Amazon and Negro rivers. After an intense drought in 2005, the assemblage assumed a different and fairly persistent taxonomic composition and functional structure. Declines in abundance after 2005 were more pronounced for species of all sizes having equilibrium life history strategy, large species with periodic life history strategy, and for all trophic levels except primary consumers. Our results suggest that the extreme drought triggered changes in the fish assemblage and subsequent anomalous hydrological conditions have hampered assemblage recovery. These findings stress the need to account for climatic-driven hydrological changes in conservation efforts addressing aquatic biodiversity and fishery resources in the central Amazon.

  19. Revisiting of Stommel's model for the understanding of the abrupt climate change

    International Nuclear Information System (INIS)

    Scatamacchia, R.; Purini, R.; Rafanelli, C.

    2010-01-01

    Despite the enormous number of papers devoted to modelling climate changes, the pionieristic Stommel paper (1961) remains a still valid tool for the understanding of the basic mechanism that governs the abrupt climate change, i.e. the existence of multipla equilibria in the governing non-linear equations. Using non-dimensional quantities, Stommel did not provide any explicit information about the temporal scale affecting the process under examination when the control parameters are varied. On the basis of this consideration, the present paper revisits the Stommel theory putting some emphasis on the quantitative estimate of how the variations of the control system parameters system modify the fundamental motor of the climate change, i.e. the thermohaline circulation.

  20. An abrupt centennial-scale drought event and mid-holocene climate change patterns in monsoon marginal zones of East Asia.

    Directory of Open Access Journals (Sweden)

    Yu Li

    Full Text Available The mid-latitudes of East Asia are characterized by the interaction between the Asian summer monsoon and the westerly winds. Understanding long-term climate change in the marginal regions of the Asian monsoon is critical for understanding the millennial-scale interactions between the Asian monsoon and the westerly winds. Abrupt climate events are always associated with changes in large-scale circulation patterns; therefore, investigations into abrupt climate changes provide clues for responses of circulation patterns to extreme climate events. In this paper, we examined the time scale and mid-Holocene climatic background of an abrupt dry mid-Holocene event in the Shiyang River drainage basin in the northwest margin of the Asian monsoon. Mid-Holocene lacustrine records were collected from the middle reaches and the terminal lake of the basin. Using radiocarbon and OSL ages, a centennial-scale drought event, which is characterized by a sand layer in lacustrine sediments both from the middle and lower reaches of the basin, was absolutely dated between 8.0-7.0 cal kyr BP. Grain size data suggest an abrupt decline in lake level and a dry environment in the middle reaches of the basin during the dry interval. Previous studies have shown mid-Holocene drought events in other places of monsoon marginal zones; however, their chronologies are not strong enough to study the mechanism. According to the absolutely dated records, we proposed a new hypothesis that the mid-Holocene dry interval can be related to the weakening Asian summer monsoon and the relatively arid environment in arid Central Asia. Furthermore, abrupt dry climatic events are directly linked to the basin-wide effective moisture change in semi-arid and arid regions. Effective moisture is affected by basin-wide precipitation, evapotranspiration, lake surface evaporation and other geographical settings. As a result, the time scales of the dry interval could vary according to locations due to

  1. Potential effects of climate change on aquatic ecosystems of the Great Plains of North America

    Science.gov (United States)

    Covich, A.P.; Fritz, S.C.; Lamb, P.J.; Marzolf, R.D.; Matthews, W.J.; Poiani, K.A.; Prepas, E.E.; Richman, M.B.; Winter, T.C.

    1997-01-01

    The Great Plains landscape is less topographically complex than most other regions within North America, but diverse aquatic ecosystems, such as playas, pothole lakes, ox-bow lakes, springs, groundwater aquifers, intermittent and ephemeral streams, as well as large rivers and wetlands, are highly dynamic and responsive to extreme climatic fluctuations. We review the evidence for climatic change that demonstrates the historical importance of extremes in north-south differences in summer temperatures and east-west differences in aridity across four large subregions. These physical driving forces alter density stratification, deoxygenation, decomposition and salinity. Biotic community composition and associated ecosystem processes of productivity and nutrient cycling respond rapidly to these climatically driven dynamics. Ecosystem processes also respond to cultural effects such as dams and diversions of water for irrigation, waste dilution and urban demands for drinking water and industrial uses. Distinguishing climatic from cultural effects in future models of aquatic ecosystem functioning will require more refinement in both climatic and economic forecasting. There is a need, for example, to predict how long-term climatic forecasts (based on both ENSO and global warming simulations) relate to the permanence and productivity of shallow water ecosystems. Aquatic ecologists, hydrologists, climatologists and geographers have much to discuss regarding the synthesis of available data and the design of future interdisciplinary research. ?? 1997 by John Wiley & Sons, Ltd.

  2. Mangrove ecosystems under climate change

    Science.gov (United States)

    Jennerjahn, T.C.; Gilman, E.; Krauss, Ken W.; Lacerda, L.D.; Nordhaus, I.; Wolanski, E.

    2017-01-01

    This chapter assesses the response of mangrove ecosystems to possible outcomes of climate change, with regard to the following categories: (i) distribution, diversity, and community composition, (ii) physiology of flora and fauna, (iii) water budget, (iv) productivity and remineralization, (v) carbon storage in biomass and sediments, and (vi) the filter function for elements beneficial or harmful to life. These categories are then used to identify the regions most vulnerable to climate change. The four most important factors determining the response of mangrove ecosystems to climate change are sea level rise, an increase in frequency and/or intensity of storms, increases in temperature, and aridity. While these changes may be beneficial for some mangrove forests at latitudinal distribution limits, they will threaten forest structure and functions and related ecosystem services in most cases. The interaction of climate change with human interventions is discussed, as well as the effects on ecosystem services including possible adaptation and management options. The chapter closes with an outlook on knowledge gaps and priority research needed to fill these gaps.

  3. Impact of an abrupt cooling event on interglacial methane emissions in northern peatlands

    Directory of Open Access Journals (Sweden)

    S. Zürcher

    2013-03-01

    Full Text Available Rapid changes in atmospheric methane (CH4, temperature and precipitation are documented by Greenland ice core data both for glacial times (the so called Dansgaard-Oeschger (D-O events as well as for a cooling event in the early Holocene (the 8.2 kyr event. The onsets of D-O warm events are paralleled by abrupt increases in CH4 by up to 250 ppb in a few decades. Vice versa, the 8.2 kyr event is accompanied by an intermittent decrease in CH4 of about 80 ppb over 150 yr. The abrupt CH4 changes are thought to mainly originate from source emission variations in tropical and boreal wet ecosystems, but complex process oriented bottom-up model estimates of the changes in these ecosystems during rapid climate changes are still missing. Here we present simulations of CH4 emissions from northern peatlands with the LPJ-Bern dynamic global vegetation model. The model represents CH4 production and oxidation in soils and transport by ebullition, through plant aerenchyma, and by diffusion. Parameters are tuned to represent site emission data as well as inversion-based estimates of northern wetland emissions. The model is forced with climate input data from freshwater hosing experiments using the NCAR CSM1.4 climate model to simulate an abrupt cooling event. A concentration reduction of ~10 ppb is simulated per degree K change of mean northern hemispheric surface temperature in peatlands. Peatland emissions are equally sensitive to both changes in temperature and in precipitation. If simulated changes are taken as an analogy to the 8.2 kyr event, boreal peatland emissions alone could only explain 23% of the 80 ppb decline in atmospheric methane concentration. This points to a significant contribution to source changes from low latitude and tropical wetlands to this event.

  4. Simulating the vegetation response in western Europe to abrupt climate changes under glacial background conditions

    Directory of Open Access Journals (Sweden)

    M.-N. Woillez

    2013-03-01

    Full Text Available The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard–Oeschger (DO and Heinrich (HE events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC and led to major changes in the terrestrial biosphere. Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. We force ORCHIDEE offline with outputs from the IPSL_CM4 general circulation model, in which the AMOC is forced to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available for comparison. The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to a hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO. For both a collapse or a recovery of the AMOC, the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  5. A multi-model analysis of risk of ecosystem shifts under climate change

    International Nuclear Information System (INIS)

    Warszawski, Lila; Ostberg, Sebastian; Frieler, Katja; Lucht, Wolfgang; Schaphoff, Sibyll; Buechner, Matthias; Piontek, Franziska; Friend, Andrew; Keribin, Rozenn; Rademacher, Tim Tito; Beerling, David; Lomas, Mark; Cadule, Patricia; Ciais, Philippe; Clark, Douglas B; Kahana, Ron; Ito, Akihiko; Nishina, Kazuya; Kleidon, Axel; Pavlick, Ryan

    2013-01-01

    Climate change may pose a high risk of change to Earth’s ecosystems: shifting climatic boundaries may induce changes in the biogeochemical functioning and structures of ecosystems that render it difficult for endemic plant and animal species to survive in their current habitats. Here we aggregate changes in the biogeochemical ecosystem state as a proxy for the risk of these shifts at different levels of global warming. Estimates are based on simulations from seven global vegetation models (GVMs) driven by future climate scenarios, allowing for a quantification of the related uncertainties. 5–19% of the naturally vegetated land surface is projected to be at risk of severe ecosystem change at 2 ° C of global warming (ΔGMT) above 1980–2010 levels. However, there is limited agreement across the models about which geographical regions face the highest risk of change. The extent of regions at risk of severe ecosystem change is projected to rise with ΔGMT, approximately doubling between ΔGMT = 2 and 3 ° C, and reaching a median value of 35% of the naturally vegetated land surface for ΔGMT = 4 °C. The regions projected to face the highest risk of severe ecosystem changes above ΔGMT = 4 °C or earlier include the tundra and shrublands of the Tibetan Plateau, grasslands of eastern India, the boreal forests of northern Canada and Russia, the savanna region in the Horn of Africa, and the Amazon rainforest. (letter)

  6. North Atlantic ocean circulation and abrupt climate change during the last glaciation.

    Science.gov (United States)

    Henry, L G; McManus, J F; Curry, W B; Roberts, N L; Piotrowski, A M; Keigwin, L D

    2016-07-29

    The most recent ice age was characterized by rapid and hemispherically asynchronous climate oscillations, whose origin remains unresolved. Variations in oceanic meridional heat transport may contribute to these repeated climate changes, which were most pronounced during marine isotope stage 3, the glacial interval 25 thousand to 60 thousand years ago. We examined climate and ocean circulation proxies throughout this interval at high resolution in a deep North Atlantic sediment core, combining the kinematic tracer protactinium/thorium (Pa/Th) with the deep water-mass tracer, epibenthic δ(13)C. These indicators suggest reduced Atlantic overturning circulation during every cool northern stadial, with the greatest reductions during episodic Hudson Strait iceberg discharges, while sharp northern warming followed reinvigorated overturning. These results provide direct evidence for the ocean's persistent, central role in abrupt glacial climate change. Copyright © 2016, American Association for the Advancement of Science.

  7. Abrupt climate changes during Termination III in Southern Europe.

    Science.gov (United States)

    Pérez-Mejías, Carlos; Moreno, Ana; Sancho, Carlos; Bartolomé, Miguel; Stoll, Heather; Cacho, Isabel; Cheng, Hai; Edwards, R Lawrence

    2017-09-19

    The Late Quaternary glacial-interglacial transitions represent the highest amplitude climate changes over the last million years. Unraveling the sequence of events and feedbacks at Termination III (T-III), including potential abrupt climate reversals similar to those of the last Termination, has been particularly challenging due to the scarcity of well-dated records worldwide. Here, we present speleothem data from southern Europe covering the interval from 262.7 to 217.9 kyBP, including the transition from marine isotope stage (MIS) 8 to MIS 7e. High-resolution δ 13 C, δ 18 O, and Mg/Ca profiles reveal major millennial-scale changes in aridity manifested in changing water availability and vegetation productivity. uranium-thorium dates provide a solid chronology for two millennial-scale events (S8.1 and S8.2) which, compared with the last two terminations, has some common features with Heinrich 1 and Heinrich 2 in Termination I (T-I).

  8. Potential climate change impacts on temperate forest ecosystem processes

    Science.gov (United States)

    Peters, Emily B.; Wythers, Kirk R.; Zhang, Shuxia; Bradford, John B.; Reich, Peter B.

    2013-01-01

    Large changes in atmospheric CO2, temperature and precipitation are predicted by 2100, yet the long-term consequences for carbon, water, and nitrogen cycling in forests are poorly understood. We applied the PnET-CN ecosystem model to compare the long-term effects of changing climate and atmospheric CO2 on productivity, evapotranspiration, runoff, and net nitrogen mineralization in current Great Lakes forest types. We used two statistically downscaled climate projections, PCM B1 (warmer and wetter) and GFDL A1FI (hotter and drier), to represent two potential future climate and atmospheric CO2 scenarios. To separate the effects of climate and CO2, we ran PnET-CN including and excluding the CO2 routine. Our results suggest that, with rising CO2 and without changes in forest type, average regional productivity could increase from 67% to 142%, changes in evapotranspiration could range from –3% to +6%, runoff could increase from 2% to 22%, and net N mineralization could increase 10% to 12%. Ecosystem responses varied geographically and by forest type. Increased productivity was almost entirely driven by CO2 fertilization effects, rather than by temperature or precipitation (model runs holding CO2 constant showed stable or declining productivity). The relative importance of edaphic and climatic spatial drivers of productivity varied over time, suggesting that productivity in Great Lakes forests may switch from being temperature to water limited by the end of the century.

  9. Abrupt climate change: Past, present and the search for precursors as an aid to predicting events in the future (Hans Oeschger Medal Lecture)

    Science.gov (United States)

    Mayewski, Paul Andrew

    2016-04-01

    The demonstration using Greenland ice cores that abrupt shifts in climate, Dansgaard-Oeschger (D-O) events, existed during the last glacial period has had a transformational impact on our understanding of climate change in the naturally forced world. The demonstration that D-O events are globally distributed and that they operated during previous glacial periods has led to extensive research into the relative hemispheric timing and causes of these events. The emergence of civilization during our current interglacial, the Holocene, has been attributed to the "relative climate quiescence" of this period relative to the massive, abrupt shifts in climate that characterized glacial periods in the form of D-O events. But, everything is relative and climate change is no exception. The demise of past civilizations, (eg., Mesopatamian, Mayan and Norse) is integrally tied to abrupt climate change (ACC) events operating at regional scales. Regionally to globally distributed ACC events have punctuated the Holocene and extreme events have always posed significant challenges to humans and ecosystems. Current warming of the Arctic, in terms of length of the summer season, is as abrupt and massive, albeit not as extensive, as the transition from the last major D-O event, the Younger Dryas into the Holocene (Mayewski et al., 2013). Tropospheric source greenhouse gas rise and ozone depletion in the stratosphere over Antarctica are triggers for the modern advent of human emission instigated ACCs. Arctic warming and Antarctic ozone depletion have resulted in significance changes to the atmospheric circulation systems that transport heat, moisture, and pollutants in both hemispheres. Climate models offer a critical tool for assessing trends, but they cannot as yet predict ACC events, as evidenced by the inability of these models to predict the rapid onset of Arctic warming and resulting changes in atmospheric circulation; and in the model vs past analog differences in projections for

  10. Climate-driven range shifts of the king penguin in a fragmented ecosystem

    Science.gov (United States)

    Cristofari, Robin; Liu, Xiaoming; Bonadonna, Francesco; Cherel, Yves; Pistorius, Pierre; Le Maho, Yvon; Raybaud, Virginie; Stenseth, Nils Christian; Le Bohec, Céline; Trucchi, Emiliano

    2018-03-01

    Range shift is the primary short-term species response to rapid climate change, but it is often hampered by natural or anthropogenic habitat fragmentation. Different critical areas of a species' niche may be exposed to heterogeneous environmental changes and modelling species response under such complex spatial and ecological scenarios presents well-known challenges. Here, we use a biophysical ecological niche model validated through population genomics and palaeodemography to reconstruct past range shifts and identify future vulnerable areas and potential refugia of the king penguin in the Southern Ocean. Integrating genomic and demographic data at the whole-species level with specific biophysical constraints, we present a refined framework for predicting the effect of climate change on species relying on spatially and ecologically distinct areas to complete their life cycle (for example, migratory animals, marine pelagic organisms and central-place foragers) and, in general, on species living in fragmented ecosystems.

  11. Functional Resilience against Climate-Driven Extinctions - Comparing the Functional Diversity of European and North American Tree Floras.

    Directory of Open Access Journals (Sweden)

    Mario Liebergesell

    Full Text Available Future global change scenarios predict a dramatic loss of biodiversity for many regions in the world, potentially reducing the resistance and resilience of ecosystem functions. Once before, during Plio-Pleistocene glaciations, harsher climatic conditions in Europe as compared to North America led to a more depauperate tree flora. Here we hypothesize that this climate driven species loss has also reduced functional diversity in Europe as compared to North America. We used variation in 26 traits for 154 North American and 66 European tree species and grid-based co-occurrences derived from distribution maps to compare functional diversity patterns of the two continents. First, we identified similar regions with respect to contemporary climate in the temperate zone of North America and Europe. Second, we compared the functional diversity of both continents and for the climatically similar sub-regions using the functional dispersion-index (FDis and the functional richness index (FRic. Third, we accounted in these comparisons for grid-scale differences in species richness, and, fourth, investigated the associated trait spaces using dimensionality reduction. For gymnosperms we find similar functional diversity on both continents, whereas for angiosperms functional diversity is significantly greater in Europe than in North America. These results are consistent across different scales, for climatically similar regions and considering species richness patterns. We decomposed these differences in trait space occupation into differences in functional diversity vs. differences in functional identity. We show that climate-driven species loss on a continental scale might be decoupled from or at least not linearly related to changes in functional diversity. This might be important when analyzing the effects of climate-driven biodiversity change on ecosystem functioning.

  12. Biological response to climate change in the Arctic Ocean: The view from the past

    Science.gov (United States)

    Cronin, Thomas M.; Cronin, Matthew A.

    2017-01-01

    The Arctic Ocean is undergoing rapid climatic changes including higher ocean temperatures, reduced sea ice, glacier and Greenland Ice Sheet melting, greater marine productivity, and altered carbon cycling. Until recently, the relationship between climate and Arctic biological systems was poorly known, but this has changed substantially as advances in paleoclimatology, micropaleontology, vertebrate paleontology, and molecular genetics show that Arctic ecosystem history reflects global and regional climatic changes over all timescales and climate states (103–107 years). Arctic climatic extremes include 25°C hyperthermal periods during the Paleocene-Eocene (56–46 million years ago, Ma), Quaternary glacial periods when thick ice shelves and sea ice cover rendered the Arctic Ocean nearly uninhabitable, seasonally sea-ice-free interglacials and abrupt climate reversals. Climate-driven biological impacts included large changes in species diversity, primary productivity, species’ geographic range shifts into and out of the Arctic, community restructuring, and possible hybridization, but evidence is not sufficient to determine whether or when major episodes of extinction occurred.

  13. What if ... abrupt and extreme climate change? Programme of VAM (Vulnerability, Adaptation, Mitigation)

    International Nuclear Information System (INIS)

    2008-10-01

    A number of researchers from different social scientific disciplines present a view in response to the question 'what will happen in our society if the climate suddenly changes?'. They answer questions such as: How will people respond to real risks such as imminent flooding? What are the economic consequences? How will it affect sectors such as inland shipping and coastal tourism? What are the costs of adapting our country to rising sea levels or sudden cold? As a society what do we consider to be socially and publicly acceptable? Can we still insure ourselves? Who will assume responsibility and what are the tasks of the various parties involved? The book merely sets the scene. Social sciences research into climate change has only just started. Besides providing answers to the question about the social and public implications of abrupt climate change, the book calls for a greater involvement of social scientists in climate change issues

  14. Diagnosis and Quantification of Climatic Sensitivity of Carbon Fluxes in Ensemble Global Ecosystem Models

    Science.gov (United States)

    Wang, W.; Hashimoto, H.; Milesi, C.; Nemani, R. R.; Myneni, R.

    2011-12-01

    Terrestrial ecosystem models are primary scientific tools to extrapolate our understanding of ecosystem functioning from point observations to global scales as well as from the past climatic conditions into the future. However, no model is nearly perfect and there are often considerable structural uncertainties existing between different models. Ensemble model experiments thus become a mainstream approach in evaluating the current status of global carbon cycle and predicting its future changes. A key task in such applications is to quantify the sensitivity of the simulated carbon fluxes to climate variations and changes. Here we develop a systematic framework to address this question solely by analyzing the inputs and the outputs from the models. The principle of our approach is to assume the long-term (~30 years) average of the inputs/outputs as a quasi-equlibrium of the climate-vegetation system while treat the anomalies of carbon fluxes as responses to climatic disturbances. In this way, the corresponding relationships can be largely linearized and analyzed using conventional time-series techniques. This method is used to characterize three major aspects of the vegetation models that are mostly important to global carbon cycle, namely the primary production, the biomass dynamics, and the ecosystem respiration. We apply this analytical framework to quantify the climatic sensitivity of an ensemble of models including CASA, Biome-BGC, LPJ as well as several other DGVMs from previous studies, all driven by the CRU-NCEP climate dataset. The detailed analysis results are reported in this study.

  15. Assessing climate-sensitive ecosystems in the southeastern United States

    Science.gov (United States)

    Costanza, Jennifer; Beck, Scott; Pyne, Milo; Terando, Adam; Rubino, Matthew J.; White, Rickie; Collazo, Jaime

    2016-08-11

    Climate change impacts ecosystems in many ways, from effects on species to phenology to wildfire dynamics. Assessing the potential vulnerability of ecosystems to future changes in climate is an important first step in prioritizing and planning for conservation. Although assessments of climate change vulnerability commonly are done for species, fewer have been done for ecosystems. To aid regional conservation planning efforts, we assessed climate change vulnerability for ecosystems in the Southeastern United States and Caribbean.First, we solicited input from experts to create a list of candidate ecosystems for assessment. From that list, 12 ecosystems were selected for a vulnerability assessment that was based on a synthesis of available geographic information system (GIS) data and literature related to 3 components of vulnerability—sensitivity, exposure, and adaptive capacity. This literature and data synthesis comprised “Phase I” of the assessment. Sensitivity is the degree to which the species or processes in the ecosystem are affected by climate. Exposure is the likely future change in important climate and sea level variables. Adaptive capacity is the degree to which ecosystems can adjust to changing conditions. Where available, GIS data relevant to each of these components were used. For example, we summarized observed and projected climate, protected areas existing in 2011, projected sea-level rise, and projected urbanization across each ecosystem’s distribution. These summaries were supplemented with information in the literature, and a short narrative assessment was compiled for each ecosystem. We also summarized all information into a qualitative vulnerability rating for each ecosystem.Next, for 2 of the 12 ecosystems (East Gulf Coastal Plain Near-Coast Pine Flatwoods and Nashville Basin Limestone Glade and Woodland), the NatureServe Habitat Climate Change Vulnerability Index (HCCVI) framework was used as an alternative approach for assessing

  16. Biodiversity increases the resistance of ecosystem productivity to climate extremes.

    Science.gov (United States)

    Isbell, Forest; Craven, Dylan; Connolly, John; Loreau, Michel; Schmid, Bernhard; Beierkuhnlein, Carl; Bezemer, T Martijn; Bonin, Catherine; Bruelheide, Helge; de Luca, Enrica; Ebeling, Anne; Griffin, John N; Guo, Qinfeng; Hautier, Yann; Hector, Andy; Jentsch, Anke; Kreyling, Jürgen; Lanta, Vojtěch; Manning, Pete; Meyer, Sebastian T; Mori, Akira S; Naeem, Shahid; Niklaus, Pascal A; Polley, H Wayne; Reich, Peter B; Roscher, Christiane; Seabloom, Eric W; Smith, Melinda D; Thakur, Madhav P; Tilman, David; Tracy, Benjamin F; van der Putten, Wim H; van Ruijven, Jasper; Weigelt, Alexandra; Weisser, Wolfgang W; Wilsey, Brian; Eisenhauer, Nico

    2015-10-22

    It remains unclear whether biodiversity buffers ecosystems against climate extremes, which are becoming increasingly frequent worldwide. Early results suggested that the ecosystem productivity of diverse grassland plant communities was more resistant, changing less during drought, and more resilient, recovering more quickly after drought, than that of depauperate communities. However, subsequent experimental tests produced mixed results. Here we use data from 46 experiments that manipulated grassland plant diversity to test whether biodiversity provides resistance during and resilience after climate events. We show that biodiversity increased ecosystem resistance for a broad range of climate events, including wet or dry, moderate or extreme, and brief or prolonged events. Across all studies and climate events, the productivity of low-diversity communities with one or two species changed by approximately 50% during climate events, whereas that of high-diversity communities with 16-32 species was more resistant, changing by only approximately 25%. By a year after each climate event, ecosystem productivity had often fully recovered, or overshot, normal levels of productivity in both high- and low-diversity communities, leading to no detectable dependence of ecosystem resilience on biodiversity. Our results suggest that biodiversity mainly stabilizes ecosystem productivity, and productivity-dependent ecosystem services, by increasing resistance to climate events. Anthropogenic environmental changes that drive biodiversity loss thus seem likely to decrease ecosystem stability, and restoration of biodiversity to increase it, mainly by changing the resistance of ecosystem productivity to climate events.

  17. A probabilistic model of ecosystem response to climate change

    International Nuclear Information System (INIS)

    Shevliakova, E.; Dowlatabadi, H.

    1994-01-01

    Anthropogenic activities are leading to rapid changes in land cover and emissions of greenhouse gases into the atmosphere. These changes can bring about climate change typified by average global temperatures rising by 1--5 C over the next century. Climate change of this magnitude is likely to alter the distribution of terrestrial ecosystems on a large scale. Options available for dealing with such change are abatement of emissions, adaptation, and geoengineering. The integrated assessment of climate change demands that frameworks be developed where all the elements of the climate problem are present (from economic activity to climate change and its impacts on market and non-market goods and services). Integrated climate assessment requires multiple impact metrics and multi-attribute utility functions to simulate the response of different key actors/decision-makers to the actual physical impacts (rather than a dollar value) of the climate-damage vs. policy-cost debate. This necessitates direct modeling of ecosystem impacts of climate change. The authors have developed a probabilistic model of ecosystem response to global change. This model differs from previous efforts in that it is statistically estimated using actual ecosystem and climate data yielding a joint multivariate probability of prevalence for each ecosystem, given climatic conditions. The authors expect this approach to permit simulation of inertia and competition which have, so far, been absent in transfer models of continental-scale ecosystem response to global change. Thus, although the probability of one ecotype will dominate others at a given point, others would have the possibility of establishing an early foothold

  18. Exploring eco-hydrological consequences of the Amazonian ecosystems under climate and land-use changes in the 21st century

    Science.gov (United States)

    Zhang, K.; Castanho, A. D.; Moghim, S.; Bras, R. L.; Coe, M. T.; Costa, M. H.; Levine, N. M.; Longo, M.; McKnight, S.; Wang, J.; Moorcroft, P. R.

    2012-12-01

    Deforestation and drought have imposed regional-scale perturbations onto Amazonian ecosystems and are predicted to cause larger negative impacts on the Amazonian ecosystems and associated regional carbon dynamics in the 21st century. However, global climate models (GCMs) vary greatly in their projections of future climate change in Amazonia, giving rise to uncertainty in the expected fate of the Amazon over the coming century. In this study, we explore the possible eco-hydrological consequences of the Amazonian ecosystems under projected climate and land-use changes in the 21st century using two state-of-the-art terrestrial ecosystem models—Ecosystem Demography Model 2.1(ED2.1) and Integrated Biosphere Simulator model (IBIS)—driven by three representative, bias-corrected climate projections from three IPCC GCMs (NCARPCM1, NCARCCSM3 and HadCM3), coupled with two land-use change scenarios (a business-as-usual and a strict governance scenario). We also analyze the relative roles of climate change, CO2 fertilization, land-use change and fire in driving the projected composition and structure of the Amazonian ecosystems. Our results show that CO2 fertilization enhances vegetation productivity and above-ground biomass (AGB) in the region, while land-use change and fire cause AGB loss and the replacement of forests by the savanna-like vegetation. The impacts of climate change depend strongly on the direction and severity of projected precipitation changes in the region. In particular, when intensified water stress is superimposed on unregulated deforestation, both ecosystem models predict large-scale dieback of Amazonian rainforests.

  19. Development and application of an interactive climate-ecosystem model system

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming; D. Pollard

    2003-01-01

    A regional climate-ecosystem model system is developed in this study. It overcomes the weakness in traditional one-way coupling models and enables detailed description of interactive process between climate and natural ecosystem. It is applied to interaction study between monsoon climate and ecosystem in East Asia, with emphasis on future climate and ecosystem change scenario forced by doubled CO2. The climate tends to be warmer and wetter under doubled CO2 in Jianghuai and the Yangzi River valley, but it becomes warmer and drier in inland areas of northern and northwestern China. The largest changes and feedbacks between vegetation and climate occur in northern China. Northern inland ecosystems experience considerable degradation and desertification, indicating a marked sensitivity and vulnerability to climatic change. The strongest vegetation response to climate change occurs in northern China and the weakest in southern China. Vegetation feedbacks intensify warming and reduce drying due to increased CO2 during summer in northern China. Generally, vegetation-climate interactions are much stronger in northern China than in southern China.

  20. Vulnerability of the global terrestrial ecosystems to climate change.

    Science.gov (United States)

    Li, Delong; Wu, Shuyao; Liu, Laibao; Zhang, Yatong; Li, Shuangcheng

    2018-05-27

    Climate change has far-reaching impacts on ecosystems. Recent attempts to quantify such impacts focus on measuring exposure to climate change but largely ignore ecosystem resistance and resilience, which may also affect the vulnerability outcomes. In this study, the relative vulnerability of global terrestrial ecosystems to short-term climate variability was assessed by simultaneously integrating exposure, sensitivity, and resilience at a high spatial resolution (0.05°). The results show that vulnerable areas are currently distributed primarily in plains. Responses to climate change vary among ecosystems and deserts and xeric shrublands are the most vulnerable biomes. Global vulnerability patterns are determined largely by exposure, while ecosystem sensitivity and resilience may exacerbate or alleviate external climate pressures at local scales; there is a highly significant negative correlation between exposure and sensitivity. Globally, 61.31% of the terrestrial vegetated area is capable of mitigating climate change impacts and those areas are concentrated in polar regions, boreal forests, tropical rainforests, and intact forests. Under current sensitivity and resilience conditions, vulnerable areas are projected to develop in high Northern Hemisphere latitudes in the future. The results suggest that integrating all three aspects of vulnerability (exposure, sensitivity, and resilience) may offer more comprehensive and spatially explicit adaptation strategies to reduce the impacts of climate change on terrestrial ecosystems. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  1. Human activities and climate variability drive fast-paced change across the world's estuarine-coastal ecosystems

    Science.gov (United States)

    Cloern, James E.; Abreu, Paulo C.; Carstensen, Jacob; Chauvaud, Laurent; Elmgren, Ragnar; Grall, Jacques; Greening, Holly; Johansson, John O.R.; Kahru, Mati; Sherwood, Edward T.; Xu, Jie; Yin, Kedong

    2016-01-01

    Time series of environmental measurements are essential for detecting, measuring and understanding changes in the Earth system and its biological communities. Observational series have accumulated over the past 2–5 decades from measurements across the world's estuaries, bays, lagoons, inland seas and shelf waters influenced by runoff. We synthesize information contained in these time series to develop a global view of changes occurring in marine systems influenced by connectivity to land. Our review is organized around four themes: (i) human activities as drivers of change; (ii) variability of the climate system as a driver of change; (iii) successes, disappointments and challenges of managing change at the sea-land interface; and (iv) discoveries made from observations over time. Multidecadal time series reveal that many of the world's estuarine–coastal ecosystems are in a continuing state of change, and the pace of change is faster than we could have imagined a decade ago. Some have been transformed into novel ecosystems with habitats, biogeochemistry and biological communities outside the natural range of variability. Change takes many forms including linear and nonlinear trends, abrupt state changes and oscillations. The challenge of managing change is daunting in the coastal zone where diverse human pressures are concentrated and intersect with different responses to climate variability over land and over ocean basins. The pace of change in estuarine–coastal ecosystems will likely accelerate as the human population and economies continue to grow and as global climate change accelerates. Wise stewardship of the resources upon which we depend is critically dependent upon a continuing flow of information from observations to measure, understand and anticipate future changes along the world's coastlines.

  2. Elevation alters ecosystem properties across temperate treelines globally

    Science.gov (United States)

    Mayor, Jordan R.; Sanders, Nathan J.; Classen, Aimée T.; Bardgett, Richard D.; Clément, Jean-Christophe; Fajardo, Alex; Lavorel, Sandra; Sundqvist, Maja K.; Bahn, Michael; Chisholm, Chelsea; Cieraad, Ellen; Gedalof, Ze'Ev; Grigulis, Karl; Kudo, Gaku; Oberski, Daniel L.; Wardle, David A.

    2017-01-01

    Temperature is a primary driver of the distribution of biodiversity as well as of ecosystem boundaries. Declining temperature with increasing elevation in montane systems has long been recognized as a major factor shaping plant community biodiversity, metabolic processes, and ecosystem dynamics. Elevational gradients, as thermoclines, also enable prediction of long-term ecological responses to climate warming. One of the most striking manifestations of increasing elevation is the abrupt transitions from forest to treeless alpine tundra. However, whether there are globally consistent above- and belowground responses to these transitions remains an open question. To disentangle the direct and indirect effects of temperature on ecosystem properties, here we evaluate replicate treeline ecotones in seven temperate regions of the world. We find that declining temperatures with increasing elevation did not affect tree leaf nutrient concentrations, but did reduce ground-layer community-weighted plant nitrogen, leading to the strong stoichiometric convergence of ground-layer plant community nitrogen to phosphorus ratios across all regions. Further, elevation-driven changes in plant nutrients were associated with changes in soil organic matter content and quality (carbon to nitrogen ratios) and microbial properties. Combined, our identification of direct and indirect temperature controls over plant communities and soil properties in seven contrasting regions suggests that future warming may disrupt the functional properties of montane ecosystems, particularly where plant community reorganization outpaces treeline advance.

  3. Key Senators Issue Call for `Meaningful' Climate Legislation

    Science.gov (United States)

    Showstack, Randy

    With the U.S. Senate currently considering national energy legislation, Senators John McCain (R-Arizona) and Joseph Lieberman (D-Connecticut) plan to offer a modified version of their bipartisan, proposed Climate Stewardship Act of 2003 (S. 139) as an amendment. The amendment would establish a market driven system of greenhouse gas tradeable allowances to reduce emission. It would also provide for a program of scientific research on abrupt climate change in order to identify and understand past instances of abrupt change; and would establish a national greenhouse gas data base.

  4. Collaborative Project: Development of an Isotope-Enabled CESM for Testing Abrupt Climate Changes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhengyu [Univ. of Wisconsin, Madison, WI (United States). Dept. of Atmospheric and Oceanic Sciences

    2018-01-24

    One of the most important validations for a state-of-art Earth System Model (ESM) with respect to climate changes is the simulation of the climate evolution and abrupt climate change events in the Earth’s history of the last 21,000 years. However, one great challenge for model validation is that ESMs usually do not directly simulate geochemical variables that can be compared directly with past proxy records. In this proposal, we have met this challenge by developing the simulation capability of major isotopes in a state-of-art ESM, the Community Earth System Model (CESM), enabling us to make direct model-data comparison by comparing the model directly against proxy climate records. Our isotope-enabled ESM incorporates the capability of simulating key isotopes and geotracers, notably δ18O, δD, δ14C, and δ13C, Nd and Pa/Th. The isotope-enabled ESM have been used to perform some simulations for the last 21000 years. The direct comparison of these simulations with proxy records has shed light on the mechanisms of important climate change events.

  5. Modelling Regional Climate Change Effects On Potential Natural Ecosystems in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Koca, D.; Smith, B.; Sykes, M.T. [Centre for GeoBiosphere Science, Department of Physical Geography and Ecosystems Analysis, Lund University, Soelvegatan 12, S-223 62 Lund (Sweden)

    2006-10-15

    This study aims to demonstrate the potential of a process-based regional ecosystem model, LPJ-GUESS, driven by climate scenarios generated by a regional climate model system (RCM) to generate predictions useful for assessing effects of climatic and CO2 change on the key ecosystem services of carbon uptake and storage. Scenarios compatible with the A2 and B2 greenhouse gas emission scenarios of the Special Report on Emission Scenarios (SRES) and with boundary conditions from two general circulation models (GCMs) - HadAM3H and ECHAM4/OPYC3 - were used in simulations to explore changes in tree species distributions, vegetation structure, productivity and ecosystem carbon stocks for the late 21st Century, thus accommodating a proportion of the GCM-based and emissions-based uncertainty in future climate development. The simulations represented in this study were of the potential natural vegetation ignoring direct anthropogenic effects. Results suggest that shifts in climatic zones may lead to changes in species distribution and community composition among seven major tree species of natural Swedish forests. All four climate scenarios were associated with an extension of the boreal forest treeline with respect to altitude and latitude. In the boreal and boreo-nemoral zones, the dominance of Norway spruce and to a lesser extent Scots pine was reduced in favour of deciduous broadleaved tree species. The model also predicted substantial increases in vegetation net primary productivity (NPP), especially in central Sweden. Expansion of forest cover and increased local biomass enhanced the net carbon sink over central and northern Sweden, despite increased carbon release through decomposition processes in the soil. In southern Sweden, reduced growing season soil moisture levels counterbalanced the positive effects of a longer growing season and increased carbon supply on NPP, with the result that many areas were converted from a sink to a source of carbon by the late 21st

  6. Modelling Regional Climate Change Effects On Potential Natural Ecosystems in Sweden

    International Nuclear Information System (INIS)

    Koca, D.; Smith, B.; Sykes, M.T.

    2006-01-01

    This study aims to demonstrate the potential of a process-based regional ecosystem model, LPJ-GUESS, driven by climate scenarios generated by a regional climate model system (RCM) to generate predictions useful for assessing effects of climatic and CO2 change on the key ecosystem services of carbon uptake and storage. Scenarios compatible with the A2 and B2 greenhouse gas emission scenarios of the Special Report on Emission Scenarios (SRES) and with boundary conditions from two general circulation models (GCMs) - HadAM3H and ECHAM4/OPYC3 - were used in simulations to explore changes in tree species distributions, vegetation structure, productivity and ecosystem carbon stocks for the late 21st Century, thus accommodating a proportion of the GCM-based and emissions-based uncertainty in future climate development. The simulations represented in this study were of the potential natural vegetation ignoring direct anthropogenic effects. Results suggest that shifts in climatic zones may lead to changes in species distribution and community composition among seven major tree species of natural Swedish forests. All four climate scenarios were associated with an extension of the boreal forest treeline with respect to altitude and latitude. In the boreal and boreo-nemoral zones, the dominance of Norway spruce and to a lesser extent Scots pine was reduced in favour of deciduous broadleaved tree species. The model also predicted substantial increases in vegetation net primary productivity (NPP), especially in central Sweden. Expansion of forest cover and increased local biomass enhanced the net carbon sink over central and northern Sweden, despite increased carbon release through decomposition processes in the soil. In southern Sweden, reduced growing season soil moisture levels counterbalanced the positive effects of a longer growing season and increased carbon supply on NPP, with the result that many areas were converted from a sink to a source of carbon by the late 21st

  7. A simple conceptual model of abrupt glacial climate events

    Directory of Open Access Journals (Sweden)

    H. Braun

    2007-11-01

    Full Text Available Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events to a few simple principles, namely (i the existence of two different climate states, (ii a threshold process and (iii an overshooting in the stability of the system at the start and the end of the events, which is followed by a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2, in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance and provide the first explicitly reported manifestation of ghost resonance in a geosystem, i.e. of a mechanism which could be relevant for other systems with thresholds and with multiple states of operation. Our work enables us to explicitly simulate realistic probability measures of Dansgaard-Oeschger events (e.g. waiting time distributions, which are a prerequisite for statistical analyses on the regularity of the events by means of Monte-Carlo simulations. We thus think that our study is an important advance in order to develop more adequate methods to test the statistical significance and the origin of the proposed glacial 1470-year climate cycle.

  8. Modeled seasonality of glacial abrupt climate events

    Energy Technology Data Exchange (ETDEWEB)

    Flueckiger, Jacqueline [Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO (United States); Environmental Physics, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zuerich, Zurich (Switzerland); Knutti, Reto [Institute for Atmospheric and Climate Science, ETH Zuerich, Zurich (Switzerland); White, James W.C. [Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO (United States); Renssen, Hans [Vrije Universiteit Amsterdam, Faculty of Earth and Life Sciences, Amsterdam (Netherlands)

    2008-11-15

    Greenland ice cores, as well as many other paleo-archives from the northern hemisphere, recorded a series of 25 warm interstadial events, the so-called Dansgaard-Oeschger (D-O) events, during the last glacial period. We use the three-dimensional coupled global ocean-atmosphere-sea ice model ECBILT-CLIO and force it with freshwater input into the North Atlantic to simulate abrupt glacial climate events, which we use as analogues for D-O events. We focus our analysis on the Northern Hemisphere. The simulated events show large differences in the regional and seasonal distribution of the temperature and precipitation changes. While the temperature changes in high northern latitudes and in the North Atlantic region are dominated by winter changes, the largest temperature increases in most other land regions are seen in spring. Smallest changes over land are found during the summer months. Our model simulations also demonstrate that the temperature and precipitation change patterns for different intensifications of the Atlantic meridional overturning circulation are not linear. The extent of the transitions varies, and local non-linearities influence the amplitude of the annual mean response as well as the response in different seasons. Implications for the interpretation of paleo-records are discussed. (orig.)

  9. Extrinsic regime shifts drive abrupt changes in regeneration dynamics at upper treeline in the Rocky Mountains, U.S.A.

    Science.gov (United States)

    Elliott, Grant P

    2012-07-01

    Given the widespread and often dramatic influence of climate change on terrestrial ecosystems, it is increasingly common for abrupt threshold changes to occur, yet explicitly testing for climate and ecological regime shifts is lacking in climatically sensitive upper treeline ecotones. In this study, quantitative evidence based on empirical data is provided to support the key role of extrinsic, climate-induced thresholds in governing the spatial and temporal patterns of tree establishment in these high-elevation environments. Dendroecological techniques were used to reconstruct a 420-year history of regeneration dynamics within upper treeline ecotones along a latitudinal gradient (approximately 44-35 degrees N) in the Rocky Mountains. Correlation analysis was used to assess the possible influence of minimum and maximum temperature indices and cool-season (November-April) precipitation on regional age-structure data. Regime-shift analysis was used to detect thresholds in tree establishment during the entire period of record (1580-2000), temperature variables significantly Correlated with establishment during the 20th century, and cool-season precipitation. Tree establishment was significantly correlated with minimum temperature during the spring (March-May) and cool season. Regime-shift analysis identified an abrupt increase in regional tree establishment in 1950 (1950-1954 age class). Coincident with this period was a shift toward reduced cool-season precipitation. The alignment of these climate conditions apparently triggered an abrupt increase in establishment that was unprecedented during the period of record. Two main findings emerge from this research that underscore the critical role of climate in governing regeneration dynamics within upper treeline ecotones. (1) Regional climate variability is capable of exceeding bioclimatic thresholds, thereby initiating synchronous and abrupt changes in the spatial and temporal patterns of tree establishment at broad

  10. Whitebark pine vulnerability to climate-driven mountain pine beetle disturbance in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Logan, Jesse A; MacFarlane, William W; Willcox, Louisa

    2010-06-01

    Widespread outbreaks of mountain pine beetles (MPB) are occurring throughout the range of this native insect. Episodic outbreaks are a common occurrence in the beetles' primary host, lodgepole pine. Current outbreaks, however, are occurring in habitats where outbreaks either did not previously occur or were limited in scale. Herein, we address widespread, ongoing outbreaks in high-elevation, whitebark pine forests of the Greater Yellowstone Ecosystem, where, due to an inhospitable climate, past outbreaks were infrequent and short lived. We address the basic question: are these outbreaks truly unprecedented and a threat to ecosystem continuity? In order to evaluate this question we (1) present evidence that the current outbreak is outside the historic range of variability; (2) examine system resiliency to MPB disturbance based on adaptation to disturbance and host defenses to MPB attack; and (3) investigate the potential domain of attraction to large-scale MPB disturbance based on thermal developmental thresholds, spatial structure of forest types, and the confounding influence of an introduced pathogen. We conclude that the loss of dominant whitebark pine forests, and the ecological services they provide, is likely under continuing climate warming and that new research and strategies are needed to respond to the crisis facing whitebark pine.

  11. Climate change impacts on ecosystems and ecosystem services in the United States: Process and prospects for sustained assessment

    Science.gov (United States)

    Grimm, Nancy B.; Groffman, Peter M; Staudinger, Michelle D.; Tallis, Heather

    2016-01-01

    The third United States National Climate Assessment emphasized an evaluation of not just the impacts of climate change on species and ecosystems, but also the impacts of climate change on the benefits that people derive from nature, known as ecosystem services. The ecosystems, biodiversity, and ecosystem services component of the assessment largely drew upon the findings of a transdisciplinary workshop aimed at developing technical input for the assessment, involving participants from diverse sectors. A small author team distilled and synthesized this and hundreds of other technical input to develop the key findings of the assessment. The process of developing and ranking key findings hinged on identifying impacts that had particular, demonstrable effects on the U.S. public via changes in national ecosystem services. Findings showed that ecosystem services are threatened by the impacts of climate change on water supplies, species distributions and phenology, as well as multiple assaults on ecosystem integrity that, when compounded by climate change, reduce the capacity of ecosystems to buffer against extreme events. As ecosystems change, such benefits as water sustainability and protection from storms that are afforded by intact ecosystems are projected to decline across the continent due to climate change. An ongoing, sustained assessment that focuses on the co-production of actionable climate science will allow scientists from a range of disciplines to ascertain the capability of their forecasting models to project environmental and ecological change and link it to ecosystem services; additionally, an iterative process of evaluation, development of management strategies, monitoring, and reevaluation will increase the applicability and usability of the science by the U.S. public.

  12. The Abrupt Onset of the Modern South Asian Monsoon Winds (iodp Exp. 359)

    Science.gov (United States)

    Betzler, C.; Eberli, G. P.; Kroon, D.; Wright, J. D.; Swart, P. K.; Nath, B. N.; Reijmer, J.; Alvarez Zarikian, C. A.

    2016-12-01

    The South Asian Monson (SAM) is one of the most extreme features in Earth's climate system, yet its initiation and variations are not well established. The SAM is a seasonal reversal of winds accompanied by changes in precipitation with heavy rain during the summer monsoon. It is one of the most intense annually recurring climatic elements and of immense importance in supplying moisture to the Indian subcontinent thus affecting human population and vegetation, as well as marine biota in the surrounding seas. The seasonal precipitation change is one of the SAM elements most noticed on land, whereas the reversal of the wind regime is the dominating driver of circulation in the central and northern Indian Ocean realm. New data acquired during International Ocean Discovery Program Expedition 359 from the Inner Sea of the Maldives provide a previously unread archive that reveals an abrupt onset of the SAM-linked ocean circulation pattern and its relationship to the long term Neogene climate cooling. In particular it registers ocean current fluctuations and changes of intermediate water mass properties for the last 25 myrs that are directly related to the monsoon. Dating the deposits of SAM wind-driven currents yields an age of 12.9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment's content of sedimentary organic matter. A weaker `proto-monsoon' existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.

  13. Arctic ecosystem responses to a warming climate

    DEFF Research Database (Denmark)

    Mortensen, Lars O.

    sheet, loss of multiannual sea-ice and significant advances in snowmelt days. The biotic components of the arctic ecosystem have also been affected by the rapid changes in climate, for instance resulting in the collapse of the collared lemming cycle, advances in spring flowering and changes in the intra...... biotic interactions. Hence, through the use of up-to-date multivariate statistical tools, this Ph.D. study has been concerned with analyzing how the observed rapid climate changes are affecting the arctic ecosystems. The primary tool has been the implementation of structural equation modeling (SEM) which....... Additionally, the study demonstrated that climate effects had distinct direct and indirect effects on different trophic levels, indicating cascading effects of climate through the trophic system. Results suggest that the Arctic is being significantly affected by the observed climate changes and depending...

  14. Adapting California’s ecosystems to a changing climate

    Science.gov (United States)

    Elizabeth Chornesky,; David Ackerly,; Paul Beier,; Frank Davis,; Flint, Lorraine E.; Lawler, Joshua J.; Moyle, Peter B.; Moritz, Max A.; Scoonover, Mary; Byrd, Kristin B.; Alvarez, Pelayo; Heller, Nicole E.; Micheli, Elisabeth; Weiss, Stuart

    2017-01-01

    Significant efforts are underway to translate improved understanding of how climate change is altering ecosystems into practical actions for sustaining ecosystem functions and benefits. We explore this transition in California, where adaptation and mitigation are advancing relatively rapidly, through four case studies that span large spatial domains and encompass diverse ecological systems, institutions, ownerships, and policies. The case studies demonstrate the context specificity of societal efforts to adapt ecosystems to climate change and involve applications of diverse scientific tools (e.g., scenario analyses, downscaled climate projections, ecological and connectivity models) tailored to specific planning and management situations (alternative energy siting, wetland management, rangeland management, open space planning). They illustrate how existing institutional and policy frameworks provide numerous opportunities to advance adaptation related to ecosystems and suggest that progress is likely to be greatest when scientific knowledge is integrated into collective planning and when supportive policies and financing enable action.

  15. A Evaluation of Effects on a Ecosystem and Countermeasures in accordance with Climate Change I- Forest Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yong Ha; Jeon, Seong Woo; Choi, Jae Yong; Jeong Hwi Chol; Kim, Jeong Won [Korea Environment Institute, Seoul (Korea)

    2000-12-01

    Climate change requests a lot of changes in the existing life style and economic developing system, which form the foundation of modern culture and economic/social development. Especially, in Korea, whose economic basis is mainly dependent on fossil energy, it is expected that the change of policies on climate change have a bigger effect on many-sided fields including ecosystem than other nations. Therefore, even though all of the Government, academic organizations, and private organizations have made efforts to estimate effects of climate change and to prepare countermeasures, the focus has been on forecast and evaluation of the mutual effect between industrial/economic activities and climate change. Forecast of ecosystem change and preservation of ecosystem according to climate change is another political field to promote. However, such a field has not been promoted systematically in Korea. The Institute recognizing such a current state, as part of the policy on ecosystem preservation according to climate change, forecasted the effect on forest ecosystem, analyzed the economic effects according to the effect of forest ecosystem, and started this study to prepare the countermeasures of the Government-level. This study collected and analyzed international trend and necessary data to develop the model, which would be executed in future, and then suggested the selection and development of the model fitted to Korea. There could be differences between Institute's view and the Government/other institutes. However, such differences are caused by the different methods in capturing the effects of various ecosystems. Such various approaching methods will be of great help to estimate the correct effects and to establish the Government's policies as base data. I hope that this study cannot only be applied to analyze the effects of forest ecosystem according to climate change but contribute to enlarging the understanding of various problems according to climate

  16. Wildland fire emissions, carbon, and climate: Science overview and knowledge needs

    Science.gov (United States)

    William T. Sommers; Rachel A. Loehman; Colin C. Hardy

    2014-01-01

    Wildland fires have influenced the global carbon cycle for 420 million years of Earth history, interacting with climate to define vegetation characteristics and distributions, trigger abrupt ecosystem shifts, and move carbon among terrestrial and atmospheric pools. Carbon dioxide (CO2) is the dominant driver of ongoing climate change and the principal emissions...

  17. Taking the pulse of mountains: Ecosystem responses to climatic variability

    Science.gov (United States)

    Fagre, Daniel B.; Peterson, David L.; Hessl, Amy E.

    2003-01-01

    An integrated program of ecosystem modeling and field studies in the mountains of the Pacific Northwest (U.S.A.) has quantified many of the ecological processes affected by climatic variability. Paleoecological and contemporary ecological data in forest ecosystems provided model parameterization and validation at broad spatial and temporal scales for tree growth, tree regeneration and treeline movement. For subalpine tree species, winter precipitation has a strong negative correlation with growth; this relationship is stronger at higher elevations and west-side sites (which have more precipitation). Temperature affects tree growth at some locations with respect to length of growing season (spring) and severity of drought at drier sites (summer). Furthermore, variable but predictable climate-growth relationships across elevation gradients suggest that tree species respond differently to climate at different locations, making a uniform response of these species to future climatic change unlikely. Multi-decadal variability in climate also affects ecosystem processes. Mountain hemlock growth at high-elevation sites is negatively correlated with winter snow depth and positively correlated with the winter Pacific Decadal Oscillation (PDO) index. At low elevations, the reverse is true. Glacier mass balance and fire severity are also linked to PDO. Rapid establishment of trees in subalpine ecosystems during this century is increasing forest cover and reducing meadow cover at many subalpine locations in the western U.S.A. and precipitation (snow depth) is a critical variable regulating conifer expansion. Lastly, modeling potential future ecosystem conditions suggests that increased climatic variability will result in increasing forest fire size and frequency, and reduced net primary productivity in drier, east-side forest ecosystems. As additional empirical data and modeling output become available, we will improve our ability to predict the effects of climatic change

  18. Community and ecosystem responses to elevational gradients

    DEFF Research Database (Denmark)

    Sundqvist, Maja K.; Sanders, Nate; Wardle, David A.

    2013-01-01

    Community structure and ecosystem processes often vary along elevational gradients. Their responses to elevation are commonly driven by changes in temperature, and many community- and ecosystem-level variables therefore frequently respond similarly to elevation across contrasting gradients...... elevational gradients for understanding community and ecosystem responses to global climate change at much larger spatial and temporal scales than is possible through conventional ecological experiments. However, future studies that integrate elevational gradient approaches with experimental manipulations...... will provide powerful information that can improve predictions of climate change impacts within and across ecosystems....

  19. Mammoth ecosystem: Climatic areal, animal's density and cause of extinctions

    Science.gov (United States)

    Zimov, S.; Zimov, N.; Zimova, G.; Chapin, S. F.

    2008-12-01

    During the last glaciations Mammoth Ecosystem (ME) occupied territory from present-day France to Canada and from the Arctic islands to China. This ecosystem played major role in global carbon cycle and human settling around the planet. Causes of extinction of this ecosystem are debatable. Analyses of hundreds of radiocarbon dates of ME animal fossil remains showed that warming and moistening of climate wasn't accompanied by animal extinction. On the opposite, on the north right after the warming rise of herbivore population was observed. Reconstruction of ME climatic areal showed that its climatic optimum lies within range of annual precipitation of 200-350 mm and average summer temperatures of +8-+12oC which corresponds with modern climate of Northern Siberia. Analyses of bones and skeletons concentrations in permafrost of Northern Siberia showed that animal density in ME was similar to African savannah. That was a high productive ecosystem that could sustain in wide variety of climates because numerous herbivores maintained there pastures themselves.

  20. Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

    Science.gov (United States)

    Yang, Hao; Luo, Peng; Wang, Jun; Mou, Chengxiang; Mo, Li; Wang, Zhiyuan; Fu, Yao; Lin, Honghui; Yang, Yongping; Bhatta, Laxmi Dutt

    2015-01-01

    Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

  1. Effects on the equine colon ecosystem of grass silage and haylage diets after an abrupt change from hay.

    Science.gov (United States)

    Muhonen, S; Julliand, V; Lindberg, J E; Bertilsson, J; Jansson, A

    2009-07-01

    The objective of this study was to investigate the effect of an abrupt change from grass hay (81% DM) to grass silage (36% DM) or grass haylage (55% DM), fed at similar DM intakes, and to compare the effects of silage and haylage on the composition and activities of the colon microflora. The forages were from the same swath harvested on the same day. Four adult colon-fistulated geldings were randomly assigned to diets in a crossover design. The study started with a preperiod when all 4 horses received the hay diet, followed by an abrupt feed change to the haylage diet for 2 horses and the silage diet for 2 horses. All 4 horses then had a new second preperiod of hay, followed by an abrupt feed change to the opposite haylage and silage diet. The periods were 21 d long, and the forage-only diets were supplemented with minerals and salt. The abrupt feed changes were made at 0800 h. Colon samples were taken before the abrupt feed change, 4 and 28 h after the feed change, and 8, 15, and 21 d after the feed change, all at 1200 h. Colon bacterial counts, VFA, pH, and DM concentrations were unchanged throughout the first 28 h after the abrupt feed change from hay to haylage and silage. Also, fecal pH and DM concentrations were unchanged during the first 28 h. During the weekly observations, colon lactobacilli counts increased (P = 0.023) in horses receiving the silage diet and were greater than on the haylage diet at 21 d. Streptococci counts decreased (P = 0.046) in horses receiving the haylage diet and were less than on the silage diet at 15 and 21 d. Total VFA concentrations and colon and fecal pH did not differ between diets and were unchanged throughout the weekly observations. The DM concentration of colon digesta and feces decreased (P = 0.030 and 0.049, respectively) on both diets during the weekly observations. The results suggest that in horses fed at the maintenance level of energy intake, an abrupt feed change from grass hay to grass silage or grass haylage from

  2. Modeling net ecosystem carbon exchange of alpine grasslands with a satellite-driven model.

    Directory of Open Access Journals (Sweden)

    Wei Yan

    Full Text Available Estimate of net ecosystem carbon exchange (NEE between the atmosphere and terrestrial ecosystems, the balance of gross primary productivity (GPP and ecosystem respiration (Reco has significant importance for studying the regional and global carbon cycles. Using models driven by satellite data and climatic data is a promising approach to estimate NEE at regional scales. For this purpose, we proposed a semi-empirical model to estimate NEE in this study. In our model, the component GPP was estimated with a light response curve of a rectangular hyperbola. The component Reco was estimated with an exponential function of soil temperature. To test the feasibility of applying our model at regional scales, the temporal variations in the model parameters derived from NEE observations in an alpine grassland ecosystem on Tibetan Plateau were investigated. The results indicated that all the inverted parameters exhibit apparent seasonality, which is in accordance with air temperature and canopy phenology. In addition, all the parameters have significant correlations with the remote sensed vegetation indexes or environment temperature. With parameters estimated with these correlations, the model illustrated fair accuracy both in the validation years and at another alpine grassland ecosystem on Tibetan Plateau. Our results also indicated that the model prediction was less accurate in drought years, implying that soil moisture is an important factor affecting the model performance. Incorporating soil water content into the model would be a critical step for the improvement of the model.

  3. Understanding Climate Change and Manifestation of its Driven ...

    African Journals Online (AJOL)

    This article examines the nature and manifestation of climate change driven impacts on the agrarian districts of Kongwa and Bahi in the semi arid areas of Dodoma region in Tanzania. A Survey of 398 households in the study area was undertaken to elicit information on the nature and manifestation of climate change driven ...

  4. Abrupt Climate Change and the Atlantic Meridional Overturning Circulation: sensitivity and non-linear response to Arctic/sub-Arctic freshwater pulses. Collaborative research. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Christopher [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)

    2015-06-15

    This project investigated possible mechanisms by which melt-water pulses can induce abrupt change in the Atlantic Meridional Overturning Circulation (AMOC) magnitude. AMOC magnitude is an important ingredient in present day climate. Previous studies have hypothesized abrupt reduction in AMOC magnitude in response to influxes of glacial melt water into the North Atlantic. Notable fresh-water influxes are associated with the terminus of the last ice age. During this period large volumes of melt water accumulated behind retreating ice sheets and subsequently drained rapidly when the ice weakened sufficiently. Rapid draining of glacial lakes into the North Atlantic is a possible origin of a number of paleo-record abrupt climate shifts. These include the Younger-Dryas cooling event and the 8,200 year cooling event. The studies undertaken focused on whether the mechanistic sequence by which glacial melt-water impacts AMOC, which then impacts Northern Hemisphere global mean surface temperature, is dynamically plausible. The work has implications for better understanding past climate stability. The work also has relevance for today’s environment, in which high-latitude ice melting in Greenland appears to be driving fresh water outflows at an accelerating pace.

  5. Are fish outside their usual ranges early indicators of climate-driven range shifts?

    Science.gov (United States)

    Fogarty, Hannah E; Burrows, Michael T; Pecl, Gretta T; Robinson, Lucy M; Poloczanska, Elvira S

    2017-05-01

    Shifts in species ranges are a global phenomenon, well known to occur in response to a changing climate. New species arriving in an area may become pest species, modify ecosystem structure, or represent challenges or opportunities for fisheries and recreation. Early detection of range shifts and prompt implementation of any appropriate management strategies is therefore crucial. This study investigates whether 'first sightings' of marine species outside their normal ranges could provide an early warning of impending climate-driven range shifts. We examine the relationships between first sightings and marine regions defined by patterns of local climate velocities (calculated on a 50-year timescale), while also considering the distribution of observational effort (i.e. number of sampling days recorded with biological observations in global databases). The marine trajectory regions include climate 'source' regions (areas lacking connections to warmer areas), 'corridor' regions (areas where moving isotherms converge), and 'sink' regions (areas where isotherms locally disappear). Additionally, we investigate the latitudinal band in which first sightings were recorded, and species' thermal affiliations. We found that first sightings are more likely to occur in climate sink and 'divergent' regions (areas where many rapid and diverging climate trajectories pass through) indicating a role of temperature in driving changes in marine species distributions. The majority of our fish first sightings appear to be tropical and subtropical species moving towards high latitudes, as would be expected in climate warming. Our results indicate that first sightings are likely related to longer-term climatic processes, and therefore have potential use to indicate likely climate-driven range shifts. The development of an approach to detect impending range shifts at an early stage will allow resource managers and researchers to better manage opportunities resulting from range

  6. Early warning signals of abrupt temperature change in different regions of China over the past 50 years

    International Nuclear Information System (INIS)

    Tong Ji-Long; Wu Hao; Hou Wei; He Wen-Ping; Zhou Jie

    2014-01-01

    In this paper, the early warning signals of abrupt temperature change in different regions of China are investigated. Seven regions are divided on the basis of different climate temperature patterns, obtained through the rotated empirical orthogonal function, and the signal-to-noise temperature ratios for each region are then calculated. Based on the concept of critical slowing down, the temperature data that contain noise in the different regions of China are preprocessed to study the early warning signals of abrupt climate change. First, the Mann–Kendall method is used to identify the instant of abrupt climate change in the temperature data. Second, autocorrelation coefficients that can identify critical slowing down are calculated. The results show that the critical slowing down phenomenon appeared in temperature data about 5–10 years before abrupt climate change occurred, which indicates that the critical slowing down phenomenon is a possible early warning signal for abrupt climate change, and that noise has less influence on the detection results of the early warning signals. Accordingly, this demonstrates that the model is reliable in identifying the early warning signals of abrupt climate change based on detecting the critical slowing down phenomenon, which provides an experimental basis for the actual application of the method. (geophysics, astronomy, and astrophysics)

  7. Ecosystem and Food Security in a Changing Climate

    Science.gov (United States)

    Field, C. B.

    2011-12-01

    Observed and projected impacts of climate change for ecosystem and food security tend to appear as changes in the risk of both desirable and undesirable outcomes. As a consequence, it is useful to frame the challenge of adaptation to a changing climate as a problem in risk management. For some kinds of impacts, the risks are relatively well characterized. For others, they are poorly known. Especially for the cases where the risks are poorly known, effective adaptation will need to consider approaches that build dynamic portfolios of options, based on learning from experience. Effective adaptation approaches also need to consider the risks of threshold-type responses, where opportunities for gradual adaptation based on learning may be limited. Finally, effective adaptation should build on the understanding that negative impacts on ecosystems and food security often result from extreme events, where a link to climate change may be unclear now and far into the future. Ecosystem and food security impacts that potentially require adaptation to a changing climate vary from region to region and interact strongly with actions not related to climate. In many ecosystems, climate change shifts the risk profile to increase risks of wildfire and biological invasions. Higher order risks from factors like pests and pathogens remain difficult to quantify. For food security, observational evidence highlights threshold-like behavior to high temperature in yields of a number of crops. But the risks to food security may be much broader, encompassing risks to availability of irrigation, degradation of topsoil, and challenges of storage and distribution. A risk management approach facilitates consideration of all these challenges with a unified framework.

  8. A Generalized Stability Analysis of the AMOC in Earth System Models: Implication for Decadal Variability and Abrupt Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, Alexey V. [Yale Univ., New Haven, CT (United States)

    2015-01-14

    The central goal of this research project was to understand the mechanisms of decadal and multi-decadal variability of the Atlantic Meridional Overturning Circulation (AMOC) as related to climate variability and abrupt climate change within a hierarchy of climate models ranging from realistic ocean models to comprehensive Earth system models. Generalized Stability Analysis, a method that quantifies the transient and asymptotic growth of perturbations in the system, is one of the main approaches used throughout this project. The topics we have explored range from physical mechanisms that control AMOC variability to the factors that determine AMOC predictability in the Earth system models, to the stability and variability of the AMOC in past climates.

  9. Assessing confidence in management adaptation approaches for climate-sensitive ecosystems

    International Nuclear Information System (INIS)

    West, J M; Julius, S H; Weaver, C P

    2012-01-01

    A number of options are available for adapting ecosystem management to improve resilience in the face of climatic changes. However, uncertainty exists as to the effectiveness of these options. A report prepared for the US Climate Change Science Program reviewed adaptation options for a range of federally managed systems in the United States. The report included a qualitative uncertainty analysis of conceptual approaches to adaptation derived from the review. The approaches included reducing anthropogenic stressors, protecting key ecosystem features, maintaining representation, replicating, restoring, identifying refugia and relocating organisms. The results showed that the expert teams had the greatest scientific confidence in adaptation options that reduce anthropogenic stresses. Confidence in other approaches was lower because of gaps in understanding of ecosystem function, climate change impacts on ecosystems, and management effectiveness. This letter discusses insights gained from the confidence exercise and proposes strategies for improving future assessments of confidence for management adaptations to climate change. (letter)

  10. Land Use, Climate Change and Ecosystem Services

    OpenAIRE

    Attavanich, Witsanu; Rashford, Benjamin S.; Adams, Richard M.; McCarl, Bruce A.

    2011-01-01

    The combination of shifts in crop production and a reduction in wetland ecosystems associated with climate change are forecast to reduce native grasslands and associated obligate species. Most estimates of climate change impacts to wildlife, however, do not account for how humans are likely to alter land use in response to climate changes. We examine the joint effect of climate change and the resulting land use response of farmers on waterfowl production in the Prairie Pothole Region of Nor...

  11. Uncertainties in carbon residence time and NPP-driven carbon uptake in terrestrial ecosystems of the conterminous USA: a Bayesian approach

    Directory of Open Access Journals (Sweden)

    Xuhui Zhou

    2012-10-01

    Full Text Available Carbon (C residence time is one of the key factors that determine the capacity of ecosystem C storage. However, its uncertainties have not been well quantified, especially at regional scales. Assessing uncertainties of C residence time is thus crucial for an improved understanding of terrestrial C sequestration. In this study, the Bayesian inversion and Markov Chain Monte Carlo (MCMC technique were applied to a regional terrestrial ecosystem (TECO-R model to quantify C residence times and net primary productivity (NPP-driven ecosystem C uptake and assess their uncertainties in the conterminous USA. The uncertainty was represented by coefficient of variation (CV. The 13 spatially distributed data sets of C pools and fluxes have been used to constrain TECO-R model for each biome (totally eight biomes. Our results showed that estimated ecosystem C residence times ranged from 16.6±1.8 (cropland to 85.9±15.3 yr (evergreen needleleaf forest with an average of 56.8±8.8 yr in the conterminous USA. The ecosystem C residence times and their CV were spatially heterogeneous and varied with vegetation types and climate conditions. Large uncertainties appeared in the southern and eastern USA. Driven by NPP changes from 1982 to 1998, terrestrial ecosystems in the conterminous USA would absorb 0.20±0.06 Pg C yr−1. Their spatial pattern was closely related to the greenness map in the summer with larger uptake in central and southeast regions. The lack of data or timescale mismatching between the available data and the estimated parameters lead to uncertainties in the estimated C residence times, which together with initial NPP resulted in the uncertainties in the estimated NPP-driven C uptake. The Bayesian approach with MCMC inversion provides an effective tool to estimate spatially distributed C residence time and assess their uncertainties in the conterminous USA.

  12. Ecosystems and climate interactions in the boreal zone of northern Eurasia

    International Nuclear Information System (INIS)

    Vygodskaya, N N; Groisman, P Ya; Tchebakova, N M; Kurbatova, J A; Panfyorov, O; Parfenova, E I; Sogachev, A F

    2007-01-01

    The climate system and terrestrial ecosystems interact as they change. In northern Eurasia these interactions are especially strong, span all spatial and timescales, and thus have become the subject of an international program: the Northern Eurasia Earth Science Partnership Initiative (NEESPI). Without trying to cover all areas of these interactions, this paper introduces three examples of the principal micrometeorological, mesometeorological and subcontinental feedbacks that control climate-terrestrial ecosystem interactions in the boreal zone of northern Eurasia. Positive and negative feedbacks of forest paludification, of windthrow, and of climate-forced displacement of vegetation zones are presented. Moreover the interplay of different scale feedbacks, the multi-faceted nature of ecosystems-climate interactions and their potential to affect the global Earth system are shown. It is concluded that, without a synergetic modeling approach that integrates all major feedbacks and relationships between terrestrial ecosystems and climate, reliable projections of environmental change in northern Eurasia are impossible, which will also bring into question the accuracy of global change projections

  13. Under pressure: Climate change, upwelling and eastern boundary upwelling ecosystems

    Directory of Open Access Journals (Sweden)

    Marisol eGarcía-Reyes

    2015-12-01

    Full Text Available The IPCC AR5 provided an overview of the likely effects of climate change on Eastern Boundary Upwelling Systems (EBUS, stimulating increased interest in research examining the issue. We use these recent studies to develop a new synthesis describing climate change impacts on EBUS. We find that model and observational data suggest coastal upwelling-favorable winds in poleward portions of EBUS have intensified and will continue to do so in the future. Although evidence is weak in data that are presently available, future projections show that this pattern might be driven by changes in the positioning of the oceanic high-pressure systems rather than by deepening of the continental low-pressure systems, as previously proposed. There is low confidence regarding the future effects of climate change on coastal temperatures and biogeochemistry due to uncertainty in the countervailing responses to increasing upwelling and coastal warming, the latter of which could increase thermal stratification and render upwelling less effective in lifting nutrient-rich deep waters into the photic zone. Although predictions of ecosystem responses are uncertain, EBUS experience considerable natural variability and may be inherently resilient. However, multi-trophic level, end-to-end (i.e., winds to whales studies are needed to resolve the resilience of EBUS to climate change, especially their response to long-term trends or extremes that exceed pre-industrial ranges.

  14. Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

    Directory of Open Access Journals (Sweden)

    Hao Yang

    Full Text Available Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET and water yield (WY of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water

  15. Climate-Driven Reshuffling of Species and Genes: Potential Conservation Roles for Species Translocations and Recombinant Hybrid Genotypes

    Directory of Open Access Journals (Sweden)

    Jon Mark Scriber

    2013-12-01

    Full Text Available Comprising 50%–75% of the world’s fauna, insects are a prominent part of biodiversity in communities and ecosystems globally. Biodiversity across all levels of biological classifications is fundamentally based on genetic diversity. However, the integration of genomics and phylogenetics into conservation management may not be as rapid as climate change. The genetics of hybrid introgression as a source of novel variation for ecological divergence and evolutionary speciation (and resilience may generate adaptive potential and diversity fast enough to respond to locally-altered environmental conditions. Major plant and herbivore hybrid zones with associated communities deserve conservation consideration. This review addresses functional genetics across multi-trophic-level interactions including “invasive species” in various ecosystems as they may become disrupted in different ways by rapid climate change. “Invasive genes” (into new species and populations need to be recognized for their positive creative potential and addressed in conservation programs. “Genetic rescue” via hybrid translocations may provide needed adaptive flexibility for rapid adaptation to environmental change. While concerns persist for some conservationists, this review emphasizes the positive aspects of hybrids and hybridization. Specific implications of natural genetic introgression are addressed with a few examples from butterflies, including transgressive phenotypes and climate-driven homoploid recombinant hybrid speciation. Some specific examples illustrate these points using the swallowtail butterflies (Papilionidae with their long-term historical data base (phylogeographical diversity changes and recent (3-decade climate-driven temporal and genetic divergence in recombinant homoploid hybrids and relatively recent hybrid speciation of Papilio appalachiensis in North America. Climate-induced “reshuffling” (recombinations of species composition, genotypes

  16. Climate-Driven Reshuffling of Species and Genes: Potential Conservation Roles for Species Translocations and Recombinant Hybrid Genotypes.

    Science.gov (United States)

    Scriber, Jon Mark

    2013-12-24

    Comprising 50%-75% of the world's fauna, insects are a prominent part of biodiversity in communities and ecosystems globally. Biodiversity across all levels of biological classifications is fundamentally based on genetic diversity. However, the integration of genomics and phylogenetics into conservation management may not be as rapid as climate change. The genetics of hybrid introgression as a source of novel variation for ecological divergence and evolutionary speciation (and resilience) may generate adaptive potential and diversity fast enough to respond to locally-altered environmental conditions. Major plant and herbivore hybrid zones with associated communities deserve conservation consideration. This review addresses functional genetics across multi-trophic-level interactions including "invasive species" in various ecosystems as they may become disrupted in different ways by rapid climate change. "Invasive genes" (into new species and populations) need to be recognized for their positive creative potential and addressed in conservation programs. "Genetic rescue" via hybrid translocations may provide needed adaptive flexibility for rapid adaptation to environmental change. While concerns persist for some conservationists, this review emphasizes the positive aspects of hybrids and hybridization. Specific implications of natural genetic introgression are addressed with a few examples from butterflies, including transgressive phenotypes and climate-driven homoploid recombinant hybrid speciation. Some specific examples illustrate these points using the swallowtail butterflies (Papilionidae) with their long-term historical data base (phylogeographical diversity changes) and recent (3-decade) climate-driven temporal and genetic divergence in recombinant homoploid hybrids and relatively recent hybrid speciation of Papilio appalachiensis in North America. Climate-induced "reshuffling" (recombinations) of species composition, genotypes, and genomes may become

  17. Modeling and Predicting Carbon and Water Fluxes Using Data-Driven Techniques in a Forest Ecosystem

    Directory of Open Access Journals (Sweden)

    Xianming Dou

    2017-12-01

    Full Text Available Accurate estimation of carbon and water fluxes of forest ecosystems is of particular importance for addressing the problems originating from global environmental change, and providing helpful information about carbon and water content for analyzing and diagnosing past and future climate change. The main focus of the current work was to investigate the feasibility of four comparatively new methods, including generalized regression neural network, group method of data handling (GMDH, extreme learning machine and adaptive neuro-fuzzy inference system (ANFIS, for elucidating the carbon and water fluxes in a forest ecosystem. A comparison was made between these models and two widely used data-driven models, artificial neural network (ANN and support vector machine (SVM. All the models were evaluated based on the following statistical indices: coefficient of determination, Nash-Sutcliffe efficiency, root mean square error and mean absolute error. Results indicated that the data-driven models are capable of accounting for most variance in each flux with the limited meteorological variables. The ANN model provided the best estimates for gross primary productivity (GPP and net ecosystem exchange (NEE, while the ANFIS model achieved the best for ecosystem respiration (R, indicating that no single model was consistently superior to others for the carbon flux prediction. In addition, the GMDH model consistently produced somewhat worse results for all the carbon flux and evapotranspiration (ET estimations. On the whole, among the carbon and water fluxes, all the models produced similar highly satisfactory accuracy for GPP, R and ET fluxes, and did a reasonable job of reproducing the eddy covariance NEE. Based on these findings, it was concluded that these advanced models are promising alternatives to ANN and SVM for estimating the terrestrial carbon and water fluxes.

  18. Biodiversity as a solution to mitigate climate change impacts on the functioning of forest ecosystems.

    Science.gov (United States)

    Hisano, Masumi; Searle, Eric B; Chen, Han Y H

    2018-02-01

    Forest ecosystems are critical to mitigating greenhouse gas emissions through carbon sequestration. However, climate change has affected forest ecosystem functioning in both negative and positive ways, and has led to shifts in species/functional diversity and losses in plant species diversity which may impair the positive effects of diversity on ecosystem functioning. Biodiversity may mitigate climate change impacts on (I) biodiversity itself, as more-diverse systems could be more resilient to climate change impacts, and (II) ecosystem functioning through the positive relationship between diversity and ecosystem functioning. By surveying the literature, we examined how climate change has affected forest ecosystem functioning and plant diversity. Based on the biodiversity effects on ecosystem functioning (B→EF), we specifically address the potential for biodiversity to mitigate climate change impacts on forest ecosystem functioning. For this purpose, we formulate a concept whereby biodiversity may reduce the negative impacts or enhance the positive impacts of climate change on ecosystem functioning. Further B→EF studies on climate change in natural forests are encouraged to elucidate how biodiversity might influence ecosystem functioning. This may be achieved through the detailed scrutiny of large spatial/long temporal scale data sets, such as long-term forest inventories. Forest management strategies based on B→EF have strong potential for augmenting the effectiveness of the roles of forests in the mitigation of climate change impacts on ecosystem functioning. © 2017 Cambridge Philosophical Society.

  19. Willingness to pay for ecosystem benefits of Agroforestry driven ...

    African Journals Online (AJOL)

    This paper investigates the Willingness To Pay (WTP) for ecosystem benefits derivable from Agroforestry (AF) driven green growth practice in Ogun state, Nigeria. The environmental service functions of AF were valued. Multi-stage sampling procedure involving purposive and simple random sampling was adopted in ...

  20. Climate Change Vulnerability of Agro-Ecosystems: Does socio-economic factors matters?

    Science.gov (United States)

    Surendran Nair, S.; Preston, B. L.; King, A. W.; Mei, R.; Post, W. M.

    2013-12-01

    Climate variability and change has direct impacts on agriculture. Despite continual adaptation to climate as well as gains in technology innovation and adoption, agriculture is still vulnerable to changes in temperature and precipitation expected in coming decades. Generally, researchers use two major methodologies to understand the vulnerability of agro-ecosystems to climate change: process-based crop models and empirical models. However, these models are not yet designed to capture the influence of socioeconomic systems on agro-ecosystem processes and outcomes.. However, socioeconomic processes are an important factor driving agro-ecological responses to biophysical processes (climate, topography and soil), because of the role of human agency in mediating the response of agro-ecosystems to climate. We have developed a framework that integrates socioeconomic and biophysical characteristics of agro-ecosystems using cluster analysis and GIS tools. This framework has been applied to the U.S. Southeast to define unique socio-ecological domains for agriculture. The results demonstrate that socioeconomic characteristics are an important factor influencing agriculture production. These results suggest that the lack of attention to socioeconomic conditions and human agency in agro-ecological modeling creates a potential bias with respect to the representation of climate change impacts.

  1. Vulnerability to climate-induced changes in ecosystem services of boreal forests

    Science.gov (United States)

    Holmberg, Maria; Rankinen, Katri; Aalto, Tuula; Akujärvi, Anu; Nadir Arslan, Ali; Liski, Jari; Markkanen, Tiina; Mäkelä, Annikki; Peltoniemi, Mikko

    2016-04-01

    Boreal forests provide an array of ecosystem services. They regulate climate, and carbon, water and nutrient fluxes, and provide renewable raw material, food, and recreational possibilities. Rapid climate warming is projected for the boreal zone, and has already been observed in Finland, which sets these services at risk. MONIMET (LIFE12 ENV/FI/000409, 2.9.2013 - 1.9.2017) is a project funded by EU Life programme about Climate Change Indicators and Vulnerability of Boreal Zone Applying Innovative Observation and Modeling Techniques. The coordinating beneficiary of the project is the Finnish Meteorological Institute. Associated beneficiaries are the Natural Resources Institute Finland, the Finnish Environment Institute and the University of Helsinki. In the MONIMET project, we use state-of-the-art models and new monitoring methods to investigate the impacts of a warming climate on the provision of ecosystem services of boreal forests. This poster presents results on carbon storage in soil and assessment of drought indices, as a preparation for assessing the vulnerability of society to climate-induced changes in ecosystem services. The risk of decreasing provision of ecosystem services depends on the sensitivity of the ecosystem as well as its exposure to climate stress. The vulnerability of society, in turn, depends on the risk of decreasing provision of a certain service in combination with society's demand for that service. In the next phase, we will look for solutions to challenges relating to the quantification of the demand for ecosystem services and differences in spatial extent and resolution of the information on future supply and demand.

  2. Tipping elements in the Arctic marine ecosystem.

    Science.gov (United States)

    Duarte, Carlos M; Agustí, Susana; Wassmann, Paul; Arrieta, Jesús M; Alcaraz, Miquel; Coello, Alexandra; Marbà, Núria; Hendriks, Iris E; Holding, Johnna; García-Zarandona, Iñigo; Kritzberg, Emma; Vaqué, Dolors

    2012-02-01

    The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem.

  3. Climate change, cranes, and temperate floodplain ecosystems

    Science.gov (United States)

    King, Sammy L.

    2010-01-01

    Floodplain ecosystems provide important habitat to cranes globally. Lateral, longitudinal, vertical, and temporal hydrologic connectivity in rivers is essential to maintaining the functions and values of these systems. Agricultural development, flood control, water diversions, dams, and other anthropogenic activities have greatly affected hydrologic connectivity of river systems worldwide and altered the functional capacity of these systems. Although the specific effects of climate change in any given area are unknown, increased intensity and frequency of flooding and droughts and increased air and water temperatures are among many potential effects that can act synergistically with existing human modifications in these systems to create even greater challenges in maintaining ecosystem productivity. In this paper, I review basic hydrologic and geomorphic processes of river systems and use three North American rivers (Guadalupe, Platte, and Rio Grande) that are important to cranes as case studies to illustrate the challenges facing managers tasked with balancing the needs of cranes and people in the face of an uncertain climatic future. Each river system has unique natural and anthropogenic characteristics that will affect conservation strategies. Mitigating the effects of climate change on river systems necessitates an understanding of river/floodplain/landscape linkages, which include people and their laws as well as existing floodplain ecosystem conditions.

  4. Simulating changes in ecosystem structure and composition in response to climate change: a case study focused on tropical nitrogen-fixing trees (Invited)

    Science.gov (United States)

    Medvigy, D.; Levy, J.; Xu, X.; Batterman, S. A.; Hedin, L.

    2013-12-01

    Ecosystems, by definition, involve a community of organisms. These communities generally exhibit heterogeneity in their structure and composition as a result of local variations in climate, soil, topography, disturbance history, and other factors. Climate-driven shifts in ecosystems will likely include an internal re-organization of community structure and composition and as well as the introduction of novel species. In terms of vegetation, this ecosystem heterogeneity can occur at relatively small scales, sometimes of the order of tens of meters or even less. Because this heterogeneous landscape generally has a variable and nonlinear response to environmental perturbations, it is necessary to carefully aggregate the local competitive dynamics between individual plants to the large scales of tens or hundreds of kilometers represented in climate models. Accomplishing this aggregation in a computationally efficient way has proven to be an extremely challenging task. To meet this challenge, the Ecosystem Demography 2 (ED2) model statistically characterizes a distribution of local resource environments, and then simulates the competition between individuals of different sizes and species (or functional groupings). Within this framework, it is possible to explicitly simulate the impacts of climate change on ecosystem structure and composition, including both internal re-organization and the introduction of novel species or functional groups. This presentation will include several illustrative applications of the evolution of ecosystem structure and composition under climate change. One application pertains to the role of nitrogen-fixing species in tropical forests. Will increasing CO2 concentrations increase the demand for nutrients and perhaps give a competitive edge to nitrogen-fixing species? Will potentially warmer and drier conditions make some tropical forests more water-limited, reducing the demand for nitrogen, thereby giving a competitive advantage to non

  5. Projecting supply and demand of hydrologic ecosystem services under future climate conditions

    Science.gov (United States)

    Chiang, Li-Chi; Huang, Tao; Lee, Tsung-Yu

    2014-05-01

    Ecosystems provide essential goods and services, such as food, clean water, water purification, soil conservation and cultural services for human being. In a watershed, these water-related ecosystem goods and services can directly or indirectly benefit both local people and downstream beneficiaries through a reservoir. Water quality and quantity in a reservoir are of importance for agricultural, industrial and domestic uses. Under the impacts of climate and land use changes, both ecosystem service supply and demand will be affected by changes in precipitation patterns, temperature, urbanization and agricultural activities. However, the linkage between ecosystem service provisioning (ESP) and ecosystem service beneficiary (ESB), and scales of supply and demand of ecosystem services are not clear yet. Therefore, to investigate water-related ecosystem service supply under climate and land use change, we took the Xindian river watershed (303 km2) as a case study, where the Feitsui Reservoir provides hydro-power and daily domestic water use of 3,450,000 m3 for 3.46 million people in Taipei, Taiwan. We integrated a hydrological model (Soil and Water Assessment Tool, SWAT) and a land use change model (Conversion of Land Use and its Effects, CLUE-s) with future climate change scenarios derived from General Circulation Models (GCMs), to assess the changes in ecosystem service supply and demand at different hydrologic scales. The results will provide useful information for decision-making on future land use management and climate change adaptation strategies in the watersheds. Keywords: climate change, land use change, ecosystem service, watershed, scale

  6. Ecosystem vulnerability to climate change in the southeastern United States

    Science.gov (United States)

    Cartwright, Jennifer M.; Costanza, Jennifer

    2016-08-11

    Two recent investigations of climate-change vulnerability for 19 terrestrial, aquatic, riparian, and coastal ecosystems of the southeastern United States have identified a number of important considerations, including potential for changes in hydrology, disturbance regimes, and interspecies interactions. Complementary approaches using geospatial analysis and literature synthesis integrated information on ecosystem biogeography and biodiversity, climate projections, vegetation dynamics, soil and water characteristics, anthropogenic threats, conservation status, sea-level rise, and coastal flooding impacts. Across a diverse set of ecosystems—ranging in size from dozens of square meters to thousands of square kilometers—quantitative and qualitative assessments identified types of climate-change exposure, evaluated sensitivity, and explored potential adaptive capacity. These analyses highlighted key gaps in scientific understanding and suggested priorities for future research. Together, these studies help create a foundation for ecosystem-level analysis of climate-change vulnerability to support effective biodiversity conservation in the southeastern United States.

  7. Temporal changes in potential regulating ecosystem services driven by urbanization

    Science.gov (United States)

    Ferreira, Carla; Amorim, Inês; Pires, Evanilton; Kalantari, Zahra; Walsh, Rory; Ferreira, António

    2017-04-01

    Ecosystem services (ES) are understood to be the capacity of the landscape of a particular area to provide goods and services to society. In terms of human benefits, four categories of ES are usually considered: provisioning (e.g. seafood), regulating (e.g. climate regulation, air quality, water purification and natural hazard protection), supporting (e.g. maintenance of biodiversity), and cultural (e.g. recreation). The potential supply of ecosystem services has receive increasing interest as a tool for natural resource management. Nevertheless, the capacity to supply ES depends on biophysical conditions, as well as climate and land-use changes, induced by human activities. This study aims to investigate the potential for regulating ecosystem service supply of a Portuguese peri-urban catchment, and attempts to understand the temporal changes in ES over the last decades driven by urbanization. The study was developed in Ribeira dos Covões catchment (6.2 km2), in Portugal. Due to its proximity to Coimbra, a major city in the central region of Portugal, the catchment has undergone major land-use changes over the last half-century. Since 1958, the agricultural area, comprising mainly olives and arable land, has declined from 48% to 4%, due to increases in urban land (from 8% to 40%) and forest (from 44% to 53%), as well as a temporary creation of open spaces (from 0% to 3%). The nature of forest cover also changed, from native species, such as oaks (Quercus sp.), to commercial timber plantations, mostly of Pinus pinaster L. and Eucaliptus globulus L.. Urbanization became more pronounced after 1973, exhibiting a discontinuous pattern until 1995, and then later more continuous urban areas through the infilling of areas between the earlier urban cores. Quantification of regulating ES in the study catchment was achieved using GIS techniques, in order to gain a spatial dimension of ES distribution (Burkhard et al., 2009). Mapping ecosystem service capacities at a 5×5m

  8. Consumer-driven nutrient dynamics in freshwater ecosystems: from individuals to ecosystems.

    Science.gov (United States)

    Atkinson, Carla L; Capps, Krista A; Rugenski, Amanda T; Vanni, Michael J

    2017-11-01

    The role of animals in modulating nutrient cycling [hereafter, consumer-driven nutrient dynamics (CND)] has been accepted as an important influence on both community structure and ecosystem function in aquatic systems. Yet there is great variability in the influence of CND across species and ecosystems, and the causes of this variation are not well understood. Here, we review and synthesize the mechanisms behind CND in fresh waters. We reviewed 131 articles on CND published between 1973 and 1 June 2015. The rate of new publications in CND has increased from 1.4 papers per year during 1973-2002 to 7.3 per year during 2003-2015. The majority of investigations are in North America with many concentrating on fish. More recent studies have focused on animal-mediated nutrient excretion rates relative to nutrient demand and indirect impacts (e.g. decomposition). We identified several mechanisms that influence CND across levels of biological organization. Factors affecting the stoichiometric plasticity of consumers, including body size, feeding history and ontogeny, play an important role in determining the impact of individual consumers on nutrient dynamics and underlie the stoichiometry of CND across time and space. The abiotic characteristics of an ecosystem affect the net impact of consumers on ecosystem processes by influencing consumer metabolic processes (e.g. consumption and excretion/egestion rates), non-CND supply of nutrients and ecosystem nutrient demand. Furthermore, the transformation and transport of elements by populations and communities of consumers also influences the flow of energy and nutrients across ecosystem boundaries. This review highlights that shifts in community composition or biomass of consumers and eco-evolutionary underpinnings can have strong effects on the functional role of consumers in ecosystem processes, yet these are relatively unexplored aspects of CND. Future research should evaluate the value of using species traits and abiotic

  9. Climate change, ecosystem impacts, and management for Pacific salmon

    Science.gov (United States)

    D.E. Schindler; X. Augerot; E. Fleishman; N.J. Mantua; B. Riddell; M. Ruckelshaus; J. Seeb; M. Webster

    2008-01-01

    As climate change intensifies, there is increasing interest in developing models that reduce uncertainties in projections of global climate and refine these projections to finer spatial scales. Forecasts of climate impacts on ecosystems are far more challenging and their uncertainties even larger because of a limited understanding of physical controls on biological...

  10. Spatially explicit integrated modeling and economic valuation of climate driven land use change and its indirect effects.

    Science.gov (United States)

    Bateman, Ian; Agarwala, Matthew; Binner, Amy; Coombes, Emma; Day, Brett; Ferrini, Silvia; Fezzi, Carlo; Hutchins, Michael; Lovett, Andrew; Posen, Paulette

    2016-10-01

    We present an integrated model of the direct consequences of climate change on land use, and the indirect effects of induced land use change upon the natural environment. The model predicts climate-driven shifts in the profitability of alternative uses of agricultural land. Both the direct impact of climate change and the induced shift in land use patterns will cause secondary effects on the water environment, for which agriculture is the major source of diffuse pollution. We model the impact of changes in such pollution on riverine ecosystems showing that these will be spatially heterogeneous. Moreover, we consider further knock-on effects upon the recreational benefits derived from water environments, which we assess using revealed preference methods. This analysis permits a multi-layered examination of the economic consequences of climate change, assessing the sequence of impacts from climate change through farm gross margins, land use, water quality and recreation, both at the individual and catchment scale. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

    Energy Technology Data Exchange (ETDEWEB)

    Heide-Joergensen, H S; Johnsen, I [Koebenhavns Univ., Botanisk Inst., Oekologisk afd. (Denmark)

    1998-12-31

    An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

  12. Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

    International Nuclear Information System (INIS)

    Heide-Joergensen, H.S.; Johnsen, I.

    1997-01-01

    An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

  13. Ecosystem vulnerability to climate change in Greenland and the Faroe Islands

    Energy Technology Data Exchange (ETDEWEB)

    Heide-Joergensen, H.S.; Johnsen, I. [Koebenhavns Univ., Botanisk Inst., Oekologisk afd. (Denmark)

    1997-12-31

    An increase in the mean yearly temperature up to 3.6 deg. C may occur in North-Greenland by the end of the 21st century, while in south-Greenland temperature may remain stable or fall slightly. Consequences of this climate change for species diversity and the structure of terrestrial and marine ecosystems are discussed. For the Faroe Islands climate change is not expected to cause notable changes in terrestrial ecosystems, but in marine ecosystems changes are highly unpredictable. (au)

  14. Increased sensitivity to climate change in disturbed ecosystems

    DEFF Research Database (Denmark)

    Kroël-Dulay, György; Ransijn, Johannes; Schmidt, Inger Kappel

    2015-01-01

    Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports this relatio......Human domination of the biosphere includes changes to disturbance regimes, which push many ecosystems towards early-successional states. Ecological theory predicts that early-successional ecosystems are more sensitive to perturbations than mature systems, but little evidence supports...... this relationship for the perturbation of climate change. Here we show that vegetation (abundance, species richness and species composition) across seven European shrublands is quite resistant to moderate experimental warming and drought, and responsiveness is associated with the dynamic state of the ecosystem...

  15. Managing uncertainty in climate-driven ecological models to inform adaptation to climate change

    Science.gov (United States)

    Jeremy S. Littell; Donald McKenzie; Becky K. Kerns; Samuel Cushman; Charles G. Shaw

    2011-01-01

    The impacts of climate change on forest ecosystems are likely to require changes in forest planning and natural resource management. Changes in tree growth, disturbance extent and intensity, and eventually species distributions are expected. In natural resource management and planning, ecosystem models are typically used to provide a "best estimate" about how...

  16. Detecting abrupt dynamic change based on changes in the fractal properties of spatial images

    Science.gov (United States)

    Liu, Qunqun; He, Wenping; Gu, Bin; Jiang, Yundi

    2017-10-01

    Many abrupt climate change events often cannot be detected timely by conventional abrupt detection methods until a few years after these events have occurred. The reason for this lag in detection is that abundant and long-term observational data are required for accurate abrupt change detection by these methods, especially for the detection of a regime shift. So, these methods cannot help us understand and forecast the evolution of the climate system in a timely manner. Obviously, spatial images, generated by a coupled spatiotemporal dynamical model, contain more information about a dynamic system than a single time series, and we find that spatial images show the fractal properties. The fractal properties of spatial images can be quantitatively characterized by the Hurst exponent, which can be estimated by two-dimensional detrended fluctuation analysis (TD-DFA). Based on this, TD-DFA is used to detect an abrupt dynamic change of a coupled spatiotemporal model. The results show that the TD-DFA method can effectively detect abrupt parameter changes in the coupled model by monitoring the changing in the fractal properties of spatial images. The present method provides a new way for abrupt dynamic change detection, which can achieve timely and efficient abrupt change detection results.

  17. On the Vulnerability of Water Limited Ecosystems to Climate Change

    Directory of Open Access Journals (Sweden)

    Kelly K. Caylor

    2013-06-01

    Full Text Available Society is facing growing environmental problems that require new research efforts to understand the way ecosystems operate and survive, and their mutual relationships with the hydrologic cycle. In this respect, ecohydrology suggests a renewed interdisciplinary approach that aims to provide a better comprehension of the effects of climatic changes on terrestrial ecosystems. With this aim, a coupled hydrological/ecological model is adopted to describe simultaneously vegetation pattern evolution and hydrological water budget at the basin scale using as test site the Upper Rio Salado basin (Sevilleta, NM, USA. The hydrological analyses have been carried out using a recently formulated framework for the water balance at the daily level linked with a spatial model for the description of the spatial organization of vegetation. This enables quantitatively assessing the effects on soil water availability on future climatic scenarios. Results highlighted that the relationship between climatic forcing (water availability and vegetation patterns is strongly non-linear. This implies, under some specific conditions which depend on the ecosystem characteristics, small changes in climatic conditions may produce significant transformation of the vegetation patterns.

  18. Montane ecosystem productivity responds more to global circulation patterns than climatic trends

    Science.gov (United States)

    Desai, A. R.; Wohlfahrt, G.; Zeeman, M. J.; Katata, G.; Eugster, W.; Montagnani, L.; Gianelle, D.; Mauder, M.; Schmid, H.-P.

    2016-02-01

    Regional ecosystem productivity is highly sensitive to inter-annual climate variability, both within and outside the primary carbon uptake period. However, Earth system models lack sufficient spatial scales and ecosystem processes to resolve how these processes may change in a warming climate. Here, we show, how for the European Alps, mid-latitude Atlantic ocean winter circulation anomalies drive high-altitude summer forest and grassland productivity, through feedbacks among orographic wind circulation patterns, snowfall, winter and spring temperatures, and vegetation activity. Therefore, to understand future global climate change influence to regional ecosystem productivity, Earth systems models need to focus on improvements towards topographic downscaling of changes in regional atmospheric circulation patterns and to lagged responses in vegetation dynamics to non-growing season climate anomalies.

  19. Montane ecosystem productivity responds more to global circulation patterns than climatic trends

    International Nuclear Information System (INIS)

    Desai, A R; Wohlfahrt, G; Zeeman, M J; Katata, G; Mauder, M; Schmid, H-P; Eugster, W; Montagnani, L; Gianelle, D

    2016-01-01

    Regional ecosystem productivity is highly sensitive to inter-annual climate variability, both within and outside the primary carbon uptake period. However, Earth system models lack sufficient spatial scales and ecosystem processes to resolve how these processes may change in a warming climate. Here, we show, how for the European Alps, mid-latitude Atlantic ocean winter circulation anomalies drive high-altitude summer forest and grassland productivity, through feedbacks among orographic wind circulation patterns, snowfall, winter and spring temperatures, and vegetation activity. Therefore, to understand future global climate change influence to regional ecosystem productivity, Earth systems models need to focus on improvements towards topographic downscaling of changes in regional atmospheric circulation patterns and to lagged responses in vegetation dynamics to non-growing season climate anomalies. (letter)

  20. Biodiversity, Ecosystem Services, and Climate Change : The Economic Problem

    OpenAIRE

    World Bank

    2010-01-01

    Climate change is both a cause and an effect of biodiversity change. Along with anthropogenic dispersion, climate change is the main driver of change in the geographical distribution of both beneficial and harmful species, crops, livestock, harvested wild species, pests, predators and pathogens. And the capacity of ecosystems to adapt to climate change depends on the diversity of species t...

  1. How climate affects ecosystems: A Canadian perspective on what we know

    International Nuclear Information System (INIS)

    Rowe, S.; Rizzo, B.

    1990-01-01

    The effects of climate change on ecosystems is discussed from the Canadian perspective. After a brief definition of terms, the implications of ecosystem theory are elaborated on. Impact models generated from altered climatic regimes can be categorized into two methodological streams: correlation modelling and dynamic modelling. Correlation modelling characterizes change on the basis of transfer functions linking climatic parameters and indices to specific ecological units. Correlation models can be applied at the species level or at the broader ecosystem level. Dynamic models are based on life history characteristics from birth to death, tracking such details as plant abundance, height and leaf area. Such models are most useful at the local rather than global scale. In Canada a number of broad scale correlation models have been attempted. These include the potential impacts of climatic change in the Praire provinces and Northwest Territories, a study relating the growing degree day isolines to ecological boundaries established in the ecoclimatic regions of Canada map, and the incorporation of nine climatic parameters in a correlation exercise, again using the ecoclimatic regions map. 14 refs

  2. Climate and fishing steer ecosystem regeneration to uncertain economic futures

    DEFF Research Database (Denmark)

    Blenckner, Thorsten; Llope, Marcos; Möllmann, Christian

    2015-01-01

    Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socio-economic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree...... lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change....

  3. Effect of interannual climate variability on carbon storage in Amazonian ecosystems

    Science.gov (United States)

    Tian, H.; Melillo, J.M.; Kicklighter, D.W.; McGuire, David A.; Helfrich, J. V. K.; Moore, B.; Vorosmarty, C.J.

    1998-01-01

    The Amazon Basin contains almost one-half of the world's undisturbed tropical evergreen forest as well as large areas of tropical savanna. The forests account for about 10 per cent of the world's terrestrial primary productivity and for a similar fraction of the carbon stored in land ecosystems, and short-term field measurements suggest that these ecosystems are globally important carbon sinks. But tropical land ecosystems have experienced substantial interannual climate variability owing to frequent El Nino episodes in recent decades. Of particular importance to climate change policy is how such climate variations, coupled with increases in atmospheric CO2 concentration, affect terrestrial carbon storage. Previous model analyses have demonstrated the importance of temperature in controlling carbon storage. Here we use a transient process-based biogeochemical model of terrestrial ecosystems to investigate interannual variations of carbon storage in undisturbed Amazonian ecosystems in response to climate variability and increasing atmospheric CO2 concentration during the period 1980 to 1994. In El Nino years, which bring hot, dry weather to much of the Amazon region, the ecosystems act as a source of carbon to the atmosphere (up to 0.2 petagrams of carbon in 1987 and 1992). In other years, these ecosystems act as a carbon sink (up to 0.7 Pg C in 1981 and 1993). These fluxes are large; they compare to a 0.3 Pg C per year source to the atmosphere associated with deforestation in the Amazon Basin in the early 1990s. Soil moisture, which is affected by both precipitation and temperature, and which affects both plant and soil processes, appears to be an important control on carbon storage.

  4. Connecting the records: exploiting tephra deposits to help understand abrupt climate change

    Science.gov (United States)

    Davies, S. M.; Abbott, P. M.; Bourne, A. J.; Chapman, M.; Pearce, N. J. G.; Griggs, A. J.; Cook, E.

    2016-12-01

    The causal mechanism of abrupt climate change during the last glacial period remains a key challenge. Although these events are well-documented in a wide range of proxy records, the triggers and drivers remain poorly understood, largely due to the dating uncertainties that prevent the integration of different archives. Unravelling the lead/lag responses (hence cause and effect) between the Earth's climate components is limited by the challenges of synchronising palaeoclimate records on a common timescale. Here we present the potential and the challenges of optimising the use of cryptotephra deposits to precisely correlate the Greenland ice-cores with North Atlantic marine records. A series of new cryptotephra deposits have been identified in Greenland, increasing the scope of identifying coeval isochrons in the marine environment. This new framework, however, brings new challenges in the search for unique and robust geochemical fingerprints for unequivocal tephra correlations. As such, some tephra deposits are proposed to be more valuable than others and underpin key snapshots in time during the last glacial period. The North Atlantic Ash Zone II, for instance, represents the most widespread isochron and constrains the cooling of GI-15. Some tephra deposits in the ice-core record originate from ultra-distal sources beyond the North Atlantic region and we also explore the potential for establishing North Pacific linkages.

  5. Attention capture by abrupt onsets: re-visiting the priority tag model

    OpenAIRE

    Meera Mary Sunny; Adrian evon Muhlenen

    2013-01-01

    Abrupt onsets have been shown to strongly attract attention in a stimulus-driven, bottom-up manner. However, the precise mechanism that drives capture by onsets is still debated. According to the new object account, abrupt onsets capture attention because they signal the appearance of a new object. Yantis and Johnson (1990) used a visual search task and showed that up to four onsets can be automatically prioritized. However, in their study the number of onsets co-varied with the total number ...

  6. Disturbances catalyze the adaptation of forest ecosystems to changing climate conditions.

    Science.gov (United States)

    Thom, Dominik; Rammer, Werner; Seidl, Rupert

    2017-01-01

    The rates of anthropogenic climate change substantially exceed those at which forest ecosystems - dominated by immobile, long-lived organisms - are able to adapt. The resulting maladaptation of forests has potentially detrimental effects on ecosystem functioning. Furthermore, as many forest-dwelling species are highly dependent on the prevailing tree species, a delayed response of the latter to a changing climate can contribute to an extinction debt and mask climate-induced biodiversity loss. However, climate change will likely also intensify forest disturbances. Here, we tested the hypothesis that disturbances foster the reorganization of ecosystems and catalyze the adaptation of forest composition to climate change. Our specific objectives were (i) to quantify the rate of autonomous forest adaptation to climate change, (ii) examine the role of disturbance in the adaptation process, and (iii) investigate spatial differences in climate-induced species turnover in an unmanaged mountain forest landscape (Kalkalpen National Park, Austria). Simulations with a process-based forest landscape model were performed for 36 unique combinations of climate and disturbance scenarios over 1000 years. We found that climate change strongly favored European beech and oak species (currently prevailing in mid- to low-elevation areas), with novel species associations emerging on the landscape. Yet, it took between 357 and 706 years before the landscape attained a dynamic equilibrium with the climate system. Disturbances generally catalyzed adaptation and decreased the time needed to attain equilibrium by up to 211 years. However, while increasing disturbance frequency and severity accelerated adaptation, increasing disturbance size had the opposite effect. Spatial analyses suggest that particularly the lowest and highest elevation areas will be hotspots of future species change. We conclude that the growing maladaptation of forests to climate and the long lead times of autonomous

  7. Climate Change Impacts on High-Altitude Ecosystems

    OpenAIRE

    Harald Pauli

    2016-01-01

    Reviewed: Climate Change Impacts on High-Altitude Ecosystems By Münir Öztürk, Khalid Rehman Hakeem, I. Faridah-Hanum and Efe. Recep, Cham, Switzerland: Springer International Publishing, 2015. xvii + 696 pp. US$ 239.00. ISBN 978-3-319-12858-0.

  8. Climate change impacts on biodiversity and ecosystems in Sri Lanka: a review

    Directory of Open Access Journals (Sweden)

    Jeevan Dananjaya Kottawa-Arachchi

    2017-10-01

    Full Text Available The climate change impacts are felt by all facets and sectors of ecosystems, covering flora, fauna and environment. Sri Lanka is considered as a vulnerable, small island country that is under serious threat from climate change impacts. The most profound impacts of climate change in Sri Lanka will be on agriculture and food security, water and coastal resources, biodiversity changes, and human health. Sri Lanka's biodiversity is significantly important both on a regional and global scale as it has the highest species density for flowering plants, amphibians, reptiles, and mammals. Sri Lanka's varied ecosystems provide many services that are of significant economic value and play a crucial role in providing goods and ecosystem services. The subsequent sections featuring specific aspects of biodiversity in forests, freshwater wetlands, coastal and marine systems and agricultural systems, provide greater detail on the ecosystem services and bio-resources. Habitat loss and fragmentation, invasive alien species, deforestation and forest degradation, development projects, environmental pollutions and climate change (global warming are the major threats to the biodiversity of the country. Climate change impacts on environment lead to a reduction in the distribution and abundance of species, especially endemics, which may even result in their global extinction. The introduction of various policies and guidelines in relation to environment is a good sign for conservation of ecosystems and biodiversity. The government of Sri Lanka has been implementing various environmental projects aiming at reducing deforestation and degradation of ecosystems. Policies and measures already developed under such initiatives will no doubt preserve natural habitats for plant and animal species. However, being a developing country with many economic challenges, the funds and expertise available for monitoring climate change impacts and biodiversity conservation are not

  9. Changes in autumn vegetation dormancy onset date and the climate controls across temperate ecosystems in China from 1982 to 2010.

    Science.gov (United States)

    Yang, Yuting; Guan, Huade; Shen, Miaogen; Liang, Wei; Jiang, Lei

    2015-02-01

    Vegetation phenology is a sensitive indicator of the dynamic response of terrestrial ecosystems to climate change. In this study, the spatiotemporal pattern of vegetation dormancy onset date (DOD) and its climate controls over temperate China were examined by analysing the satellite-derived normalized difference vegetation index and concurrent climate data from 1982 to 2010. Results show that preseason (May through October) air temperature is the primary climatic control of the DOD spatial pattern across temperate China, whereas preseason cumulative precipitation is dominantly associated with the DOD spatial pattern in relatively cold regions. Temporally, the average DOD over China's temperate ecosystems has delayed by 0.13 days per year during the past three decades. However, the delay trends are not continuous throughout the 29-year period. The DOD experienced the largest delay during the 1980s, but the delay trend slowed down or even reversed during the 1990s and 2000s. Our results also show that interannual variations in DOD are most significantly related with preseason mean temperature in most ecosystems, except for the desert ecosystem for which the variations in DOD are mainly regulated by preseason cumulative precipitation. Moreover, temperature also determines the spatial pattern of temperature sensitivity of DOD, which became significantly lower as temperature increased. On the other hand, the temperature sensitivity of DOD increases with increasing precipitation, especially in relatively dry areas (e.g. temperate grassland). This finding stresses the importance of hydrological control on the response of autumn phenology to changes in temperature, which must be accounted in current temperature-driven phenological models. © 2014 John Wiley & Sons Ltd.

  10. Climate Change Impacts on High-Altitude Ecosystems

    Directory of Open Access Journals (Sweden)

    Harald Pauli

    2016-02-01

    Full Text Available Reviewed: Climate Change Impacts on High-Altitude Ecosystems By Münir Öztürk, Khalid Rehman Hakeem, I. Faridah-Hanum and Efe. Recep, Cham, Switzerland: Springer International Publishing, 2015. xvii + 696 pp. US$ 239.00. ISBN 978-3-319-12858-0.

  11. Ecosystem heterogeneity determines the ecological resilience of the Amazon to climate change.

    Science.gov (United States)

    Levine, Naomi M; Zhang, Ke; Longo, Marcos; Baccini, Alessandro; Phillips, Oliver L; Lewis, Simon L; Alvarez-Dávila, Esteban; Segalin de Andrade, Ana Cristina; Brienen, Roel J W; Erwin, Terry L; Feldpausch, Ted R; Monteagudo Mendoza, Abel Lorenzo; Nuñez Vargas, Percy; Prieto, Adriana; Silva-Espejo, Javier Eduardo; Malhi, Yadvinder; Moorcroft, Paul R

    2016-01-19

    Amazon forests, which store ∼ 50% of tropical forest carbon and play a vital role in global water, energy, and carbon cycling, are predicted to experience both longer and more intense dry seasons by the end of the 21st century. However, the climate sensitivity of this ecosystem remains uncertain: several studies have predicted large-scale die-back of the Amazon, whereas several more recent studies predict that the biome will remain largely intact. Combining remote-sensing and ground-based observations with a size- and age-structured terrestrial ecosystem model, we explore the sensitivity and ecological resilience of these forests to changes in climate. We demonstrate that water stress operating at the scale of individual plants, combined with spatial variation in soil texture, explains observed patterns of variation in ecosystem biomass, composition, and dynamics across the region, and strongly influences the ecosystem's resilience to changes in dry season length. Specifically, our analysis suggests that in contrast to existing predictions of either stability or catastrophic biomass loss, the Amazon forest's response to a drying regional climate is likely to be an immediate, graded, heterogeneous transition from high-biomass moist forests to transitional dry forests and woody savannah-like states. Fire, logging, and other anthropogenic disturbances may, however, exacerbate these climate change-induced ecosystem transitions.

  12. Climate-change-driven deterioration of water quality in a mineralized watershed.

    Science.gov (United States)

    Todd, Andrew S; Manning, Andrew H; Verplanck, Philip L; Crouch, Caitlin; McKnight, Diane M; Dunham, Ryan

    2012-09-04

    A unique 30-year streamwater chemistry data set from a mineralized alpine watershed with naturally acidic, metal-rich water displays dissolved concentrations of Zn and other metals of ecological concern increasing by 100-400% (400-2000 μg/L) during low-flow months, when metal concentrations are highest. SO(4) and other major ions show similar increases. A lack of natural or anthropogenic land disturbances in the watershed during the study period suggests that climate change is the underlying cause. Local mean annual and mean summer air temperatures have increased at a rate of 0.2-1.2 °C/decade since the 1980s. Other climatic and hydrologic indices, including stream discharge during low-flow months, do not display statistically significant trends. Consideration of potential specific causal mechanisms driven by rising temperatures suggests that melting of permafrost and falling water tables (from decreased recharge) are probable explanations for the increasing concentrations. The prospect of future widespread increases in dissolved solutes from mineralized watersheds is concerning given likely negative impacts on downstream ecosystems and water resources, and complications created for the establishment of attainable remediation objectives at mine sites.

  13. Regional Approach for Linking Ecosystem Services and Livelihood Strategies Under Climate Change of Pastoral Communities in the Mongolian Steppe Ecosystem

    Science.gov (United States)

    Ojima, D. S.; Galvin, K.; Togtohyn, C.

    2012-12-01

    Dramatic changes due to climate and land use dynamics in the Mongolian Plateau affecting ecosystem services and agro-pastoral systems in Mongolia. Recently, market forces and development strategies are affecting land and water resources of the pastoral communities which are being further stressed due to climatic changes. Evaluation of pastoral systems, where humans depend on livestock and grassland ecosystem services, have demonstrated the vulnerability of the social-ecological system to climate change. Current social-ecological changes in ecosystem services are affecting land productivity and carrying capacity, land-atmosphere interactions, water resources, and livelihood strategies. The general trend involves greater intensification of resource exploitation at the expense of traditional patterns of extensive range utilization. Thus we expect climate-land use-land cover relationships to be crucially modified by the social-economic forces. The analysis incorporates information about the social-economic transitions taking place in the region which affect land-use, food security, and ecosystem dynamics. The region of study extends from the Mongolian plateau in Mongolia. Our research indicate that sustainability of pastoral systems in the region needs to integrate the impact of climate change on ecosystem services with socio-economic changes shaping the livelihood strategies of pastoral systems in the region. Adaptation strategies which incorporate integrated analysis of landscape management and livelihood strategies provides a framework which links ecosystem services to critical resource assets. Analysis of the available livelihood assets provides insights to the adaptive capacity of various agents in a region or in a community. Sustainable development pathways which enable the development of these adaptive capacity elements will lead to more effective adaptive management strategies for pastoral land use and herder's living standards. Pastoralists will have the

  14. Climate change impacts utilizing regional models for agriculture, hydrology and natural ecosystems

    Science.gov (United States)

    Kafatos, M.; Asrar, G. R.; El-Askary, H. M.; Hatzopoulos, N.; Kim, J.; Kim, S.; Medvigy, D.; Prasad, A. K.; Smith, E.; Stack, D. H.; Tremback, C.; Walko, R. L.

    2012-12-01

    Climate change impacts the entire Earth but with crucial and often catastrophic impacts at local and regional levels. Extreme phenomena such as fires, dust storms, droughts and other natural hazards present immediate risks and challenges. Such phenomena will become more extreme as climate change and anthropogenic activities accelerate in the future. We describe a major project funded by NIFA (Grant # 2011-67004-30224), under the joint NSF-DOE-USDA Earth System Models (EaSM) program, to investigate the impacts of climate variability and change on the agricultural and natural (i.e. rangeland) ecosystems in the Southwest USA using a combination of historical and present observations together with climate, and ecosystem models, both in hind-cast and forecast modes. The applicability of the methodology to other regions is relevant (for similar geographic regions as well as other parts of the world with different agriculture and ecosystems) and should advance the state of knowledge for regional impacts of climate change. A combination of multi-model global climate projections from the decadal predictability simulations, to downscale dynamically these projections using three regional climate models, combined with remote sensing MODIS and other data, in order to obtain high-resolution climate data that can be used with hydrological and ecosystem models for impacts analysis, is described in this presentation. Such analysis is needed to assess the future risks and potential impacts of projected changes on these natural and managed ecosystems. The results from our analysis can be used by scientists to assist extended communities to determine agricultural coping strategies, and is, therefore, of interest to wide communities of stakeholders. In future work we will be including surface hydrologic modeling and water resources, extend modeling to higher resolutions and include significantly more crops and geographical regions with different weather and climate conditions

  15. A Review of the Detection Methods for Climate Regime Shifts

    Directory of Open Access Journals (Sweden)

    Qunqun Liu

    2016-01-01

    Full Text Available An abrupt climate change means that the climate system shifts from a steady state to another steady state. Study on the phenomenon and theory of the abrupt climate change is a new research field of modern climatology, and it is of great significance for the prediction of future climate change. The climate regime shift is one of the most common forms of abrupt climate change, which mainly refers to the statistical significant changes on the variable of climate system at one time scale. These detection methods can be roughly divided into five categories based on different types of abrupt changes, namely, abrupt mean value change, abrupt variance change, abrupt frequency change, abrupt probability density change, and the multivariable analysis. The main research progress of abrupt climate change detection methods is reviewed. What is more, some actual applications of those methods in observational data are provided. With the development of nonlinear science, many new methods have been presented for detecting an abrupt dynamic change in recent years, which is useful supplement for the abrupt change detection methods.

  16. Spatially Explicit Assessment of Ecosystem Resilience: An Approach to Adapt to Climate Changes

    Directory of Open Access Journals (Sweden)

    Haiming Yan

    2014-01-01

    Full Text Available The ecosystem resilience plays a key role in maintaining a steady flow of ecosystem services and enables quick and flexible responses to climate changes, and maintaining or restoring the ecosystem resilience of forests is a necessary societal adaptation to climate change; however, there is a great lack of spatially explicit ecosystem resilience assessments. Drawing on principles of the ecosystem resilience highlighted in the literature, we built on the theory of dissipative structures to develop a conceptual model of the ecosystem resilience of forests. A hierarchical indicator system was designed with the influencing factors of the forest ecosystem resilience, including the stand conditions and the ecological memory, which were further disaggregated into specific indicators. Furthermore, indicator weights were determined with the analytic hierarchy process (AHP and the coefficient of variation method. Based on the remote sensing data and forest inventory data and so forth, the resilience index of forests was calculated. The result suggests that there is significant spatial heterogeneity of the ecosystem resilience of forests, indicating it is feasible to generate large-scale ecosystem resilience maps with this assessment model, and the results can provide a scientific basis for the conservation of forests, which is of great significance to the climate change mitigation.

  17. Climate change and anthropogenic impacts on marine ecosystems and countermeasures in China

    Directory of Open Access Journals (Sweden)

    Nian-Zhi Jiao

    2015-06-01

    Full Text Available The ecosystems of China seas and coasts are undergoing rapid changes under the strong influences of both global climate change and anthropogenic activities. To understand the scope of these changes and the mechanisms behind them is of paramount importance for the sustainable development of China, and for the establishment of national policies on environment protection and climate change mitigation. Here we provide a brief review of the impacts of global climate change and human activities on the oceans in general, and on the ecosystems of China seas and coasts in particular. More importantly, we discuss the challenges we are facing and propose several research foci for China seas/coasts ecosystem studies, including long-term time series observations on multiple scales, facilities for simulation study, blue carbon, coastal ecological security, prediction of ecosystem evolution and ecosystem-based management. We also establish a link to the Future Earth program from the perspectives of two newly formed national alliances, the China Future Ocean Alliance and the Pan-China Ocean Carbon Alliance.

  18. The Swedish Research Infrastructure for Ecosystem Science - SITES

    Science.gov (United States)

    Lindroth, A.; Ahlström, M.; Augner, M.; Erefur, C.; Jansson, G.; Steen Jensen, E.; Klemedtsson, L.; Langenheder, S.; Rosqvist, G. N.; Viklund, J.

    2017-12-01

    The vision of SITES is to promote long-term field-based ecosystem research at a world class level by offering an infrastructure with excellent technical and scientific support and services attracting both national and international researchers. In addition, SITES will make data freely and easily available through an advanced data portal which will add value to the research. During the first funding period, three innovative joint integrating facilities were established through a researcher-driven procedure: SITES Water, SITES Spectral, and SITES AquaNet. These new facilities make it possible to study terrestrial and limnic ecosystem processes across a range of ecosystem types and climatic gradients, with common protocols and similar equipment. In addition, user-driven development at the nine individual stations has resulted in e.g. design of a long-term agricultural systems experiment, and installation of weather stations, flux systems, etc. at various stations. SITES, with its integrative approach and broad coverage of climate and ecosystem types across Sweden, constitutes an excellent platform for state-of-the-art research projects. SITES' support the development of: A better understanding of the way in which key ecosystems function and interact with each other at the landscape level and with the climate system in terms of mass and energy exchanges. A better understanding of the role of different organisms in controlling different processes and ultimately the functioning of ecosystems. New strategies for forest management to better meet the many and varied requirements from nature conservation, climate and wood, fibre, and energy supply points of view. Agricultural systems that better utilize resources and minimize adverse impacts on the environment. Collaboration with other similar infrastructures and networks is a high priority for SITES. This will enable us to make use of each others' experiences, harmonize metadata for easier exchange of data, and support each

  19. Ecosystem based approaches to climate adaptation

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Jensen, Anne; Termansen, Mette

    This report analyses the prospects and barriers of applying ecosystem based approaches systematically to climate adaptation in urban areas, taking the case of green roofs in Copenhagen Municipality. It looks at planning aspects of green roofs in Copenhagen as well as citizen views and preferences...... regarding green roofs using policy document analysis, interviews with city planners and deliberative valuation methods....

  20. Abrupt millennial variability and interdecadal-interstadial oscillations in a global coupled model: sensitivity to the background climate state

    Energy Technology Data Exchange (ETDEWEB)

    Arzel, Olivier [The University of New South Wales, Climate Change Research Centre (CCRC), Sydney (Australia); Universite de Bretagne Occidentale, Laboratoire de Physique des Oceans (LPO), Brest (France); England, Matthew H. [The University of New South Wales, Climate Change Research Centre (CCRC), Sydney (Australia); Verdiere, Alain Colin de; Huck, Thierry [Universite de Bretagne Occidentale, Laboratoire de Physique des Oceans (LPO), Brest (France)

    2012-07-15

    The origin and bifurcation structure of abrupt millennial-scale climate transitions under steady external solar forcing and in the absence of atmospheric synoptic variability is studied by means of a global coupled model of intermediate complexity. We show that the origin of Dansgaard-Oeschger type oscillations in the model is caused by the weaker northward oceanic heat transport in the Atlantic basin. This is in agreement with previous studies realized with much simpler models, based on highly idealized geometries and simplified physics. The existence of abrupt millennial-scale climate transitions during glacial times can therefore be interpreted as a consequence of the weakening of the negative temperature-advection feedback. This is confirmed through a series of numerical experiments designed to explore the sensitivity of the bifurcation structure of the Atlantic meridional overturning circulation to increased atmospheric CO{sub 2} levels under glacial boundary conditions. Contrasting with the cold, stadial, phases of millennial oscillations, we also show the emergence of strong interdecadal variability in the North Atlantic sector during warm interstadials. The instability driving these interdecadal-interstadial oscillations is shown to be identical to that found in ocean-only models forced by fixed surface buoyancy fluxes, that is, a large-scale baroclinic instability developing in the vicinity of the western boundary current in the North Atlantic. Comparisons with modern observations further suggest a physical mechanism similar to that driving the 30-40 years time scale associated with the Atlantic multidecadal oscillation. (orig.)

  1. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Science.gov (United States)

    Zhao, Dongsheng; Wu, Shaohong; Yin, Yunhe

    2013-01-01

    The impact of regional climate change on net primary productivity (NPP) is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN), a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  2. Responses of terrestrial ecosystems' net primary productivity to future regional climate change in China.

    Directory of Open Access Journals (Sweden)

    Dongsheng Zhao

    Full Text Available The impact of regional climate change on net primary productivity (NPP is an important aspect in the study of ecosystems' response to global climate change. China's ecosystems are very sensitive to climate change owing to the influence of the East Asian monsoon. The Lund-Potsdam-Jena Dynamic Global Vegetation Model for China (LPJ-CN, a global dynamical vegetation model developed for China's terrestrial ecosystems, was applied in this study to simulate the NPP changes affected by future climate change. As the LPJ-CN model is based on natural vegetation, the simulation in this study did not consider the influence of anthropogenic activities. Results suggest that future climate change would have adverse effects on natural ecosystems, with NPP tending to decrease in eastern China, particularly in the temperate and warm temperate regions. NPP would increase in western China, with a concentration in the Tibetan Plateau and the northwest arid regions. The increasing trend in NPP in western China and the decreasing trend in eastern China would be further enhanced by the warming climate. The spatial distribution of NPP, which declines from the southeast coast to the northwest inland, would have minimal variation under scenarios of climate change.

  3. Future climate and wildfire: ecosystem projections of area burned in the western US

    Science.gov (United States)

    Littell, J. S.; Duffy, P.; Battisti, D. S.; McKenzie, D.; Peterson, D. L.

    2010-12-01

    The area burned by fire in ecosystems of the western United States has been closely linked to climate in the paleoecological record and in the modern record. Statistical models of area burned show that the climatic controls on area burned vary with vegetation type (Littell et al. 2009). In more arid or systems (grasslands, shrublands, woodlands), antecedent climatic controls on fire were associated first with the production of fuels and secondarily with drought in the year of fire. These relationships typically manifested as wetter and sometimes cooler conditions in the seasons prior to the fire season. Area burned in forest ecosystems and some woodlands was primarily associated with drought conditions, specifically increased temperature and decreased precipitation in the year of fire and the seasons leading up to the fire season. These climatic controls indicate the role of climate in drying existing fuels. Statistical fire models trained on the late 20th century for ecoprovinces in the West would be useful for projecting area burned, at least until vegetation type conversion driven by climate and disturbance occurs. To that end, we used ~ 2.5 degree gridded future climate fields derived for a multi-GCM ensemble of 1C and 2C temperature increase forcing to develop future ecoprovince monthly and seasonal average temperature and associated precipitation and used these as predictors in statistical fire models of future projected area burned. We also conducted modeling scenarios with the ensemble temperature increase paired with historical precipitation. Most ecoprovinces had increases in area burned, with a range of ~ 67% to over 600% . Ecoprovinces that are primarily sensitive to precipitation changes exhibit smaller increases than those most sensitive to temperature (forest systems). We also developed exceedance probabilities. Some ecoprovinces show large increases in area burned but low exceedance probabilities, suggest that the area burned is concentrated more

  4. Nitrogen cycling in heathland ecosystems and effects of climate change

    DEFF Research Database (Denmark)

    Andresen, Louise Christoffersen

    Terrestrial ecosystems are currently exposed to climatic and air quality changes with increased atmospheric CO2, increased temperature and periodical droughts. At a temperate heath site this was investigated in a unique full factorial in situ experiment (CLIMAITE). The climate change treatments...

  5. Plant responses, climate pivot points, and trade-offs in water-limited ecosystems

    Science.gov (United States)

    Munson, S. M.; Bunting, E.

    2017-12-01

    Ecosystem transitions and thresholds are conceptually well-defined and have become a framework to address vegetation response to climate change and land-use intensification, yet there are few approaches to define the environmental conditions which can lead to them. We demonstrate a novel climate pivot point approach using long-term monitoring data from a broad network of permanent plots, satellite imagery, and experimental treatments across the southwestern U.S. The climate pivot point identifies conditions that lead to decreased plant performance and serves as an early warning sign of increased vulnerability of crossing a threshold into an altered ecosystem state. Plant responses and climate pivot points aligned with the lifespan and structural characteristics of species, were modified by soil and landscape attributes of a site, and had non-linear dynamics in some cases. Species with strong increases in abundance when water was available were most susceptible to losses during water shortages, reinforcing plant energetic and physiological tradeoffs. Future research to uncover the heterogeneity of plant responses and climate pivot points at multiple scales can lead to greater understanding of shifts in ecosystem productivity and vulnerability to climate change.

  6. Divergence of ecosystem services in U.S. National Forests and Grasslands under a changing climate.

    Science.gov (United States)

    Duan, Kai; Sun, Ge; Sun, Shanlei; Caldwell, Peter V; Cohen, Erika C; McNulty, Steven G; Aldridge, Heather D; Zhang, Yang

    2016-04-21

    The 170 National Forests and Grasslands (NFs) in the conterminous United States are public lands that provide important ecosystem services such as clean water and timber supply to the American people. This study investigates the potential impacts of climate change on two key ecosystem functions (i.e., water yield and ecosystem productivity) using the most recent climate projections derived from 20 Global Climate Models (GCMs) of the Coupled Model Intercomparison Project phase 5 (CMIP5). We find that future climate change may result in a significant reduction in water yield but an increase in ecosystem productivity in NFs. On average, gross ecosystem productivity is projected to increase by 76 ~ 229 g C m(-2) yr(-1) (8% ~ 24%) while water yield is projected to decrease by 18 ~ 31 mm yr(-1) (4% ~ 7%) by 2100 as a result of the combination of increased air temperature (+1.8 ~ +5.2 °C) and precipitation (+17 ~ +51 mm yr(-1)). The notable divergence in ecosystem services of water supply and carbon sequestration is expected to intensify under higher greenhouse gas emission and associated climate change in the future, posing greater challenges to managing NFs for both ecosystem services.

  7. Cumulative effects of planned industrial development and climate change on marine ecosystems

    Directory of Open Access Journals (Sweden)

    Cathryn Clarke Murray

    2015-07-01

    Full Text Available With increasing human population, large scale climate changes, and the interaction of multiple stressors, understanding cumulative effects on marine ecosystems is increasingly important. Two major drivers of change in coastal and marine ecosystems are industrial developments with acute impacts on local ecosystems, and global climate change stressors with widespread impacts. We conducted a cumulative effects mapping analysis of the marine waters of British Columbia, Canada, under different scenarios: climate change and planned developments. At the coast-wide scale, climate change drove the largest change in cumulative effects with both widespread impacts and high vulnerability scores. Where the impacts of planned developments occur, planned industrial and pipeline activities had high cumulative effects, but the footprint of these effects was comparatively localized. Nearshore habitats were at greatest risk from planned industrial and pipeline activities; in particular, the impacts of planned pipelines on rocky intertidal habitats were predicted to cause the highest change in cumulative effects. This method of incorporating planned industrial development in cumulative effects mapping allows explicit comparison of different scenarios with the potential to be used in environmental impact assessments at various scales. Its use allows resource managers to consider cumulative effect hotspots when making decisions regarding industrial developments and avoid unacceptable cumulative effects. Management needs to consider both global and local stressors in managing marine ecosystems for the protection of biodiversity and the provisioning of ecosystem services.

  8. Global climate change and California's natural ecosystems

    International Nuclear Information System (INIS)

    Botkin, D.B.; Nisbet, R.A.; Woodhouse, C.; Ferren, W.; Bicknell, S.; Bentley, B.

    1991-01-01

    If projections of global climate models are correct, the natural ecosystems of California might undergo major changes during the next century. Such changes might include large economic losses in timber, fisheries, and recreation; major changes in our national and state parks and forests and in our nature preserves and conservation areas; increase in extinction of endangered species; loss of large areas of existing habitats; and development of new habitats whose location and areal extent can only be surmised. Many areas currently set aside for the conservation of specific ecosystems might no longer be suitable to them. Yet, in spite of the potential seriousness of these problems, which could dwarf all other environmental changes, California is at present in a poor situation to project what the effects of global change on its natural ecosystems might be

  9. Interactive effects of climate change and biodiversity loss on ecosystem functioning.

    Science.gov (United States)

    Pires, Aliny P F; Srivastava, Diane S; Marino, Nicholas A C; MacDonald, A Andrew M; Figueiredo-Barros, Marcos Paulo; Farjalla, Vinicius F

    2018-05-01

    Climate change and biodiversity loss are expected to simultaneously affect ecosystems, however research on how each driver mediates the effect of the other has been limited in scope. The multiple stressor framework emphasizes non-additive effects, but biodiversity may also buffer the effects of climate change, and climate change may alter which mechanisms underlie biodiversity-function relationships. Here, we performed an experiment using tank bromeliad ecosystems to test the various ways that rainfall changes and litter diversity may jointly determine ecological processes. Litter diversity and rainfall changes interactively affected multiple functions, but how depends on the process measured. High litter diversity buffered the effects of altered rainfall on detritivore communities, evidence of insurance against impacts of climate change. Altered rainfall affected the mechanisms by which litter diversity influenced decomposition, reducing the importance of complementary attributes of species (complementarity effects), and resulting in an increasing dependence on the maintenance of specific species (dominance effects). Finally, altered rainfall conditions prevented litter diversity from fueling methanogenesis, because such changes in rainfall reduced microbial activity by 58%. Together, these results demonstrate that the effects of climate change and biodiversity loss on ecosystems cannot be understood in isolation and interactions between these stressors can be multifaceted. © 2018 by the Ecological Society of America.

  10. Climate engineering and the risk of rapid climate change

    International Nuclear Information System (INIS)

    Ross, Andrew; Damon Matthews, H

    2009-01-01

    Recent research has highlighted risks associated with the use of climate engineering as a method of stabilizing global temperatures, including the possibility of rapid climate warming in the case of abrupt removal of engineered radiative forcing. In this study, we have used a simple climate model to estimate the likely range of temperature changes associated with implementation and removal of climate engineering. In the absence of climate engineering, maximum annual rates of warming ranged from 0.015 to 0.07 deg. C/year, depending on the model's climate sensitivity. Climate engineering resulted in much higher rates of warming, with the temperature change in the year following the removal of climate engineering ranging from 0.13 to 0.76 deg. C. High rates of temperature change were sustained for two decades following the removal of climate engineering; rates of change of 0.5 (0.3,0.1) deg. C/decade were exceeded over a 20 year period with 15% (75%, 100%) likelihood. Many ecosystems could be negatively affected by these rates of temperature change; our results suggest that climate engineering in the absence of deep emissions cuts could arguably constitute increased risk of dangerous anthropogenic interference in the climate system under the criteria laid out in the United Nations Framework Convention on Climate Change.

  11. Tropical climate and vegetation cover during Heinrich event 1: Simulations with coupled climate vegetation models

    OpenAIRE

    Handiani, Dian Noor

    2012-01-01

    This study focuses on the climate and vegetation responses to abrupt climate change in the Northern Hemisphere during the last glacial period. Two abrupt climate events are explored: the abrupt cooling of the Heinrich event 1 (HE1), followed by the abrupt warming of the Bølling-Allerød interstadial (BA). These two events are simulated by perturbing the freshwater balance of the Atlantic Ocean, with the intention of altering the Atlantic Meridional Overturning Circulation (AMOC) and also of in...

  12. Research frontiers in climate change: Effects of extreme meteorological events on ecosystems

    International Nuclear Information System (INIS)

    Jentsch, A.; Jentsch, A.; Beierkuhnlein, C.

    2008-01-01

    Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests that modifications in extreme weather events pose stronger threats to ecosystem functioning than global trends and shifts in average conditions. As ecosystem functioning is connected with ecological services, this has far-reaching effects on societies in the 21. century. Here, we: (i) present the rationale for the increasing frequency and magnitude of extreme weather events in the near future; (ii) discuss recent findings on meteorological extremes and summarize their effects on ecosystems and (iii) identify gaps in current ecological climate change research. (authors)

  13. Natural resilience: healthy ecosystems as climate shock insurance

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Joanna [Royal Society for the Protection of the Birds (United Kingdom); Heath, Melanie [Birdlife International (United Kingdom); Reid, Hannah

    2009-12-15

    Resilience to climate change has many roots. A healthy, biodiverse environment is increasingly recognised as key to resilience, particularly in poor communities directly dependent on natural resources. Knowledge about ways of coping with climate variability is also essential - and for many of the poor who live in climate-vulnerable regions, already an area of expertise. A look at the National Adaptation Programmes of Action of the Least Developed Countries shows that many of these nations recognize and prioritise the role that biodiversity, ecosystems and natural habitats play in adaptation. It is now up to policymakers to follow suit.

  14. Evaluating the relative impact of climate and economic changes on forest and agricultural ecosystem services in mountain regions.

    Science.gov (United States)

    Briner, Simon; Elkin, Ché; Huber, Robert

    2013-11-15

    Provisioning of ecosystem services (ES) in mountainous regions is predicted to be influenced by i) the direct biophysical impacts of climate change, ii) climate mediated land use change, and iii) socioeconomic driven changes in land use. The relative importance and the spatial distribution of these factors on forest and agricultural derived ES, however, is unclear, making the implementation of ES management schemes difficult. Using an integrated economic-ecological modeling framework, we evaluated the impact of these driving forces on the provision of forest and agricultural ES in a mountain region of southern Switzerland. Results imply that forest ES will be strongly influenced by the direct impact of climate change, but that changes in land use will have a comparatively small impact. The simulation of direct impacts of climate change affects forest ES at all elevations, while land use changes can only be found at high elevations. In contrast, changes to agricultural ES were found to be primarily due to shifts in economic conditions that alter land use and land management. The direct influence of climate change on agriculture is only predicted to be substantial at high elevations, while socioeconomic driven shifts in land use are projected to affect agricultural ES at all elevations. Our simulation results suggest that policy schemes designed to mitigate the negative impact of climate change on forests should focus on suitable adaptive management plans, accelerating adaptation processes for currently forested areas. To maintain provision of agricultural ES policy needs to focus on economic conditions rather than on supporting adaptation to new climate. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Bioaerosols in the Earth system: Climate, health, and ecosystem interactions

    Energy Technology Data Exchange (ETDEWEB)

    Fröhlich-Nowoisky, Janine; Kampf, Christopher J.; Weber, Bettina; Huffman, J. Alex; Pöhlker, Christopher; Andreae, Meinrat O.; Lang-Yona, Naama; Burrows, Susannah M.; Gunthe, Sachin S.; Elbert, Wolfgang; Su, Hang; Hoor, Peter; Thines, Eckhard; Hoffmann, Thorsten; Després, Viviane R.; Pöschl, Ulrich

    2016-12-01

    Aerosols of biological origin play a vital role in the Earth system, particularly in the in-teractions between atmosphere, biosphere, climate, and public health. Airborne bacteria, fungal spores, pollen, and other bioparticles are essential for the reproduction and spread of organisms across various ecosystems, and they can cause or enhance human, animal, and plant diseases. Moreover, they can serve as nuclei for cloud droplets, ice crystals, and precipitation, thus influencing the hydrological cycle and climate. The actual formation, abundance, composition, and effects of biological aerosols and the atmospheric microbi-ome are, however, not yet well characterized and constitute a large gap in the scientific understanding of the interaction and co-evolution of life and climate in the Earth system. This review presents an overview of the state of bioaerosol research and highlights recent advances in terms of bioaerosol identification, characterization, transport, and transfor-mation processes, as well as their interactions with climate, health, and ecosystems, focus-ing on the role bioaerosols play in the Earth system.

  16. Data-driven diagnostics of terrestrial carbon dynamics over North America

    Science.gov (United States)

    Jingfeng Xiao; Scott V. Ollinger; Steve Frolking; George C. Hurtt; David Y. Hollinger; Kenneth J. Davis; Yude Pan; Xiaoyang Zhang; Feng Deng; Jiquan Chen; Dennis D. Baldocchi; Bevery E. Law; M. Altaf Arain; Ankur R. Desai; Andrew D. Richardson; Ge Sun; Brian Amiro; Hank Margolis; Lianhong Gu; Russell L. Scott; Peter D. Blanken; Andrew E. Suyker

    2014-01-01

    The exchange of carbon dioxide is a key measure of ecosystem metabolism and a critical intersection between the terrestrial biosphere and the Earth's climate. Despite the general agreement that the terrestrial ecosystems in North America provide a sizeable carbon sink, the size and distribution of the sink remain uncertain. We use a data-driven approach to upscale...

  17. Ecosystem Management: Tomorrow’s Approach to Enhancing Food Security under a Changing Climate

    Directory of Open Access Journals (Sweden)

    Mike Rivington

    2011-06-01

    Full Text Available This paper argues that a sustainable ecosystem management approach is vital to ensure the delivery of essential ‘life support’ ecosystem services and must be mainstreamed into societal conscience, political thinking and economic processes. Feeding the world at a time of climate change, environmental degradation, increasing human population and demand for finite resources requires sustainable ecosystem management and equitable governance. Ecosystem degradation undermines food production and the availability of clean water, hence threatening human health, livelihoods and ultimately societal stability. Degradation also increases the vulnerability of populations to the consequences of natural disasters and climate change impacts. With 10 million people dying from hunger each year, the linkages between ecosystems and food security are important to recognize. Though we all depend on ecosystems for our food and water, about seventy per cent of the estimated 1.1 billion people in poverty around the world live in rural areas and depend directly on the productivity of ecosystems for their livelihoods. Healthy ecosystems provide a diverse range of food sources and support entire agricultural systems, but their value to food security and sustainable livelihoods are often undervalued or ignored. There is an urgent need for increased financial investment for integrating ecosystem management with food security and poverty alleviation priorities. As the world’s leaders worked towards a new international climate change agenda in Cancun, Mexico, 29 November–10 December 2010 (UNFCCC COP16, it was clear that without a deep and decisive post-2012 agreement and major concerted effort to reduce the food crisis, the Millennium Development Goals will not be attained. Political commitment at the highest level will be needed to raise the profile of ecosystems on the global food agenda. It is recommended that full recognition and promotion be given of the linkages

  18. Damped trophic cascades driven by fishing in model marine ecosystems

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Pedersen, Martin

    2010-01-01

    The largest perturbation on upper trophic levels of many marine ecosystems stems from fishing. The reaction of the ecosystem goes beyond the trophic levels directly targeted by the fishery. This reaction has been described either as a change in slope of the overall size spectrum or as a trophic...... cascade triggered by the removal of top predators. Here we use a novel size- and trait-based model to explore how marine ecosystems might react to perturbations from different types of fishing pressure. The model explicitly resolves the whole life history of fish, from larvae to adults. The results show...... that fishing does not change the overall slope of the size spectrum, but depletes the largest individuals and induces trophic cascades. A trophic cascade can propagate both up and down in trophic levels driven by a combination of changes in predation mortality and food limitation. The cascade is damped...

  19. Direct and indirect effects of climatic variations on the interannual variability in net ecosystem exchange across terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    Junjiong Shao

    2016-08-01

    Full Text Available Climatic variables not only directly affect the interannual variability (IAV in net ecosystem exchange of CO2 (NEE but also indirectly drive it by changing the physiological parameters. Identifying these direct and indirect paths can reveal the underlying mechanisms of carbon (C dynamics. In this study, we applied a path analysis using flux data from 65 sites to quantify the direct and indirect climatic effects on IAV in NEE and to evaluate the potential relationships among the climatic variables and physiological parameters that represent physiology and phenology of ecosystems. We found that the maximum photosynthetic rate was the most important factor for the IAV in gross primary productivity (GPP, which was mainly induced by the variation in vapour pressure deficit. For ecosystem respiration (RE, the most important drivers were GPP and the reference respiratory rate. The biome type regulated the direct and indirect paths, with distinctive differences between forests and non-forests, evergreen needleleaf forests and deciduous broadleaf forests, and between grasslands and croplands. Different paths were also found among wet, moist and dry ecosystems. However, the climatic variables can only partly explain the IAV in physiological parameters, suggesting that the latter may also result from other biotic and disturbance factors. In addition, the climatic variables related to NEE were not necessarily the same as those related to GPP and RE, indicating the emerging difficulty encountered when studying the IAV in NEE. Overall, our results highlight the contribution of certain physiological parameters to the IAV in C fluxes and the importance of biome type and multi-year water conditions, which should receive more attention in future experimental and modelling research.

  20. Climate-mediated changes in marine ecosystem regulation during El Niño

    DEFF Research Database (Denmark)

    Lindegren, Martin; Checkley, David M.; Koslow, J. Anthony

    2017-01-01

    concentrations and primary production). The shifts in ecosystem regulation are caused by changes in ocean-atmosphere forcing and triggered by highly variable climate conditions associated with El Niño. Furthermore, we show that biota respond differently to major El Niño events during positive or negative phases......, or whether the relative importance of bottom-up and top-down forcing may shift in response to climate change. In this study, we investigate the effects and relative importance of bottom-up, top-down and physical forcing during changing climate conditions on ecosystem regulation in the Southern California...

  1. The Inter-Annual Variability Analysis of Carbon Exchange in Low Artic Fen Uncovers The Climate Sensitivity And The Uncertainties Around Net Ecosystem Exchange Partitioning

    Science.gov (United States)

    Blanco, E. L.; Lund, M.; Williams, M. D.; Christensen, T. R.; Tamstorf, M. P.

    2015-12-01

    An improvement in our process-based understanding of CO2 exchanges in the Arctic, and their climate sensitivity, is critical for examining the role of tundra ecosystems in changing climates. Arctic organic carbon storage has seen increased attention in recent years due to large potential for carbon releases following thaw. Our knowledge about the exact scale and sensitivity for a phase-change of these C stocks are, however, limited. Minor variations in Gross Primary Production (GPP) and Ecosystem Respiration (Reco) driven by changes in the climate can lead to either C sink or C source states, which likely will impact the overall C cycle of the ecosystem. Eddy covariance data is usually used to partition Net Ecosystem Exchange (NEE) into GPP and Reco achieved by flux separation algorithms. However, different partitioning approaches lead to different estimates. as well as undefined uncertainties. The main objectives of this study are to use model-data fusion approaches to (1) determine the inter-annual variability in C source/sink strength for an Arctic fen, and attribute such variations to GPP vs Reco, (2) investigate the climate sensitivity of these processes and (3) explore the uncertainties in NEE partitioning. The intention is to elaborate on the information gathered in an existing catchment area under an extensive cross-disciplinary ecological monitoring program in low Arctic West Greenland, established under the auspices of the Greenland Ecosystem Monitoring (GEM) program. The use of such a thorough long-term (7 years) dataset applied to the exploration in inter-annual variability of carbon exchange, related driving factors and NEE partition uncertainties provides a novel input into our understanding about land-atmosphere CO2 exchange.

  2. Impact of climate change on carbon cycle in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kankaala, P; Ojala, A; Tulonen, T; Haapamaeki, J; Arvola, L [Helsinki Univ., Lammi (Finland). Lammi Biological Station

    1997-12-31

    The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric CO{sub 2} concentration and ambient temperature as well as longer growing season will enhance the overall productivity of littoral macrophytes. The higher productivity of the littoral zone will be reflected in the pelagic zone an thus may change the whole ecosystem of the lake

  3. Impact of climate change on carbon cycle in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Kankaala, P.; Ojala, A.; Tulonen, T.; Haapamaeki, J.; Arvola, L. [Helsinki Univ., Lammi (Finland). Lammi Biological Station

    1996-12-31

    The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric CO{sub 2} concentration and ambient temperature as well as longer growing season will enhance the overall productivity of littoral macrophytes. The higher productivity of the littoral zone will be reflected in the pelagic zone an thus may change the whole ecosystem of the lake

  4. Integrating Climate and Ecosystem-Response Sciences in Temperate Western North American Mountains: The CIRMOUNT Initiative

    Science.gov (United States)

    Millar, C. I.; Fagre, D. B.

    2004-12-01

    Mountain regions are uniquely sensitive to changes in climate, vulnerable to climate effects on biotic and physical factors of intense social concern, and serve as critical early-warning systems of climate impacts. Escalating demands on western North American (WNA) mountain ecosystems increasingly stress both natural resources and rural community capacities; changes in mountain systems cascade to issues of national concern. Although WNA has long been a focus for climate- and climate-related environmental research, these efforts remain disciplinary and poorly integrated, hindering interpretation into policy and management. Knowledge is further hampered by lack of standardized climate monitoring stations at high-elevations in WNA. An initiative is emerging as the Consortium for Integrated Climate Research in Western Mountains (CIRMOUNT) whose primary goal is to improve knowledge of high-elevation climate systems and to better integrate physical, ecological, and social sciences relevant to climate change, ecosystem response, and natural-resource policy in WNA. CIRMOUNT seeks to focus research on climate variability and ecosystem response (progress in understanding synoptic scale processes) that improves interpretation of linkages between ecosystem functions and human processing (progress in understanding human-environment integration), which in turn would yield applicable information and understanding on key societal issues such as mountains as water towers, biodiversity, carbon forest sinks, and wildland hazards such as fire and forest dieback (progress in understanding ecosystem services and key thresholds). Achieving such integration depends first on implementing a network of high-elevation climate-monitoring stations, and linking these with integrated ecosystem-response studies. Achievements since 2003 include convening the 2004 Mountain Climate Sciences Symposium (1, 2) and several special sessions at technical conferences; initiating a biennial mountain climate

  5. Modeling the response of plants and ecosystems to elevated CO sub 2 and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  6. Modeling the response of plants and ecosystems to elevated CO{sub 2} and climate change

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

    1992-03-01

    While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth`s surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society`s ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

  7. Predicting climate-driven regime shifts versus rebound potential in coral reefs.

    Science.gov (United States)

    Graham, Nicholas A J; Jennings, Simon; MacNeil, M Aaron; Mouillot, David; Wilson, Shaun K

    2015-02-05

    Climate-induced coral bleaching is among the greatest current threats to coral reefs, causing widespread loss of live coral cover. Conditions under which reefs bounce back from bleaching events or shift from coral to algal dominance are unknown, making it difficult to predict and plan for differing reef responses under climate change. Here we document and predict long-term reef responses to a major climate-induced coral bleaching event that caused unprecedented region-wide mortality of Indo-Pacific corals. Following loss of >90% live coral cover, 12 of 21 reefs recovered towards pre-disturbance live coral states, while nine reefs underwent regime shifts to fleshy macroalgae. Functional diversity of associated reef fish communities shifted substantially following bleaching, returning towards pre-disturbance structure on recovering reefs, while becoming progressively altered on regime shifting reefs. We identified threshold values for a range of factors that accurately predicted ecosystem response to the bleaching event. Recovery was favoured when reefs were structurally complex and in deeper water, when density of juvenile corals and herbivorous fishes was relatively high and when nutrient loads were low. Whether reefs were inside no-take marine reserves had no bearing on ecosystem trajectory. Although conditions governing regime shift or recovery dynamics were diverse, pre-disturbance quantification of simple factors such as structural complexity and water depth accurately predicted ecosystem trajectories. These findings foreshadow the likely divergent but predictable outcomes for reef ecosystems in response to climate change, thus guiding improved management and adaptation.

  8. Effects of the global changes on the aquatic ecosystems in West Europe - role of the plankton communities; Effets des changements globaux sur les ecosystemes aquatiques d'Europe Occidentale - role des communautes planctoniques

    Energy Technology Data Exchange (ETDEWEB)

    Souissi, S. [Universite des Sciences et Technologies de Lille, Ecosystem COmplexity REsearch Group, Station Marine de Wimereux, CNRS - FRE 2816 ELICO, 62 - Wimereux (France)

    2007-07-01

    Examination of long-term records of aquatic ecosystems has provided useful information to find out their major driving forces. Understanding the impact of climate change on these ecosystems, the management of their resources and the extrapolation between sites are the main scopes of actual and emerging studies. Such goals can be achieved by inter-site and inter-ecosystem comparisons. This approach was undertaken during our project which has the originality to tackle with marine and freshwater ecosystems. It allowed us to compile and validate several multi-decadal time series of planktonic and other physical driving forces at local and regional scales. Then, the same methodology based on the analysis of the variability of climate indices and biological data across several spatial scales was used. The different ecosystems analyzed here showed clear response to the North Atlantic climate variability. Although the local differences abrupt changes in community composition occurred in all ecosystems in the middle of the years 80. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors. Phenological changes were also observed in plankton communities in all sites. The consequences of the modifications of plankton dynamics on higher trophic levels were also showed. Fluctuations in plankton have resulted in long-term changes in cod recruitment in the North Sea (bottom-up control). On the other hand, both climate change and the improvement of trophic status in Geneva Lake favored the outbreak of whitefish during the years 90. Lower larval mortality and better recruitment are supposed to be linked to faster growth associated with warmer temperatures and better food conditions induced by better temporal overlap between larvae hatching and zooplankton development. (author)

  9. Structural and functional loss in restored wetland ecosystems.

    Directory of Open Access Journals (Sweden)

    David Moreno-Mateos

    2012-01-01

    Full Text Available Wetlands are among the most productive and economically valuable ecosystems in the world. However, because of human activities, over half of the wetland ecosystems existing in North America, Europe, Australia, and China in the early 20th century have been lost. Ecological restoration to recover critical ecosystem services has been widely attempted, but the degree of actual recovery of ecosystem functioning and structure from these efforts remains uncertain. Our results from a meta-analysis of 621 wetland sites from throughout the world show that even a century after restoration efforts, biological structure (driven mostly by plant assemblages, and biogeochemical functioning (driven primarily by the storage of carbon in wetland soils, remained on average 26% and 23% lower, respectively, than in reference sites. Either recovery has been very slow, or postdisturbance systems have moved towards alternative states that differ from reference conditions. We also found significant effects of environmental settings on the rate and degree of recovery. Large wetland areas (>100 ha and wetlands restored in warm (temperate and tropical climates recovered more rapidly than smaller wetlands and wetlands restored in cold climates. Also, wetlands experiencing more (riverine and tidal hydrologic exchange recovered more rapidly than depressional wetlands. Restoration performance is limited: current restoration practice fails to recover original levels of wetland ecosystem functions, even after many decades. If restoration as currently practiced is used to justify further degradation, global loss of wetland ecosystem function and structure will spread.

  10. Modeling Past Abrupt Climate Changes

    DEFF Research Database (Denmark)

    Marchionne, Arianna

    of the orbital variations on Earth's climate; however, the knowledge and tools needed to complete a unied theory for ice ages have not been developed yet. Here, we focus on the climatic variations that have occurred over the last few million years. Paleoclimatic records show that the glacial cycles are linked...... to those present in the astronomical forcing. We shall do this in terms of a general framework of conceptual dynamical models, which may or may not exhibit internal self-sustained oscillations. We introduce and discuss two distinct mechanisms for a periodic response at a dierent period to a periodic...

  11. Challenges for Ecosystem Services Provided by Coral Reefs In the Face of Climate Change

    Science.gov (United States)

    Kikuchi, R. K.; Elliff, C. I.

    2014-12-01

    Coral reefs provide many ecosystem services of which coastal populations are especially dependent upon, both in cases of extreme events and in daily life. However, adaptation to climate change is still relatively unknown territory regarding the ecosystem services provided by coastal environments, such as coral reefs. Management strategies usually consider climate change as a distant issue and rarely include ecosystem services in decision-making. Coral reefs are among the most vulnerable environments to climate change, considering the impact that increased ocean temperature and acidity have on the organisms that compose this ecosystem. If no actions are taken, the most likely scenario to occur will be of extreme decline in the ecosystem services provided by coral reefs. Loss of biodiversity due to the pressures of ocean warming and acidification will lead to increased price of seafood products, negative impact on food security, and ecological imbalances. Also, sea-level rise and fragile structures due to carbonate dissolution will increase vulnerability to storms, which can lead to shoreline erosion and ultimately threaten coastal communities. Both these conditions will undoubtedly affect recreation and tourism, which are often the most important use values in the case of coral reef systems. Adaptation strategies to climate change must take on an ecosystem-based approach with continuous monitoring programs, so that multiple ecosystem services are considered and not only retrospective trends are analyzed. Brazilian coral reefs have been monitored on a regular basis since 2000 and, considering that these marginal coral reefs of the eastern Atlantic are naturally under stressful conditions (e.g. high sedimentation rates), inshore reefs of Brazil, such as those in Tinharé-Boipeba, have shown lower vitality rates due to greater impacts from the proximity to the coastal area (e.g. pollution, overfishing, sediment run-off). This chronic negative impact must be addressed

  12. Abrupt climatic events recorded by the Ili loess during the last glaciation in Central Asia: Evidence from grain-size and minerals

    Science.gov (United States)

    Song, Yougui; Zeng, Mengxiu; Chen, Xiuling; Li, Yue; Chang, Hong; An, Zhisheng; Guo, Xiaohua

    2018-04-01

    The loess record of Central Asia provides an important archive of regional climate and environmental changes. In contrast to the widely investigated loess deposits in the Chinese Loess Plateau, Central Asian loess-paleosol sequences remain poorly understood. Here, we present an aeolian loess section in the southern Ili Basin. Based on granularity and mineralogical analyses, we reconstruct climatic changes during the last glaciation. The results indicated that most of the abrupt climatic events (such as Dansgaard-Oeschger events and Heinrich events) were imprinted in this loess section, although their amplitudes and ages showed some differences. Compared with the millennial oscillations recoded in loess and stalagmites in East Asia, the arid Central Asia responded more sensitively to the warming events than to the cooling events. The shifting trajectory of westerlies across Central Asia played an important role in dust deposition during the stadials. The North Atlantic climatic signals may have been transmitted from Central Asia to the East Asian monsoon regions via the westerlies.

  13. Climate, ecosystems, and planetary futures: The challenge to predict life in Earth system models.

    Science.gov (United States)

    Bonan, Gordon B; Doney, Scott C

    2018-02-02

    Many global change stresses on terrestrial and marine ecosystems affect not only ecosystem services that are essential to humankind, but also the trajectory of future climate by altering energy and mass exchanges with the atmosphere. Earth system models, which simulate terrestrial and marine ecosystems and biogeochemical cycles, offer a common framework for ecological research related to climate processes; analyses of vulnerability, impacts, and adaptation; and climate change mitigation. They provide an opportunity to move beyond physical descriptors of atmospheric and oceanic states to societally relevant quantities such as wildfire risk, habitat loss, water availability, and crop, fishery, and timber yields. To achieve this, the science of climate prediction must be extended to a more multifaceted Earth system prediction that includes the biosphere and its resources. Copyright © 2018, American Association for the Advancement of Science.

  14. Abrupt Climatic Change during the Latest Maastrichtian: Establishing Robust Temporal Links with the Onset of Deccan Volcanism and K/Pg Mass Extinction

    Science.gov (United States)

    Barnet, J.; Littler, K.; Kroon, D.; Leng, M. J.; Westerhold, T.; Roehl, U.; Zachos, J. C.

    2017-12-01

    A transient period of climate change, characterized by a global warming of 2.5-5°C followed by a cooling to pre-excursion conditions, occurred during the last 300 kyr of the Maastrichtian ( 66.34-66.02 Ma). This instability may have played a role in destabilizing marine and terrestrial ecosystems, priming the system for abrupt extinction at the K-Pg boundary, likely triggered by a large bolide impact. This pre-K-Pg warming event has often been linked to the main phase of Deccan Trap volcanism, however large uncertainties associated with radio-isotopic dating methods of basalts, along with low sedimentation rates and hiatuses in many studied sedimentary sequences, have long hampered a definitive correlation. To complement recent advances in dating of the traps, we have generated the first complete and highest resolution (2.5-4 kyr) benthic stable δ13C and δ18O record for the final million years of the Maastrichtian using the epifaunal foraminifera species Nuttallides truempyi from ODP Site 1262, Walvis Ridge, South Atlantic, calibrated to an updated orbitally-tuned age model. We then compare our data to other previously published geochemical data from other sites in the high, middle, and low latitudes. Our data confirms that the onset of the warming event coincides with the onset of the main phase of Deccan volcanism, strongly suggesting a causal link. Furthermore, spectral analysis of our extended late Maastrichtian-Early Eocene record suggests that the onset of the warming event corresponds to a 405-kyr eccentricity minima, in contrast to many transient warming events (hyperthermals) of the Paleogene, suggesting a control by orbital forcing alone is unlikely. A peculiar feature of the event, compared to other hyperthermals, is a muted carbon cycle response during warming, which may be related to the comparatively heavier δ13C signature of volcanogenic CO2 (-7‰), compared to other sources of light carbon invoked to explain Paleogene hyperthermals. The warming

  15. The abrupt climate change near 4,400 yr BP on the cultural transition in Yuchisi, China and its global linkage.

    Science.gov (United States)

    Wang, Jianjun; Sun, Liguang; Chen, Liqi; Xu, Libin; Wang, Yuhong; Wang, Xinming

    2016-06-10

    Extreme climatic events have profound impacts on human society. Here we present the results of a study of organic biomarkers within a sedimentary section at the archaeological site of Yuchisi, eastern China, in order to reconstruct climatic variability during the Dawenkou (5,050-4,400 yr BP) and Longshan (4,400-4,000 yr BP) cultures. At ~4,400 yr BP, within the cultural transition horizon, abrupt changes in biomarkers, such as the fatty acid ratio C18:2/C18:0, 2C31/(C27 + C29), n-C18-ol and n-C30-ol, indicate the occurrence of local climate changes over the course of a few decades. These changes occurred during the transition from the Holocene warm period to a subsequent cold period which lasted for the following 600 years. This climatic shift has been recorded at numerous sites worldwide, and it is likely to have been the main cause of the widespread collapse of many isolated cultures at that time. The palaeoclimatic and archaeological data from the Yuchisi sediments may provide new insights into the relationship between climate change and prehistoric cultural transitions.

  16. Macroclimatic change expected to transform coastal wetland ecosystems this century

    Science.gov (United States)

    Gabler, Christopher A.; Osland, Michael J.; Grace, James B.; Stagg, Camille L.; Day, Richard H.; Hartley, Stephen B.; Enwright, Nicholas M.; From, Andrew S.; McCoy, Meagan L.; McLeod, Jennie L.

    2017-01-01

    Coastal wetlands, existing at the interface between land and sea, are highly vulnerable to climate change. Macroclimate (for example, temperature and precipitation regimes) greatly influences coastal wetland ecosystem structure and function. However, research on climate change impacts in coastal wetlands has concentrated primarily on sea-level rise and largely ignored macroclimatic drivers, despite their power to transform plant community structure and modify ecosystem goods and services. Here, we model wetland plant community structure based on macroclimate using field data collected across broad temperature and precipitation gradients along the northern Gulf of Mexico coast. Our analyses quantify strongly nonlinear temperature thresholds regulating the potential for marsh-to-mangrove conversion. We also identify precipitation thresholds for dominance by various functional groups, including succulent plants and unvegetated mudflats. Macroclimate-driven shifts in foundation plant species abundance will have large effects on certain ecosystem goods and services. Based on current and projected climatic conditions, we project that transformative ecological changes are probable throughout the region this century, even under conservative climate scenarios. Coastal wetland ecosystems are functionally similar worldwide, so changes in this region are indicative of potential future changes in climatically similar regions globally.

  17. River piracy and drainage basin reorganization led by climate-driven glacier retreat

    Science.gov (United States)

    Shugar, Daniel H.; Clague, John J.; Best, James L.; Schoof, Christian; Willis, Michael J.; Copland, Luke; Roe, Gerard H.

    2017-04-01

    River piracy--the diversion of the headwaters of one stream into another one--can dramatically change the routing of water and sediment, with a profound effect on landscape evolution. Stream piracy has been investigated in glacial environments, but so far it has mainly been studied over Quaternary or longer timescales. Here we document how retreat of Kaskawulsh Glacier--one of Canada's largest glaciers--abruptly and radically altered the regional drainage pattern in spring 2016. We use a combination of hydrological measurements and drone-generated digital elevation models to show that in late May 2016, meltwater from the glacier was re-routed from discharge in a northward direction into the Bering Sea, to southward into the Pacific Ocean. Based on satellite image analysis and a signal-to-noise ratio as a metric of glacier retreat, we conclude that this instance of river piracy was due to post-industrial climate change. Rapid regional drainage reorganizations of this type can have profound downstream impacts on ecosystems, sediment and carbon budgets, and downstream communities that rely on a stable and sustained discharge. We suggest that the planforms of Slims and Kaskawulsh rivers will adjust in response to altered flows, and the future Kaskawulsh watershed will extend into the now-abandoned headwaters of Slims River and eventually capture the Kluane Lake drainage.

  18. Ecosystem services and livelihoods - Vulnerability and adaption to a changing climate. VACCIA Synthesis Report

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, I.; Mattson, T.; Niemelae, E.; Vuorenmaa, J.; Forsius, M. (eds.)

    2011-12-15

    This report is a summary of results from the project Vulnerability Assessment of Ecosystem Services for Climate Change Impacts and Adaptation (VACCIA), funded by the European Union's LIFE+ programme. Partners in the extensive three-year (2009-2011) project, coordinated by the Finnish Environment Institute (SYKE), included the Finnish Meteorological Institute, the University of Helsinki, the University of Jyvaeskylae and the University of Oulu. Key results from the 13 VACCIA Actions are compiled in the summary. The Actions assessed the threats and challenges posed by climate change to ecosystem services and livelihoods, and suggested methods for adapting to changing conditions. The report also highlights further research needs. The publication's introduction describes the ecosystem service concept and provides an insight into policy processes for handling ecosystem services and their adaptation to a changing climate. Results of the Actions are assembled in the following three chapters, the first presenting key methods used in the project for monitoring changes and predicting future changes, the second describing the change in ecosystem services, and the third reviewing vulnerability and adaptation. An extensive summary section is also included. Annexed tables present the project's key results and conclusions compactly, alongside the resulting adaptation challenges and needs for further research. Monitoring and prediction of changes is based, e.g. on climate and air quality scenarios produced by the project, and remote sensing and geographic information materials. Of ecosystem services, those produced by catchments and water bodies are examined, alongside changes in the biodiversity of coastal, water and forest environments, studied with the help of sample species. Ecosystem services needed by urban areas are examined from the viewpoint of climate change and changes in land use. Among livelihoods, agriculture, forestry, fisheries and tourism are

  19. Ocean circulation and climate during the past 120,000 years

    Science.gov (United States)

    Rahmstorf, Stefan

    2002-09-01

    Oceans cover more than two-thirds of our blue planet. The waters move in a global circulation system, driven by subtle density differences and transporting huge amounts of heat. Ocean circulation is thus an active and highly nonlinear player in the global climate game. Increasingly clear evidence implicates ocean circulation in abrupt and dramatic climate shifts, such as sudden temperature changes in Greenland on the order of 5-10 °C and massive surges of icebergs into the North Atlantic Ocean - events that have occurred repeatedly during the last glacial cycle.

  20. Impact intensities of climatic changes on grassland ecosystems in ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-03-22

    Mar 22, 2012 ... Construction of the impact intensity model of climatic changes on grassland ecosystem ... the temperature and rainfall (Sun and Mu, 2011). Thus, the study ... of the equation, the study transformed the measurement unit Mu of.

  1. Climate Change Altered Disturbance Regimes in High Elevation Pine Ecosystems

    Science.gov (United States)

    Logan, J. A.

    2004-12-01

    Insects in aggregate are the greatest cause of forest disturbance. Outbreaks of both native and exotic insects can be spectacular events in both their intensity and spatial extent. In the case of native species, forest ecosystems have co-evolved (or at least co-adapted) in ways that incorporate these disturbances into the normal cycle of forest maturation and renewal. The time frame of response to changing climate, however, is much shorter for insects (typically one year) than for their host forests (decades or longer). As a result, outbreaks of forest insects, particularly bark beetles, are occurring at unprecedented levels throughout western North America, resulting in the loss of biodiversity and potentially entire ecosystems. In this talk, I will describe one such ecosystem, the whitebark pine association at high elevations in the north-central Rocky Mountains of the United States. White bark pines are keystone species, which in consort with Clark's nutcracker, build entire ecosystems at high elevations. These ecosystems provide valuable ecological services, including the distribution and abundance of water resources. I will briefly describe the keystone nature of whitebark pine and the historic role of mountain pine beetle disturbance in these ecosystems. The mountain pine beetle is the most important outbreak insect in forests of the western United States. Although capable of spectacular outbreak events, in historic climate regimes, outbreak populations were largely restricted to lower elevation pines; for example, lodgepole and ponderosa pines. The recent series of unusually warm years, however, has allowed this insect to expand its range into high elevation, whitebark pine ecosystems with devastating consequences. The aspects of mountain pine beetle thermal ecology that has allowed it to capitalize so effectively on a warming climate will be discussed. A model that incorporates critical thermal attributes of the mountain pine beetle's life cycle was

  2. The influence of climate variability and change on the science and practice of restoration ecology

    Science.gov (United States)

    Donald A. Falk; Connie Millar

    2016-01-01

    Variation in Earth’s climate system has always been a primary driver of ecosystem processes and biological evolution. In recent decades, however, the prospect of anthropogenically driven change to the climate system has become an increasingly dominant concern for scientists and conservation biologists. Understanding how ecosystems may...

  3. The potential of Norwegian ecosystems for climate mitigation and adaptation

    Energy Technology Data Exchange (ETDEWEB)

    Rusch, Graciela M.

    2012-07-01

    The concept of ecosystem services encompasses the many benefits that society receives from nature and that are often taken for granted. The conceptual framework highlights the connection between ecosystems and its components, and human well-being, and aims to complement current conservation measures and practices which have turned to be insufficient to achieve the 2010 targets of controlling the drivers of biodiversity loss. Ecosystem services are the aspects of nature that society uses, consumes, or enjoys. In some cases, i.e. when individuals or the society make choices that imply the allocation of resources, the benefits from nature have an economic dimension and can potentially be attached an economic value. At the same time many other aspects of nature are valuable but cannot be valued in an economic sense because they are not associated with social or individual economic choices. This report is about some of the benefits that society receives form nature and that are linked with the challenges that society faces regarding climate change. Two areas in which nature brings benefits to society are highlighted and supported with examples which show the ecological and biological characteristics and processes that underpin the level of service supply. The first one is associated with the capacity of nature to counteract or mitigate the increase in global greenhouse gas emissions. This benefit is ultimately delivered by the growth of plants and the processes that accumulate carbon in biomass and in the soil. In addition, natural vegetation and undisturbed soil in terrestrial ecosystems form large reservoirs of carbon that are released as carbon dioxide when the vegetation cover and the soil are transformed through burning, tillage and draining, or through soil erosion. A second group of benefits is related to the capacity of nature to buffer against hazards produced by climatic extremes, for example, events with high rainfall which are often the cause of floods and

  4. Ecohydrology of adjacent sagebrush and lodgepole pine ecosystems: the consequences of climate change and disturbance

    Science.gov (United States)

    Bradford, John B.; Schlaepfer, Daniel R.; Lauenroth, William K.

    2014-01-01

    Sagebrush steppe and lodgepole pine forests are two of the most widespread vegetation types in the western United States and they play crucial roles in the hydrologic cycle of these water-limited regions. We used a process-based ecosystem water model to characterize the potential impact of climate change and disturbance (wildfire and beetle mortality) on water cycling in adjacent sagebrush and lodgepole pine ecosystems. Despite similar climatic and topographic conditions between these ecosystems at the sites examined, lodgepole pine, and sagebrush exhibited consistent differences in water balance, notably more evaporation and drier summer soils in the sagebrush and greater transpiration and less water yield in lodgepole pine. Canopy disturbances (either fire or beetle) have dramatic impacts on water balance and availability: reducing transpiration while increasing evaporation and water yield. Results suggest that climate change may reduce snowpack, increase evaporation and transpiration, and lengthen the duration of dry soil conditions in the summer, but may have uncertain effects on drainage. Changes in the distribution of sagebrush and lodgepole pine ecosystems as a consequence of climate change and/or altered disturbance regimes will likely alter ecosystem water balance.

  5. Adaptation of Australia’s Marine Ecosystems to Climate Change: Using Science to Inform Conservation Management

    Directory of Open Access Journals (Sweden)

    Johanna E. Johnson

    2014-01-01

    Full Text Available The challenges that climate change poses for marine ecosystems are already manifesting in impacts at the species, population, and community levels in Australia, particularly in Tasmania and tropical northern Australia. Many species and habitats are already under threat as a result of human activities, and the additional pressure from climate change significantly increases the challenge for marine conservation and management. Climate change impacts are expected to magnify as sea surface temperatures, ocean chemistry, ocean circulation, sea level, rainfall, and storm patterns continue to change this century. In particular, keystone species that form the foundation of marine habitats, such as coral reefs, kelp beds, and temperate rocky reefs, are projected to pass thresholds with subsequent implications for communities and ecosystems. This review synthesises recent science in this field: the observed impacts and responses of marine ecosystems to climate change, ecological thresholds of change, and strategies for marine conservation to promote adaptation. Increasing observations of climate-related impacts on Australia’s marine ecosystems—both temperate and tropical—are making adaptive management more important than ever before. Our increased understanding of the impacts and responses of marine ecosystems to climate change provides a focus for “no-regrets” adaptations that can be implemented now and refined as knowledge improves.

  6. Assessing climate change effects on mountain ecosystems using integrated models: A case study

    Science.gov (United States)

    Fagre, Daniel B.; Running, Steven W.; Keane, Robert E.; Peterson, David L.

    2005-01-01

    Mountain systems are characterized by strong environmental gradients, rugged topography and extreme spatial heterogeneity in ecosystem structure and composition. Consequently, most mountainous areas have relatively high rates of endemism and biodiversity, and function as species refugia in many areas of the world. Mountains have long been recognized as critical entities in regional climatic and hydrological dynamics but their importance as terrestrial carbon stores has only been recently underscored (Schimel et al. 2002; this volume). Mountain ecosystems, therefore, are globally important as well as unusually complex. These ecosystems challenge our ability to understand their dynamics and predict their response to climatic variability and global-scale environmental change.

  7. Climate Extremes and Land-Use Change: Effects on Ecosystem Processes and Services

    Science.gov (United States)

    Bahn, Michael; Erb, Karlheinz; Hasibeder, Roland; Mayr, Stefan; Niedertscheider, Maria; Oberhuber, Walter; Tappeiner, Ulrike; Tasser, Erich; Viovy, Nicolas; Wieser, Gerhard

    2016-04-01

    Extreme climatic events, in particular droughts and heatwaves, have significant impacts on ecosystem carbon and water cycles and a range of related ecosystem services. It is expected that in the coming decades the return intervals and severities of extreme droughts will increase substantially and may result in the passing of thresholds of ecosystem functioning, potentially causing legacy effects, which are so far poorly understood. Observational evidence suggests that different land cover types (forest, grassland) are differently influenced by extreme drought, but there is a lack of knowledge whether and how future, increasingly severe climate extremes will affect their concurrent and lagged responses, as well as land-use decisions determining future shifts in land cover. The ClimLUC project aims to understand how extreme summer drought affects carbon and water dynamics of mountain ecosystems under different land uses, and to analyse implications for ecosystem service provisioning. Overall, we hypothesize that land-use change alters the effects of extreme summer drought on ecosystem processes and the related services, grassland responding more rapidly and strongly but being more resilient to extreme drought than forest. To address the aims and hypotheses, we will 1) test experimentally how (a) a managed, (b) an abandoned mountain grassland and (c) an adjacent subalpine forest respond to a progressive extreme drought and will analyse threshold responses of carbon and water dynamics and their implications for ecosystem services (timber and fodder production, carbon sequestration, water provisioning); 2) quantify carry-over effects of the extreme event on ecosystem processes and services; 3) project and attribute future carbon and water cycle responses to extreme drought and related socio-economic changes, based on a process-based dynamic general vegetation model; 4) analyse the interrelation between land-use changes and the occurrence and severity of past and future

  8. Evaluation of the significance of abrupt changes in precipitation and runoff process in China

    Science.gov (United States)

    Xie, Ping; Wu, Ziyi; Sang, Yan-Fang; Gu, Haiting; Zhao, Yuxi; Singh, Vijay P.

    2018-05-01

    Abrupt changes are an important manifestation of hydrological variability. How to accurately detect the abrupt changes in hydrological time series and evaluate their significance is an important issue, but methods for dealing with them effectively are lacking. In this study, we propose an approach to evaluate the significance of abrupt changes in time series at five levels: no, weak, moderate, strong, and dramatic. The approach was based on an index of correlation coefficient calculated for the original time series and its abrupt change component. A bigger value of correlation coefficient reflects a higher significance level of abrupt change. Results of Monte-Carlo experiments verified the reliability of the proposed approach, and also indicated the great influence of statistical characteristics of time series on the significance level of abrupt change. The approach was derived from the relationship between correlation coefficient index and abrupt change, and can estimate and grade the significance levels of abrupt changes in hydrological time series. Application of the proposed approach to ten major watersheds in China showed that abrupt changes mainly occurred in five watersheds in northern China, which have arid or semi-arid climate and severe shortages of water resources. Runoff processes in northern China were more sensitive to precipitation change than those in southern China. Although annual precipitation and surface water resources amount (SWRA) exhibited a harmonious relationship in most watersheds, abrupt changes in the latter were more significant. Compared with abrupt changes in annual precipitation, human activities contributed much more to the abrupt changes in the corresponding SWRA, except for the Northwest Inland River watershed.

  9. A decade of sea level rise slowed by climate-driven hydrology.

    Science.gov (United States)

    Reager, J T; Gardner, A S; Famiglietti, J S; Wiese, D N; Eicker, A; Lo, M-H

    2016-02-12

    Climate-driven changes in land water storage and their contributions to sea level rise have been absent from Intergovernmental Panel on Climate Change sea level budgets owing to observational challenges. Recent advances in satellite measurement of time-variable gravity combined with reconciled global glacier loss estimates enable a disaggregation of continental land mass changes and a quantification of this term. We found that between 2002 and 2014, climate variability resulted in an additional 3200 ± 900 gigatons of water being stored on land. This gain partially offset water losses from ice sheets, glaciers, and groundwater pumping, slowing the rate of sea level rise by 0.71 ± 0.20 millimeters per year. These findings highlight the importance of climate-driven changes in hydrology when assigning attribution to decadal changes in sea level. Copyright © 2016, American Association for the Advancement of Science.

  10. Climate change on arctic environment, ecosystem services and society (CLICHE)

    Science.gov (United States)

    Weckström, J.; Korhola, A.; Väliranta, M.; Seppä, H.; Luoto, M.; Tuittila, E.-S.; Leppäranta, M.; Kahilainen, K.; Saarinen, J.; Heikkinen, H.

    2012-04-01

    The predicted climate warming has raised many questions and concerns about its impacts on the environment and society. As a respond to the need of holistic studies comprising both of these areas, The Academy of Finland launched The Finnish Research Programme on Climate Change (FICCA 2011-2014) in spring 2010 with the main aim to focus on the interaction between the environment and society. Ultimately 11 national consortium projects were funded (total budget 12 million EUR). Here we shortly present the main objectives of the largest consortium project "Climate change on arctic environment, ecosystem services and society" (CLICHE). The CLICHE consortium comprises eight interrelated work packages (treeline, diversity, peatlands, snow, lakes, fish, tourism, and traditional livelihoods), each led by a prominent research group and a team leader. The research consortium has three main overall objectives: 1) Investigate, map and model the past, present and future climate change-induced changes in central ecosystems of the European Arctic with unprecedented precision 2) Deepen our understanding of the basic principles of ecosystem and social resilience and dynamics; identify key taxa, structures or processes that clearly indicate impending or realised global change through their loss, occurrence or behaviour, using analogues from the past (e.g. Holocene Thermal Maximum, Medieval Warm Period), experiments, observations and models 3) Develop adaptation and mitigation strategies to minimize the adverse effects of climate change on local communities, traditional livelihoods, fisheries, and tourism industry, and promote sustainable development of local community structures and enhance the quality of life of local human populations. As the project has started only recently no final results are available yet. However, the fieldwork as well as the co-operation between the research teams has thus far been very successful. Thus, the expectations for the final outcome of the project

  11. Regime shifts and resilience in China's coastal ecosystems.

    Science.gov (United States)

    Zhang, Ke

    2016-02-01

    Regime shift often results in large, abrupt, and persistent changes in the provision of ecosystem services and can therefore have significant impacts on human wellbeing. Understanding regime shifts has profound implications for ecosystem recovery and management. China's coastal ecosystems have experienced substantial deterioration within the past decades, at a scale and speed the world has never seen before. Yet, information about this coastal ecosystem change from a dynamics perspective is quite limited. In this review, I synthesize existing information on coastal ecosystem regime shifts in China and discuss their interactions and cascading effects. The accumulation of regime shifts in China's coastal ecosystems suggests that the desired system resilience has been profoundly eroded, increasing the potential of abrupt shifts to undesirable states at a larger scale, especially given multiple escalating pressures. Policy and management strategies need to incorporate resilience approaches in order to cope with future challenges and avoid major losses in China's coastal ecosystem services.

  12. Climatic and pollution influences on ecosystem processes in northern hardwood forests

    Science.gov (United States)

    Kurt S. Pregitzer; David D. Reed; Glenn D. Mroz; Andrew J. Burton; John A. Witter; Donald A. Zak

    1996-01-01

    The Michigan gradient study was established in 1987 to examine the effects of climate and atmospheric deposition on forest productivity and ecosystem processes in the Great Lakes region. Four intensively-monitored northern hardwood study sites are located along a climatic and pollutant gradient extending from southern lower Michigan to northwestern upper Michigan. The...

  13. Regionalizing indicators for marine ecosystems: Bering Sea–Aleutian Island seabirds, climate, and competitors

    Science.gov (United States)

    Sydeman, William J.; Thompson, Sarah Ann; Piatt, John F.; García-Reyes, Marisol; Zador, Stephani; Williams, Jeffrey C.; Romano, Marc; Renner, Heather

    2017-01-01

    Seabirds are thought to be reliable, real-time indicators of forage fish availability and the climatic and biotic factors affecting pelagic food webs in marine ecosystems. In this study, we tested the hypothesis that temporal trends and interannual variability in seabird indicators reflect simultaneously occurring bottom-up (climatic) and competitor (pink salmon) forcing of food webs. To test this hypothesis, we derived multivariate seabird indicators for the Bering Sea–Aleutian Island (BSAI) ecosystem and related them to physical and biological conditions known to affect pelagic food webs in the ecosystem. We examined covariance in the breeding biology of congeneric pelagic gulls (kittiwakes Rissa tridactyla and R. brevirostris) andauks (murres Uria aalge and U. lomvia), all of whichare abundant and well-studiedinthe BSAI. At the large ecosystem scale, kittiwake and murre breeding success and phenology (hatch dates) covaried among congeners, so data could be combined using multivariate techniques, but patterns of responsedifferedsubstantially betweenthe genera.Whiledata fromall sites (n = 5)inthe ecosystemcould be combined, the south eastern Bering Sea shelf colonies (St. George, St. Paul, and Cape Peirce) provided the strongest loadings on indicators, and hence had the strongest influence on modes of variability. The kittiwake breeding success mode of variability, dominated by biennial variation, was significantly related to both climatic factors and potential competitor interactions. The murre indicator mode was interannual and only weakly related to the climatic factors measured. The kittiwake phenology indicator mode of variability showed multi-year periods (“stanzas”) of late or early breeding, while the murre phenology indicator showed a trend towards earlier timing. Ocean climate relationships with the kittiwake breeding success indicator suggestthat early-season (winter–spring) environmental conditions and the abundance of pink salmon affect the

  14. Combined effects of climate and land-use change on the provision of ecosystem services in rice agro-ecosystems

    Science.gov (United States)

    Langerwisch, Fanny; Václavík, Tomáš; von Bloh, Werner; Vetter, Tobias; Thonicke, Kirsten

    2018-01-01

    Irrigated rice croplands are among the world’s most important agro-ecosystems. They provide food for more than 3.5 billion people and a range of other ecosystem services (ESS). However, the sustainability of rice agro-ecosystems is threatened by continuing climate and land-use changes. To estimate their combined effects on a bundle of ESS, we applied the vegetation and hydrology model LPJmL to seven study areas in the Philippines and Vietnam. We quantified future changes in the provision of four essential ESS (carbon storage, carbon sequestration, provision of irrigation water and rice production) under two climate scenarios (until 2100) and three site-specific land-use scenarios (until 2030), and examined the synergies and trade-offs in ESS responses to these drivers. Our results show that not all services can be provided in the same amounts in the future. In the Philippines and Vietnam the projections estimated a decrease in rice yields (by approximately 30%) and in carbon storage (by 15%) and sequestration (by 12%) towards the end of the century under the current land-use pattern. In contrast, the amount of available irrigation water was projected to increase in all scenarios by 10%-20%. However, the results also indicate that land-use change may partially offset the negative climate impacts in regions where cropland expansion is possible, although only at the expense of natural vegetation. When analysing the interactions between ESS, we found consistent synergies between rice production and carbon storage and trade-offs between carbon storage and provision of irrigation water under most scenarios. Our results show that not only the effects of climate and land-use change alone but also the interaction between ESS have to be considered to allow sustainable management of rice agro-ecosystems under global change.

  15. Ecosystem vulnerability assessment and synthesis: a report from the Climate Change Response Framework Project in northern Wisconsin

    Science.gov (United States)

    Chris Swanston; Maria Janowiak; Louis Iverson; Linda Parker; David Mladenoff; Leslie Brandt; Patricia Butler; Matt St. Pierre; Anantha Prasad; Stephen Matthews; Matthew Peters; Dale Higgins; Avery Dorland

    2011-01-01

    The forests of northern Wisconsin will likely experience dramatic changes over the next 100 years as a result of climate change. This assessment evaluates key forest ecosystem vulnerabilities to climate change across northern Wisconsin under a range of future climate scenarios. Warmer temperatures and shifting precipitation patterns are expected to influence ecosystem...

  16. Scales and sources of pH and dissolved oxygen variability in a shallow, upwelling-driven ecosystem

    Science.gov (United States)

    Tanner, C. A.; Martz, T.; Levin, L. A.

    2011-12-01

    In the coastal zone extreme variability in carbonate chemistry and oxygen is driven by fluctuations in temperature, salinity, air-sea gas exchange, mixing processes, and biology. This variability appears to be magnified in upwelling-driven ecosystems where low oxygen and low pH waters intrude into shallow depths. The oxygen and carbon chemistry signal can be further confounded by highly productive ecosystems such as kelp beds where photosynthesis and respiration consume and release significant amounts of dissolved inorganic carbon and oxygen. This variability poses a challenge for scientists assessing the impacts of climate change on nearshore ecosystems. We deployed physical & biogeochemical sensors in order to observe these processes in situ. The "SeapHOx" instruments used in this study consist of a modified Honeywell Durafet° ISFET pH sensor, an Aanderra Optode Oxygen sensor, and a SBE-37 conductivity, temperature, pressure sensor. The instruments were deployed on and around the La Jolla Kelp Forest at a variety of depths. Our goals were to (a) characterize the link between pH and oxygen and identify the magnitude of pH and oxygen variability over a range of intra-annual time scales and (b) investigate spatial patterns of pH and oxygen variability associated with depth, proximity to shore, and presence of kelp. Results thus far reveal a strong relationship between oxygen and pH. Temporal variability is greatest at the semidiurnal frequency where pH (at 7 m) can range up to 0.3 units and oxygen can change 50% over 6 h. Diurnal variability is a combination of the diurnal tidal component and diel cycles of production and respiration. Event-scale dynamics associated with upwelling can maintain pH and oxygen below 7.8 units and 200 μmol kg-1, respectively, for multiple days. Frequent current reversals drive changes in the observed oxygen and pH variability. When alongshore currents are flowing southward, driven by upwelling-favorable winds, the magnitude of

  17. Climate change impact on a groundwater-influenced hillslope ecosystem

    NARCIS (Netherlands)

    Brolsma, R.J.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2010-01-01

    This study investigates the effect of climate change on a groundwater‐influenced ecosystem on a hill slope consisting of two vegetation types, one adapted to wet and one adapted to dry soil conditions. The individual effects of changes in precipitation, temperature, and atmospheric CO2

  18. Effects of the global changes on the aquatic ecosystems in West Europe - role of the plankton communities

    International Nuclear Information System (INIS)

    Souissi, S.

    2007-01-01

    Examination of long-term records of aquatic ecosystems has provided useful information to find out their major driving forces. Understanding the impact of climate change on these ecosystems, the management of their resources and the extrapolation between sites are the main scopes of actual and emerging studies. Such goals can be achieved by inter-site and inter-ecosystem comparisons. This approach was undertaken during our project which has the originality to tackle with marine and freshwater ecosystems. It allowed us to compile and validate several multi-decadal time series of planktonic and other physical driving forces at local and regional scales. Then, the same methodology based on the analysis of the variability of climate indices and biological data across several spatial scales was used. The different ecosystems analyzed here showed clear response to the North Atlantic climate variability. Although the local differences abrupt changes in community composition occurred in all ecosystems in the middle of the years 80. During this period there was also a major shift in climatic conditions during winter and early spring, suggesting an impact of climatic factors. Phenological changes were also observed in plankton communities in all sites. The consequences of the modifications of plankton dynamics on higher trophic levels were also showed. Fluctuations in plankton have resulted in long-term changes in cod recruitment in the North Sea (bottom-up control). On the other hand, both climate change and the improvement of trophic status in Geneva Lake favored the outbreak of whitefish during the years 90. Lower larval mortality and better recruitment are supposed to be linked to faster growth associated with warmer temperatures and better food conditions induced by better temporal overlap between larvae hatching and zooplankton development. (author)

  19. Major threats of pollution and climate change to global coastal ecosystems and enhanced management for sustainability.

    Science.gov (United States)

    Lu, Yonglong; Yuan, Jingjing; Lu, Xiaotian; Su, Chao; Zhang, Yueqing; Wang, Chenchen; Cao, Xianghui; Li, Qifeng; Su, Jilan; Ittekkot, Venugopalan; Garbutt, Richard Angus; Bush, Simon; Fletcher, Stephen; Wagey, Tonny; Kachur, Anatolii; Sweijd, Neville

    2018-08-01

    Coastal zone is of great importance in the provision of various valuable ecosystem services. However, it is also sensitive and vulnerable to environmental changes due to high human populations and interactions between the land and ocean. Major threats of pollution from over enrichment of nutrients, increasing metals and persistent organic pollutants (POPs), and climate change have led to severe ecological degradation in the coastal zone, while few studies have focused on the combined impacts of pollution and climate change on the coastal ecosystems at the global level. A global overview of nutrients, metals, POPs, and major environmental changes due to climate change and their impacts on coastal ecosystems was carried out in this study. Coasts of the Eastern Atlantic and Western Pacific were hotspots of concentrations of several pollutants, and mostly affected by warming climate. These hotspots shared the same features of large populations, heavy industry and (semi-) closed sea. Estimation of coastal ocean capital, integrated management of land-ocean interaction in the coastal zone, enhancement of integrated global observation system, and coastal ecosystem-based management can play effective roles in promoting sustainable management of coastal marine ecosystems. Enhanced management from the perspective of mitigating pollution and climate change was proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Are abrupt climate changes predictable?

    Science.gov (United States)

    Ditlevsen, Peter

    2013-04-01

    It is taken for granted that the limited predictability in the initial value problem, the weather prediction, and the predictability of the statistics are two distinct problems. Lorenz (1975) dubbed this predictability of the first and the second kind respectively. Predictability of the first kind in a chaotic dynamical system is limited due to the well-known critical dependence on initial conditions. Predictability of the second kind is possible in an ergodic system, where either the dynamics is known and the phase space attractor can be characterized by simulation or the system can be observed for such long times that the statistics can be obtained from temporal averaging, assuming that the attractor does not change in time. For the climate system the distinction between predictability of the first and the second kind is fuzzy. This difficulty in distinction between predictability of the first and of the second kind is related to the lack of scale separation between fast and slow components of the climate system. The non-linear nature of the problem furthermore opens the possibility of multiple attractors, or multiple quasi-steady states. As the ice-core records show, the climate has been jumping between different quasi-stationary climates, stadials and interstadials through the Dansgaard-Oechger events. Such a jump happens very fast when a critical tipping point has been reached. The question is: Can such a tipping point be predicted? This is a new kind of predictability: the third kind. If the tipping point is reached through a bifurcation, where the stability of the system is governed by some control parameter, changing in a predictable way to a critical value, the tipping is predictable. If the sudden jump occurs because internal chaotic fluctuations, noise, push the system across a barrier, the tipping is as unpredictable as the triggering noise. In order to hint at an answer to this question, a careful analysis of the high temporal resolution NGRIP isotope

  1. Adaptation approaches for conserving ecosystems services and biodiversity in dynamic landscapes caused by climate change

    Science.gov (United States)

    Oswald J. Schmitz; Anne M. Trainor

    2014-01-01

    Climate change stands to cause animal species to shift their geographic ranges. This will cause ecosystems to become reorganized across landscapes as species migrate into and out of specific locations with attendant impacts on values and services that ecosystems provide to humans. Conservation in an era of climate change needs to ensure that landscapes are resilient by...

  2. The role of the Asian winter monsoon in the rapid propagation of abrupt climate changes during the last deglaciation

    Science.gov (United States)

    Chu, Guoqiang; Sun, Qing; Zhu, Qingzeng; Shan, Yabing; Shang, Wenyu; Ling, Yuan; Su, Youliang; Xie, Manman; Wang, Xishen; Liu, Jiaqi

    2017-12-01

    High-resolution temperature records spanning the last deglaciation from low latitudes are scarce; however, they are important for understanding the rapid propagation of abrupt climate events throughout the Northern Hemisphere and the tropics. Here, we present a branched GDGTs-based temperature reconstruction from the sediments of Maar Lake Huguangyan in tropical China. The record reveals that the mean temperature during the Oldest Dryas was 17.8 °C, which was followed by a two-step increase of 2-3 °C to the Bølling-Allerød, a decrease to 19.8 °C during the Younger Dryas, and a rapid warming at the onset of the Holocene. The Oldest Dryas was about 2 °C warmer than the Younger Dryas. The reconstructed temperature was weighted towards the wintertime since the lake is monomictic and the mixing process in winter supplies nutrients from the lake bottom to the entire water column, greatly promoting biological productivity. In addition, the winter-biased temperature changes observed in the study are more distinctive than the summer-biased temperature records from extra-tropical regions of East Asia. This implies that the temperature decreases during abrupt climatic events were mainly a winter phenomenon. Within the limits of the dating uncertainties, the broadly similar pattern of winter-weighted temperature change observed in both tropical Lake Huguangyan and in Greenland ice cores indicates the occurrence of tightly-coupled interactions between high latitude ice sheets and land areas in the tropics. We suggest that the winter monsoon (especially cold surges) could play an important role in the rapid transmission of the temperature signal from the Arctic to the tropics.

  3. Bridging the Divide: Linking Genomics to Ecosystem Responses to Climate Change: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Melinda D.

    2014-03-15

    Over the project period, we have addressed the following objectives: 1) assess the effects of altered precipitation patterns (i.e., increased variability in growing season precipitation) on genetic diversity of the dominant C4 grass species, Andropogon gerardii, and 2) experimentally assess the impacts of extreme climatic events (heat wave, drought) on responses of the dominant C4 grasses, A. gerardii and Sorghastrum nutans, and the consequences of these response for community and ecosystem structure and function. Below is a summary of how we have addressed these objectives. Objective 1 After ten years of altered precipitation, we found the number of genotypes of A. gerardii was significantly reduced compared to the ambient precipitation treatments (Avolio et al., 2013a). Although genotype number was reduced, the remaining genotypes were less related to one another indicating that the altered precipitation treatment was selecting for increasingly dissimilar genomes (based on mean pairwise Dice distance among individuals). For the four key genotypes that displayed differential abundances depending on the precipitation treatment (G1, G4, and G11 in the altered plots and G2 in the ambient plots), we identified phenotypic differences in the field that could account for ecological sorting (Avolio & Smith, 2013a). The three altered rainfall genotypes also have very different phenotypic traits in the greenhouse in response to different soil moisture availabilities (Avolio and Smith, 2013c). Two of the genotypes that increased in abundance in the altered precipitation plots had greater allocation to root biomass (G4 and G11), while G1 allocated more biomass aboveground. These phenotypic differences among genotypes suggests that changes in genotypic structure between the altered and the ambient treatments has likely occurred via niche differentiation, driven by changes in soil moisture dynamics (reduced mean, increased variability and changes in the depth distribution of

  4. Integrating Science and Management to Assess Forest Ecosystem Vulnerability to Climate Change

    Science.gov (United States)

    Leslie A. Brandt; Patricia R. Butler; Stephen D. Handler; Maria K. Janowiak; P. Danielle Shannon; Christopher W. Swanston

    2017-01-01

    We developed the ecosystem vulnerability assessment approach (EVAA) to help inform potential adaptation actions in response to a changing climate. EVAA combines multiple quantitative models and expert elicitation from scientists and land managers. In each of eight assessment areas, a panel of local experts determined potential vulnerability of forest ecosystems to...

  5. Response of the mean global vegetation distribution to interannual climate variability

    Energy Technology Data Exchange (ETDEWEB)

    Notaro, Michael [University of Wisconsin-Madison, Center for Climatic Research, Madison, WI (United States)

    2008-06-15

    The impact of interannual variability in temperature and precipitation on global terrestrial ecosystems is investigated using a dynamic global vegetation model driven by gridded climate observations for the twentieth century. Contrasting simulations are driven either by repeated mean climatology or raw climate data with interannual variability included. Interannual climate variability reduces net global vegetation cover, particularly over semi-arid regions, and favors the expansion of grass cover at the expense of tree cover, due to differences in growth rates, fire impacts, and interception. The area burnt by global fires is substantially enhanced by interannual precipitation variability. The current position of the central United States' ecotone, with forests to the east and grasslands to the west, is largely attributed to climate variability. Among woody vegetation, climate variability supports expanded deciduous forest growth and diminished evergreen forest growth, due to difference in bioclimatic limits, leaf longevity, interception rates, and rooting depth. These results offer insight into future ecosystem distributions since climate models generally predict an increase in climate variability and extremes. (orig.)

  6. Climate change impact on a groundwater-influenced hillslope ecosystem

    NARCIS (Netherlands)

    Brolsma, R.J.; Vliet, van M.T.H.; Bierkens, M.F.P.

    2010-01-01

    This study investigates the effect of climate change on a groundwater-influenced ecosystem on a hill slope consisting of two vegetation types, one adapted to wet and one adapted to dry soil conditions. The individual effects of changes in precipitation, temperature, and atmospheric CO2 concentration

  7. Forest ecosystems and the global climatic change. Background and need to act

    International Nuclear Information System (INIS)

    Bellmann, K.; Grassl, H.; Kaiser, M.; Kuerzinger, J.; Lindner, M.; Mueller-Kraenner, S.; Schmidt, R.; Schuett, P.; Sperber, G.

    1994-01-01

    The consequences of the climatic change and of the depletion of the stratospheric ozone layer are of global significance and can only be controlled through worldwide measures. Mainly fossil fuels which cover most of our energy demand, industrial production, traffic, industrial intensive agriculture, and deforestation are responsible for trace gases which cause the greenhouse effect. The possible effects of the expected climatic change are discussed, and suitable political, social and silvicultural approaches to the maintenance of stable forest ecosystems are pointed out. Emphasis is placed on forestry and on ecosystems research in Central Europe. (MG) [de

  8. Assessment of vulnerability of forest ecosystems to climate change and adaptation planning in Nepal

    Science.gov (United States)

    Matin, M. A.; Chitale, V. S.

    2016-12-01

    Understanding ecosystem level vulnerability of forests and dependence of local communities on these ecosystems is a first step towards developing effective adaptation strategies. As forests are important components of livelihoods system for a large percentage of the population in the Himalayan region, they offer an important basis for creating and safeguarding more climate-resilient communities. Increased frequency, duration, and/or severity of drought and heat stress, changes in winter ecology, and pest and fire outbreaksunder climate change scenarios could fundamentally alter the composition, productivity and biogeography of forests affecting the potential ecosystem services offered and forest-based livelihoods. Hence, forest ecosystem vulnerability assessment to climate change and the development of a knowledgebase to identify and support relevant adaptation strategies is identified as an urgent need. Climate change vulnerability is measured as a function of exposure, sensitivity and the adaptive capacity of the system towards climate variability and extreme events. Effective adaptation to climate change depends on the availability of two important prerequisites: a) information on what, where, and how to adapt, and b) availability of resources to implement the adaptation measures. In the present study, we introduce the concept of two way multitier approach, which can support effective identification and implementation of adaptation measures in Nepal and the framework can be replicated in other countries in the HKH region. The assessment of overall vulnerability of forests comprises of two components: 1) understanding the relationship between exposure and sensitivity and positive feedback from adaptive capacity of forests; 2) quantifying the dependence of local communities on these ecosystems. We use climate datasets from Bioclim and biophysical products from MODIS, alongwith field datasets. We report that most of the forests along the high altitude areas and few

  9. Ecosystem biophysical memory in the southwestern North America climate system

    International Nuclear Information System (INIS)

    Forzieri, G; Feyen, L; Vivoni, E R

    2013-01-01

    To elucidate the potential role of vegetation to act as a memory source in the southwestern North America climate system, we explore correlation structures of remotely sensed vegetation dynamics with precipitation, temperature and teleconnection indices over 1982–2006 for six ecoregions. We found that lagged correlations between vegetation dynamics and climate variables are modulated by the dominance of monsoonal or Mediterranean regimes and ecosystem-specific physiological processes. Subtropical and tropical ecosystems exhibit a one month lag positive correlation with precipitation, a zero- to one-month lag negative correlation with temperature, and modest negative effects of sea surface temperature (SST). Mountain forests have a zero month lag negative correlation with precipitation, a zero–one month lag negative correlation with temperature, and no significant correlation with SSTs. Deserts show a strong one–four month lag positive correlation with precipitation, a low zero–two month lag negative correlation with temperature, and a high four–eight month lag positive correlation with SSTs. The ecoregion-specific biophysical memories identified offer an opportunity to improve the predictability of land–atmosphere interactions and vegetation feedbacks onto climate. (letter)

  10. Projected future climate change and Baltic Sea ecosystem management.

    Science.gov (United States)

    Andersson, Agneta; Meier, H E Markus; Ripszam, Matyas; Rowe, Owen; Wikner, Johan; Haglund, Peter; Eilola, Kari; Legrand, Catherine; Figueroa, Daniela; Paczkowska, Joanna; Lindehoff, Elin; Tysklind, Mats; Elmgren, Ragnar

    2015-06-01

    Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 °C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase ~30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.

  11. Solutions for ecosystem-level protection of ocean systems under climate change.

    Science.gov (United States)

    Queirós, Ana M; Huebert, Klaus B; Keyl, Friedemann; Fernandes, Jose A; Stolte, Willem; Maar, Marie; Kay, Susan; Jones, Miranda C; Hamon, Katell G; Hendriksen, Gerrit; Vermard, Youen; Marchal, Paul; Teal, Lorna R; Somerfield, Paul J; Austen, Melanie C; Barange, Manuel; Sell, Anne F; Allen, Icarus; Peck, Myron A

    2016-12-01

    The Paris Conference of Parties (COP21) agreement renewed momentum for action against climate change, creating the space for solutions for conservation of the ocean addressing two of its largest threats: climate change and ocean acidification (CCOA). Recent arguments that ocean policies disregard a mature conservation research field and that protected areas cannot address climate change may be oversimplistic at this time when dynamic solutions for the management of changing oceans are needed. We propose a novel approach, based on spatial meta-analysis of climate impact models, to improve the positioning of marine protected areas to limit CCOA impacts. We do this by estimating the vulnerability of ocean ecosystems to CCOA in a spatially explicit manner and then co-mapping human activities such as the placement of renewable energy developments and the distribution of marine protected areas. We test this approach in the NE Atlantic considering also how CCOA impacts the base of the food web which supports protected species, an aspect often neglected in conservation studies. We found that, in this case, current regional conservation plans protect areas with low ecosystem-level vulnerability to CCOA, but disregard how species may redistribute to new, suitable and productive habitats. Under current plans, these areas remain open to commercial extraction and other uses. Here, and worldwide, ocean conservation strategies under CCOA must recognize the long-term importance of these habitat refuges, and studies such as this one are needed to identify them. Protecting these areas creates adaptive, climate-ready and ecosystem-level policy options for conservation, suitable for changing oceans. © 2016 John Wiley & Sons Ltd.

  12. Global comparison reveals biogenic weathering as driven by nutrient limitation at ecosystem scale

    Science.gov (United States)

    Boy, Jens; Godoy, Roberto; Dechene, Annika; Shibistova, Olga; Amir, Hamid; Iskandar, Issi; Fogliano, Bruno; Boy, Diana; McCulloch, Robert; Andrino, Alberto; Gschwendtner, Silvia; Marin, Cesar; Sauheitl, Leopold; Dultz, Stefan; Mikutta, Robert; Guggenberger, Georg

    2017-04-01

    A substantial contribution of biogenic weathering in ecosystem nutrition, especially by symbiotic microorganisms, has often been proposed, but large-scale in vivo studies are still missing. Here we compare a set of ecosystems spanning from the Antarctic to tropical forests for their potential biogenic weathering and its drivers. To address biogenic weathering rates, we installed mineral mesocosms only accessible for bacteria and fungi for up to 4 years, which contained freshly broken and defined nutrient-baring minerals in soil A horizons of ecosystems along a gradient of soil development differing in climate and plant species communities. Alterations of the buried minerals were analyzed by grid-intersection, confocal lascer scanning microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy on the surface and on thin sections. On selected sites, carbon fluxes were tracked by 13C labeling, and microbial community was identified by DNA sequencing. In young ecosystems (protosoils) biogenic weathering is almost absent and starts after first carbon accumulation by aeolian (later litter) inputs and is mainly performed by bacteria. With ongoing soil development and appearance of symbiotic (mycorrhized) plants, nutrient availability in soil increasingly drove biogenic weathering, and fungi became the far more important players than bacteria. We found a close relation between fungal biogenic weathering and available potassium across all 16 forested sites in the study, regardless of the dominant mycorrhiza type (AM or EM), climate, and plant-species composition. We conclude that nutrient limitations at ecosystem scale are generally counteracted by adapted fungal biogenic weathering. The close relation between fungal weathering and plant-available nutrients over a large range of severely contrasting ecosystems points towards a direct energetic support of these weathering processes by the photoautotrophic community, making biogenic weathering a

  13. Plant trait-based models identify direct and indirect effects of climate change on bundles of grassland ecosystem services.

    Science.gov (United States)

    Lamarque, Pénélope; Lavorel, Sandra; Mouchet, Maud; Quétier, Fabien

    2014-09-23

    Land use and climate change are primary causes of changes in the supply of ecosystem services (ESs). Although the consequences of climate change on ecosystem properties and associated services are well documented, the cascading impacts of climate change on ESs through changes in land use are largely overlooked. We present a trait-based framework based on an empirical model to elucidate how climate change affects tradeoffs among ESs. Using alternative scenarios for mountain grasslands, we predicted how direct effects of climate change on ecosystems and indirect effects through farmers' adaptations are likely to affect ES bundles through changes in plant functional properties. ES supply was overall more sensitive to climate than to induced management change, and ES bundles remained stable across scenarios. These responses largely reflected the restricted extent of management change in this constrained system, which was incorporated when scaling up plot level climate and management effects on ecosystem properties to the entire landscape. The trait-based approach revealed how the combination of common driving traits and common responses to changed fertility determined interactions and tradeoffs among ESs.

  14. Assessment of long-term effects of climate change on biodiversity and vulnerability of terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Oene, H.; Berendse, F.; De Kovel, C.G.F. [Nature Consevation and Plant Ecology Group, Wageningen University, Wageningen (Netherlands); Alkemade, J.R.M.; Bakkenes, M.; Ihle, F. [National Institute of Public Health and the Environment RIVM, Bilthoven (Netherlands)

    1999-07-01

    The aim of this project was to analyze the effects of climatic change on plant species diversity and ecosystem functioning. The direct effects of climatic change on plant species diversity are analyzed using a species based probabilistic Model (EUROMOVE) that relates the probability of occurrence of ca 1400 European plant species to climatic variables as the mean temperature of the coldest month, the effective temperature sum, the annual precipitation, the annual potential and actual evapotranspiration, the length of the growing season, and the mean growing season temperature. The indirect effects of raised C0{sub 2} levels and increased temperatures on ecosystem functioning and the consequences of these indirect effects for plant diversity are analyzed by combining a mechanistic simulation model (NUCOM) with regression models. NUCOM predicts the effects of environmental changes on dominant plant species composition and ecosystem variables. The predicted ecosystem variables are linked to plant species diversity of subordinate species by regression models, using Ellenberg indices for N availability, soil acidity, soil moisture, and light intensity. With these two approaches, the consequences of climatic change scenarios (IPCC Baseline A, IPCC Stabilization 450) and N deposition scenarios (reduced, constant) are analyzed for Europe (EUROMOVE) and part of the Netherlands (NUCOM). The results showed that the direct effects of climatic change may have large impact on plant species diversity and distribution. The indirect effects of climatic change on plant diversity appeared minor but effects of changes in soil moisture are not included. Other environmental changes like eutrofication and human impact have large effect on ecosystem variables and plant species diversity. Reductions in nitrogen emission have a positive effect but take time to become apparent. 49 refs.

  15. Coastal Wetland Ecosystem Responses to Climate Change: the Role of Macroclimatic Drivers along the Northern Gulf of Mexico

    Science.gov (United States)

    Osland, M. J.; Enwright, N.; Day, R. H.; Gabler, C. A.; Stagg, C. L.; From, A. S.

    2014-12-01

    Across the globe, macroclimatic drivers greatly influence coastal wetland ecosystem structure and function. However, changing macroclimatic conditions are rarely incorporated into coastal wetland vulnerability assessments. Here, we quantify the influence of macroclimatic drivers upon coastal wetland ecosystems along the Northern Gulf of Mexico (NGOM) coast. From a global perspective, the NGOM coast provides several excellent opportunities to examine the effects of climate change upon coastal wetlands. The abundant coastal wetland ecosystems in the region span two major climatic gradients: (1) a winter temperature gradient that crosses temperate to tropical climatic zones; and (2) a precipitation gradient that crosses humid to semi-arid zones. We present analyses where we used geospatial data (historical climate, hydrology, and coastal wetland coverage) and field data (soil, elevation, and plant community composition and structure) to quantify climate-mediated ecological transitions. We identified winter climate and precipitation-based thresholds that separate mangrove forests from salt marshes and vegetated wetlands from unvegetated wetlands, respectively. We used simple distribution and abundance models to evaluate the potential ecological effects of alternative future climate change scenarios. Our results illustrate and quantify the importance of macroclimatic drivers and indicate that climate change could result in landscape-scale changes in coastal wetland ecosystem structure and function. These macroclimate-mediated ecological changes could affect the supply of some ecosystem goods and services as well as the resilience of these ecosystems to stressors, including accelerated sea level rise. Collectively, our findings highlight the importance of incorporating macroclimatic drivers within future-focused coastal wetland vulnerability assessments.

  16. Bottom-up effects of climate on fish populations: data from the Continuous Plankton Recorder

    DEFF Research Database (Denmark)

    Pitois, S.G.; Lynam, C.P.; Jansen, Teunis

    2012-01-01

    The Continuous Plankton Recorder (CPR) dataset on fish larvae has an extensive spatio-temporal coverage that allows the responses of fish populations to past changes in climate variability, including abrupt changes such as regime shifts, to be investigated. The newly available dataset offers...... in the plankton ecosystem, while the larvae of migratory species such as Atlantic mackerel responded more to hydrographic changes. Climate variability seems more likely to influence fish populations through bottom-up control via a cascading effect from changes in the North Atlantic Oscillation (NAO) impacting...... with fishing effects interacting with climate effects and this study supports furthering our under - standing of such interactions before attempting to predict how fish populations respond to climate variability...

  17. Climate regulates alpine lake ice cover phenology and aquatic ecosystem structure

    Science.gov (United States)

    Preston, Daniel L.; Caine, Nel; McKnight, Diane M.; Williams, Mark W.; Hell, Katherina; Miller, Matthew P.; Hart, Sarah J.; Johnson, Pieter T.J.

    2016-01-01

    High-elevation aquatic ecosystems are highly vulnerable to climate change, yet relatively few records are available to characterize shifts in ecosystem structure or their underlying mechanisms. Using a long-term dataset on seven alpine lakes (3126 to 3620 m) in Colorado, USA, we show that ice-off dates have shifted seven days earlier over the past 33 years and that spring weather conditions – especially snowfall – drive yearly variation in ice-off timing. In the most well-studied lake, earlier ice-off associated with increases in water residence times, thermal stratification, ion concentrations, dissolved nitrogen, pH, and chlorophyll-a. Mechanistically, low spring snowfall and warm temperatures reduce summer stream flow (increasing lake residence times) but enhance melting of glacial and permafrost ice (increasing lake solute inputs). The observed links among hydrological, chemical, and biological responses to climate factors highlight the potential for major shifts in the functioning of alpine lakes due to forecasted climate change.

  18. Impact of climatic change on alpine ecosystems: inference and prediction

    Directory of Open Access Journals (Sweden)

    Nigel G. Yoccoz

    2011-01-01

    Full Text Available Alpine ecosystems will be greatly impacted by climatic change, but other factors, such as land use and invasive species, are likely to play an important role too. Climate can influence ecosystems at several levels. We describe some of them, stressing methodological approaches and available data. Climate can modify species phenology, such as flowering date of plants and hatching date in insects. It can also change directly population demography (survival, reproduction, dispersal, and therefore species distribution. Finally it can effect interactions among species – snow cover for example can affect the success of some predators. One characteristic of alpine ecosystems is the presence of snow cover, but surprisingly the role played by snow is relatively poorly known, mainly for logistical reasons. Even if we have made important progress regarding the development of predictive models, particularly so for distribution of alpine plants, we still need to set up observational and experimental networks which properly take into account the variability of alpine ecosystems and of their interactions with climate.Les écosystèmes alpins vont être grandement influencés par les changements climatiques à venir, mais d’autres facteurs, tels que l’utilisation des terres ou les espèces invasives, pourront aussi jouer un rôle important. Le climat peut influencer les écosystèmes à différents niveaux, et nous en décrivons certains, en mettant l’accent sur les méthodes utilisées et les données disponibles. Le climat peut d’abord modifier la phénologie des espèces, comme la date de floraison des plantes ou la date d’éclosion des insectes. Il peut ensuite affecter directement la démographie des espèces (survie, reproduction, dispersion et donc à terme leur répartition. Il peut enfin agir sur les interactions entre espèces – le couvert neigeux par exemple modifie le succès de certains prédateurs. Une caractéristique des

  19. Climate-change-driven accelerated sea-level rise detected in the altimeter era.

    Science.gov (United States)

    Nerem, R S; Beckley, B D; Fasullo, J T; Hamlington, B D; Masters, D; Mitchum, G T

    2018-02-27

    Using a 25-y time series of precision satellite altimeter data from TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3, we estimate the climate-change-driven acceleration of global mean sea level over the last 25 y to be 0.084 ± 0.025 mm/y 2 Coupled with the average climate-change-driven rate of sea level rise over these same 25 y of 2.9 mm/y, simple extrapolation of the quadratic implies global mean sea level could rise 65 ± 12 cm by 2100 compared with 2005, roughly in agreement with the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5) model projections. Copyright © 2018 the Author(s). Published by PNAS.

  20. Climate-driven Sympatry does not Lead to Foraging Competition Between Adélie and Gentoo Penguins

    Science.gov (United States)

    Cimino, M. A.; Moline, M. A.; Fraser, W.; Patterson-Fraser, D.; Oliver, M. J.

    2016-02-01

    Climate-driven sympatry may lead to competition for food resources between species, population shifts and changes in ecosystem structure. Rapid warming in the West Antarctic Peninsula (WAP) is coincident with increasing gentoo penguin and decreasing Adélie penguin populations, suggesting that competition for food may exacerbate the Adélie penguin decline. At Palmer Station, we tested for foraging competition between these species by comparing their prey, Antarctic krill, distributions and penguin foraging behaviors on fine scales. To study these predator-prey dynamics, we simultaneously deployed penguin satellite transmitters, and a REMUS autonomous underwater vehicle that acoustically detected krill aggregations and measured physical and biological properties of the water column. We detected krill aggregations within the horizontal and vertical foraging ranges of Adélie and gentoo penguin. In the upper 100 m of the water column, the distribution of krill aggregations were mainly associated with CHL and light, suggesting that krill selected for habitats that balance the need to consume food and avoid predation. Adélie and gentoo penguins mainly had spatially segregated foraging areas but in areas of overlap, gentoo penguins switched foraging behavior by foraging at deeper depths, a strategy which limits competition with Adélie penguins. This suggests that climate-driven sympatry does not necessarily result in competitive exclusion. Contrary to a recent theory, which suggests that increased competition for krill is the major driver of Adélie penguin population declines, we suggest that declines in Adélie penguins along the WAP are more likely due to direct and indirect climate impacts on their life histories.

  1. Detecting mismatches in the phenology of cotton bollworm larvae and cotton flowering in response to climate change

    Science.gov (United States)

    Huang, Jian; Hao, HongFei

    2018-05-01

    Current evidence suggests that climate change has directly affected the phenology of many invertebrate species associated with agriculture. Such changes in phenology have the potential to cause temporal mismatches between predators and prey and may lead to a disruption in natural pest control ecosystem. Understanding the synchrony between pest insects and host plant responses to climate change is a key step to improve integrated pest management strategies. Cotton bollworm larvae damage cotton, and thus, data from Magaiti County, China, collected during the period of 1990-2015 were analyzed to assess the effects of climate change on cotton bollworm larvae and cotton flowering. The results showed that a warming climate advanced the phenology of cotton bollworm larvae and cotton flowering. However, the phenological rate of change was faster in cotton bollworm larvae than that in cotton flowering, and the larval period was prolonged, resulting in a great increase of the larval population. The abrupt phenological changes in cotton bollworm larvae occurred earlier than that in cotton, and the abrupt phenological changes in cotton flowering occurred earlier than that in larval abundance. However, the timing of abrupt changes in larval abundance all occurred later than that in temperature. Thus, the abrupt changes that occurred in larvae, cotton flowering and climate were asynchronous. The interval days between the cotton flowering date (CFD) and the half-amount larvae date (HLD) expanded by 3.41 and 4.41 days with a 1 °C increase of T mean in May and June, respectively. The asynchrony between cotton bollworm larvae and cotton flowering will likely broaden as the climate changes. The effective temperature in March and April and the end date of larvae (ED) were the primary factors affecting asynchrony.

  2. Detecting mismatches in the phenology of cotton bollworm larvae and cotton flowering in response to climate change.

    Science.gov (United States)

    Huang, Jian; Hao, HongFei

    2018-05-11

    Current evidence suggests that climate change has directly affected the phenology of many invertebrate species associated with agriculture. Such changes in phenology have the potential to cause temporal mismatches between predators and prey and may lead to a disruption in natural pest control ecosystem. Understanding the synchrony between pest insects and host plant responses to climate change is a key step to improve integrated pest management strategies. Cotton bollworm larvae damage cotton, and thus, data from Magaiti County, China, collected during the period of 1990-2015 were analyzed to assess the effects of climate change on cotton bollworm larvae and cotton flowering. The results showed that a warming climate advanced the phenology of cotton bollworm larvae and cotton flowering. However, the phenological rate of change was faster in cotton bollworm larvae than that in cotton flowering, and the larval period was prolonged, resulting in a great increase of the larval population. The abrupt phenological changes in cotton bollworm larvae occurred earlier than that in cotton, and the abrupt phenological changes in cotton flowering occurred earlier than that in larval abundance. However, the timing of abrupt changes in larval abundance all occurred later than that in temperature. Thus, the abrupt changes that occurred in larvae, cotton flowering and climate were asynchronous. The interval days between the cotton flowering date (CFD) and the half-amount larvae date (HLD) expanded by 3.41 and 4.41 days with a 1 °C increase of T mean in May and June, respectively. The asynchrony between cotton bollworm larvae and cotton flowering will likely broaden as the climate changes. The effective temperature in March and April and the end date of larvae (ED) were the primary factors affecting asynchrony.

  3. Investigating the Influence of Climate Changes on Rodent Communities at a Regional-Scale (MIS 1-3, Southwestern France.

    Directory of Open Access Journals (Sweden)

    Aurélien Royer

    Full Text Available Terrestrial ecosystems have continuously evolved throughout the Late Pleistocene and the Holocene, deeply affected by both progressive environmental and climatic modifications, as well as by abrupt and large climatic changes such as the Heinrich or Dansgaard-Oeschger events. Yet, the impacts of these different events on terrestrial mammalian communities are poorly known, as is the role played by potential refugia on geographical species distributions. This study examines community changes in rodents of southwestern France between 50 and 10 ky BP by integrating 94 dated faunal assemblages coming from 37 archaeological sites. This work reveals that faunal distributions were modified in response to abrupt and brief climatic events, such as Heinrich events, without actually modifying the rodent community on a regional scale. However, the succession of events which operated between the Late Pleistocene and the Holocene gradually led to establishing a new rodent community at the regional scale, with intermediate communities occurring between the Bølling and the Allerød.

  4. Past Changes in Arctic Terrestrial Ecosystems, Climate and UV Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Callaghan, Terry V. [Abisko Scientific Research Station, Abisko (Sweden); Bjoern, Lars Olof [Lund Univ. (Sweden). Dept. of Cell and Organism Biology; Chernov, Yuri [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Severtsov Inst. of Evolutionary Morphology and Animal Ecology] (and others)

    2004-11-01

    At the last glacial maximum, vast ice sheets covered many continental areas. The beds of some shallow seas were exposed thereby connecting previously separated landmasses. Although some areas were ice-free and supported a flora and fauna, mean annual temperatures were 10-13 deg C colder than during the Holocene. Within a few millennia of the glacial maximum, deglaciation started, characterized by a series of climatic fluctuations between about 18,000 and 11,400 years ago. Following the general thermal maximum in the Holocene, there has been a modest overall cooling trend, superimposed upon which have been a series of millennial and centennial fluctuations in climate such as the 'Little Ice Age' spanning approximately the late 13th to early 19th centuries. Throughout the climatic fluctuations of the last 150,000 years, Arctic ecosystems and biota have been close to their minimum extent within the most recent 10,000 years. They suffered loss of diversity as a result of extinctions during the most recent large-magnitude rapid global warming at the end of the last glacial stage. Consequently, Arctic ecosystems and biota such as large vertebrates are already under pressure and are particularly vulnerable to current and projected future global warming. Evidence from the past indicates that the treeline will very probably advance, perhaps rapidly, into tundra areas, as it did during the early Holocene, reducing the extent of tundra and increasing the risk of species extinction. Species will very probably extend their ranges northwards, displacing Arctic species as in the past. However, unlike the early Holocene, when lower relative sea level allowed a belt of tundra to persist around at least some parts of the Arctic basin when treelines advanced to the present coast, sea level is very likely to rise in future, further restricting the area of tundra and other treeless Arctic ecosystems. The negative response of current Arctic ecosystems to global climatic

  5. High-resolution Greenland Ice Core data show abrupt climate change happens in few years

    DEFF Research Database (Denmark)

    Steffensen, Jørgen Peder; Andersen, Katrine Krogh; Bigler, Matthias

    2008-01-01

    The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture...... source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition...

  6. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S; Haenninen, H; Karjalainen, T [Joensuu Univ. (Finland). Faculty of Forestry; and others

    1997-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  7. Response of the boreal forest ecosystem to climatic change and its silvicultural implications

    Energy Technology Data Exchange (ETDEWEB)

    Kellomaeki, S.; Haenninen, H.; Karjalainen, T. [Joensuu Univ. (Finland). Faculty of Forestry] [and others

    1996-12-31

    During the next 100 years, the mean annual temperature is expected to be 1-6 deg C higher than at present. It is also expected to be accompanied by a lengthening of the thermal growing season and increased precipitation. Consequently, climatic change will increase the uncertainty of the management of forest ecosystems in the future. In this context, this research project aimed to outline the ecological and silvicultural implications of climatic change with regard to (1) how the expected climatic change might modify the functioning and structure of the boreal forest ecosystem, and (2) how the silvicultural management of the forest ecosystem should be modified in order to maintain sustainable forest yield under changing climatic conditions. The experimental component of the project concerned first the effect that elevating temperature and elevating concentration of atmospheric carbon have on the ontogenetic development of Scots pine (Pinus sylvestris L) and on the subsequent increase in frost damage during winter. The second part of the study looked the effect of elevating temperature and elevating concentration of atmospheric carbon on the growth of Scots pine through photosynthesis, respiration, transpiration, nutrient supply, and changes in crown structure. This experiment was utilised in several subprojects of the overall project

  8. Climate change science applications and needs in forest ecosystem management: a workshop organized as part of the northern Wisconsin Climate Change Response Framework Project

    Science.gov (United States)

    Leslie Brandt; Chris Swanston; Linda Parker; Maria Janowiak; Richard Birdsey; Louis Iverson; David Mladenoff; Patricia. Butler

    2012-01-01

    Climate change is leading to direct and indirect impacts on forest tree species and ecosystems in northern Wisconsin. Land managers will need to prepare for and respond to these impacts, so we designed a workshop to identify forest management approaches that can enhance the ability of ecosystems in northern Wisconsin to cope with climate change and address how National...

  9. Multiple stressors, nonlinear effects and the implications of climate change impacts on marine coastal ecosystems.

    Science.gov (United States)

    Hewitt, Judi E; Ellis, Joanne I; Thrush, Simon F

    2016-08-01

    Global climate change will undoubtedly be a pressure on coastal marine ecosystems, affecting not only species distributions and physiology but also ecosystem functioning. In the coastal zone, the environmental variables that may drive ecological responses to climate change include temperature, wave energy, upwelling events and freshwater inputs, and all act and interact at a variety of spatial and temporal scales. To date, we have a poor understanding of how climate-related environmental changes may affect coastal marine ecosystems or which environmental variables are likely to produce priority effects. Here we use time series data (17 years) of coastal benthic macrofauna to investigate responses to a range of climate-influenced variables including sea-surface temperature, southern oscillation indices (SOI, Z4), wind-wave exposure, freshwater inputs and rainfall. We investigate responses from the abundances of individual species to abundances of functional traits and test whether species that are near the edge of their tolerance to another stressor (in this case sedimentation) may exhibit stronger responses. The responses we observed were all nonlinear and some exhibited thresholds. While temperature was most frequently an important predictor, wave exposure and ENSO-related variables were also frequently important and most ecological variables responded to interactions between environmental variables. There were also indications that species sensitive to another stressor responded more strongly to weaker climate-related environmental change at the stressed site than the unstressed site. The observed interactions between climate variables, effects on key species or functional traits, and synergistic effects of additional anthropogenic stressors have important implications for understanding and predicting the ecological consequences of climate change to coastal ecosystems. © 2015 John Wiley & Sons Ltd.

  10. Rising climate variability and synchrony in North Pacific ecosystems

    Science.gov (United States)

    Black, Bryan

    2017-04-01

    Rising climate variability and synchrony in North Pacific ecosystems Evidence is growing that climate variability of the northeast Pacific Ocean has increased over the last century, culminating in such events as the record-breaking El Niño years 1983, 1998, and 2016 and the unusually persistent 2014/15 North Pacific Ocean heat wave known as "The Blob." Of particular concern is that rising variability could increase synchrony within and among North Pacific ecosystems, which could reduce the diversity of biological responses to climate (i.e. the "portfolio effect"), diminish resilience, and leave populations more prone to extirpation. To test this phenomenon, we use a network of multidecadal fish otolith growth-increment chronologies that were strongly correlated to records of winter (Jan-Mar) sea level. These biological and physical datasets spanned the California Current through the Gulf of Alaska. Synchrony was quantified as directional changes in running (31-year window) mean pairwise correlation within sea level and then within otolith time series. Synchrony in winter sea level at the nine stations with the longest records has increased by more than 40% over the 1950-2015 interval. Likewise, synchrony among the eight longest otolith chronologies has increased more than 100% over a comparable time period. These directional changes in synchrony are highly unlikely due to chance alone, as confirmed by comparing trends in observed data to those in simulated data (n = 10,000 iterations) with time series of identical number, length, and autocorrelation. Ultimately, this trend in rising synchrony may be linked to increased impacts of the El Niño Southern Oscillation (ENSO) on mid-latitude ecosystems of North America, and may therefore reflect a much broader, global-scale signature.

  11. Human used upper montane ecosystem in the Horton Plains, central Sri Lanka - a link to Lateglacial and early Holocene climate and environmental changes

    Science.gov (United States)

    Premathilake, Rathnasiri

    2012-09-01

    This study utilizes radiocarbon-dated pollen, spores, Sphagnum spp. macrofossils and total organic carbon proxies to examine variability of past climate, environment and human activity in montane rainforest, grassland and wetland of the Horton Plains (HP), central Sri Lanka since the Last Glacial Maximum (LGM). The LGM is largely characterized by grasslands and xerophytic herbs dominated open habitats. Arid-LGM punctuated climatic ameliorations, which took place in short episodes. Humans appear to have reached the HP ecosystem after 18,000 cal yrs BP occasionally. The first Intertropical Convergence Zone (ITCZ) induced changes in South West Monsoon (SWM) rains occurred at low latitudes between 16,200 and 15,900 cal yrs BP suggesting an onset of monsoon rains. After this event, monsoon rains weakened for several millennia except the period 13,700-13,000 cal yrs BP, but human activity seems to have continued with biomass burning and clearances by slash and burn. Very large size grass pollen grains, which are morphologically similar to pollen from closer forms of Oryza nivara, were found after 13,800 cal yrs BP. Early Holocene extreme and abrupt climate changes seem to have promoted the forms of O. nivara populations in association with humans. New data from the HP would therefore be most interesting to investigate the dispersal and use of domesticated rice in South Asia.

  12. Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems.

    NARCIS (Netherlands)

    Dirnböck, Thomas; Djukic, Ika; Kitzler, Barbara; Kobler, Johannes; Mol-Dijkstra, Janet P; Posch, Max; Reinds, Gert Jan; Schlutow, Angela; Starlinger, Franz; Wamelink, Wieger G W

    2017-01-01

    Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the

  13. Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems

    NARCIS (Netherlands)

    Dirnböck, Thomas; Djukic, Ika; Kitzler, Barbara; Kobler, Johannes; Mol, Janet; Posch, Max; Reinds, Gert Jan; Schlutow, Angela; Starlinger, Franz; Wamelink, Wieger G.W.

    2017-01-01

    Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the

  14. Climate change on the Shoshone National Forest, Wyoming: a synthesis of past climate, climate projections, and ecosystem implications

    Science.gov (United States)

    Janine Rice; Andrew Tredennick; Linda A. Joyce

    2012-01-01

    The Shoshone National Forest (Shoshone) covers 2.4 million acres of mountainous topography in northwest Wyoming and is a vital ecosystem that provides clean water, wildlife habitat, timber, grazing, recreational opportunities, and aesthetic value. The Shoshone has experienced and adapted to changes in climate for many millennia, and is currently experiencing a warming...

  15. Climatic and biotic controls on annual carbon storage in Amazonian ecosystems

    Science.gov (United States)

    Tian, H.; Melillo, J.M.; Kicklighter, D.W.; McGuire, A.D.; Helfrich, J.; Moore, B.; Vorosmarty, C.J.

    2000-01-01

    1 The role of undisturbed tropical land ecosystems in the global carbon budget is not well understood. It has been suggested that inter-annual climate variability can affect the capacity of these ecosystems to store carbon in the short term. In this paper, we use a transient version of the Terrestrial Ecosystem Model (TEM) to estimate annual carbon storage in undisturbed Amazonian ecosystems during the period 1980-94, and to understand the underlying causes of the year-to-year variations in net carbon storage for this region. 2 We estimate that the total carbon storage in the undisturbed ecosystems of the Amazon Basin in 1980 was 127.6 Pg C, with about 94.3 Pg C in vegetation and 33.3 Pg C in the reactive pool of soil organic carbon. About 83% of the total carbon storage occurred in tropical evergreen forests. Based on our model's results, we estimate that, over the past 15 years, the total carbon storage has increased by 3.1 Pg C (+ 2%), with a 1.9-Pg C (+2%) increase in vegetation carbon and a 1.2-Pg C (+4%) increase in reactive soil organic carbon. The modelled results indicate that the largest relative changes in net carbon storage have occurred in tropical deciduous forests, but that the largest absolute changes in net carbon storage have occurred in the moist and wet forests of the Basin. 3 Our results show that the strength of interannual variations in net carbon storage of undisturbed ecosystems in the Amazon Basin varies from a carbon source of 0.2 Pg C/year to a carbon sink of 0.7 Pg C/year. Precipitation, especially the amount received during the drier months, appears to be a major controller of annual net carbon storage in the Amazon Basin. Our analysis indicates further that changes in precipitation combine with changes in temperature to affect net carbon storage through influencing soil moisture and nutrient availability. 4 On average, our results suggest that the undisturbed Amazonian ecosystems accumulated 0.2 Pg C/year as a result of climate

  16. A data-driven approach to identify controls on global fire activity from satellite and climate observations (SOFIA V1

    Directory of Open Access Journals (Sweden)

    M. Forkel

    2017-12-01

    Full Text Available Vegetation fires affect human infrastructures, ecosystems, global vegetation distribution, and atmospheric composition. However, the climatic, environmental, and socioeconomic factors that control global fire activity in vegetation are only poorly understood, and in various complexities and formulations are represented in global process-oriented vegetation-fire models. Data-driven model approaches such as machine learning algorithms have successfully been used to identify and better understand controlling factors for fire activity. However, such machine learning models cannot be easily adapted or even implemented within process-oriented global vegetation-fire models. To overcome this gap between machine learning-based approaches and process-oriented global fire models, we introduce a new flexible data-driven fire modelling approach here (Satellite Observations to predict FIre Activity, SOFIA approach version 1. SOFIA models can use several predictor variables and functional relationships to estimate burned area that can be easily adapted with more complex process-oriented vegetation-fire models. We created an ensemble of SOFIA models to test the importance of several predictor variables. SOFIA models result in the highest performance in predicting burned area if they account for a direct restriction of fire activity under wet conditions and if they include a land cover-dependent restriction or allowance of fire activity by vegetation density and biomass. The use of vegetation optical depth data from microwave satellite observations, a proxy for vegetation biomass and water content, reaches higher model performance than commonly used vegetation variables from optical sensors. We further analyse spatial patterns of the sensitivity between anthropogenic, climate, and vegetation predictor variables and burned area. We finally discuss how multiple observational datasets on climate, hydrological, vegetation, and socioeconomic variables together with

  17. A data-driven approach to identify controls on global fire activity from satellite and climate observations (SOFIA V1)

    Science.gov (United States)

    Forkel, Matthias; Dorigo, Wouter; Lasslop, Gitta; Teubner, Irene; Chuvieco, Emilio; Thonicke, Kirsten

    2017-12-01

    Vegetation fires affect human infrastructures, ecosystems, global vegetation distribution, and atmospheric composition. However, the climatic, environmental, and socioeconomic factors that control global fire activity in vegetation are only poorly understood, and in various complexities and formulations are represented in global process-oriented vegetation-fire models. Data-driven model approaches such as machine learning algorithms have successfully been used to identify and better understand controlling factors for fire activity. However, such machine learning models cannot be easily adapted or even implemented within process-oriented global vegetation-fire models. To overcome this gap between machine learning-based approaches and process-oriented global fire models, we introduce a new flexible data-driven fire modelling approach here (Satellite Observations to predict FIre Activity, SOFIA approach version 1). SOFIA models can use several predictor variables and functional relationships to estimate burned area that can be easily adapted with more complex process-oriented vegetation-fire models. We created an ensemble of SOFIA models to test the importance of several predictor variables. SOFIA models result in the highest performance in predicting burned area if they account for a direct restriction of fire activity under wet conditions and if they include a land cover-dependent restriction or allowance of fire activity by vegetation density and biomass. The use of vegetation optical depth data from microwave satellite observations, a proxy for vegetation biomass and water content, reaches higher model performance than commonly used vegetation variables from optical sensors. We further analyse spatial patterns of the sensitivity between anthropogenic, climate, and vegetation predictor variables and burned area. We finally discuss how multiple observational datasets on climate, hydrological, vegetation, and socioeconomic variables together with data-driven

  18. Ecosystem-based management of coastal zones in face of climate change impacts: Challenges and inequalities.

    Science.gov (United States)

    Fernandino, Gerson; Elliff, Carla I; Silva, Iracema R

    2018-06-01

    Climate change effects have the potential of affecting both ocean and atmospheric processes. These changes pose serious threats to the millions of people that live by the coast. Thus, the objective of the present review is to discuss how climate change is altering (and will continue to alter) atmospheric and oceanic processes, what are the main implications of these alterations along the coastline, and which are the ecosystem-based management (EBM) strategies that have been proposed and applied to address these issues. While ocean warming, ocean acidification and increasing sea level have been more extensively studied, investigations on the effects of climate change to wind and wave climates are less frequent. Coastal ecosystems and their respective natural resources will respond differently according to location, environmental drivers and coastal processes. EBM strategies have mostly concentrated on improving ecosystem services, which can be used to assist in mitigating climate change effects. The main challenge for developing nations regards gaps in information and scarcity of resources. Thus, for effective management and adaptive EBM strategies to be developed worldwide, information at a local level is greatly needed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. An Integrated Coral Reef Ecosystem Model to Support Resource Management under a Changing Climate.

    NARCIS (Netherlands)

    Weijerman, Mariska; Fulton, Elizabeth A.; Kaplan, Isaac C.; Gorton, Rebecca; Leemans, Rik; Mooij, W.M.; Brainard, Russell E.

    2015-01-01

    Millions of people rely on the ecosystem services provided by coral reefs, but sustaining these benefits requires an understanding of how reefs and their biotic communities are affected by local human-induced disturbances and global climate change. Ecosystem-based management that explicitly

  20. An Integrated Coral Reef Ecosystem Model to Support Resource Management under a Changing Climate

    NARCIS (Netherlands)

    Weijerman, Mariska; Fulton, Elizabeth A.; Kaplan, Isaac C.; Gorton, Rebecca; Leemans, R.; Mooij, W.M.; Brainard, Russell E.

    2015-01-01

    Millions of people rely on the ecosystem services provided by coral reefs, but sustaining these benefits requires an understanding of how reefs and their biotic communities are affected by local human-induced disturbances and global climate change. Ecosystem-based management that explicitly

  1. A dynamic, climate-driven model of Rift Valley fever

    Directory of Open Access Journals (Sweden)

    Joseph Leedale

    2016-03-01

    Full Text Available Outbreaks of Rift Valley fever (RVF in eastern Africa have previously occurred following specific rainfall dynamics and flooding events that appear to support the emergence of large numbers of mosquito vectors. As such, transmission of the virus is considered to be sensitive to environmental conditions and therefore changes in climate can impact the spatiotemporal dynamics of epizootic vulnerability. Epidemiological information describing the methods and parameters of RVF transmission and its dependence on climatic factors are used to develop a new spatio-temporal mathematical model that simulates these dynamics and can predict the impact of changes in climate. The Liverpool RVF (LRVF model is a new dynamic, process-based model driven by climate data that provides a predictive output of geographical changes in RVF outbreak susceptibility as a result of the climate and local livestock immunity. This description of the multi-disciplinary process of model development is accessible to mathematicians, epidemiological modellers and climate scientists, uniting dynamic mathematical modelling, empirical parameterisation and state-of-the-art climate information.

  2. Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems.

    Directory of Open Access Journals (Sweden)

    Nicholas A J Graham

    Full Text Available Coral reefs have emerged as one of the ecosystems most vulnerable to climate variation and change. While the contribution of a warming climate to the loss of live coral cover has been well documented across large spatial and temporal scales, the associated effects on fish have not. Here, we respond to recent and repeated calls to assess the importance of local management in conserving coral reefs in the context of global climate change. Such information is important, as coral reef fish assemblages are the most species dense vertebrate communities on earth, contributing critical ecosystem functions and providing crucial ecosystem services to human societies in tropical countries. Our assessment of the impacts of the 1998 mass bleaching event on coral cover, reef structural complexity, and reef associated fishes spans 7 countries, 66 sites and 26 degrees of latitude in the Indian Ocean. Using Bayesian meta-analysis we show that changes in the size structure, diversity and trophic composition of the reef fish community have followed coral declines. Although the ocean scale integrity of these coral reef ecosystems has been lost, it is positive to see the effects are spatially variable at multiple scales, with impacts and vulnerability affected by geography but not management regime. Existing no-take marine protected areas still support high biomass of fish, however they had no positive affect on the ecosystem response to large-scale disturbance. This suggests a need for future conservation and management efforts to identify and protect regional refugia, which should be integrated into existing management frameworks and combined with policies to improve system-wide resilience to climate variation and change.

  3. Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems.

    Science.gov (United States)

    Graham, Nicholas A J; McClanahan, Tim R; MacNeil, M Aaron; Wilson, Shaun K; Polunin, Nicholas V C; Jennings, Simon; Chabanet, Pascale; Clark, Susan; Spalding, Mark D; Letourneur, Yves; Bigot, Lionel; Galzin, René; Ohman, Marcus C; Garpe, Kajsa C; Edwards, Alasdair J; Sheppard, Charles R C

    2008-08-27

    Coral reefs have emerged as one of the ecosystems most vulnerable to climate variation and change. While the contribution of a warming climate to the loss of live coral cover has been well documented across large spatial and temporal scales, the associated effects on fish have not. Here, we respond to recent and repeated calls to assess the importance of local management in conserving coral reefs in the context of global climate change. Such information is important, as coral reef fish assemblages are the most species dense vertebrate communities on earth, contributing critical ecosystem functions and providing crucial ecosystem services to human societies in tropical countries. Our assessment of the impacts of the 1998 mass bleaching event on coral cover, reef structural complexity, and reef associated fishes spans 7 countries, 66 sites and 26 degrees of latitude in the Indian Ocean. Using Bayesian meta-analysis we show that changes in the size structure, diversity and trophic composition of the reef fish community have followed coral declines. Although the ocean scale integrity of these coral reef ecosystems has been lost, it is positive to see the effects are spatially variable at multiple scales, with impacts and vulnerability affected by geography but not management regime. Existing no-take marine protected areas still support high biomass of fish, however they had no positive affect on the ecosystem response to large-scale disturbance. This suggests a need for future conservation and management efforts to identify and protect regional refugia, which should be integrated into existing management frameworks and combined with policies to improve system-wide resilience to climate variation and change.

  4. An Integrated Coral Reef Ecosystem Model to Support Resource Management under a Changing Climate.

    Science.gov (United States)

    Weijerman, Mariska; Fulton, Elizabeth A; Kaplan, Isaac C; Gorton, Rebecca; Leemans, Rik; Mooij, Wolf M; Brainard, Russell E

    2015-01-01

    Millions of people rely on the ecosystem services provided by coral reefs, but sustaining these benefits requires an understanding of how reefs and their biotic communities are affected by local human-induced disturbances and global climate change. Ecosystem-based management that explicitly considers the indirect and cumulative effects of multiple disturbances has been recommended and adopted in policies in many places around the globe. Ecosystem models give insight into complex reef dynamics and their responses to multiple disturbances and are useful tools to support planning and implementation of ecosystem-based management. We adapted the Atlantis Ecosystem Model to incorporate key dynamics for a coral reef ecosystem around Guam in the tropical western Pacific. We used this model to quantify the effects of predicted climate and ocean changes and current levels of current land-based sources of pollution (LBSP) and fishing. We used the following six ecosystem metrics as indicators of ecosystem state, resilience and harvest potential: 1) ratio of calcifying to non-calcifying benthic groups, 2) trophic level of the community, 3) biomass of apex predators, 4) biomass of herbivorous fishes, 5) total biomass of living groups and 6) the end-to-start ratio of exploited fish groups. Simulation tests of the effects of each of the three drivers separately suggest that by mid-century climate change will have the largest overall effect on this suite of ecosystem metrics due to substantial negative effects on coral cover. The effects of fishing were also important, negatively influencing five out of the six metrics. Moreover, LBSP exacerbates this effect for all metrics but not quite as badly as would be expected under additive assumptions, although the magnitude of the effects of LBSP are sensitive to uncertainty associated with primary productivity. Over longer time spans (i.e., 65 year simulations), climate change impacts have a slight positive interaction with other drivers

  5. An Integrated Coral Reef Ecosystem Model to Support Resource Management under a Changing Climate.

    Directory of Open Access Journals (Sweden)

    Mariska Weijerman

    Full Text Available Millions of people rely on the ecosystem services provided by coral reefs, but sustaining these benefits requires an understanding of how reefs and their biotic communities are affected by local human-induced disturbances and global climate change. Ecosystem-based management that explicitly considers the indirect and cumulative effects of multiple disturbances has been recommended and adopted in policies in many places around the globe. Ecosystem models give insight into complex reef dynamics and their responses to multiple disturbances and are useful tools to support planning and implementation of ecosystem-based management. We adapted the Atlantis Ecosystem Model to incorporate key dynamics for a coral reef ecosystem around Guam in the tropical western Pacific. We used this model to quantify the effects of predicted climate and ocean changes and current levels of current land-based sources of pollution (LBSP and fishing. We used the following six ecosystem metrics as indicators of ecosystem state, resilience and harvest potential: 1 ratio of calcifying to non-calcifying benthic groups, 2 trophic level of the community, 3 biomass of apex predators, 4 biomass of herbivorous fishes, 5 total biomass of living groups and 6 the end-to-start ratio of exploited fish groups. Simulation tests of the effects of each of the three drivers separately suggest that by mid-century climate change will have the largest overall effect on this suite of ecosystem metrics due to substantial negative effects on coral cover. The effects of fishing were also important, negatively influencing five out of the six metrics. Moreover, LBSP exacerbates this effect for all metrics but not quite as badly as would be expected under additive assumptions, although the magnitude of the effects of LBSP are sensitive to uncertainty associated with primary productivity. Over longer time spans (i.e., 65 year simulations, climate change impacts have a slight positive interaction with

  6. Land use compounds habitat losses under projected climate change in a threatened California ecosystem.

    Directory of Open Access Journals (Sweden)

    Erin Coulter Riordan

    Full Text Available Given the rapidly growing human population in mediterranean-climate systems, land use may pose a more immediate threat to biodiversity than climate change this century, yet few studies address the relative future impacts of both drivers. We assess spatial and temporal patterns of projected 21(st century land use and climate change on California sage scrub (CSS, a plant association of considerable diversity and threatened status in the mediterranean-climate California Floristic Province. Using a species distribution modeling approach combined with spatially-explicit land use projections, we model habitat loss for 20 dominant shrub species under unlimited and no dispersal scenarios at two time intervals (early and late century in two ecoregions in California (Central Coast and South Coast. Overall, projected climate change impacts were highly variable across CSS species and heavily dependent on dispersal assumptions. Projected anthropogenic land use drove greater relative habitat losses compared to projected climate change in many species. This pattern was only significant under assumptions of unlimited dispersal, however, where considerable climate-driven habitat gains offset some concurrent climate-driven habitat losses. Additionally, some of the habitat gained with projected climate change overlapped with projected land use. Most species showed potential northern habitat expansion and southern habitat contraction due to projected climate change, resulting in sharply contrasting patterns of impact between Central and South Coast Ecoregions. In the Central Coast, dispersal could play an important role moderating losses from both climate change and land use. In contrast, high geographic overlap in habitat losses driven by projected climate change and projected land use in the South Coast underscores the potential for compounding negative impacts of both drivers. Limiting habitat conversion may be a broadly beneficial strategy under climate change

  7. Evidence and implications of recent and projected climate change in Alaska's forest ecosystems

    Science.gov (United States)

    Wolken, Jane M.; Hollingsworth, Teresa N.; Rupp, T. Scott; Chapin, Stuart III; Trainor, Sarah F.; Barrett, Tara M.; Sullivan, Patrick F.; McGuire, A. David; Euskirchen, Eugénie S.; Hennon, Paul E.; Beever, Erik A.; Conn, Jeff S.; Crone, Lisa K.; D'Amore, David V.; Fresco, Nancy; Hanley, Thomas A.; Kielland, Knut; Kruse, James J.; Patterson, Trista; Schuur, Edward A.G.; Verbyla, David L.; Yarie, John

    2011-01-01

    The structure and function of Alaska's forests have changed significantly in response to a changing climate, including alterations in species composition and climate feedbacks (e.g., carbon, radiation budgets) that have important regional societal consequences and human feedbacks to forest ecosystems. In this paper we present the first comprehensive synthesis of climate-change impacts on all forested ecosystems of Alaska, highlighting changes in the most critical biophysical factors of each region. We developed a conceptual framework describing climate drivers, biophysical factors and types of change to illustrate how the biophysical and social subsystems of Alaskan forests interact and respond directly and indirectly to a changing climate. We then identify the regional and global implications to the climate system and associated socio-economic impacts, as presented in the current literature. Projections of temperature and precipitation suggest wildfire will continue to be the dominant biophysical factor in the Interior-boreal forest, leading to shifts from conifer- to deciduous-dominated forests. Based on existing research, projected increases in temperature in the Southcentral- and Kenai-boreal forests will likely increase the frequency and severity of insect outbreaks and associated wildfires, and increase the probability of establishment by invasive plant species. In the Coastal-temperate forest region snow and ice is regarded as the dominant biophysical factor. With continued warming, hydrologic changes related to more rapidly melting glaciers and rising elevation of the winter snowline will alter discharge in many rivers, which will have important consequences for terrestrial and marine ecosystem productivity. These climate-related changes will affect plant species distribution and wildlife habitat, which have regional societal consequences, and trace-gas emissions and radiation budgets, which are globally important. Our conceptual framework facilitates

  8. Preliminary review of adaptation options for climate-sensitive ecosystems and resources. A report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research

    Science.gov (United States)

    Baron, Jill S.; Griffith, Brad; Joyce, Linda A.; Kareiva, Peter; Keller, Brian D.; Palmer, Margaret A.; Peterson, Charles H.; Scott, J. Michael; Julius, Susan Herrod; West, Jordan M.

    2008-01-01

    Climate variables are key determinants of geographic distributions and biophysical characteristics of ecosystems, communities, and species. Climate change is therefore affecting many species attributes, ecological interactions, and ecosystem processes. Because changes in the climate system will continue into the future regardless of emissions mitigation, strategies for protecting climate-sensitive ecosystems through management will be increasingly important. While there will always be uncertainties associated with the future path of climate change, the response of ecosystems to climate impacts, and the effects of management, it is both possible and essential for adaptation to proceed using the best available science. This report provides a preliminary review of adaptation options for climate-sensitive ecosystems and resources in the United States. The term “adaptation” in this document refers to adjustments in human social systems (e.g., management) in response to climate stimuli and their effects. Since management always occurs in the context of desired ecosystem conditions or natural resource management goals, it is instructive to examine particular goals and processes used by different organizations to fulfill their objectives. Such an examination allows for discussion of specific adaptation options as well as potential barriers and opportunities for implementation. Using this approach, this report presents a series of chapters on the following selected management systems: National Forests, National Parks, National Wildlife Refuges, Wild and Scenic Rivers, National Estuaries, and Marine Protected Areas. For these chapters, the authors draw on the literature, their own expert opinion, and expert workshops composed of resource management scientists and representatives of managing agencies. The information drawn from across these chapters is then analyzed to develop the key synthetic messages presented below.

  9. Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems.

    Science.gov (United States)

    Dirnböck, Thomas; Djukic, Ika; Kitzler, Barbara; Kobler, Johannes; Mol-Dijkstra, Janet P; Posch, Max; Reinds, Gert Jan; Schlutow, Angela; Starlinger, Franz; Wamelink, Wieger G W

    2017-01-01

    Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+) together with a novel niche-based plant response model (PROPS) to 5 forest habitat types (18 forest sites) protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered.

  10. GLOBEC (Global Ocean Ecosystems Dynamics: Northwest Atlantic program

    Science.gov (United States)

    1991-01-01

    The specific objective of the meeting was to plan an experiment in the Northwestern Atlantic to study the marine ecosystem and its role, together with that of climate and physical dynamics, in determining fisheries recruitment. The underlying focus of the GLOBEC initiative is to understand the marine ecosystem as it related to marine living resources and to understand how fluctuation in these resources are driven by climate change and exploitation. In this sense the goal is a solid scientific program to provide basic information concerning major fisheries stocks and the environment that sustains them. The plan is to attempt to reach this understanding through a multidisciplinary program that brings to bear new techniques as disparate as numerical fluid dynamic models of ocean circulation, molecular biology and modern acoustic imaging. The effort will also make use of the massive historical data sets on fisheries and the state of the climate in a coordinated manner.

  11. Constraining Transient Climate Sensitivity Using Coupled Climate Model Simulations of Volcanic Eruptions

    KAUST Repository

    Merlis, Timothy M.; Held, Isaac M.; Stenchikov, Georgiy L.; Zeng, Fanrong; Horowitz, Larry W.

    2014-01-01

    Coupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR; defined with the 1%yr-1 CO2-increase scenario) can be estimated from shorter-time-scale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes but is 5%-15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10 yr) time scales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure. The response of the GMST to volcanic eruptions is similar in GFDL CM2.1 and GFDL Climate Model, version 3 (CM3), even though the latter has a higher TCR associated with a multidecadal time scale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.

  12. Constraining Transient Climate Sensitivity Using Coupled Climate Model Simulations of Volcanic Eruptions

    KAUST Repository

    Merlis, Timothy M.

    2014-10-01

    Coupled climate model simulations of volcanic eruptions and abrupt changes in CO2 concentration are compared in multiple realizations of the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (GFDL CM2.1). The change in global-mean surface temperature (GMST) is analyzed to determine whether a fast component of the climate sensitivity of relevance to the transient climate response (TCR; defined with the 1%yr-1 CO2-increase scenario) can be estimated from shorter-time-scale climate changes. The fast component of the climate sensitivity estimated from the response of the climate model to volcanic forcing is similar to that of the simulations forced by abrupt CO2 changes but is 5%-15% smaller than the TCR. In addition, the partition between the top-of-atmosphere radiative restoring and ocean heat uptake is similar across radiative forcing agents. The possible asymmetry between warming and cooling climate perturbations, which may affect the utility of volcanic eruptions for estimating the TCR, is assessed by comparing simulations of abrupt CO2 doubling to abrupt CO2 halving. There is slightly less (~5%) GMST change in 0.5 × CO2 simulations than in 2 × CO2 simulations on the short (~10 yr) time scales relevant to the fast component of the volcanic signal. However, inferring the TCR from volcanic eruptions is more sensitive to uncertainties from internal climate variability and the estimation procedure. The response of the GMST to volcanic eruptions is similar in GFDL CM2.1 and GFDL Climate Model, version 3 (CM3), even though the latter has a higher TCR associated with a multidecadal time scale in its response. This is consistent with the expectation that the fast component of the climate sensitivity inferred from volcanic eruptions is a lower bound for the TCR.

  13. Modeling Impacts of Climate and Land Use Change on Ecosystem Processes to Quantify Exposure to Climate Change in Two Landscape Conservation Cooperatives

    Science.gov (United States)

    Quackenbush, A.

    2015-12-01

    Urban land cover and associated impervious surface area is expected to increase by as much as 50% over the next few decades across substantial portions of the United States. In combination with urban expansion, increases in temperature and changes in precipitation are expected to impact ecosystems through changes in productivity, disturbance and hydrological properties. In this study, we use the NASA Terrestrial Observation and Prediction System Biogeochemical Cycle (TOPS-BGC) model to explore the combined impacts of urbanization and climate change on hydrologic dynamics (snowmelt, runoff, and evapotranspiration) and vegetation carbon uptake (gross productivity). The model is driven using land cover predictions from the Spatially Explicit Regional Growth Model (SERGoM) to quantify projected changes in impervious surface area, and climate projections from the 30 arc-second NASA Earth Exchange Downscaled Climate Projection (NEX-DCP30) dataset derived from the CMIP5 climate scenarios. We present the modeling approach and an analysis of the ecosystem impacts projected to occur in the US, with an emphasis on protected areas in the Great Northern and Appalachian Landscape Conservation Cooperatives (LCC). Under the ensemble average of the CMIP5 models and land cover change scenarios for both representative concentration pathways (RCPs) 4.5 and 8.5, both LCCs are predicted to experience increases in maximum and minimum temperatures as well as annual average precipitation. In the Great Northern LCC, this is projected to lead to increased annual runoff, especially under RCP 8.5. Earlier melt of the winter snow pack and increased evapotranspiration, however, reduces summer streamflow and soil water content, leading to a net reduction in vegetation productivity across much of the Great Northern LCC, with stronger trends occurring under RCP 8.5. Increased runoff is also projected to occur in the Appalachian LCC under both RCP 4.5 and 8.5. However, under RCP 4.5, the model

  14. Project Summary (2012-2015) – Carbon Dynamics of the Greater Everglades Watershed and Implications of Climate Change

    Energy Technology Data Exchange (ETDEWEB)

    Hinkle, Ross [University of Central Florida; Benscoter, Brian [Florida Atlantic University; Comas, Xavier [Florida Atlantic University; Sumner, David [USGS; DeAngelis, Donald [USGS

    2015-04-07

    Carbon Dynamics of the Greater Everglades Watershed and Implications of Climate Change The objectives of this project are to: 1) quantify above- and below-ground carbon stocks of terrestrial ecosystems along a seasonal hydrologic gradient in the headwaters region of the Greater Everglades watershed; 2) develop budgets of ecosystem gaseous carbon exchange (carbon dioxide and methane) across the seasonal hydrologic gradient; 3) assess the impact of climate drivers on ecosystem carbon exchange in the Greater Everglades headwater region; and 4) integrate research findings with climate-driven terrestrial ecosystem carbon models to examine the potential influence of projected future climate change on regional carbon cycling. Note: this project receives a one-year extension past the original performance period - David Sumner (USGS) is not included in this extension.

  15. The economics of ecosystems and biodiversity, REDD+ and climate change in mangrove ecosystems of Southeast Asia

    Directory of Open Access Journals (Sweden)

    Filiberto Pollisco

    2013-07-01

    Full Text Available Mangroves are trees and shrubs that grow in saline coastal habitats. They occupy large stretches of the sub-tropical and tropical coastlines around the world. They not only provide valuable goods such as timber, fish and medicinal plants but also vital ecological services, such as prevention of coastal erosion. They also help buffer coastal communities from storms and floods. During the ASEAN Conference on Biodiversity held in Singapore in 2009, Ellison reported that mangrove forests in South East Asia are among the highest biodiversity resources in the world, occupying an area of 60.9 x 102 km2. Unfortunately, the region also has the highest rates of mangrove loss in the world, losing 628 km2 per year in two decades. In many parts of the world, where mangrove forests have been cleared, there are now problems of erosion and siltation, and loss of life and property have occurred due to destructive hurricanes, storms and tsunamis. The complex relationship between climate change and mangrove ecosystems can be seen from two different angles. On the one hand, mangrove ecosystems have a critical function in combating climate change; on the other hand, they are affected by climate change. The values of ecosystems vary according to local biophysical and ecological circumstances and the social, economic and cultural context. Intangible values, which may be reflected in society’s willingness to pay to conserve particular species or landscapes, or to protect common resources, must be considered alongside more tangible values such as food or timber to provide a complete economic picture. This has important implications for mangrove conservation strategies and suggests that the preservation of contiguous areas is preferable to patches that are spatially dispersed.

  16. Effects of Climatic Factors and Ecosystem Responses on the Inter-Annual Variability of Evapotranspiration in a Coniferous Plantation in Subtropical China

    Science.gov (United States)

    Xu, Mingjie; Wen, Xuefa; Wang, Huimin; Zhang, Wenjiang; Dai, Xiaoqin; Song, Jie; Wang, Yidong; Fu, Xiaoli; Liu, Yunfen; Sun, Xiaomin; Yu, Guirui

    2014-01-01

    Because evapotranspiration (ET) is the second largest component of the water cycle and a critical process in terrestrial ecosystems, understanding the inter-annual variability of ET is important in the context of global climate change. Eight years of continuous eddy covariance measurements (2003–2010) in a subtropical coniferous plantation were used to investigate the impacts of climatic factors and ecosystem responses on the inter-annual variability of ET. The mean and standard deviation of annual ET for 2003–2010 were 786.9 and 103.4 mm (with a coefficient of variation of 13.1%), respectively. The inter-annual variability of ET was largely created in three periods: March, May–June, and October, which are the transition periods between seasons. A set of look-up table approaches were used to separate the sources of inter-annual variability of ET. The annual ETs were calculated by assuming that (a) both the climate and ecosystem responses among years are variable (Vcli-eco), (b) the climate is variable but the ecosystem responses are constant (Vcli), and (c) the climate is constant but ecosystem responses are variable (Veco). The ETs that were calculated under the above assumptions suggested that the inter-annual variability of ET was dominated by ecosystem responses and that there was a negative interaction between the effects of climate and ecosystem responses. These results suggested that for long-term predictions of water and energy balance in global climate change projections, the ecosystem responses must be taken into account to better constrain the uncertainties associated with estimation. PMID:24465610

  17. Forecasting sagebrush ecosystem components and greater sage-grouse habitat for 2050: learning from past climate patterns and Landsat imagery to predict the future

    Science.gov (United States)

    Homer, Collin G.; Xian, George Z.; Aldridge, Cameron L.; Meyer, Debra K.; Loveland, Thomas R.; O'Donnell, Michael S.

    2015-01-01

    Sagebrush (Artemisia spp.) ecosystems constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. Disturbances have altered and reduced this ecosystem historically, but climate change may ultimately represent the greatest future risk. Improved ways to quantify, monitor, and predict climate-driven gradual change in this ecosystem is vital to its future management. We examined the annual change of Daymet precipitation (daily gridded climate data) and five remote sensing ecosystem sagebrush vegetation and soil components (bare ground, herbaceous, litter, sagebrush, and shrub) from 1984 to 2011 in southwestern Wyoming. Bare ground displayed an increasing trend in abundance over time, and herbaceous, litter, shrub, and sagebrush showed a decreasing trend. Total precipitation amounts show a downward trend during the same period. We established statistically significant correlations between each sagebrush component and historical precipitation records using a simple least squares linear regression. Using the historical relationship between sagebrush component abundance and precipitation in a linear model, we forecasted the abundance of the sagebrush components in 2050 using Intergovernmental Panel on Climate Change (IPCC) precipitation scenarios A1B and A2. Bare ground was the only component that increased under both future scenarios, with a net increase of 48.98 km2 (1.1%) across the study area under the A1B scenario and 41.15 km2 (0.9%) under the A2 scenario. The remaining components decreased under both future scenarios: litter had the highest net reductions with 49.82 km2 (4.1%) under A1B and 50.8 km2 (4.2%) under A2, and herbaceous had the smallest net reductions with 39.95 km2 (3.8%) under A1B and 40.59 km2 (3.3%) under A2. We applied the 2050 forecast sagebrush component values to contemporary (circa 2006) greater sage-grouse (Centrocercus

  18. Can Payments for Ecosystem Services Contribute to Adaptation to Climate Change? Insights from a Watershed in Kenya

    Directory of Open Access Journals (Sweden)

    Isabel van de Sand

    2014-03-01

    Full Text Available Climate change presents new challenges for the management of social-ecological systems and the ecosystem services they provide. Although the instrument of payments for ecosystem services (PES has emerged as a promising tool to safeguard or enhance the provision of ecosystem services (ES, little attention has been paid to the potential role of PES in climate change adaptation. As an external stressor climate change has an impact on the social-ecological system in which PES takes place, including the various actors taking part in the PES scheme. Following a short description of the conceptual link between PES and adaptation to climate change, we provide practical insights into the relationship between PES and adaptation to climate change by presenting results from a case study of a rural watershed in Kenya. Drawing upon the results of a participatory vulnerability assessment among potential ecosystem service providers in Sasumua watershed north of Nairobi, we show that PES can play a role in enhancing adaptation to climate change by influencing certain elements of adaptive capacity and incentivizing adaptation measures. In addition, trade-offs and synergies between proposed measures under PES and adaptation to climate change are identified. Results show that although it may not be possible to establish PES schemes based on water utilities as the sole source of financing, embedding PES in a wider adaptation framework creates an opportunity for the development of watershed PES schemes in Africa and ensures their sustainability. We conclude that there is a need to embed PES in a wider institutional framework and that extra financial resources are needed to foster greater integration between PES and adaptation to climate change. This can be achieved through scaling up PES by bringing in other buyers and additional ecosystem services. PES can achieve important coadaptation benefits, but for more effective adaptation outcomes it needs to be combined

  19. Community ecology, climate change and ecohydrology in desert grassland and shrubland

    Science.gov (United States)

    Mathew Daniel Petrie

    2014-01-01

    This dissertation explores the climate, ecology and hydrology of Chihuahuan Desert ecosystems in the context of global climate change. In coming decades, the southwestern United States is projected to experience greater temperature-driven aridity, possible small decreases in annual precipitation, and a later onset of summer monsoon rainfall. These changes may have...

  20. Mammalian herbivores confer resilience of Arctic shrub-dominated ecosystems to changing climate.

    Science.gov (United States)

    Kaarlejärvi, Elina; Hoset, Katrine S; Olofsson, Johan

    2015-09-01

    Climate change is resulting in a rapid expansion of shrubs in the Arctic. This expansion has been shown to be reinforced by positive feedbacks, and it could thus set the ecosystem on a trajectory toward an alternate, more productive regime. Herbivores, on the other hand, are known to counteract the effects of simultaneous climate warming on shrub biomass. However, little is known about the impact of herbivores on resilience of these ecosystems, that is, the capacity of a system to absorb disturbance and still remain in the same regime, retaining the same function, structure, and feedbacks. Here, we investigated how herbivores affect resilience of shrub-dominated systems to warming by studying the change of shrub biomass after a cessation of long-term experimental warming in a forest-tundra ecotone. As predicted, warming increased the biomass of shrubs, and in the absence of herbivores, shrub biomass in tundra continued to increase 4 years after cessation of the artificial warming, indicating that positive effects of warming on plant growth may persist even over a subsequent colder period. Herbivores contributed to the resilience of these systems by returning them back to the original low-biomass regime in both forest and tundra habitats. These results support the prediction that higher shrub biomass triggers positive feedbacks on soil processes and microclimate, which enable maintaining the rapid shrub growth even in colder climates. Furthermore, the results show that in our system, herbivores facilitate the resilience of shrub-dominated ecosystems to climate warming. © 2015 John Wiley & Sons Ltd.

  1. Climate bifurcation during the last deglaciation?

    NARCIS (Netherlands)

    Lenton, T.M.; Livina, V.N.; Dakos, V.; Scheffer, M.

    2012-01-01

    There were two abrupt warming events during the last deglaciation, at the start of the Bolling-Allerod and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state

  2. Contemporary white-band disease in Caribbean corals driven by climate change

    Science.gov (United States)

    Randall, C. J.; van Woesik, R.

    2015-04-01

    Over the past 40 years, two of the dominant reef-building corals in the Caribbean, Acropora palmata and Acropora cervicornis, have experienced unprecedented declines. That loss has been largely attributed to a syndrome commonly referred to as white-band disease. Climate change-driven increases in sea surface temperature (SST) have been linked to several coral diseases, yet, despite decades of research, the attribution of white-band disease to climate change remains unknown. Here we hindcasted the potential relationship between recent ocean warming and outbreaks of white-band disease on acroporid corals. We quantified eight SST metrics, including rates of change in SST and contemporary thermal anomalies, and compared them with records of white-band disease on A. palmata and A. cervicornis from 473 sites across the Caribbean, surveyed from 1997 to 2004. The results of our models suggest that decades-long climate-driven changes in SST, increases in thermal minima, and the breach of thermal maxima have all played significant roles in the spread of white-band disease. We conclude that white-band disease has been strongly coupled with thermal stresses associated with climate change, which has contributed to the regional decline of these once-dominant reef-building corals.

  3. Climate-induced warming imposes a threat to north European spring ecosystems.

    Science.gov (United States)

    Jyväsjärvi, Jussi; Marttila, Hannu; Rossi, Pekka M; Ala-Aho, Pertti; Olofsson, Bo; Nisell, Jakob; Backman, Birgitta; Ilmonen, Jari; Virtanen, Risto; Paasivirta, Lauri; Britschgi, Ritva; Kløve, Bjørn; Muotka, Timo

    2015-12-01

    Interest in climate change effects on groundwater has increased dramatically during the last decade. The mechanisms of climate-related groundwater depletion have been thoroughly reviewed, but the influence of global warming on groundwater-dependent ecosystems (GDEs) remains poorly known. Here we report long-term water temperature trends in 66 northern European cold-water springs. A vast majority of the springs (82%) exhibited a significant increase in water temperature during 1968-2012. Mean spring water temperatures were closely related to regional air temperature and global radiative forcing of the corresponding year. Based on three alternative climate scenarios representing low (RCP2.6), intermediate (RCP6) and high-emission scenarios (RCP8.5), we estimate that increase in mean spring water temperature in the region is likely to range from 0.67 °C (RCP2.6) to 5.94 °C (RCP8.5) by 2086. According to the worst-case scenario, water temperature of these originally cold-water ecosystems (regional mean in the late 1970s: 4.7 °C) may exceed 12 °C by the end of this century. We used bryophyte and macroinvertebrate species data from Finnish springs and spring-fed streams to assess ecological impacts of the predicted warming. An increase in spring water temperature by several degrees will likely have substantial biodiversity impacts, causing regional extinction of native, cold-stenothermal spring specialists, whereas species diversity of headwater generalists is likely to increase. Even a slight (by 1 °C) increase in water temperature may eliminate endemic spring species, thus altering bryophyte and macroinvertebrate assemblages of spring-fed streams. Climate change-induced warming of northern regions may thus alter species composition of the spring biota and cause regional homogenization of biodiversity in headwater ecosystems. © 2015 John Wiley & Sons Ltd.

  4. Shrubline but not treeline advance matches climate velocity in montane ecosystems of south-central Alaska.

    Science.gov (United States)

    Dial, Roman J; Smeltz, T Scott; Sullivan, Patrick F; Rinas, Christina L; Timm, Katriina; Geck, Jason E; Tobin, S Carl; Golden, Trevor S; Berg, Edward C

    2016-05-01

    Tall shrubs and trees are advancing into many tundra and wetland ecosystems but at a rate that often falls short of that predicted due to climate change. For forest, tall shrub, and tundra ecosystems in two pristine mountain ranges of Alaska, we apply a Bayesian, error-propagated calculation of expected elevational rise (climate velocity), observed rise (biotic velocity), and their difference (biotic inertia). We show a sensitive dependence of climate velocity on lapse rate and derive biotic velocity as a rigid elevational shift. Ecosystem presence identified from recent and historic orthophotos ~50 years apart was regressed on elevation. Biotic velocity was estimated as the difference between critical point elevations of recent and historic logistic fits divided by time between imagery. For both mountain ranges, the 95% highest posterior density of climate velocity enclosed the posterior distributions of all biotic velocities. In the Kenai Mountains, mean tall shrub and climate velocities were both 2.8 m y(-1). In the better sampled Chugach Mountains, mean tundra retreat was 1.2 m y(-1) and climate velocity 1.3 m y(-1). In each mountain range, the posterior mode of tall woody vegetation velocity (the complement of tundra) matched climate velocity better than either forest or tall shrub alone, suggesting competitive compensation can be important. Forest velocity was consistently low at 0.1-1.1 m y(-1), indicating treeline is advancing slowly. We hypothesize that the high biotic inertia of forest ecosystems in south-central Alaska may be due to competition with tall shrubs and/or more complex climate controls on the elevational limits of trees than tall shrubs. Among tall shrubs, those that disperse farthest had lowest inertia. Finally, the rapid upward advance of woody vegetation may be contributing to regional declines in Dall's sheep (Ovis dalli), a poorly dispersing alpine specialist herbivore with substantial biotic inertia due to dispersal reluctance. © 2015

  5. Understanding and Managing the Effects of Climate Change on Ecosystem Services in the Rocky Mountains

    Directory of Open Access Journals (Sweden)

    Jessica E. Halofsky

    2017-08-01

    Full Text Available Public lands in the US Rocky Mountains provide critical ecosystem services, especially to rural communities that rely on these lands for fuel, food, water, and recreation. Climate change will likely affect the ability of these lands to provide ecosystem services. We describe 2 efforts to assess climate change vulnerabilities and develop adaptation options on federal lands in the Rocky Mountains. We specifically focus on aspects that affect community economic security and livelihood security, including water quality and quantity, timber, livestock grazing, and recreation. Headwaters of the Rocky Mountains serve as the primary source of water for large populations, and these headwaters are located primarily on public land. Thus, federal agencies will play a key role in helping to protect water quantity and quality by promoting watershed function and water conservation. Although increased temperatures and atmospheric concentration of CO2 have the potential to increase timber and forage production in the Rocky Mountains, those gains may be offset by wildfires, droughts, insect outbreaks, non-native species, and altered species composition. Our assessment identified ways in which federal land managers can help sustain forest and range productivity, primarily by increasing ecosystem resilience and minimizing current stressors, such as invasive species. Climate change will likely increase recreation participation. However, recreation managers will need more flexibility to adjust practices, provide recreation opportunities, and sustain economic benefits to communities. Federal agencies are now transitioning from the planning phase of climate change adaptation to implementation to ensure that ecosystem services will continue to be provided from federal lands in a changing climate.

  6. Circumpolar dynamics of a marine top-predator track ocean warming rates.

    Science.gov (United States)

    Descamps, Sébastien; Anker-Nilssen, Tycho; Barrett, Robert T; Irons, David B; Merkel, Flemming; Robertson, Gregory J; Yoccoz, Nigel G; Mallory, Mark L; Montevecchi, William A; Boertmann, David; Artukhin, Yuri; Christensen-Dalsgaard, Signe; Erikstad, Kjell-Einar; Gilchrist, H Grant; Labansen, Aili L; Lorentsen, Svein-Håkon; Mosbech, Anders; Olsen, Bergur; Petersen, Aevar; Rail, Jean-Francois; Renner, Heather M; Strøm, Hallvard; Systad, Geir H; Wilhelm, Sabina I; Zelenskaya, Larisa

    2017-09-01

    Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to climate warming is needed to assess the consequences of ongoing climate change. Here, we demonstrate that the population dynamics of a long-lived, wide-ranging marine predator are associated with changes in the rate of ocean warming. Data from 556 colonies of black-legged kittiwakes Rissa tridactyla distributed throughout its breeding range revealed that an abrupt warming of sea-surface temperature in the 1990s coincided with steep kittiwake population decline. Periods of moderate warming in sea temperatures did not seem to affect kittiwake dynamics. The rapid warming observed in the 1990s may have driven large-scale, circumpolar marine ecosystem shifts that strongly affected kittiwakes through bottom-up effects. Our study sheds light on the nonlinear response of a circumpolar seabird to large-scale changes in oceanographic conditions and indicates that marine top predators may be more sensitive to the rate of ocean warming rather than to warming itself. © 2017 John Wiley & Sons Ltd.

  7. Potential Carbon Stock Changes in Arizona's Ecosystems Due to Projected Climate Change

    Science.gov (United States)

    Finley, B. K.; Ironside, K.; Hungate, B. A.; Hurteau, M.; Koch, G. W.

    2011-12-01

    Climate change can alter the role of plants and soils as sources or sinks of atmospheric carbon dioxide and result in changes in long-term carbon storage. To understand the sensitivity of Arizona's ecosystems to climate change, we quantified the present carbon stocks in Arizona's major ecosystem types using the NASA-CASA (Carnegie Ames Stanford Approach) model. Carbon stocks for each vegetation type included surface mineral soil, dead wood litter, standing wood and live leaf biomass. The total Arizona ecosystem carbon stock is presently 1775 MMtC, 545 MMtC of which is in Pinus ponderosa and Pinus edulis forests and woodlands. Evergreen forest vegetation, predominately Pinus ponderosa, has the largest current C density at 11.3 kgC/m2, while Pinus edulis woodlands have a C density of 6.0 kgC/m2. A change in climate will impact the suitable range for each tree species, and consequentially the amount of C stored. Present habitat ranges for these tree species are projected to have widespread mortality and likely will be replaced by herbaceous species, resulting in a loss of C stored. We evaluated the C storage implications over the 2010 to 2099 period of climate change based on output from GCMs with contrasting projections for the southwestern US: MPI-ECHAM5, which projects warming and reduced precipitation, and UKMO-HadGEM, which projects warming and increased precipitation. These projected changes are end points of a spectrum of possible future climate scenarios. The vegetation distribution models used describe potential suitable habitat, and we assumed that the growth rate for each vegetation type would be one-third of the way to full C density for each 30 year period up to 2099. With increasing temperature and decreasing precipitation predictions under the MPI-ECHAM5 model, P. ponderosa and P. edulis vegetation show a decrease in carbon stored from 545 MMtC presently to 116 MMtC. With the combined increase in temperature and precipitation, C storage in these

  8. Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems

    Science.gov (United States)

    Djukic, Ika; Kitzler, Barbara; Kobler, Johannes; Mol-Dijkstra, Janet P.; Posch, Max; Reinds, Gert Jan; Schlutow, Angela; Starlinger, Franz; Wamelink, Wieger G. W.

    2017-01-01

    Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+) together with a novel niche-based plant response model (PROPS) to 5 forest habitat types (18 forest sites) protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered. PMID:28898262

  9. Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems.

    Directory of Open Access Journals (Sweden)

    Thomas Dirnböck

    Full Text Available Climate change and excess deposition of airborne nitrogen (N are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+ together with a novel niche-based plant response model (PROPS to 5 forest habitat types (18 forest sites protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered.

  10. Conservation threats due to human-caused increases in fire frequency in Mediterranean-climate ecosystems.

    Science.gov (United States)

    Syphard, Alexandra D; Radeloff, Volker C; Hawbaker, Todd J; Stewart, Susan I

    2009-06-01

    Periodic wildfire is an important natural process in Mediterranean-climate ecosystems, but increasing fire recurrence threatens the fragile ecology of these regions. Because most fires are human-caused, we investigated how human population patterns affect fire frequency. Prior research in California suggests the relationship between population density and fire frequency is not linear. There are few human ignitions in areas with low population density, so fire frequency is low. As population density increases, human ignitions and fire frequency also increase, but beyond a density threshold, the relationship becomes negative as fuels become sparser and fire suppression resources are concentrated. We tested whether this hypothesis also applies to the other Mediterranean-climate ecosystems of the world. We used global satellite databases of population, fire activity, and land cover to evaluate the spatial relationship between humans and fire in the world's five Mediterranean-climate ecosystems. Both the mean and median population densities were consistently and substantially higher in areas with than without fire, but fire again peaked at intermediate population densities, which suggests that the spatial relationship is complex and nonlinear. Some land-cover types burned more frequently than expected, but no systematic differences were observed across the five regions. The consistent association between higher population densities and fire suggests that regardless of differences between land-cover types, natural fire regimes, or overall population, the presence of people in Mediterranean-climate regions strongly affects the frequency of fires; thus, population growth in areas now sparsely settled presents a conservation concern. Considering the sensitivity of plant species to repeated burning and the global conservation significance of Mediterranean-climate ecosystems, conservation planning needs to consider the human influence on fire frequency. Fine-scale spatial

  11. Seasonal and inter-annual variability of the net ecosystem CO2 exchange of a temperate mountain grassland: effects of climate and management.

    Science.gov (United States)

    Wohlfahrt, Georg; Hammerle, Albin; Haslwanter, Alois; Bahn, Michael; Tappeiner, Ulrike; Cernusca, Alexander

    2008-04-27

    The role and relative importance of climate and cutting for the seasonal and inter-annual variability of the net ecosystem CO 2 (NEE) of a temperate mountain grassland was investigated. Eddy covariance CO 2 flux data and associated measurements of the green area index and the major environmental driving forces acquired during 2001-2006 at the study site Neustift (Austria) were analyzed. Driven by three cutting events per year which kept the investigated grassland in a stage of vigorous growth, the seasonal variability of NEE was primarily modulated by gross primary productivity (GPP). The role of environmental parameters in modulating the seasonal variability of NEE was obscured by the strong response of GPP to changes in the amount of green area, as well as the cutting-mediated decoupling of phenological development and the seasonal course of climate drivers. None of the climate and management metrics examined was able to explain the inter-annual variability of annual NEE. This is thought to result from (1) a high covariance between GPP and ecosystem respiration (R eco ) at the annual time scale which results in a comparatively small inter-annual variation of NEE, (2) compensating effects between carbon exchange during and outside the management period, and (3) changes in the biotic response to rather than the climate variables per se. GPP was more important in modulating inter-annual variations in NEE in spring and before the first and second cut, while R eco explained a larger fraction of the inter-annual variability of NEE during the remaining, in particular the post-cut, periods.

  12. Effects of disturbance and climate change on ecosystem performance in the Yukon River Basin boreal forest

    Science.gov (United States)

    Wylie, Bruce K.; Rigge, Matthew B.; Brisco, Brian; Mrnaghan, Kevin; Rover, Jennifer R.; Long, Jordan

    2014-01-01

    A warming climate influences boreal forest productivity, dynamics, and disturbance regimes. We used ecosystem models and 250 m satellite Normalized Difference Vegetation Index (NDVI) data averaged over the growing season (GSN) to model current, and estimate future, ecosystem performance. We modeled Expected Ecosystem Performance (EEP), or anticipated productivity, in undisturbed stands over the 2000–2008 period from a variety of abiotic data sources, using a rule-based piecewise regression tree. The EEP model was applied to a future climate ensemble A1B projection to quantify expected changes to mature boreal forest performance. Ecosystem Performance Anomalies (EPA), were identified as the residuals of the EEP and GSN relationship and represent performance departures from expected performance conditions. These performance data were used to monitor successional events following fire. Results suggested that maximum EPA occurs 30–40 years following fire, and deciduous stands generally have higher EPA than coniferous stands. Mean undisturbed EEP is projected to increase 5.6% by 2040 and 8.7% by 2070, suggesting an increased deciduous component in boreal forests. Our results contribute to the understanding of boreal forest successional dynamics and its response to climate change. This information enables informed decisions to prepare for, and adapt to, climate change in the Yukon River Basin forest.

  13. Climate change alters seedling emergence and establishment in an old-field ecosystem.

    Directory of Open Access Journals (Sweden)

    Aimée T Classen

    2010-10-01

    Full Text Available Ecological succession drives large-scale changes in ecosystem composition over time, but the mechanisms whereby climatic change might alter succession remain unresolved. Here, we asked if the effects of atmospheric and climatic change would alter tree seedling emergence and establishment in an old-field ecosystem, recognizing that small shifts in rates of seedling emergence and establishment of different species may have long-term repercussions on the transition of fields to forests in the future.We introduced seeds from three early successional tree species into constructed old-field plant communities that had been subjected for 4 years to altered temperature, precipitation, and atmospheric CO(2 regimes in an experimental facility. Our experiment revealed that different combinations of atmospheric CO(2 concentration, air temperature, and soil moisture altered seedling emergence and establishment. Treatments directly and indirectly affected soil moisture, which was the best predictor of seedling establishment, though treatment effects differed among species.The observed impacts, coupled with variations in the timing of seed arrival, are demonstrated as predictors of seedling emergence and establishment in ecosystems under global change.

  14. Living in an oasis: Rapid transformations, resilience, and resistance in the North Water Area societies and ecosystems.

    Science.gov (United States)

    Jeppesen, Erik; Appelt, Martin; Hastrup, Kirsten; Grønnow, Bjarne; Mosbech, Anders; Smol, John P; Davidson, Thomas A

    2018-04-01

    Based on lake sediment data, archaeological findings, and historical records, we describe rapid transformations, resilience and resistance in societies and ecosystems, and their interactions in the past in the North Water area related to changes in climate and historical events. Examples are the formation of the polynya itself and the early arrival of people, ca. 4500 years ago, and later major human immigrations (different societies, cultural encounters, or abandonment) from other regions in the Arctic. While the early immigrations had relatively modest and localised effect on the ecosystem, the later-incoming culture in the early thirteenth century was marked by extensive migrations into and out of the area and abrupt shifts in hunting technologies. This has had long-lasting consequences for the local lake ecosystems. Large natural transformations in the ecosystems have also occurred over relatively short time periods related to changes in the polynya. Finally, we discuss the future perspectives for the North Water area given the many threats, but also opportunities.

  15. Climate and fishing steer ecosystem regeneration to uncertain economic futures

    Science.gov (United States)

    Blenckner, Thorsten; Llope, Marcos; Möllmann, Christian; Voss, Rudi; Quaas, Martin F.; Casini, Michele; Lindegren, Martin; Folke, Carl; Chr. Stenseth, Nils

    2015-01-01

    Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socio-economic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree to which recovery is possible. By applying a statistical food-web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. Instead, the ecosystem regenerates towards a new ecological baseline. This new baseline is characterized by lower and more variable biomass of cod, the commercially most important fish stock in the Baltic Sea, even under very low exploitation pressure. Furthermore, a socio-economic assessment shows that this signal is amplified at the level of societal costs, owing to increased uncertainty in biomass and reduced consumer surplus. Specifically, the combined economic losses amount to approximately 120 million € per year, which equals half of today's maximum economic yield for the Baltic cod fishery. Our analyses suggest that shifts in ecological and economic baselines can lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change. PMID:25694626

  16. Evaluating the Collaborative Ecosystem for an Innovation-Driven Economy: A Systems Analysis and Case Study of Science Parks

    Directory of Open Access Journals (Sweden)

    Min-Ren Yan

    2018-03-01

    Full Text Available National policies for science parks and innovation have been identified as one of the major driving forces for the innovation-driven economy, especially for publicly funded science parks. To investigate this collaborative ecosystem (government-academia-industry for growth and sustainable development, this paper proposes a nation-wide economic impact analysis of science parks and innovation policy based on historical data drawn from one of the globally recognized high-technology industrial clusters in Taiwan. Systems thinking with causal loop analysis are adopted to improve our understanding of the collaborative ecosystem with science park policies. First, from a holistic viewpoint, the role of government in a science parks and innovation ecosystem is reviewed. A systems analysis of an innovation-driven economy with a science park policy is presented as a strategy map for policy implementers. Second, the added economic value and employment of the benchmarked science parks is evaluated from a long range perspective. Third, the concepts of government-academia-industry collaboration and policies to innovation ecosystem are introduced while addressing the measures and performance of innovation and applied R&D in the science parks. We conclude with a discussion of lessons learned and the policy implications of science park development and an innovation ecosystem.

  17. Acclimation of methane production weakens ecosystem response to climate warming in a northern peatland

    Science.gov (United States)

    MA, S.; Huang, Y.; Jiang, J.; Ricciuto, D. M.; Hanson, P. J.; Luo, Y.

    2017-12-01

    Warming-induced increases in greenhouse gases from terrestrial ecosystems represent a positive feedback to twenty-first-century climate warming, but the magnitude of this stimulatory effect remains uncertain. Acclimation of soil respiration and photosynthesis have been found to slow down the feedback due to the substrate limitation and thermal adaptation. However, acclimation of ecosystem methane emission to climate warming has not been well illustrated, despite that methane is directly responsible for approximately 20% of global warming since pre-industrial time. In this study, we used the data-model fusion approach to explore the potential acclimation of methane emission to climate warming. We assimilated CH4 static chamber flux data at the Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) experimental site into the ecosystem model, TECO_SPRUCE. The SPRUCE project has been conducted to study the responses of northern peatland to climate warming (+0, +2.25, +4.5, +6.75, +9 °C) and elevated atmospheric CO2 concentration (+0 and +500 ppm). The warming treatments were initiated from June 2014. We estimated parameter values using environmental and flux data in those five warming treatment levels from 2014 to 2016 for the acclimation study. The key parameters that were estimated for methane emissions are the potential ratio of CO2 converted to CH4 (r_me), Q10 for CH4 production (Q10_pro), maximum oxidation rate (Omax) and the factor of transport ability at plant community level (Tveg). Among them, r_me and Q10_pro were well constrained in each treatment plot. Q10 decreased from 3.33 (control) to 1.22 (+9˚C treatment) and r_me decreased from 0.675 (control) to 0.505 (+9˚C treatment). The acclimation will dampen the warming effect on methane production and emission. Current ecosystem models assumed constant Q10 for CH4 production and CH4/CO2 conversion ratio in the future warmed climate. The assumption is likely to overestimate the methane

  18. Global peatland initiation driven by regionally asynchronous warming.

    Science.gov (United States)

    Morris, Paul J; Swindles, Graeme T; Valdes, Paul J; Ivanovic, Ruza F; Gregoire, Lauren J; Smith, Mark W; Tarasov, Lev; Haywood, Alan M; Bacon, Karen L

    2018-05-08

    Widespread establishment of peatlands since the Last Glacial Maximum represents the activation of a globally important carbon sink, but the drivers of peat initiation are unclear. The role of climate in peat initiation is particularly poorly understood. We used a general circulation model to simulate local changes in climate during the initiation of 1,097 peatlands around the world. We find that peat initiation in deglaciated landscapes in both hemispheres was driven primarily by warming growing seasons, likely through enhanced plant productivity, rather than by any increase in effective precipitation. In Western Siberia, which remained ice-free throughout the last glacial period, the initiation of the world's largest peatland complex was globally unique in that it was triggered by an increase in effective precipitation that inhibited soil respiration and allowed wetland plant communities to establish. Peat initiation in the tropics was only weakly related to climate change, and appears to have been driven primarily by nonclimatic mechanisms such as waterlogging due to tectonic subsidence. Our findings shed light on the genesis and Holocene climate space of one of the world's most carbon-dense ecosystem types, with implications for understanding trajectories of ecological change under changing future climates.

  19. The theory, direction, and magnitude of ecosystem fire probability as constrained by precipitation and temperature.

    Science.gov (United States)

    Guyette, Richard; Stambaugh, Michael C; Dey, Daniel; Muzika, Rose Marie

    2017-01-01

    The effects of climate on wildland fire confronts society across a range of different ecosystems. Water and temperature affect the combustion dynamics, irrespective of whether those are associated with carbon fueled motors or ecosystems, but through different chemical, physical, and biological processes. We use an ecosystem combustion equation developed with the physical chemistry of atmospheric variables to estimate and simulate fire probability and mean fire interval (MFI). The calibration of ecosystem fire probability with basic combustion chemistry and physics offers a quantitative method to address wildland fire in addition to the well-studied forcing factors such as topography, ignition, and vegetation. We develop a graphic analysis tool for estimating climate forced fire probability with temperature and precipitation based on an empirical assessment of combustion theory and fire prediction in ecosystems. Climate-affected fire probability for any period, past or future, is estimated with given temperature and precipitation. A graphic analyses of wildland fire dynamics driven by climate supports a dialectic in hydrologic processes that affect ecosystem combustion: 1) the water needed by plants to produce carbon bonds (fuel) and 2) the inhibition of successful reactant collisions by water molecules (humidity and fuel moisture). These two postulates enable a classification scheme for ecosystems into three or more climate categories using their position relative to change points defined by precipitation in combustion dynamics equations. Three classifications of combustion dynamics in ecosystems fire probability include: 1) precipitation insensitive, 2) precipitation unstable, and 3) precipitation sensitive. All three classifications interact in different ways with variable levels of temperature.

  20. The theory, direction, and magnitude of ecosystem fire probability as constrained by precipitation and temperature.

    Directory of Open Access Journals (Sweden)

    Richard Guyette

    Full Text Available The effects of climate on wildland fire confronts society across a range of different ecosystems. Water and temperature affect the combustion dynamics, irrespective of whether those are associated with carbon fueled motors or ecosystems, but through different chemical, physical, and biological processes. We use an ecosystem combustion equation developed with the physical chemistry of atmospheric variables to estimate and simulate fire probability and mean fire interval (MFI. The calibration of ecosystem fire probability with basic combustion chemistry and physics offers a quantitative method to address wildland fire in addition to the well-studied forcing factors such as topography, ignition, and vegetation. We develop a graphic analysis tool for estimating climate forced fire probability with temperature and precipitation based on an empirical assessment of combustion theory and fire prediction in ecosystems. Climate-affected fire probability for any period, past or future, is estimated with given temperature and precipitation. A graphic analyses of wildland fire dynamics driven by climate supports a dialectic in hydrologic processes that affect ecosystem combustion: 1 the water needed by plants to produce carbon bonds (fuel and 2 the inhibition of successful reactant collisions by water molecules (humidity and fuel moisture. These two postulates enable a classification scheme for ecosystems into three or more climate categories using their position relative to change points defined by precipitation in combustion dynamics equations. Three classifications of combustion dynamics in ecosystems fire probability include: 1 precipitation insensitive, 2 precipitation unstable, and 3 precipitation sensitive. All three classifications interact in different ways with variable levels of temperature.

  1. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    DEFF Research Database (Denmark)

    Selsted, Merete Bang

    on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO2 concentrations will increase...... carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO2. The methodology of static chamber CO2 flux measurements and applying the technology in a FACE (free air CO2 enrichment) facility is a challenge...... on the atmospheric CO2 concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO2 concentration and the CO2 soil-atmosphere gradient....

  2. Intrinsic climate dependency of ecosystem light and water-use-efficiencies across Australian biomes

    International Nuclear Information System (INIS)

    Shi, Hao; Li, Longhui; Eamus, Derek; Cleverly, James; Huete, Alfredo; Yu, Qiang; Beringer, Jason; Van Gorsel, Eva; Hutley, Lindsay

    2014-01-01

    The sensitivity of ecosystem gross primary production (GPP) to availability of water and photosynthetically active radiation (PAR) differs among biomes. Here we investigated variations of ecosystem light-use-efficiency (eLUE: GPP/PAR) and water-use-efficiency (eWUE: GPP/evapotranspiration) among seven Australian eddy covariance sites with differing annual precipitation, species composition and temperature. Changes to both eLUE and eWUE were primarily correlated with atmospheric vapor pressure deficit (VPD) at multiple temporal scales across biomes, with minor additional correlations observed with soil moisture and temperature. The effects of leaf area index on eLUE and eWUE were also relatively weak compared to VPD, indicating an intrinsic dependency of eLUE and eWUE on climate. Additionally, eLUE and eWUE were statistically different for biomes between summer and winter, except eWUE for savannas and the grassland. These findings will improve our understanding of how light- and water-use traits in Australian ecosystems may respond to climate change. (letter)

  3. Global patterns in the vulnerability of ecosystems to vegetation shifts due to climate change

    Science.gov (United States)

    Patrick Gonzalez; Ronald P. Neilson; James M. Lenihan; Raymond J. Drapek

    2010-01-01

    Climate change threatens to shift vegetation, disrupting ecosystems and damaging human well-being. Field observations in boreal, temperate and tropical ecosystems have detected biome changes in the 20th century, yet a lack of spatial data on vulnerability hinders organizations that manage natural resources from identifying priority areas for adaptation measures. We...

  4. Enhanced science-stakeholder communication to improve ecosystem model performances for climate change impact assessments.

    Science.gov (United States)

    Jönsson, Anna Maria; Anderbrant, Olle; Holmér, Jennie; Johansson, Jacob; Schurgers, Guy; Svensson, Glenn P; Smith, Henrik G

    2015-04-01

    In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science-stakeholder collaboration, and in a two-way dialog link empirical experience and impact modelling with policy and strategies for sustainable management. In this paper we give a brief overview of different ecosystem modelling methods, discuss how to include ecological and management aspects, and highlight the importance of science-stakeholder communication. By this, we hope to stimulate a discussion among the science-stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models.

  5. Ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bang Selsted, M

    2010-07-15

    Global change is a reality. Atmospheric CO{sub 2} levels are rising as well as mean global temperature and precipitation patterns are changing. These three environmental factors have separately and in combination effect on ecosystem processes. Terrestrial ecosystems hold large amounts of carbon, why understanding plant and soil responses to such changes are necessary, as ecosystems potentially can ameliorate or accelerate global change. To predict the feedback of ecosystems to the atmospheric CO{sub 2} concentrations experiments imitating global change effects are therefore an important tool. This work on ecosystem-atmosphere exchange of carbon in a heathland under future climatic conditions, shows that extended summer drought in combination with elevated temperature will ensure permanent dryer soil conditions, which decreases carbon turnover, while elevated atmospheric CO{sub 2} concentrations will increase carbon turnover. In the full future climate scenario, carbon turnover is over all expected to increase and the heathland to become a source of atmospheric CO{sub 2}. The methodology of static chamber CO{sub 2} flux measurements and applying the technology in a FACE (free air CO{sub 2} enrichment) facility is a challenge. Fluxes of CO{sub 2} from soil to atmosphere depend on a physical equilibrium between those two medias, why it is important to keep the CO{sub 2} gradient between soil and atmosphere unchanged during measurement. Uptake to plants via photosynthesis depends on a physiological process, which depends strongly on the atmospheric CO{sub 2} concentration. Photosynthesis and respiration run in parallel during measurements of net ecosystem exchange, and these measurements should therefore be performed with care to both the atmospheric CO{sub 2} concentration and the CO{sub 2} soil-atmosphere gradient. (author)

  6. The response of terrestrial ecosystems to global climate change: Towards an integrated approach

    International Nuclear Information System (INIS)

    Rustad, Lindsey E.

    2008-01-01

    Accumulating evidence points to an anthropogenic 'fingerprint' on the global climate change that has occurred in the last century. Climate change has, and will continue to have, profound effects on the structure and function of terrestrial ecosystems. As such, there is a critical need to continue to develop a sound scientific basis for national and international policies regulating carbon sequestration and greenhouse gas emissions. This paper reflects on the nature of current global change experiments, and provides recommendations for a unified multidisciplinary approach to future research in this dynamic field. These recommendations include: (1) better integration between experiments and models, and amongst experimental, monitoring, and space-for-time studies; (2) stable and increased support for long-term studies and multi-factor experiments; (3) explicit inclusion of biodiversity, disturbance, and extreme events in experiments and models; (4) consideration of timing vs intensity of global change factors in experiments and models; (5) evaluation of potential thresholds or ecosystem 'tipping points'; and (6) increased support for model-model and model-experiment comparisons. These recommendations, which reflect discussions within the TERACC international network of global change scientists, will facilitate the unraveling of the complex direct and indirect effects of global climate change on terrestrial ecosystems and their components

  7. Carbon exchange between ecosystems and atmosphere in the Czech Republic is affected by climate factors

    International Nuclear Information System (INIS)

    Marek, Michal V.; Janous, Dalibor; Taufarova, Klara; Havrankova, Katerina; Pavelka, Marian; Kaplan, Veroslav; Markova, Irena

    2011-01-01

    By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. - Highlights: → Highest carbon sequestration potential in evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). → The final carbon gain of the grassland was negative (massive ecosystem respiration). → Climate is important factor of net primary productivity. → Carbon uptake is strongly affected by the ontogeny and a production strategy of ecosystem. - Identification of the apparent differences in the carbon storage by different ecosystem types.

  8. Climate change impacts on lake thermal dynamics and ecosystem vulnerabilities

    Science.gov (United States)

    Sahoo, G. B; Forrest, A. L; Schladow, S. G ;; Reuter, J. E; Coats, R.; Dettinger, Michael

    2016-01-01

    Using water column temperature records collected since 1968, we analyzed the impacts of climate change on thermal properties, stability intensity, length of stratification, and deep mixing dynamics of Lake Tahoe using a modified stability index (SI). This new SI is easier to produce and is a more informative measure of deep lake stability than commonly used stability indices. The annual average SI increased at 16.62 kg/m2/decade although the summer (May–October) average SI increased at a higher rate (25.42 kg/m2/decade) during the period 1968–2014. This resulted in the lengthening of the stratification season by approximately 24 d. We simulated the lake thermal structure over a future 100 yr period using a lake hydrodynamic model driven by statistically downscaled outputs of the Geophysical Fluid Dynamics Laboratory Model (GFDL) for two different green house gas emission scenarios (the A2 in which greenhouse-gas emissions increase rapidly throughout the 21st Century, and the B1 in which emissions slow and then level off by the late 21st Century). The results suggest a continuation and intensification of the already observed trends. The length of stratification duration and the annual average lake stability are projected to increase by 38 d and 12 d and 30.25 kg/m2/decade and 8.66 kg/m2/decade, respectively for GFDLA2 and GFDLB1, respectively during 2014–2098. The consequences of this change bear the hallmarks of climate change induced lake warming and possible exacerbation of existing water quality, quantity and ecosystem changes. The developed methodology could be extended and applied to other lakes as a tool to predict changes in stratification and mixing dynamics.

  9. A global examination of the response of ecosystem water-use efficiency to drought based on MODIS data.

    Science.gov (United States)

    Huang, Ling; He, Bin; Han, Le; Liu, Junjie; Wang, Haiyan; Chen, Ziyue

    2017-12-01

    Ecosystem water-use efficiency (WUE) plays an important role in carbon and water cycles. Currently, the response of WUE to drought disturbance remains controversial. Based on the global ecosystem gross primary productivity (GPP) product and the evapotranspiration product (ET), both of which were retrieved from the moderate resolution imaging spectroradiometer (MODIS), as well as the drought index, this study comprehensively examined the relationship between ecosystem WUE (WUE=GPP/ET) and drought at the global scale. The response of WUE to drought showed large differences in various regions and biomes. WUE for arid ecosystems typically showed a negative response to drought, whereas WUE for humid ecosystems showed both positive and negative response to drought. Legacy effects of drought on ecosystem WUE were observed. Furthermore, ecosystems showed a sensitive response to abrupt changes in hydrological climatic conditions. The transition from wet to dry years should increase ecosystem WUE, and the opposite change in WUE should occur when an ecosystem experiences a transition from dry to wet years. This indicates the resilience of ecosystems to drought disturbance. Knowledge from this study should provide an in-depth understanding of ecosystem strategies for coping with drought. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Ecosystem-Based Adaptation to Climate Change in Caribbean Small Island Developing States: Integrating Local and External Knowledge

    Directory of Open Access Journals (Sweden)

    Tiina Kurvits

    2012-08-01

    Full Text Available Caribbean Small Island Developing States (SIDS are vulnerable to climate change impacts including sea level rise, invasive species, ocean acidification, changes in rainfall patterns, increased temperatures, and changing hazard regimes including hurricanes, floods and drought. Given high dependencies in Caribbean SIDS on natural resources for livelihoods, a focus on ecosystems and their interaction with people is essential for climate change adaptation. Increasingly, ecosystem-based adaptation (EbA approaches are being highlighted as an approach to address climate change impacts. Specifically, EbA encourages the use of local and external knowledge about ecosystems to identify climate change adaptation approaches. This paper critically reviews EbA in Caribbean SIDS, focusing on the need to integrate local and external knowledge. An analysis of current EbA in the Caribbean is undertaken alongside a review of methodologies used to integrate local and external expertise for EbA. Finally key gaps, lessons learnt and suggested ways forward for EbA in Caribbean SIDS and potentially further afield are identified.

  11. Water quality and ecosystem management: Data-driven reality check of effects in streams and lakes

    Science.gov (United States)

    Destouni, Georgia; Fischer, Ida; Prieto, Carmen

    2017-08-01

    This study investigates nutrient-related water quality conditions and change trends in the first management periods of the EU Water Framework Directive (WFD; since 2009) and Baltic Sea Action Plan (BASP; since 2007). With mitigation of nutrients in inland waters and their discharges to the Baltic Sea being a common WFD and BSAP target, we use Sweden as a case study of observable effects, by compiling and analyzing all openly available water and nutrient monitoring data across Sweden since 2003. The data compilation reveals that nutrient monitoring covers only around 1% (down to 0.2% for nutrient loads) of the total number of WFD-classified stream and lake water bodies in Sweden. The data analysis further shows that the hydro-climatically driven water discharge dominates the determination of waterborne loads of both total phosphorus and total nitrogen across Sweden. Both water discharge and the related nutrient loads are in turn well correlated with the ecosystem status classification of Swedish water bodies. Nutrient concentrations do not exhibit such correlation and their changes over the study period are on average small, but concentration increases are found for moderate-to-bad status waters, for which both the WFD and the BSAP have instead targeted concentration decreases. In general, these results indicate insufficient distinction and mitigation of human-driven nutrient components in inland waters and their discharges to the sea by the internationally harmonized applications of the WFD and the BSAP. The results call for further comparative investigations of observable large-scale effects of such regulatory/management frameworks in different parts of the world.

  12. Structure, functioning, and cumulative stressors of Mediterranean deep-sea ecosystems

    Science.gov (United States)

    Tecchio, Samuele; Coll, Marta; Sardà, Francisco

    2015-06-01

    Environmental stressors, such as climate fluctuations, and anthropogenic stressors, such as fishing, are of major concern for the management of deep-sea ecosystems. Deep-water habitats are limited by primary productivity and are mainly dependent on the vertical input of organic matter from the surface. Global change over the latest decades is imparting variations in primary productivity levels across oceans, and thus it has an impact on the amount of organic matter landing on the deep seafloor. In addition, anthropogenic impacts are now reaching the deep ocean. The Mediterranean Sea, the largest enclosed basin on the planet, is not an exception. However, ecosystem-level studies of response to varying food input and anthropogenic stressors on deep-sea ecosystems are still scant. We present here a comparative ecological network analysis of three food webs of the deep Mediterranean Sea, with contrasting trophic structure. After modelling the flows of these food webs with the Ecopath with Ecosim approach, we compared indicators of network structure and functioning. We then developed temporal dynamic simulations varying the organic matter input to evaluate its potential effect. Results show that, following the west-to-east gradient in the Mediterranean Sea of marine snow input, organic matter recycling increases, net production decreases to negative values and trophic organisation is overall reduced. The levels of food-web activity followed the gradient of organic matter availability at the seafloor, confirming that deep-water ecosystems directly depend on marine snow and are therefore influenced by variations of energy input, such as climate-driven changes. In addition, simulations of varying marine snow arrival at the seafloor, combined with the hypothesis of a possible fishery expansion on the lower continental slope in the western basin, evidence that the trawling fishery may pose an impact which could be an order of magnitude stronger than a climate-driven

  13. Ground Water and Climate Change

    Science.gov (United States)

    Taylor, Richard G.; Scanlon, Bridget; Doell, Petra; Rodell, Matt; van Beek, Rens; Wada, Yoshihide; Longuevergne, Laurent; Leblanc, Marc; Famiglietti, James S.; Edmunds, Mike; hide

    2013-01-01

    As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

  14. Effects of Climate and Ecosystem Disturbances on Biogeochemical Cycling in a Semi-Natural Terrestrial Ecosystem

    International Nuclear Information System (INIS)

    Beier, Claus; Schmidt, Inger Kappel; Kristensen, Hanne Lakkenborg

    2004-01-01

    The effects of increased temperature and potential ecosystem disturbances on biogeochemical cycling were investigated by manipulation of temperature in a mixed Calluna/grass heathland in Denmark. A reflective curtain covered the vegetation during the night to reduce the heat loss of IR radiation from the ecosystem to the atmosphere. This 'night time warming' was done for 3 years and warmed the air and soil by 1.1 deg. C. Warming was combined with ecosystem disturbances, including infestation by Calluna heather beetles (Lochmaea suturalis Thompson) causing complete defoliation of Calluna leaves during the summer 2000, and subsequent harvesting of all aboveground biomass during the autumn. Small increases in mineralisation rates were induced by warming and resulted in increased leaching of nitrogen from the organic soil layer. The increased nitrogen leaching from the organic soil layer was re-immobilised in the mineral soil layer as warming stimulated plant growth and thereby increased nitrogen immobilisation. Contradictory to the generally moderate effects of warming, the heather beetle infestation had very strong effects on mineralisation rates and the plant community. The grasses completely out-competed the Calluna plants which had not re-established two years after the infestation, probably due to combined effects of increased nutrient availability and the defoliation of Calluna. On the short term, ecosystem disturbances may have very strong effects on internal ecosystem processes and plant community structure compared to the more long-term effects of climate change

  15. Climate change and watershed mercury export in a Coastal Plain watershed

    Science.gov (United States)

    Heather Golden; Christopher D. Knightes; Paul A. Conrads; Toby D. Feaster; Gary M. Davis; Stephen T. Benedict; Paul M. Bradley

    2016-01-01

    Future changes in climatic conditions may affect variations in watershed processes (e.g., hydrological, biogeochemical) and surface water quality across a wide range of physiographic provinces, ecosystems, and spatial scales. How such climatic shifts will impact watershed mercury (Hg) dynamics and hydrologically-driven Hg transport is a significant concern.

  16. Change in terrestrial ecosystem water-use efficiency over the last three decades.

    Science.gov (United States)

    Huang, Mengtian; Piao, Shilong; Sun, Yan; Ciais, Philippe; Cheng, Lei; Mao, Jiafu; Poulter, Ben; Shi, Xiaoying; Zeng, Zhenzhong; Wang, Yingping

    2015-06-01

    Defined as the ratio between gross primary productivity (GPP) and evapotranspiration (ET), ecosystem-scale water-use efficiency (EWUE) is an indicator of the adjustment of vegetation photosynthesis to water loss. The processes controlling EWUE are complex and reflect both a slow evolution of plants and plant communities as well as fast adjustments of ecosystem functioning to changes of limiting resources. In this study, we investigated EWUE trends from 1982 to 2008 using data-driven models derived from satellite observations and process-oriented carbon cycle models. Our findings suggest positive EWUE trends of 0.0056, 0.0007 and 0.0001 g C m(-2)  mm(-1)  yr(-1) under the single effect of rising CO2 ('CO2 '), climate change ('CLIM') and nitrogen deposition ('NDEP'), respectively. Global patterns of EWUE trends under different scenarios suggest that (i) EWUE-CO2 shows global increases, (ii) EWUE-CLIM increases in mainly high latitudes and decreases at middle and low latitudes, (iii) EWUE-NDEP displays slight increasing trends except in west Siberia, eastern Europe, parts of North America and central Amazonia. The data-driven MTE model, however, shows a slight decline of EWUE during the same period (-0.0005 g C m(-2)  mm(-1)  yr(-1) ), which differs from process-model (0.0064 g C m(-2)  mm(-1)  yr(-1) ) simulations with all drivers taken into account. We attribute this discrepancy to the fact that the nonmodeled physiological effects of elevated CO2 reducing stomatal conductance and transpiration (TR) in the MTE model. Partial correlation analysis between EWUE and climate drivers shows similar responses to climatic variables with the data-driven model and the process-oriented models across different ecosystems. Change in water-use efficiency defined from transpiration-based WUEt (GPP/TR) and inherent water-use efficiency (IWUEt , GPP×VPD/TR) in response to rising CO2 , climate change, and nitrogen deposition are also discussed. Our analyses will

  17. Partitioning inter annual variability in net ecosystem exchange between climatic variability and functional change

    International Nuclear Information System (INIS)

    Hui, D.; Luo, Y.; Katul, G.

    2003-01-01

    Inter annual variability in net ecosystem exchange of carbon is investigated using a homogeneity-of-slopes model to identify the function change contributing to inter annual variability, net ecosystem carbon exchange, and night-time ecosystem respiration. Results of employing this statistical approach to a data set collected at the Duke Forest AmeriFlux site from August 1997 to December 2001 are discussed. The results demonstrate that it is feasible to partition the variation in ecosystem carbon fluxes into direct effects of seasonal and inter annual climatic variability and functional change. 51 refs., 4 tabs., 5 figs

  18. Assessing the Impact of Climate Change on Land-Water-Ecosystem Quality in Polar and Mountainous Regions: A New Interregional Project (INT5153)

    Energy Technology Data Exchange (ETDEWEB)

    Dercon, Gerd [Soil and Water Management and Crop Nutrition Subprogramme, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, IAEA, Seibersdorf (Austria); Gerardo-Abaya, Jane [Division for Asia and the Pacific Section 2, Department of Technical Cooperation, IAEA, Vienna (Austria); Mavlyudov, Bulat [Institute of Geography, Russian Academy of Sciences, Moscow (Russian Federation); others, and

    2014-07-15

    The INT5153 project aims to improve the understanding of the impact of climate change on fragile polar and mountainous ecosystems on both a local and global scale for their better management and conservation. Seven core and five related benchmark sites have been selected from different global regions for specific assessments of the impact of climate change with the following expected outcomes and outputs: Outcomes: • Improved understanding of the impact of climate change on the cryosphere in polar and mountainous ecosystems and its effects on landwater- ecosystem quality at both local and global scales. • Recommendations for improvement of regional policies for soil and agricultural water management, conservation, and environmental protection in polar and mountainous regions. Outputs: • Specific strategies to minimize the adverse effects of, and adapt to, reduced seasonal snow and glacier covered areas on land-water-ecosystem quality in polar and mountain regions across the world. • Enhanced interregional network of laboratories and institutions competent in the assessment of climate change impacts on the cryosphere and land-water-ecosystem quality, using isotopic and nuclear techniques. • Increased number of young scientists trained in the use of isotope and nuclear techniques to assess the impact of climate change on the cryosphere and land-water-ecosystem quality in polar and mountainous ecosystems. • Platform/database with global access for continuing work and monitoring of impact of climate change on fragile polar and mountainous ecosystems at local and global scales, as well as for communicating findings to policy makers and communities. • Improved understanding of the effects of climate change disseminated through appropriate publications, policy briefs, and through a dedicated internet platform. • Methodologies and protocols for investigations in specific ecosystems and conservation/adaptation measures for agriculture areas.

  19. Assessing the Impact of Climate Change on Land-Water-Ecosystem Quality in Polar and Mountainous Regions: A New Interregional Project (INT5153)

    International Nuclear Information System (INIS)

    Dercon, Gerd; Gerardo-Abaya, Jane; Mavlyudov, Bulat

    2014-01-01

    The INT5153 project aims to improve the understanding of the impact of climate change on fragile polar and mountainous ecosystems on both a local and global scale for their better management and conservation. Seven core and five related benchmark sites have been selected from different global regions for specific assessments of the impact of climate change with the following expected outcomes and outputs: Outcomes: • Improved understanding of the impact of climate change on the cryosphere in polar and mountainous ecosystems and its effects on landwater- ecosystem quality at both local and global scales. • Recommendations for improvement of regional policies for soil and agricultural water management, conservation, and environmental protection in polar and mountainous regions. Outputs: • Specific strategies to minimize the adverse effects of, and adapt to, reduced seasonal snow and glacier covered areas on land-water-ecosystem quality in polar and mountain regions across the world. • Enhanced interregional network of laboratories and institutions competent in the assessment of climate change impacts on the cryosphere and land-water-ecosystem quality, using isotopic and nuclear techniques. • Increased number of young scientists trained in the use of isotope and nuclear techniques to assess the impact of climate change on the cryosphere and land-water-ecosystem quality in polar and mountainous ecosystems. • Platform/database with global access for continuing work and monitoring of impact of climate change on fragile polar and mountainous ecosystems at local and global scales, as well as for communicating findings to policy makers and communities. • Improved understanding of the effects of climate change disseminated through appropriate publications, policy briefs, and through a dedicated internet platform. • Methodologies and protocols for investigations in specific ecosystems and conservation/adaptation measures for agriculture areas

  20. Climate Change Impacts for the Conterminous USA. An Integrated Assessment. Part 6. Distribution and Productivity of Unmanaged Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Izaurralde, R.C.; Thomson, A.M.; Rosenberg, N.J. [The Joint Global Change Research Institute, 8400 Baltimore Avenue, Suite 201, College Park, Maryland, 20740-2496 (United States); Brown, R.A. [Independent Project Analysis, 11150 Sunset Hills Rd., Suite 3, Reston, Virginia, 20190 (United States)

    2005-03-01

    Human activities have altered the distribution and quality of terrestrial ecosystems. Future demands for goods and services from terrestrial ecosystems will occur in a world experiencing human-induced climate change. In this study, we characterize the range in response of unmanaged ecosystems in the conterminous U.S. to 12 climate change scenarios. We obtained this response by simulating the climatically induced shifts in net primary productivity and geographical distribution of major biomes in the conterminous U.S. with the BIOME 3 model. BIOME 3 captured well the potential distribution of major biomes across the U.S. under baseline (current) climate. BIOME 3 also reproduced the general trends of observed net primary production (NPP) acceptably. The NPP projections were reasonable for forests, but not for grasslands where the simulated values were always greater than those observed. Changes in NPP would be most severe under the BMRC climate change scenario in which severe changes in regional temperatures are projected. Under the UIUC and UIUC + Sulfate scenarios, NPP generally increases, especially in the West where increases in precipitation are projected to be greatest. A CO2-fertilization effect either amplified increases or alleviated losses in modeled NPP. Changes in NPP were also associated with changes in the geographic distribution of major biomes. Temperate/boreal mixed forests would cover less land in the U.S. under most of the climate change scenarios examined. Conversely, the temperate conifer and temperate deciduous forests would increase in areal extent under the UIUC and UIUC + Sulfate scenarios. The Arid Shrubland/Steppe would spread significantly across the southwest U.S. under the BMRC scenario. A map overlay of the simulated regions that would lose or gain capacity to produce corn and wheat on top of the projected distribution of natural ecosystems under the BMRC and UIUC scenarios (Global mean temperature increase of +2.5C, no CO2 effect

  1. Impact of environmental pollution and climate change on forest ecosystems: the activity of the IUFRO Research Group 7.01

    Directory of Open Access Journals (Sweden)

    Paoletti E

    2007-12-01

    Full Text Available Impact of environmental pollution and climate change on forest ecosystems: the activity of the IUFRO Research Group 7.01. The IUFRO RG 7.01 deals with "Impacts of Air Pollution and Climate Change on Forest Ecosystems". Climate change and air pollution are closely linked, although in applied scientific research and even more in political negotiations they have been largely separated. Many of the traditional air pollutants and greenhouse gases have not only common sources, but may also interact physically and chemically in the atmosphere causing a variety of environmental impacts on the local, regional and global scales. The impacts on forest ecosystems have been traditionally treated separately for air pollution and climate change. However, the combined effects of numerous climate change and air pollution factors may significantly differ from a sum of separate effects due to an array of various synergistic or antagonistic interactions. The net effect varies for different ecosystem types and geographic regions, and depends on magnitude of climate or air pollution drivers, and types of interactions between them. This paper reviews the links between air pollution and climate change and their interactive effects on forests. A simultaneous addressing of the air pollution and climate change effects on forests is an opportunity for capturing synergies and avoiding overlaps between two lines of traditional research. This could result in more effective research, monitoring and management as well as better integration of environmental policies.

  2. Dynamic behaviour of lagoon ecosystems

    International Nuclear Information System (INIS)

    Cioffi, F.

    2008-01-01

    The dynamic behaviour of primary producers in coastal lagoons due to change of external control parameters, phosphorous external load and maximum tidal flow rate, is investigated by using a eutrophication model. The eutrophication model allows the simulation of the temporal evolution of the concentration of the following species: a) in the water column: dissolved oxygen, vegetal organic carbon, particulate and dissolved organic carbon, dissolved phosphorous and hydrogen sulphide; b) in sediments: dissolved oxygen, particulate and dissolved organic carbon, dissolved and adsorbed phosphorous, hydrogen sulphide. The vegetal organic carbon is distinguished in three components related to the main groups of primary producers, namely eel grass, macro algae and microalgae, having different modalities of nutrient uptake and kinetics parameters depending on the S/V ratio. Diagrams representing the ecosystems dynamic response to the changes of the control parameters were constructed by simulations. The response diagrams suggest the existence of regime shifts which border different ecosystem stability ranges, characterized by the dominance of a specific group of primary producers and by different ecosystem vulnerability at summer water anoxia. A catastrophic bifurcation or abrupt regime shift, evidenced by Poincare sections obtained mapping, at a prefixed time period, the values of the concentration of the species, occurs for a critical value of the control parameter and manifests itself as an abrupt change of the dominant species from eel grass to macro algae. An analogous abrupt change from eel grass to macro algae occurs for a critical value of the tidal flowrate assumed as control parameter in simulations conducted for an assigned value of external phosphorous load.

  3. North Sea ecosystem change from swimming crabs to seagulls.

    Science.gov (United States)

    Luczak, C; Beaugrand, G; Lindley, J A; Dewarumez, J-M; Dubois, P J; Kirby, R R

    2012-10-23

    A recent increase in sea temperature has established a new ecosystem dynamic regime in the North Sea. Climate-induced changes in decapods have played an important role. Here, we reveal a coincident increase in the abundance of swimming crabs and lesser black-backed gull colonies in the North Sea, both in time and in space. Swimming crabs are an important food source for lesser black-backed gulls during the breeding season. Inhabiting the land, but feeding mainly at sea, lesser black-backed gulls provide a link between marine and terrestrial ecosystems, since the bottom-up influence of allochthonous nutrient input from seabirds to coastal soils can structure the terrestrial food web. We, therefore, suggest that climate-driven changes in trophic interactions in the marine food web may also have ensuing ramifications for the coastal ecology of the North Sea.

  4. Potential effects of climate change on freshwater ecosystems of the New England/Mid-Atlantic Region

    Science.gov (United States)

    Moore, M.V.; Pace, M.L.; Mather, J.R.; Murdoch, Peter S.; Howarth, R.W.; Folt, C.L.; Chen, C.-Y.; Hemond, Harold F.; Flebbe, P.A.; Driscoll, C.T.

    1997-01-01

    Numerous freshwater ecosystems, dense concentrations of humans along the eastern seaboard, extensive forests and a history of intensive land use distinguish the New England/Mid-Atlantic Region. Human population densities are forecast to increase in portions of the region at the same time that climate is expected to be changing. Consequently, the effects of humans and climatic change are likely to affect freshwater ecosystems within the region interactively. The general climate, at present, is humid continental, and the region receives abundant precipitation. Climatic projections for a 2 ??CO2 atmosphere, however, suggest warmer and drier conditions for much of this region. Annual temperature increases ranging from 3-5??C are projected, with the greatest increases occurring in autumn or winter. According to a water balance model, the projected increase in temperature will result in greater rates of evaporation and evapotranspiration. This could cause a 21 and 31% reduction in annual stream flow in the southern and northern sections of the region, respectively, with greatest reductions occurring in autumn and winter. The amount and duration of snow cover is also projected to decrease across the region, and summer convective thunderstorms are likely to decrease in frequency but increase in intensity. The dual effects of climate change and direct anthropogenic stress will most likely alter hydrological and biogeochemical processes, and, hence, the floral and faunal communities of the region's freshwater ecosystems. For example, the projected increase in evapotranspiration and evaporation could eliminate most bog ecosystems, and increases in water temperature may increase bioaccumulation, and possibly biomagnification, of organic and inorganic contaminants. Not all change may be adverse. For example, a decrease in runoff may reduce the intensity of ongoing estuarine eutrophication, and acidification of aquatic habitats during the spring snowmelt period may be

  5. Lead-Lag relationships? Asynchrounous and Abrupt Shifts in Atmospheric Circulation, Temperature, and Vegetation during the 8.2 ka Event in the Eastern Mediterranean at Tenaghi Philippon, Greece

    Science.gov (United States)

    Niedermeyer, E. M.; Mulch, A.; Pross, J.

    2017-12-01

    The "8.2 ka event" has been an abrupt and prominent climate perturbation during the Holocene, and is characterized by an episode of generally colder and dryer conditions in the Northern Hemisphere realm. However, evidence to what extent this event has had an impact on climate in the Mediterranean region is ambiguous, in particular with respect to rainfall, temperature and vegetation change on land. Here we present a new, high-resolution record (ø 15 years during the event) of paleotemperatures from the Tenaghi Philippon peat deposit, Eastern Macedonia, Greece, using the MBT'/CBT index based on brGDGTs (branched Glycerol-Dialkyl-Glycerol-Tetraethers). Our data show fairly stable temperatures before the event, which is initiated at 8.1 ka by an abrupt and continuous cooling during the first 35 years of the event. After a short, 10-year episode of minimum temperatures, the event is ended by a similarly abrupt and continuous warming within 38 years. Comparison of our record with a previous study of the stable hydrogen isotopic composition of higher-plant waxes (δDwax) on the same core1 shows that changes in temperature occurred simultaneously with shifts in atmospherics moisture sources (Mediterranean vs Atlantic). Interestingly, further comparison of our data with a previous palynological study of the same core2 reveals that changes in vegetation associated with the 8.2 ka event precede shifts in hydrology and temperature by 100 years. This suggests either pronounced changes in seasonality of temperature and rainfall after the onset of the 8.2 ka event, i.e. at the peak of the event, or that changes in local atmospheric circulation (moisture sources) and temperature where not the initial trigger of changes in vegetation. References: Pross, J., Kotthoff, U., Müller, U.C., Peyron, O., Dormoy, I., Schmiedl, G., Kalaitzidis, S. and Smith, A.M. (2009): Massive perturbation in terrestrial ecosystems of the Eastern Mediterranean region associated with the 8.2 kyr B

  6. Ecological forecasting under climate change: the case of Baltic cod

    DEFF Research Database (Denmark)

    Lindegren, Martin; Möllmann, Christian; Nielsen, Anders

    2010-01-01

    Good decision making for fisheries and marine ecosystems requires a capacity to anticipate the consequences of management under different scenarios of climate change. The necessary ecological forecasting calls for ecosystem-based models capable of integrating multiple drivers across trophic levels...... and properly including uncertainty. The methodology presented here assesses the combined impacts of climate and fishing on marine food-web dynamics and provides estimates of the confidence envelope of the forecasts. It is applied to cod (Gadus morhua) in the Baltic Sea, which is vulnerable to climate......-related decline in salinity owing to both direct and indirect effects (i.e. through species interactions) on early-life survival. A stochastic food web-model driven by regional climate scenarios is used to produce quantitative forecasts of cod dynamics in the twenty-first century. The forecasts show how...

  7. Abrupt increases in Amazonian tree mortality due to drought–fire interactions

    Science.gov (United States)

    Brando, Paulo Monteiro; Balch, Jennifer K.; Nepstad, Daniel C.; Morton, Douglas C.; Putz, Francis E.; Coe, Michael T.; Silvério, Divino; Macedo, Marcia N.; Davidson, Eric A.; Nóbrega, Caroline C.; Alencar, Ane; Soares-Filho, Britaldo S.

    2014-01-01

    Interactions between climate and land-use change may drive widespread degradation of Amazonian forests. High-intensity fires associated with extreme weather events could accelerate this degradation by abruptly increasing tree mortality, but this process remains poorly understood. Here we present, to our knowledge, the first field-based evidence of a tipping point in Amazon forests due to altered fire regimes. Based on results of a large-scale, long-term experiment with annual and triennial burn regimes (B1yr and B3yr, respectively) in the Amazon, we found abrupt increases in fire-induced tree mortality (226 and 462%) during a severe drought event, when fuel loads and air temperatures were substantially higher and relative humidity was lower than long-term averages. This threshold mortality response had a cascading effect, causing sharp declines in canopy cover (23 and 31%) and aboveground live biomass (12 and 30%) and favoring widespread invasion by flammable grasses across the forest edge area (80 and 63%), where fires were most intense (e.g., 220 and 820 kW⋅m−1). During the droughts of 2007 and 2010, regional forest fires burned 12 and 5% of southeastern Amazon forests, respectively, compared with Amazon forests. Future projections of vegetation responses to climate change across drier portions of the Amazon require more than simulation of global climate forcing alone and must also include interactions of extreme weather events, fire, and land-use change. PMID:24733937

  8. Paleoecological studies on variability in marine fish populations: A long-term perspective on the impacts of climatic change on marine ecosystems

    Science.gov (United States)

    Finney, Bruce P.; Alheit, Jürgen; Emeis, Kay-Christian; Field, David B.; Gutiérrez, Dimitri; Struck, Ulrich

    2010-02-01

    The use of historical fishing records to understand relationships between climatic change and fish abundance is limited by the relatively short duration of these records, and complications due to the strong influence of human activity in addition to climatic change. Sedimentary records containing scales, bones or geochemical proxies of variability in fish populations provide unique insights on long-term ecosystem dynamics and relationships with climatic change. Available records from Holocene sediments are summarized and synthesized. The records are from several widespread locations near or along the continental margins of the South Atlantic and Pacific oceans, including Alaska, USA (Pacific salmon), Saanich and Effingham Inlets, British Columbia, Canada (pelagic fish), Santa Barbara Basin, California, USA (Northern anchovies and Pacific sardines), Gulf of California, Mexico (Pacific sardines, Northern anchovies and Pacific hake), Peru upwelling system (sardines, anchovies and hake), and Benguela Current System, South Africa (sardines, anchovies and hake). These records demonstrate that fish population sizes are not constant, and varied significantly over a range of time scales prior to the advent of large-scale commercial fishing. In addition to the decadal-scale variability commonly observed in historical records, the long-term records reveal substantial variability over centennial and millennial time scales. Shifts in abundance are often, but not always, correlated with regional and/or global climatic changes. The long-term perspective reveals different patterns of variability in fish populations, as well as fish-climate relationships, than suggested by analysis of historical records. Many records suggest prominent changes in fish abundance at ca. 1000-1200 AD, during the Little Ice Age, and during the transition at the end of the Little Ice Age in the 19th century that may be correlative, and that were likely driven by major hemispheric or global

  9. Predicting Plant-Accessible Water in the Critical Zone: Mountain Ecosystems in a Mediterranean Climate

    Science.gov (United States)

    Klos, P. Z.; Goulden, M.; Riebe, C. S.; Tague, C.; O'Geen, A. T.; Flinchum, B. A.; Safeeq, M.; Conklin, M. H.; Hart, S. C.; Asefaw Berhe, A.; Hartsough, P. C.; Holbrook, S.; Bales, R. C.

    2017-12-01

    Enhanced understanding of subsurface water storage, and the below-ground architecture and processes that create it, will advance our ability to predict how the impacts of climate change - including drought, forest mortality, wildland fire, and strained water security - will take form in the decades to come. Previous research has examined the importance of plant-accessible water in soil, but in upland landscapes within Mediterranean climates the soil is often only the upper extent of subsurface water storage. We draw insights from both this previous research and a case study of the Southern Sierra Critical Zone Observatory to: define attributes of subsurface storage, review observed patterns in its distribution, highlight nested methods for its estimation across scales, and showcase the fundamental processes controlling its formation. We observe that forest ecosystems at our sites subsist on lasting plant-accessible stores of subsurface water during the summer dry period and during multi-year droughts. This indicates that trees in these forest ecosystems are rooted deeply in the weathered, highly porous saprolite, which reaches up to 10-20 m beneath the surface. This confirms the importance of large volumes of subsurface water in supporting ecosystem resistance to climate and landscape change across a range of spatiotemporal scales. This research enhances the ability to predict the extent of deep subsurface storage across landscapes; aiding in the advancement of both critical zone science and the management of natural resources emanating from similar mountain ecosystems worldwide.

  10. The nexus between climate change, ecosystem services and human health: Towards a conceptual framework.

    Science.gov (United States)

    Chiabai, Aline; Quiroga, Sonia; Martinez-Juarez, Pablo; Higgins, Sahran; Taylor, Tim

    2018-09-01

    This paper addresses the impact that changes in natural ecosystems can have on health and wellbeing focusing on the potential co-benefits that green spaces could provide when introduced as climate change adaptation measures. Ignoring such benefits could lead to sub-optimal planning and decision-making. A conceptual framework, building on the ecosystem-enriched Driver, Pressure, State, Exposure, Effect, Action model (eDPSEEA), is presented to aid in clarifying the relational structure between green spaces and human health, taking climate change as the key driver. The study has the double intention of (i) summarising the literature with a special emphasis on the ecosystem and health perspectives, as well as the main theories behind these impacts, and (ii) modelling these findings into a framework that allows for multidisciplinary approaches to the underlying relations between human health and green spaces. The paper shows that while the literature based on the ecosystem perspective presents a well-documented association between climate, health and green spaces, the literature using a health-based perspective presents mixed evidence in some cases. The role of contextual factors and the exposure mechanism are rarely addressed. The proposed framework could serve as a multidisciplinary knowledge platform for multi-perspecitve analysis and discussion among experts and stakeholders, as well as to support the operationalization of quantitative assessment and modelling exercises. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Interannual abundance changes of gelatinous carnivore zooplankton unveil climate-driven hydrographic variations in the Iberian Peninsula, Portugal.

    Science.gov (United States)

    D'Ambrosio, Mariaelena; Molinero, Juan C; Azeiteiro, Ulisses M; Pardal, Miguel A; Primo, Ana L; Nyitrai, Daniel; Marques, Sónia C

    2016-09-01

    The persistent massive blooms of gelatinous zooplankton recorded during recent decades may be indicative of marine ecosystem changes. In this study, we investigated the potential influence of the North Atlantic climate (NAO) variability on decadal abundance changes of gelatinous carnivore zooplankton in the Mondego estuary, Portugal, over the period 2003-2013. During the 11-year study, the community of gelatinous carnivores encompassed a larger diversity of hydromedusae than siphonophores; the former dominated by Obelia spp., Lizzia blondina, Clythia hemisphaerica, Liriope tetraphylla and Solmaris corona, while the latter dominated by Muggiaea atlantica. Gelatinous carnivore zooplankton displayed marked interannual variability and mounting species richness over the period examined. Their pattern of abundance shifted towards larger abundances ca. 2007 and significant phenological changes. The latter included a shift in the mean annual pattern (from unimodal to bimodal peak, prior and after 2007 respectively) and an earlier timing of the first annual peak concurrent with enhanced temperatures. These changes were concurrent with the climate-driven environmental variability mainly controlled by the NAO, which displayed larger variance after 2007 along with an enhanced upwelling activity. Structural equation modelling allowed depicting cascading effects derived from the NAO influence on regional climate and upwelling variability further shaping water temperature. Such cascading effect percolated the structure and dynamics of the community of gelatinous carnivore zooplankton in the Mondego estuary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic

    Science.gov (United States)

    Gustine, David D.; Brinkman, Todd J.; Lindgren, Michael A.; Schmidt, Jennifer I.; Rupp, T. Scott; Adams, Layne G.

    2014-01-01

    Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (−21%) than the Central Arctic herd that wintered primarily in the arctic tundra (−11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  13. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

    Directory of Open Access Journals (Sweden)

    David D Gustine

    Full Text Available Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs, and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21% than the Central Arctic herd that wintered primarily in the arctic tundra (-11%. Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  14. Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

    Science.gov (United States)

    Gustine, David D; Brinkman, Todd J; Lindgren, Michael A; Schmidt, Jennifer I; Rupp, T Scott; Adams, Layne G

    2014-01-01

    Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21%) than the Central Arctic herd that wintered primarily in the arctic tundra (-11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

  15. Michigan forest ecosystem vulnerability assessment and synthesis: a report from the Northwoods Climate Change Response Framework project

    Science.gov (United States)

    Stephen Handler; Matthew J. Duveneck; Louis Iverson; Emily Peters; Robert M. Scheller; Kirk R. Wythers; Leslie Brandt; Patricia Butler; Maria Janowiak; P. Danielle Shannon; Chris Swanston; Amy Clark Eagle; Joshua G. Cohen; Rich Corner; Peter B. Reich; Tim Baker; Sophan Chhin; Eric Clark; David Fehringer; Jon Fosgitt; James Gries; Christine Hall; Kimberly R. Hall; Robert Heyd; Christopher L. Hoving; Ines Ibáñez; Don Kuhr; Stephen Matthews; Jennifer Muladore; Knute Nadelhoffer; David Neumann; Matthew Peters; Anantha Prasad; Matt Sands; Randy Swaty; Leiloni Wonch; Jad Daley; Mae Davenport; Marla R. Emery; Gary Johnson; Lucinda Johnson; David Neitzel; Adena Rissman; Chadwick Rittenhouse; Robert. Ziel

    2014-01-01

    Forests in northern Michigan will be affected directly and indirectly by a changing climate during the next 100 years. This assessment evaluates the vulnerability of forest ecosystems in Michigan's eastern Upper Peninsula and northern Lower Peninsula to a range of future climates. Information on current forest conditions, observed climate trends, projected climate...

  16. The biophysical link between climate, water, and vegetation in bioenergy agro-ecosystems

    International Nuclear Information System (INIS)

    Bagley, Justin E.; Davis, Sarah C.; Georgescu, Matei; Hussain, Mir Zaman; Miller, Jesse; Nesbitt, Stephen W.; VanLoocke, Andy; Bernacchi, Carl J.

    2014-01-01

    Land use change for bioenergy feedstocks is likely to intensify as energy demand rises simultaneously with increased pressure to minimize greenhouse gas emissions. Initial assessments of the impact of adopting bioenergy crops as a significant energy source have largely focused on the potential for bioenergy agroecosystems to provide global-scale climate regulating ecosystem services via biogeochemical processes. Such as those processes associated with carbon uptake, conversion, and storage that have the potential to reduce global greenhouse gas emissions (GHG). However, the expansion of bioenergy crops can also lead to direct biophysical impacts on climate through water regulating services. Perturbations of processes influencing terrestrial energy fluxes can result in impacts on climate and water across a spectrum of spatial and temporal scales. Here, we review the current state of knowledge about biophysical feedbacks between vegetation, water, and climate that would be affected by bioenergy-related land use change. The physical mechanisms involved in biophysical feedbacks are detailed, and interactions at leaf, field, regional, and global spatial scales are described. Locally, impacts on climate of biophysical changes associated with land use change for bioenergy crops can meet or exceed the biogeochemical changes in climate associated with rising GHG's, but these impacts have received far less attention. Realization of the importance of ecosystems in providing services that extend beyond biogeochemical GHG regulation and harvestable yields has led to significant debate regarding the viability of various feedstocks in many locations. The lack of data, and in some cases gaps in knowledge associated with biophysical and biochemical influences on land–atmosphere interactions, can lead to premature policy decisions. - Highlights: • The physical basis for biophysical impacts of expanding bioenergy agroecosystems on climate and water is described. • We

  17. Insular ecosystems of the southeastern United States—A regional synthesis to support biodiversity conservation in a changing climate

    Science.gov (United States)

    Cartwright, Jennifer M.; Wolfe, William J.

    2016-08-11

    In the southeastern United States, insular ecosystems—such as rock outcrops, depression wetlands, high-elevation balds, flood-scoured riparian corridors, and insular prairies and barrens—occupy a small fraction of land area but constitute an important source of regional and global biodiversity, including concentrations of rare and endemic plant taxa. Maintenance of this biodiversity depends upon regimes of abiotic stress and disturbance, incorporating factors such as soil surface temperature, widely fluctuating hydrologic conditions, fires, flood scouring, and episodic droughts that may be subject to alteration by climate change. Over several decades, numerous localized, site-level investigations have yielded important information about the floristics, physical environments, and ecological dynamics of these insular ecosystems; however, the literature from these investigations has generally remained fragmented. This report consists of literature syntheses for eight categories of insular ecosystems of the southeastern United States, concerning (1) physical geography, (2) ecological determinants of community structures including vegetation dynamics and regimes of abiotic stress and disturbance, (3) contributions to regional and global biodiversity, (4) historical and current anthropogenic threats and conservation approaches, and (5) key knowledge gaps relevant to conservation, particularly in terms of climate-change effects on biodiversity. This regional synthesis was undertaken to discern patterns across ecosystems, identify knowledge gaps, and lay the groundwork for future analyses of climate-change vulnerability. Findings from this synthesis indicate that, despite their importance to regional and global biodiversity, insular ecosystems of the southeastern United States have been subjected to a variety of direct and indirect human alterations. In many cases, important questions remain concerning key determinants of ecosystem function. In particular, few

  18. Forests, fire, floods and fish: nonlinear biophysical responses to changing climate

    Science.gov (United States)

    Pierce, J. L.; Baxter, C.; Yager, E. M.; Fremier, A. K.; Crosby, B. T.; Smith, A. M.; Kennedy, B.; Hicke, J. A.; Feris, K.

    2009-12-01

    One goal of interdisciplinarity is to develop a more holistic understanding of a set of interlinked, complex system processes. Studies rarely couple both a mechanistic understanding of individual processes with their coupled influence on the entire system structure, yet the prospects for climate driven changes in western river systems provide justification for such an effort. We apply such a mechanistic and systems approach to understanding the effects of climate on fire frequency, plant-soil infiltration, sediment transport and stream community and ecosystem dynamics in a large wilderness setting that is likely to experience shifts in the timing or intensity of physical forces if projected climate change scenarios are realized. The Middle Fork Salmon River in central Idaho runs through the Frank Church Wilderness area and is the largest roadless area in the conterminous United States. The relatively southern continental position, complex mountain terrain and wealth of long-term landscape and ecological data in this region make it a tractable system to study the multifaceted and potentially non-linear processes of system change. This presents a unique opportunity to study the effects of climate change in the absence of substantial management effects in a system on the cusp of change. This collection of studies investigates the effects of climate-driven changes in hillslope processes on stream geomorphic and ecologic processes. We investigate 1) how wildfire alters the magnitude, timing and size of sediment delivered to stream channels, 2) how climate-driven changes in the proportion of rain vs. snow dominated basins alter stream hydrology, 3) how wildfire and insect disturbances modify aquatic ecosystems through inputs of nutrients and changes to habitat, 4) how paleo-records of drought, fire, and fire-related debris flows compare with recent data, 5) how fire-related inputs of sediment and wood influence the structure and dynamics of aquatic habitats, and their

  19. Exploring Pacific Northwest ecosystem resilience: packaging climate change science for federal managers

    Science.gov (United States)

    Bachelet, D. M.

    2014-12-01

    Climate change is projected to jeopardize ecosystems in the Pacific Northwest. Managing ecosystems for future resilience requires collaboration, innovation and communication. The abundance of data and documents describing the uncertainty around both climate change projections and impacts has become challenging to managers who have little funding and limited time to digest and incorporate these materials into planning and implementation documents. We worked with US Forest Service and BLM managers to help them develop vulnerability assessments and identify on-the-ground strategies to address climate change challenges on the federal lands in northwest Oregon (Siuslaw, Willamette and Mt. Hood National Forests; Eugene and Salem BLM Districts). We held workshops to promote dialogue about climate change, which were particularly effective in fostering discussions between the managers who often do not have the time to share their knowledge and compare experiences across administrative boundaries. We used the Adaptation for Conservation Targets (ACT) framework to identify measurable management objectives and rapidly assess local vulnerabilities. We used databasin.org to centralize usable information, including state-of-the-art CMIP5 climate projections, for the mandated assessments of vulnerability and resilience. We introduced participants to a decision support framework providing opportunities to develop more effective adaptation strategies. We built a special web page to hold the information gathered at the workshops and provide easy access to climate change information. We are now working with several Landscape Conservation Cooperatives (LCCs) to design gateways - conservation atlases - to their relevant data repositories on databasin.org and working with them to develop web tools that can provide usable information for their own vulnerability assessments.

  20. Extrinsic and Intrinsic Responses to Environmental Change: Insights from Terrestrial Paleoecological Archives

    Science.gov (United States)

    Seddon, A. W. R.; Mackay, A. W.

    2015-12-01

    Current understanding of ecological behaviour indicates that systems can experience sudden and abrupt changes in state, driven either by a large external change in environmental conditions (extrinsically forced), or the result of a set local feedbacks and site-specific interactions (intrinsically mediated responses). Responses mediated by intrinsic processes are notoriously diffi- cult to predict, they can occur as slow environmental variables gradually erode the resilience of the system eventually resulting in threshold transitions between alternative stable states. Finding ways to identify, model and predict such complex ecosystem behavior has been identified as a priority research challenge for both ecology and paleoecology. The paleoecological record can play a role in understanding the processes behind abrupt ecological change because it enables the reconstruction of processes occurring over decadal-centennial timescales or longer. Therefore, paleoecological data can be used to identify the existence of ecological thresholds and to investigate the environmental processes that can lead to loss of resilience and abrupt transitions between alternate states. In addition, incidences of abrupt vegetation changes in the past can serve as palaeoecological model systems; analogues of abrupt dynamics which can be used to test theories surrounding ecological responses to climate change. Here, I present examples from a range of terrestrial ecosystems (Holocene environmental changes from a coastal lagoon in the Galapagos Islands; Northern European vegetation changes since the last deglaciation; the North American hemlock decline) demonstrating evidence of abrupt ecosystem change. For each system I present a set of statistical techniques tailored to distin- guish between extrinsic versus intrinsically mediated ecological responses. Examples are provided from both single sites (i.e. landscape scale) and multiple sites (regional-continental scale). These techniques provide a

  1. Uncertainties in projecting climate-change impacts in marine ecosystems

    DEFF Research Database (Denmark)

    Payne, Mark; Barange, Manuel; Cheung, William W. L.

    2016-01-01

    with a projection and building confidence in its robustness. We review how uncertainties in such projections are handled in marine science. We employ an approach developed in climate modelling by breaking uncertainty down into (i) structural (model) uncertainty, (ii) initialization and internal variability......Projections of the impacts of climate change on marine ecosystems are a key prerequisite for the planning of adaptation strategies, yet they are inevitably associated with uncertainty. Identifying, quantifying, and communicating this uncertainty is key to both evaluating the risk associated...... and highlight the opportunities and challenges associated with doing a better job. We find that even within a relatively small field such as marine science, there are substantial differences between subdisciplines in the degree of attention given to each type of uncertainty. We find that initialization...

  2. The problem of latent attentional capture: Easy visual search conceals capture by task-irrelevant abrupt onsets.

    Science.gov (United States)

    Gaspelin, Nicholas; Ruthruff, Eric; Lien, Mei-Ching

    2016-08-01

    Researchers are sharply divided regarding whether irrelevant abrupt onsets capture spatial attention. Numerous studies report that they do and a roughly equal number report that they do not. This puzzle has inspired numerous attempts at reconciliation, none gaining general acceptance. The authors propose that abrupt onsets routinely capture attention, but the size of observed capture effects depends critically on how long attention dwells on distractor items which, in turn, depends critically on search difficulty. In a series of spatial cuing experiments, the authors show that irrelevant abrupt onsets produce robust capture effects when visual search is difficult, but not when search is easy. Critically, this effect occurs even when search difficulty varies randomly across trials, preventing any strategic adjustments of the attentional set that could modulate probability of capture by the onset cue. The authors argue that easy visual search provides an insensitive test for stimulus-driven capture by abrupt onsets: even though onsets truly capture attention, the effects of capture can be latent. This observation helps to explain previous failures to find capture by onsets, nearly all of which used an easy visual search. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  3. Understanding of Grassland Ecosystems under Climate Change and Economic Development Pressures in the Mongolia Plateau

    Science.gov (United States)

    Qi, J.; Chen, J.; Shan, P.; Pan, X.; Wei, Y.; Wang, M.; Xin, X.

    2011-12-01

    The land use and land cover change, especially in the form of grassland degradation, in the Mongolian Plateau, exhibited a unique spatio-temporal pattern that is a characteristic of a mixed stress from economic development and climate change of the region. The social dimension of the region played a key role in shaping the landscape and land use change, including the cultural clashes with economic development, conflicts between indigenous people and business ventures, and exogenous international influences. Various research projects have been conducted in the region to focus on physical degradation of grasslands and/or on economic development but there is a lack of understanding how the social and economic dimensions interact with grassland ecosystems and changes. In this talk, a synthesis report was made based on the most recent workshop held in Hohhot, Inner Mongolia, of China, that specifically focused on climate change and grassland ecosystems. The report analyzed the degree of grassland degradation, its climate and social drivers, and coupling nature of economic development and conservation of traditional grassland values. The goal is to fully understand the socio-ecological-economic interactions that together shape the trajectory of the grassland ecosystems in the Mongolia Plateau.

  4. Climate change impacts on marine biodiversity and habitats in the Baltic Sea - and possible human adaptations: Baltadapt report 3

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, K.; Josefson, A.B.; Goeke, C. [Aarhus Univ.. Dept. of Bioscience, Aarhus (Denmark)] [and others

    2012-12-15

    Climate change is likely to induce substantial changes in the Baltic Sea, as it is a species-poor ecosystem where virtually all species live close to their environmental tolerance range. The vitality of the fish stocks and viability of fisheries should be supported by consideration of global change in the management of environment (protection, sustainable use and restoration) and of fisheries. A shift away from sector-by-sector management towards the integrated management of land, water and living resources may be necessary to sustain the productivity of fish stocks. The climate change and other concomitant human pressures induce substantial uncertainties for the future, especially as responses of marine ecosystems to changes in temperatures and in other forcing factors may not be linear, but abrupt changes may occur, which also need to be considered in exploitation of fish resources. (Author)

  5. Modeling impacts of climate change on carbon dynamics in a steppe ecosystem in Inner Mongolia, China

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Xiaoming; Wang, Jinzhi; Rui, Yichao; Niu, Haishan [Graduate Univ. of Chinese Academy of Sciences, Beijing (China). College of Resources and Environment; Hao, Yanbin; Cui, Xiaoyong; Wang, Yanfen [Graduate Univ. of Chinese Academy of Sciences, Beijing (China). College of Life Sciences; Li, Changsheng [New Hampshire Univ., Durham, NH (United States). Inst. for the Study of Earth, Ocean and Space

    2011-06-15

    Purpose: In this study, a process-oriented biogeochemistry model, denitrification-decomposition (DNDC), was employed and adapted to interpret and integrate the field observations that the tested ecosystem was a weak sink of atmospheric carbon dioxide (CO{sub 2}) in 2004 but a strong source in 2005 during the growing seasons. Then we applied the model to predict long-term impacts of climate change on carbon (C) dynamics in the semiarid grassland. Materials and methods: To adapt DNDC for the targeted grassland, we modified the default values of several grass parameters such as maximum biomass production, biomass partitions, plant tissue C/N ratio, and accumulative thermal degree days based on local observations. Daily weather data for 2004 and 2005 in conjunction with soil properties and management practices for the location were utilized as inputs to simulate the grass growth and soil C dynamics. The modeled C fluxes were compared with the eddy tower data. Sensitivity tests were conducted with a baseline and twelve alternative climate scenarios of 100 years for the target grassland. Results and discussion: The observed and modeled CO{sub 2} fluxes data were well in agreement (P < 0.0001), both showing that the grassland shifted from a sink to a source of atmospheric CO{sub 2} from a wet year (2004) to a dry year (2005) over growing season. Simulations of 100 years found that, under the fenced conditions, (1) the tested ecosystem would gain C with the baseline climate conditions at a rate of 200 kg C/ha/year; (2) the warmer and drier climate scenario made the worst case having the lowest grass production with 72 kg C/ha/year lost from the soil carbon pool; and (3) the cooler and wetter climate scenario made the best case having the highest biomass production with 790 kg C/ha/year sequestered in the soil during the simulated 100 years. Conclusions: DNDC model could be used for the prediction of C dynamics in this semiarid grassland ecosystem. Since the ecosystem

  6. Climatic sensitivity of hydrology and carbon exchanges in boreal peatland ecosystems, with implications on sustainable management of reed canary grass (Phalaris arundinacea, L.) on cutaway peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Gong Jinnan

    2013-11-01

    The aim of the study was to investigate the effects of climate change on soil hydrology and carbon (C) fluxes in boreal peatland ecosystems, with implications for the feasibility of cultivating reed canary grass (Phalaris arundinacea, L; RCG) as a way to restore the C sink in cutaway peatlands under Finnish conditions. First, hydrological models were developed for pristine peatland ecosystems and the cutaway peatlands under RCG cultivation. Concurrently, the hydrological responses to varying climatic forcing and mire types were investigated for these ecosystems. Thereafter, process-based models for estimating the seasonal and annual C exchanges were developed for the pristine mires and cutaway peatlands. The C models incorporated the hydrological models for corresponding ecosystems. Model simulations based on the climate scenarios (ACCLIM, developed by the Finnish Meteorological Institute, FMI) were further carried out to study the impacts of climate change on the C exchanges in the peatland ecosystems during the 21st century. The simulation showed that the water table (WT) in the pristine Finnish mires would draw down slightly during the 21st century. Such a chance in WT would be related to a decrease in the CO{sub 2} sink but an increase in the CH{sub 4} source at the country scale, as driven mainly by the rising temperature (Ta) and increasing precipitation (P). These changes in CO{sub 2}/ CH{sub 4} fluxes would decrease the total C-greenhouse gas (GHG) sink (CO{sub 2} equilibrium) by 68% at the country scale, and the changes would be more pronounced toward the end of the century. The majority of pristine fens in southern and western Finland and the pristine bogs near the coastal areas would become centurial CO{sub 2} sources under the changing climate. On the other hand, the major distribution of fens in northern Finland would act to increase the CH{sub 4} source at the country scale, whereas the CH{sub 4} emission would tend to decrease with WT in the southern

  7. Adaptation of Australia’s Marine Ecosystems to Climate Change: Using Science to Inform Conservation Management

    OpenAIRE

    Johnson, Johanna E.; Holbrook, Neil J.

    2014-01-01

    The challenges that climate change poses for marine ecosystems are already manifesting in impacts at the species, population, and community levels in Australia, particularly in Tasmania and tropical northern Australia. Many species and habitats are already under threat as a result of human activities, and the additional pressure from climate change significantly increases the challenge for marine conservation and management. Climate change impacts are expected to magnify as sea surface temper...

  8. Disturbance and net ecosystem production across three climatically distinct forest landscapes

    Science.gov (United States)

    John L. Campbell; O.J. Sun; B.E. Law

    2004-01-01

    Biometric techniques were used to measure net ecosystem production (NEP) across three climatically distinct forest chronosequences in Oregon. NEP was highly negative immediately following stand-replacing disturbance in all forests and recovered to positive values by 10, 20, and 30 years of age for the mild mesic Coast Range, mesic West Cascades, and semi-arid East...

  9. Millennial climatic fluctuations are key to the structure of last glacial ecosystems.

    Directory of Open Access Journals (Sweden)

    Brian Huntley

    Full Text Available Whereas fossil evidence indicates extensive treeless vegetation and diverse grazing megafauna in Europe and northern Asia during the last glacial, experiments combining vegetation models and climate models have to-date simulated widespread persistence of trees. Resolving this conflict is key to understanding both last glacial ecosystems and extinction of most of the mega-herbivores. Using a dynamic vegetation model (DVM we explored the implications of the differing climatic conditions generated by a general circulation model (GCM in "normal" and "hosing" experiments. Whilst the former approximate interstadial conditions, the latter, designed to mimic Heinrich Events, approximate stadial conditions. The "hosing" experiments gave simulated European vegetation much closer in composition to that inferred from fossil evidence than did the "normal" experiments. Given the short duration of interstadials, and the rate at which forest cover expanded during the late-glacial and early Holocene, our results demonstrate the importance of millennial variability in determining the character of last glacial ecosystems.

  10. Millennial climatic fluctuations are key to the structure of last glacial ecosystems.

    Science.gov (United States)

    Huntley, Brian; Allen, Judy R M; Collingham, Yvonne C; Hickler, Thomas; Lister, Adrian M; Singarayer, Joy; Stuart, Anthony J; Sykes, Martin T; Valdes, Paul J

    2013-01-01

    Whereas fossil evidence indicates extensive treeless vegetation and diverse grazing megafauna in Europe and northern Asia during the last glacial, experiments combining vegetation models and climate models have to-date simulated widespread persistence of trees. Resolving this conflict is key to understanding both last glacial ecosystems and extinction of most of the mega-herbivores. Using a dynamic vegetation model (DVM) we explored the implications of the differing climatic conditions generated by a general circulation model (GCM) in "normal" and "hosing" experiments. Whilst the former approximate interstadial conditions, the latter, designed to mimic Heinrich Events, approximate stadial conditions. The "hosing" experiments gave simulated European vegetation much closer in composition to that inferred from fossil evidence than did the "normal" experiments. Given the short duration of interstadials, and the rate at which forest cover expanded during the late-glacial and early Holocene, our results demonstrate the importance of millennial variability in determining the character of last glacial ecosystems.

  11. Improving predictions of tropical forest response to climate change through integration of field studies and ecosystem modeling

    Science.gov (United States)

    Feng, Xiaohui; Uriarte, María; González, Grizelle; Reed, Sasha C.; Thompson, Jill; Zimmerman, Jess K.; Murphy, Lora

    2018-01-01

    Tropical forests play a critical role in carbon and water cycles at a global scale. Rapid climate change is anticipated in tropical regions over the coming decades and, under a warmer and drier climate, tropical forests are likely to be net sources of carbon rather than sinks. However, our understanding of tropical forest response and feedback to climate change is very limited. Efforts to model climate change impacts on carbon fluxes in tropical forests have not reached a consensus. Here we use the Ecosystem Demography model (ED2) to predict carbon fluxes of a Puerto Rican tropical forest under realistic climate change scenarios. We parameterized ED2 with species-specific tree physiological data using the Predictive Ecosystem Analyzer workflow and projected the fate of this ecosystem under five future climate scenarios. The model successfully captured inter-annual variability in the dynamics of this tropical forest. Model predictions closely followed observed values across a wide range of metrics including above-ground biomass, tree diameter growth, tree size class distributions, and leaf area index. Under a future warming and drying climate scenario, the model predicted reductions in carbon storage and tree growth, together with large shifts in forest community composition and structure. Such rapid changes in climate led the forest to transition from a sink to a source of carbon. Growth respiration and root allocation parameters were responsible for the highest fraction of predictive uncertainty in modeled biomass, highlighting the need to target these processes in future data collection. Our study is the first effort to rely on Bayesian model calibration and synthesis to elucidate the key physiological parameters that drive uncertainty in tropical forests responses to climatic change. We propose a new path forward for model-data synthesis that can substantially reduce uncertainty in our ability to model tropical forest responses to future climate.

  12. An Inquiry-Based Science Activity Centred on the Effects of Climate Change on Ocean Ecosystems

    Science.gov (United States)

    Boaventura, Diana; Guilherme, Elsa; Faria, Cláudia

    2016-01-01

    We propose an inquiry-based science activity centred on the effects of climate change on ocean ecosystems. This activity can be used to improve acquisition of knowledge on the effects of climate change and to promote inquiry skills, such as researching, reading and selecting relevant information, identifying a problem, focusing on a research…

  13. Evaluating the effects of future climate change and elevated CO2 on the water use efficiency in terrestrial ecosystems of China

    Science.gov (United States)

    Zhu, Q.; Jiang, H.; Peng, C.; Liu, J.; Wei, X.; Fang, X.; Liu, S.; Zhou, G.; Yu, S.

    2011-01-01

    Water use efficiency (WUE) is an important variable used in climate change and hydrological studies in relation to how it links ecosystem carbon cycles and hydrological cycles together. However, obtaining reliable WUE results based on site-level flux data remains a great challenge when scaling up to larger regional zones. Biophysical, process-based ecosystem models are powerful tools to study WUE at large spatial and temporal scales. The Integrated BIosphere Simulator (IBIS) was used to evaluate the effects of climate change and elevated CO2 concentrations on ecosystem-level WUE (defined as the ratio of gross primary production (GPP) to evapotranspiration (ET)) in relation to terrestrial ecosystems in China for 2009–2099. Climate scenario data (IPCC SRES A2 and SRES B1) generated from the Third Generation Coupled Global Climate Model (CGCM3) was used in the simulations. Seven simulations were implemented according to the assemblage of different elevated CO2 concentrations scenarios and different climate change scenarios. Analysis suggests that (1) further elevated CO2concentrations will significantly enhance the WUE over China by the end of the twenty-first century, especially in forest areas; (2) effects of climate change on WUE will vary for different geographical regions in China with negative effects occurring primarily in southern regions and positive effects occurring primarily in high latitude and altitude regions (Tibetan Plateau); (3) WUE will maintain the current levels for 2009–2099 under the constant climate scenario (i.e. using mean climate condition of 1951–2006 and CO2concentrations of the 2008 level); and (4) WUE will decrease with the increase of water resource restriction (expressed as evaporation ratio) among different ecosystems.

  14. The Role of Environmental Driving Factors in Historical and Projected Carbon Dynamics of Wetland Ecosystems in Alaska.

    Science.gov (United States)

    Lyu, Zhou; Genet, Hélène; He, Yujie; Zhuang, Qianlai; McGuire, A David; Bennett, Alec; Breen, Amy; Clein, Joy; Euskirchen, Eugénie S; Johnson, Kristofer; Kurkowski, Tom; Pastick, Neal J; Rupp, T Scott; Wylie, Bruce K; Zhu, Zhiliang

    2018-05-29

    Wetlands are critical terrestrial ecosystems in Alaska, covering ~177,000 km 2 , an area greater than all the wetlands in the remainder of the United States. To assess the relative influence of changing climate, atmospheric carbon dioxide (CO 2 ) concentration, and fire regime on carbon balance in wetland ecosystems of Alaska, a modeling framework that incorporates a fire disturbance model and two biogeochemical models was used. Spatially explicit simulations were conducted at 1 km-resolution for the historical period (1950-2009) and future projection period (2010-2099). Simulations estimated that wetland ecosystems of Alaska lost 175 Tg carbon (C) in the historical period. Ecosystem C storage in 2009 was 5556 Tg, with 89% of the C stored in soils. The estimated loss of C as CO 2 and biogenic methane (CH 4 ) emissions resulted in wetlands of Alaska increasing the greenhouse gas forcing of climate warming. Simulations for the projection period were conducted for six climate change scenarios constructed from two climate models forced under three CO 2 emission scenarios. Ecosystem C storage averaged among climate scenarios increased 3.94 TgC/yr by 2099, with variability among the simulations ranging from 2.02 to 4.42 TgC/yr. These increases were driven primarily by increases in net primary production (NPP) that were greater than losses from increased decomposition and fire. The NPP increase was driven by CO 2 fertilization (~5% per 100 ppmv increase) and by increases in air temperature (~1% per °C increase). Increases in air temperature were estimated to be the primary cause for a projected 47.7% mean increase in biogenic CH 4 emissions among the simulations (~15% per °C increase). Ecosystem CO 2 sequestration offset the increase in CH 4 emissions during the 21 st century to decrease the greenhouse gas forcing of climate warming. However, beyond 2100, we expect that this forcing will ultimately increase as wetland ecosystems transition from being a sink to a source

  15. Microbial Community Dynamics from Permafrost Across the Pleistocene-Holocene Boundary and Response to Abrupt Climate Change

    Science.gov (United States)

    Hammad, A.; Mahony, M.; Froese, D. G.; Lanoil, B. D.

    2014-12-01

    Earth is currently undergoing rapid warming similar to that observed about 10,000 years ago at the end of the Pleistocene. We know a considerable amount about the adaptations and extinctions of mammals and plants at the Pleistocene/Holocene (P/H) boundary, but relatively little about changes at the microbial level. Due to permafrost soils' freezing anoxic conditions, they act as microbial diversity archives allowing us to determine how microbial communities adapted to the abrupt warming at the end of P. Since microbial community composition only helps differentiate viable and extant microorganisms in frozen permafrost, microbial activity in thawing permafrost must be investigated to provide a clear understanding of microbial response to climate change. Current increased temperatures will result in warming and potential thaw of permafrost and release of stored organic carbon, freeing it for microbial utilization; turning permafrost into a carbon source. Studying permafrost viable microbial communities' diversity and activity will provide a better understanding of how these microorganisms respond to soil edaphic variability due to climate change across the P/H boundary, providing insight into the changes that the soil community is currently undergoing in this modern era of rapid climate change. Modern soil, H and P permafrost cores were collected from Lucky Lady II site outside Dawson City, Yukon. 16S rRNA high throughput sequencing of permafrost DNA showed the same trends for total and viable community richness and diversity with both decreasing with permafrost depth and only the richness increasing in mid and early P. The modern, H and P soils had 50.9, 33.9, and 27.3% unique viable species and only 14% of the total number of viable species were shared by all soils. Gas flux measurements of thawed permafrost showed metabolic activity in modern and permafrost soils, aerobic CH­­4 consumption in modern, some H and P soils, and anaerobic CH­­4 production in one H

  16. Future Climate Impacts on Harmful Algal Blooms in an Agriculturally Dominated Ecosystem

    Science.gov (United States)

    Aloysius, N. R.; Martin, J.; Ludsin, S.; Stumpf, R. P.

    2015-12-01

    Cyanobacteria blooms have become a major problem worldwide in aquatic ecosystems that receive excessive runoff of limiting nutrients from terrestrial drainage. Such blooms often are considered harmful because they degrade ecosystem services, threaten public health, and burden local economies. Owing to changing agricultural land-use practices, Lake Erie, the most biologically productive of the North American Great Lakes, has begun to undergo a re-eutrophication in which the frequency and extent of harmful algal blooms (HABs) has increased. Continued climate change has been hypothesized to magnify the HAB problem in Lake Erie in the absence of new agricultural management practices, although this hypothesis has yet to be formally tested empirically. Herein, we tested this hypothesis by predicting how the frequency and extent of potentially harmful cyanobacteria blooms will change in Lake Erie during the 21st century under the Intergovernmental Panel on Climate Change Fifth Assessment climate projections in the region. To do so, we used 80 ensembles of climate projections from 20 Global Climate Models (GCMs) and two greenhouse gas emission scenarios (moderate reduction, RCP4.5; business-as-usual, RCP8.5) to drive a spatiotemporally explicit watershed-hydrology model that was linked to several statistical predictive models of annual cyanobacteria blooms in Lake Erie. Owing to anticipated increases in precipitation during spring and warmer temperatures during summer, our ensemble of predictions revealed that, if current land-management practices continue, the frequency of severe HABs in Lake Erie will increase during the 21st century. These findings identify a real need to consider future climate projections when developing nutrient reduction strategies in the short term, with adaptation also needing to be encouraged under both greenhouse gas emissions scenarios in the absence of effective nutrient mitigation strategies.

  17. Modeling European ruminant production systems: facing the challenges of climate change

    DEFF Research Database (Denmark)

    Kipling, Richard Philip; Bannink, Andre; Bellocchi, Gianni

    2016-01-01

    Ruminant production systems are important producers of food, support rural communities and culture, and help to maintain a range of ecosystem services including the sequestering of carbon in grassland soils. However, these systems also contribute significantly to climate change through greenhouse...... gas (GHG) emissions, while intensification of production has driven biodiversity and nutrient loss, and soil degradation. Modeling can offer insights into the complexity underlying the relationships between climate change, management and policy choices, food production, and the maintenance...... of ecosystem services. This paper 1) provides an overview of how ruminant systems modeling supports the efforts of stakeholders and policymakers to predict, mitigate and adapt to climate change and 2) provides ideas for enhancing modeling to fulfil this role. Many grassland models can predict plant growth...

  18. The Role of Driving Factors in Historical and Projected Carbon Dynamics in Wetland Ecosystems of Alaska

    Science.gov (United States)

    Lyu, Z.; Helene, G.; He, Y.; Zhuang, Q.; McGuire, A. D.; Bennett, A.; Breen, A. L.; Clein, J.; Euskirchen, E. S.; Johnson, K. D.; Kurkowski, T. A.; Pastick, N. J.; Rupp, S. T.; Wylie, B. K.; Zhu, Z.

    2017-12-01

    Wetlands are important terrestrial ecosystems in Alaska. It is important to understand and assess their role in the regional carbon dynamics in response to historical and projected environmental conditions. A coupled modeling framework that incorporates a fire disturbance model and two biogeochemical models was used to assess the relative influence of changing climate, atmospheric carbon dioxide (CO2) concentration, and fire regime on the historical and future carbon balance in wetland ecosystems of the four main Landscape Conservation Cooperatives (LCCs) of Alaska. Simulations were conducted for the historical period (1950-2009) and future projection period (2010-2099). These simulations estimate that the total carbon (C) storage in wetland ecosystems of Alaska is 5556 Tg C in 2009, with 89% of the C stored in soils. An estimated 175 Tg C was lost during the historical period, which is attributed to greater C lost from the Northwest Boreal LCC than C gained from the other three LCCs. The simulations for the projection period were conducted for six different scenarios driven by climate forcings from two different climate models for each of three CO2 emission scenarios. The mean total carbon storage increased 3.94 Tg C/yr by 2099, with variability among the simulations ranging from 2.02 Tg C/yr to 4.42 Tg C/yr. Across the four LCCs, the largest relative C storage increase occurred in the Arctic and North Pacific LCCs. These increases were primarily driven by increases in net primary production (NPP) that were greater than increases in heterotrophic respiration and fire emissions. Our analysis further indicates that NPP increase was primarily driven by CO2 fertilization ( 5% per 100 ppmv increase) as well as by increases in air temperature ( 1% per ° increase). Increases air temperature were estimated to be the primary cause for a projected 47.7% mean increase in wetlands biogenic CH4 emissions among the simulations ( 15% per ° increase). The combined effects of

  19. Future vegetation ecosystem response to warming climate over the Tibetan Plateau

    Science.gov (United States)

    Bao, Y.; Gao, Y.; Wang, Y.

    2017-12-01

    The amplified vegetation response to climate variability has been found over the Tibetan Plateau (TP) in recent decades. In this study, the potential impacts of 21st century climate change on the vegetation ecosystem over the TP are assessed based on the dynamic vegetation outputs of models from Coupled Model Intercomparison Project Phase 5 (CMIP5), and the sensitivity of the TP vegetation in response to warming climate was investigated. Models project a continuous and accelerating greening in future, especially in the eastern TP, which closely associates with the plant type upgrade due to the pronouncing warming in growing season.Vegetation leaf area index (LAI) increase well follows the global warming, suggesting the warming climate instead of co2 fertilization controlls the future TP plant growth. The warming spring may advance the start of green-up day and extend the growing season length. More carbon accumulation in vegetation and soil will intensify the TP carbon cycle and will keep it as a carbon sink in future. Keywords: Leaf Area Index (LAI), Climate Change, Global Dynamic Vegetation Models (DGVMs), CMIP5, Tibetan Plateau (TP)

  20. ICES and PICES strategies for coordinating research on the impacts of climate change on marine ecosystems

    DEFF Research Database (Denmark)

    Kim, S.; Hollowed, Anne B.; Barange, Manuel

    2014-01-01

    organizations to develop a research initiative that focuses on their shared interests. A phased implementation will ensure that SICCME will be responsive to a rapidly evolving research area while delivering ongoing syntheses of existing knowledge, thereby advancing new science and methodologies......The social, economic, and ecological consequences of projected climate change on fish and fisheries are issues of global concern. In 2012, the International Council for the Exploration of the Sea (ICES) and the North Pacific Marine Science Organization (PICES) established a Strategic Initiative...... on Climate Change Effects on Marine Ecosystems (SICCME) to synthesize and to promote innovative, credible, and objective science-based advice on the impacts of climate change on marine ecosystems in the Northern Hemisphere. SICCME takes advantage of the unique and complementary strengths of the two...

  1. Climate change and wildfire effects in aridland riparian ecosystems: An examination of current and future conditions

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch

    2017-01-01

    Aridland riparian ecosystems are limited, the climate is changing, and further hydrological change is likely in the American Southwest. To protect riparian ecosystems and organisms, we need to understand how they are affected by disturbance processes and stressors such as fire, drought, and non-native plant invasions. Riparian vegetation is critically important as...

  2. Population cycles and species diversity in dynamic Kill-the-Winner model of microbial ecosystems

    Science.gov (United States)

    Maslov, Sergei; Sneppen, Kim

    2017-01-01

    Determinants of species diversity in microbial ecosystems remain poorly understood. Bacteriophages are believed to increase the diversity by the virtue of Kill-the-Winner infection bias preventing the fastest growing organism from taking over the community. Phage-bacterial ecosystems are traditionally described in terms of the static equilibrium state of Lotka-Volterra equations in which bacterial growth is exactly balanced by losses due to phage predation. Here we consider a more dynamic scenario in which phage infections give rise to abrupt and severe collapses of bacterial populations whenever they become sufficiently large. As a consequence, each bacterial population in our model follows cyclic dynamics of exponential growth interrupted by sudden declines. The total population of all species fluctuates around the carrying capacity of the environment, making these cycles cryptic. While a subset of the slowest growing species in our model is always driven towards extinction, in general the overall ecosystem diversity remains high. The number of surviving species is inversely proportional to the variation in their growth rates but increases with the frequency and severity of phage-induced collapses. Thus counter-intuitively we predict that microbial communities exposed to more violent perturbations should have higher diversity. PMID:28051127

  3. Forest ecosystem vulnerability assessment and synthesis for northern Wisconsin and western Upper Michigan: a report from the Northwoods Climate Change Response Framework project

    Science.gov (United States)

    Maria K. Janowiak; Louis R. Iverson; David J. Mladenoff; Emily Peters; Kirk R. Wythers; Weimin Xi; Leslie A. Brandt; Patricia R. Butler; Stephen D. Handler; P. Danielle Shannon; Chris Swanston; Linda R. Parker; Amy J. Amman; Brian Bogaczyk; Christine Handler; Ellen Lesch; Peter B. Reich; Stephen Matthews; Matthew Peters; Anantha Prasad; Sami Khanal; Feng Liu; Tara Bal; Dustin Bronson; Andrew Burton; Jim Ferris; Jon Fosgitt; Shawn Hagan; Erin Johnston; Evan Kane; Colleen Matula; Ryan O' Connor; Dale Higgins; Matt St. Pierre; Jad Daley; Mae Davenport; Marla R. Emery; David Fehringer; Christopher L. Hoving; Gary Johnson; David Neitzel; Michael Notaro; Adena Rissman; Chadwick Rittenhouse; Robert Ziel

    2014-01-01

    Forest ecosystems across the Northwoods will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems in the Laurentian Mixed Forest Province of northern Wisconsin and western Upper Michigan under a range of future climates. Information on current forest conditions, observed climate...

  4. Enabling Data-Driven Methodologies Across the Data Lifecycle and Ecosystem

    Science.gov (United States)

    Doyle, R. J.; Crichton, D.

    2017-12-01

    NASA has unlocked unprecedented scientific knowledge through exploration of the Earth, our solar system, and the larger universe. NASA is generating enormous amounts of data that are challenging traditional approaches to capturing, managing, analyzing and ultimately gaining scientific understanding from science data. New architectures, capabilities and methodologies are needed to span the entire observing system, from spacecraft to archive, while integrating data-driven discovery and analytic capabilities. NASA data have a definable lifecycle, from remote collection point to validated accessibility in multiple archives. Data challenges must be addressed across this lifecycle, to capture opportunities and avoid decisions that may limit or compromise what is achievable once data arrives at the archive. Data triage may be necessary when the collection capacity of the sensor or instrument overwhelms data transport or storage capacity. By migrating computational and analytic capability to the point of data collection, informed decisions can be made about which data to keep; in some cases, to close observational decision loops onboard, to enable attending to unexpected or transient phenomena. Along a different dimension than the data lifecycle, scientists and other end-users must work across an increasingly complex data ecosystem, where the range of relevant data is rarely owned by a single institution. To operate effectively, scalable data architectures and community-owned information models become essential. NASA's Planetary Data System is having success with this approach. Finally, there is the difficult challenge of reproducibility and trust. While data provenance techniques will be part of the solution, future interactive analytics environments must support an ability to provide a basis for a result: relevant data source and algorithms, uncertainty tracking, etc., to assure scientific integrity and to enable confident decision making. Advances in data science offer

  5. Climate-dependence of ecosystem services in a nature reserve in northern China.

    Science.gov (United States)

    Fang, Jiaohui; Song, Huali; Zhang, Yiran; Li, Yanran; Liu, Jian

    2018-01-01

    Evaluation of ecosystem services has become a hotspot in terms of research focus, but uncertainties over appropriate methods remain. Evaluation can be based on the unit price of services (services value method) or the unit price of the area (area value method). The former takes meteorological factors into account, while the latter does not. This study uses Kunyu Mountain Nature Reserve as a study site at which to test the effects of climate on the ecosystem services. Measured data and remote sensing imagery processed in a geographic information system were combined to evaluate gas regulation and soil conservation, and the influence of meteorological factors on ecosystem services. Results were used to analyze the appropriateness of the area value method. Our results show that the value of ecosystem services is significantly affected by meteorological factors, especially precipitation. Use of the area value method (which ignores the impacts of meteorological factors) could considerably impede the accuracy of ecosystem services evaluation. Results were also compared with the valuation obtained using the modified equivalent value factor (MEVF) method, which is a modified area value method that considers changes in meteorological conditions. We found that MEVF still underestimates the value of ecosystem services, although it can reflect to some extent the annual variation in meteorological factors. Our findings contribute to increasing the accuracy of evaluation of ecosystem services.

  6. Linking an ecosystem model and a landscape model to study forest species response to climate warming

    Science.gov (United States)

    Hong S. He; David J. Mladenoff; Thomas R. Crow

    1999-01-01

    No single model can address forest change from single tree to regional scales. We discuss a framework linking an ecosystem process model {LINKAGES) with a spatial landscape model (LANDIS) to examine forest species responses to climate warming for a large, heterogeneous landscape in northern Wisconsin, USA. Individual species response at the ecosystem scale was...

  7. Enhanced science-stakeholder communication to improve ecosystem model performances for climate change impact assessments

    DEFF Research Database (Denmark)

    Jonsson, Anna Maria; Anderbrant, Olle; Holmer, Jennie

    2015-01-01

    In recent years, climate impact assessments of relevance to the agricultural and forestry sectors have received considerable attention. Current ecosystem models commonly capture the effect of a warmer climate on biomass production, but they rarely sufficiently capture potential losses caused...... by pests, pathogens and extreme weather events. In addition, alternative management regimes may not be integrated in the models. A way to improve the quality of climate impact assessments is to increase the science–stakeholder collaboration, and in a two-way dialog link empirical experience and impact...... a discussion among the science–stakeholder communities on how to quantify the potential for climate change adaptation by improving the realism in the models....

  8. A human-driven decline in global burned area

    Science.gov (United States)

    Andela, N.

    2017-12-01

    Fire regimes are changing rapidly across the globe, driven by human land management and climate. We assessed long-term trends in fire activity using multiple satellite data sets and developed a new global data set on individual fire dynamics to understand the implications of changing fire regimes. Despite warming climate, burned area declined across most of the tropics, contributing to a global decline in burned area of 24.3 ± 8.8% over the past 18 years. The estimated decrease in burned area was largest in savannas and grasslands, where agricultural expansion and intensification were primary drivers of declining fire activity. In tropical forests, frequent fires for deforestation and agricultural management yield a sharp rise in fire activity with the expansion of settled land uses, but the use of fire decreases with increasing investment in agricultural areas in both savanna and forested landscapes. Disparate patterns of recent socieconomic development resulted in contrasting fire trends between southern Africa (increase) and South America (decrease). A strong inverse relationship between burned area and economic development in savannas and grasslands suggests that despite potential increasing fire risk from climate change, ongoing socioeconomic development will likely sustain observed declines in fire in these ecosystems during coming decades. Fewer and smaller fires reduced aerosol concentrations, modified vegetation structure, and increased the magnitude of the terrestrial carbon sink. The spatiotemporal distribution of fire size, duration, speed and direction of spread provided new insights in continental scale differences in fire regimes driven by human and climatic factors. Understanding these dynamics over larger scales is critical to achieve a balance between conservation of fire-dependent ecosystems and increasing agricultural production to support growing populations that will require careful management of fire activity in human-dominated landscapes.

  9. Streamflow in the upper Mississippi river basin as simulated by SWAT driven by 20{sup th} century contemporary results of global climate models and NARCCAP regional climate models

    Energy Technology Data Exchange (ETDEWEB)

    Takle, Eugene S.; Jha, Manoj; Lu, Er; Arritt, Raymond W.; Gutowski, William J. [Iowa State Univ. Ames, IA (United States)

    2010-06-15

    We use Soil and Water Assessment Tool (SWAT) when driven by observations and results of climate models to evaluate hydrological quantities, including streamflow, in the Upper Mississippi River Basin (UMRB) for 1981-2003 in comparison to observed streamflow. Daily meteorological conditions used as input to SWAT are taken from (1) observations at weather stations in the basin, (2) daily meteorological conditions simulated by a collection of regional climate models (RCMs) driven by reanalysis boundary conditions, and (3) daily meteorological conditions simulated by a collection of global climate models (GCMs). Regional models used are those whose data are archived by the North American Regional Climate Change Assessment Program (NARCCAP). Results show that regional models correctly simulate the seasonal cycle of precipitation, temperature, and streamflow within the basin. Regional models also capture interannual extremes represented by the flood of 1993 and the dry conditions of 2000. The ensemble means of both the GCM-driven and RCM-driven simulations by SWAT capture both the timing and amplitude of the seasonal cycle of streamflow with neither demonstrating significant superiority at the basin level. (orig.)

  10. Isotopic composition of ice core air reveals abrupt Antarctic warming during and after Heinrich Event 1a

    Science.gov (United States)

    Morgan, J. D.; Bereiter, B.; Baggenstos, D.; Kawamura, K.; Shackleton, S. A.; Severinghaus, J. P.

    2017-12-01

    Antarctic temperature variations during Heinrich events, as recorded by δ18O­ice­, generally show more gradual changes than the abrupt warmings seen in Greenland ice. However, quantitative temperature interpretation of the water isotope temperature proxy is difficult as the relationship between δ18Oice and temperature is not constant through time. Fortunately, ice cores offer a second temperature proxy based on trapped gases. During times of surface warming, thermal fractionation of gases in the column of unconsolidated snow (firn) on top of the ice sheet results in isotopically heavier nitrogen (N2) and argon (Ar) being trapped in the ice core bubbles. During times of surface cooling, isotopically lighter gases are trapped. Measurements of δ15N and δ40Ar can therefore be used, in combination with a model for the height of the column of firn, to quantitatively reconstruct surface temperatures. In the WAIS Divide Ice Core, the two temperature proxies show a brief disagreement during Heinrich Stadial 1. Despite δ18Oice recording relatively constant temperature, the nitrogen and argon isotopes imply an abrupt warming between 16 and 15.8 kyr BP, manifest as an abrupt 1.25oC increase in the firn temperature gradient. To our knowledge, this would be the first evidence that such abrupt climate change has been recorded in an Antarctic climate proxy. If confirmed by more detailed studies, this event may represent warming due to an extreme southward shift of the Earth's thermal equator (and the southern hemisphere westerly wind belt), caused by the 16.1 ka Heinrich Event.

  11. Climate-based models for pulsed resources improve predictability of consumer population dynamics: outbreaks of house mice in forest ecosystems.

    Directory of Open Access Journals (Sweden)

    E Penelope Holland

    Full Text Available Accurate predictions of the timing and magnitude of consumer responses to episodic seeding events (masts are important for understanding ecosystem dynamics and for managing outbreaks of invasive species generated by masts. While models relating consumer populations to resource fluctuations have been developed successfully for a range of natural and modified ecosystems, a critical gap that needs addressing is better prediction of resource pulses. A recent model used change in summer temperature from one year to the next (ΔT for predicting masts for forest and grassland plants in New Zealand. We extend this climate-based method in the framework of a model for consumer-resource dynamics to predict invasive house mouse (Mus musculus outbreaks in forest ecosystems. Compared with previous mast models based on absolute temperature, the ΔT method for predicting masts resulted in an improved model for mouse population dynamics. There was also a threshold effect of ΔT on the likelihood of an outbreak occurring. The improved climate-based method for predicting resource pulses and consumer responses provides a straightforward rule of thumb for determining, with one year's advance warning, whether management intervention might be required in invaded ecosystems. The approach could be applied to consumer-resource systems worldwide where climatic variables are used to model the size and duration of resource pulses, and may have particular relevance for ecosystems where global change scenarios predict increased variability in climatic events.

  12. Climatic, landform, microtopographic, and overstory canopy controls of tree invasion in a subalpine meadow landscape, Oregon Cascades, USA

    Science.gov (United States)

    Harold S.J. Zald; Thomas A. Spies; Manuela Huso; Demetrios. Gatziolis

    2012-01-01

    Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and...

  13. Climate change adaptation and mitigation options a guide for natural resource managers in southern forest ecosystems

    Science.gov (United States)

    James M. Vose; Kier D. Klepzig

    2014-01-01

    The rapid pace of climate change and its direct and indirect effects on forest ecosystems present a pressing need for better scientific understanding and the development of new science-management partnerships. Understanding the effects of stressors and disturbances (including climatic variability), and developing and testing science-based management options to deal...

  14. Global topics and novel approaches in the study of air pollution, climate change and forest ecosystems

    Science.gov (United States)

    P. Sicard; A. Augustaitis; S. Belyazid; C. Calfapietra; A. De Marco; Mark E. Fenn; Andrzej Bytnerowicz; Nancy Grulke; S. He; R. Matyssek; Y. Serengil; G. Wieser; E. Paoletti

    2016-01-01

    Research directions from the 27th conference for Specialists in Air Pollution and Climate Change Effects on Forest Ecosystems (2015) reflect knowledge advancements about (i) Mechanistic bases of tree responses to multiple climate and pollution stressors, in particular the interaction of ozone (O3) with nitrogen (N) deposition and drought; (ii)...

  15. Climate change adaptation via targeted ecosystem service provision: a sustainable land management strategy for the Segura catchment (SE Spain)

    Science.gov (United States)

    Zagaria, Cecilia; de Vente, Joris; Perez-Cutillas, Pedro

    2014-05-01

    Topical research investigating climate, land-use and management scenarios in the Segura catchment (SE Spain), depicts a landscape at high-risk of, quite literally, deserting agriculture. Land degradation in the semi-arid region of SE Spain is characterized by water shortage, high erosion rates and salinization, increasingly exacerbated by climatic changes, scarce vegetation cover and detrimental farming practices. Future climate scenarios predict increases in aridity, variability and intensity of rainfall events, leading to increasing pressure on scarce soil and water resources. This study conceptualized the impending crisis of agro-ecological systems of the Segura basin (18800 km2) as a crisis of ecosystem service deterioration. In light of existing land degradation drivers and future climate scenarios, the potential of Sustainable Land Management (SLM) strategies was evaluated to target three priority ecosystem services (water provision, sediment retention and carbon sequestration) as a means to achieve climate change adaptation and mitigation. A preceding thorough process of stakeholder engagement (as part of the EU funded DESIRE project) indicated five SLM technologies for potential implementation, all with a focus upon reducing soil erosion, increasing soil water holding capacity and soil organic matter content. These technologies have been tested for over four years in local experimental field plots, and have provided results on the local effects upon individual environmental parameters. Despite the growing emphasis witnessed in literature upon the context-specificity which characterizes adaptation solutions, the frequent analysis at the field scale is limited in both scope and utility. There is a need to investigate the effects of adaptive SLM solutions at wider, regional scales. Thus, this study modeled the cumulative effect of each of the five selected SLM technologies with InVEST, a spatial analyst tool designed for ecosystem service quantification and

  16. The abrupt onset of the modern South Asian monsoon winds

    Digital Repository Service at National Institute of Oceanography (India)

    Betzler, C.; Eberli, G.P.; Kroon, D.; Wright, J.D.; Swart, P.K.; Nath, B.N.; Alvarez-Zarikian, C.A.; Alonso-Garcia, M.; Bialik, O.M.; Blattler, C.L.; Guo, J.; Haffen, S.; Horozal, S.; Inoue, M.; Jovane, L.; Lanci, L.; Laya, J.C.; Mee, A.L.H.; Ludmann, T.; Nakakuni, M.; Niino, K.; Petruny, L.M.; Pratiwi, S.D.; Reijmer, J.J.G.; Reolid, J.; Slagle, A.L.; Sloss, C.R.; Su, X.; Yao, Z.; Young, J.R.

    :29838 | DOI: 10.1038/srep29838 www.nature.com/scientificreports The abrupt onset of the modern South Asian Monsoon winds Christian Betzler1, Gregor P. Eberli2, Dick Kroon3, James D. Wright4, Peter K. Swart2, Bejugam Nagender Nath5, Carlos A. Alvarez....betzler@uni-hamburg.de) Received: 25 April 2016 accepted: 21 June 2016 Published: 20 July 2016 OPEN www.nature.com/scientificreports/ 2Scientific RepoRts | 6:29838 | DOI: 10.1038/srep29838 control, and we propose that the post Miocene Climate Optimum cooling, together...

  17. Combined fishing and climate forcing in the southern Benguela upwelling ecosystem: an end-to-end modelling approach reveals dampened effects.

    Directory of Open Access Journals (Sweden)

    Morgane Travers-Trolet

    Full Text Available The effects of climate and fishing on marine ecosystems have usually been studied separately, but their interactions make ecosystem dynamics difficult to understand and predict. Of particular interest to management, the potential synergism or antagonism between fishing pressure and climate forcing is analysed in this paper, using an end-to-end ecosystem model of the southern Benguela ecosystem, built from coupling hydrodynamic, biogeochemical and multispecies fish models (ROMS-N2P2Z2D2-OSMOSE. Scenarios of different intensities of upwelling-favourable wind stress combined with scenarios of fishing top-predator fish were tested. Analyses of isolated drivers show that the bottom-up effect of the climate forcing propagates up the food chain whereas the top-down effect of fishing cascades down to zooplankton in unfavourable environmental conditions but dampens before it reaches phytoplankton. When considering both climate and fishing drivers together, it appears that top-down control dominates the link between top-predator fish and forage fish, whereas interactions between the lower trophic levels are dominated by bottom-up control. The forage fish functional group appears to be a central component of this ecosystem, being the meeting point of two opposite trophic controls. The set of combined scenarios shows that fishing pressure and upwelling-favourable wind stress have mostly dampened effects on fish populations, compared to predictions from the separate effects of the stressors. Dampened effects result in biomass accumulation at the top predator fish level but a depletion of biomass at the forage fish level. This should draw our attention to the evolution of this functional group, which appears as both structurally important in the trophic functioning of the ecosystem, and very sensitive to climate and fishing pressures. In particular, diagnoses considering fishing pressure only might be more optimistic than those that consider combined effects

  18. Tales from the Jungle: The Evolving Climate Services Ecosystem

    Science.gov (United States)

    Redmond, K. T.

    2015-12-01

    In 2001 the NRC Report "A Climate Services Vision: First Steps Toward the Future" examined the state and trends of climate services. That report included a definition of this term that has lost no relevance: "The timely production and delivery of useful climate data, information, and knowledge to decision makers." The original entities delivering such services, at the state level, are represented by the American Association of State Climatologists (AASC). In 1986 the NOAA Regional Climate Center program was initiated, followed in 1994 by the NOAA Regional Climate Sciences and Assessments. Since 2010 we have seen the establishment of the USDI Climate Science Centers and the Landscape Conservation Cooperatives, the NOAA Regional Climate Service Directors, and the USDA Regional Climate Hubs. The recent expansion of formal programs has essentially filled out the agency "niche space." Other non-governmental and private entities are also expanding into this space. The present profusion runs a risk of creating a perception of excessive duplication in some quarters, including those funding these enterprises. Collectively these activities form what can be thought of as an ecosystem of climate services. A certain amount of replication is desirable, healthy, and necessary, but beyond some point can be excessive unless the total capacity remains insufficient. Each component has come into existence for a different set of reasons. Since these components were invented by human beings, their subsequent evolution can in theory be guided by humans. The history and purpose of each component needs to be borne in mind, with capsule descriptions suitable for rapid delivery to the decision-makers who approve the support for the various components. Good communication among the components is therefore essential for a healthy and functional overall system. This in turn calls for the ability to adequately represent the role of each of those components, a purpose best informed through actual

  19. Impacts of climate and land use on N2 O and CH4 fluxes from tropical ecosystems in the Mt. Kilimanjaro region, Tanzania.

    Science.gov (United States)

    Gütlein, Adrian; Gerschlauer, Friederike; Kikoti, Imani; Kiese, Ralf

    2018-03-01

    In this study, we quantify the impacts of climate and land use on soil N 2 O and CH 4 fluxes from tropical forest, agroforest, arable and savanna ecosystems in Africa. To do so, we measured greenhouse gases (GHG) fluxes from 12 different ecosystems along climate and land-use gradients at Mt. Kilimanjaro, combining long-term in situ chamber and laboratory soil core incubation techniques. Both methods showed similar patterns of GHG exchange. Although there were distinct differences from ecosystem to ecosystem, soils generally functioned as net sources and sinks for N 2 O and CH 4 respectively. N 2 O emissions correlated positively with soil moisture and total soil nitrogen content. CH 4 uptake rates correlated negatively with soil moisture and clay content and positively with SOC. Due to moderate soil moisture contents and the dominance of nitrification in soil N turnover, N 2 O emissions of tropical montane forests were generally low (<1.2 kg N ha -1  year -1 ), and it is likely that ecosystem N losses are driven instead by nitrate leaching (~10 kg N ha -1  year -1 ). Forest soils with well-aerated litter layers were a significant sink for atmospheric CH 4 (up to 4 kg C ha -1  year -1 ) regardless of low mean annual temperatures at higher elevations. Land-use intensification significantly increased the soil N 2 O source strength and significantly decreased the soil CH 4 sink. Compared to decreases in aboveground and belowground carbon stocks enhanced soil non-CO 2 GHG emissions following land-use conversion from tropical forests to homegardens and coffee plantations were only a small factor in the total GHG budget. However, due to lower ecosystem carbon stock changes, enhanced N 2 O emissions significantly contributed to total GHG emissions following conversion of savanna into grassland and particularly maize. Overall, we found that the protection and sustainable management of aboveground and belowground carbon and nitrogen stocks of agroforestry and

  20. Modeling the Effects of Drought Events on Forest Ecosystem Functioning Historically and Under Scenarios of Climate Change

    Science.gov (United States)

    Ren, J.; Hanan, E. J.; Kolden, C.; Abatzoglou, J. T.; Tague, C.; Liu, M.; Adam, J. C.

    2017-12-01

    Drought events have been increasing across the western United States in recent years. Many studies have shown that, in the context of climate change, droughts will continue to be stronger, more frequent, and prolonged in the future. However, the response of forest ecosystems to droughts, particularly multi-year droughts, is not well understood. The objectives of this study are to examine how drought events of varying characteristics (e.g. intensity, duration, frequency, etc.) have affected the functioning of forest ecosystems historically, and how changing drought characteristics (including multi-year droughts) may affect forest functioning in a future climate. We utilize the Regional Hydro-Ecological Simulation System (RHESSys) to simulate impacts of both historical droughts and scenarios of future droughts on forest ecosystems. RHESSys is a spatially-distributed and process-based model that captures the interactions between coupled biogeochemical and hydrologic cycles at catchment scales. Here our case study is the Trail Creek catchment of the Big Wood River basin in Idaho, the Northwestern USA. For historical simulations, we use the gridded meteorological data of 1979 to 2016; for future climate scenarios, we utilize downscaled data from GCMs that have been demonstrated to capture drought events in the Northwest of the USA. From these climate projections, we identify various types of drought in intensity and duration, including multi-year drought events. We evaluate the following responses of ecosystems to these events: 1) evapotranspiration and streamflow; 2) gross primary productivity; 3) the post-drought recovery of plant biomass; and 4) the forest functioning and recovery after multi-year droughts. This research is part of an integration project to examine the roles of drought, insect outbreak, and forest management activities on wildfire activity and its impacts. This project will provide improved information for forest managers and communities in the wild

  1. Fixing Climate: What Past Climate Changes Reveal About the Current Threat-And How to Counter It

    Science.gov (United States)

    McKinley, Galen A.

    2008-10-01

    The Earth's climate is changing due to human activities. Recent polls suggest that the U.S. public generally recognizes this fact, and the efforts that led the Intergovernmental Panel on Climate Change (IPCC) and former U.S. vice president Al Gore to win the 2007 Nobel Peace Prize have played no small role in bringing most of the public to realize what scientists have been discussing for years. Yet aside from distorted Hollywood movie accounts such as The Day After Tomorrow, the public knows little about the potential for abrupt change in the climate system. With support from climate science philanthropist Gary Comer, climate scientist Wally Broecker has teamed with science writer Robert Kunzig in this book to bring abrupt climate change into public view. They do this elegantly and convincingly, making the first 12 chapters quite enjoyable.

  2. Widespread climate change in the Himalayas and associated changes in local ecosystems.

    Science.gov (United States)

    Shrestha, Uttam Babu; Gautam, Shiva; Bawa, Kamaljit S

    2012-01-01

    Climate change in the Himalayas, a biodiversity hotspot, home of many sacred landscapes, and the source of eight largest rivers of Asia, is likely to impact the well-being of ~20% of humanity. However, despite the extraordinary environmental, cultural, and socio-economic importance of the Himalayas, and despite their rapidly increasing ecological degradation, not much is known about actual changes in the two most critical climatic variables: temperature and rainfall. Nor do we know how changes in these parameters might impact the ecosystems including vegetation phenology. By analyzing temperature and rainfall data, and NDVI (Normalized Difference Vegetation Index) values from remotely sensed imagery, we report significant changes in temperature, rainfall, and vegetation phenology across the Himalayas between 1982 and 2006. The average annual mean temperature during the 25 year period has increased by 1.5 °C with an average increase of 0.06 °C yr(-1). The average annual precipitation has increased by 163 mm or 6.52 mmyr(-1). Since changes in temperature and precipitation are immediately manifested as changes in phenology of local ecosystems, we examined phenological changes in all major ecoregions. The average start of the growing season (SOS) seems to have advanced by 4.7 days or 0.19 days yr(-1) and the length of growing season (LOS) appears to have advanced by 4.7 days or 0.19 days yr(-1), but there has been no change in the end of the growing season (EOS). There is considerable spatial and seasonal variation in changes in climate and phenological parameters. This is the first time that large scale climatic and phenological changes at the landscape level have been documented for the Himalayas. The rate of warming in the Himalayas is greater than the global average, confirming that the Himalayas are among the regions most vulnerable to climate change.

  3. Tree mortality from drought, insects, and their interactions in a changing climate

    Science.gov (United States)

    Anderegg, William R.L.; Hicke, Jeffrey A.; Fisher, Rosie A.; Allen, Craig D.; Aukema, Juliann E.; Bentz, Barbara; Hood, Sharon; Lichstein, Jeremy W.; Macalady, Alison K.; McDowell, Nate G.; Pan, Yude; Raffa, Kenneth; Sala, Anna; Shaw, John D.; Stephenson, Nathan L.; Tague, Christina L.; Zeppel, Melanie

    2015-01-01

    Climate change is expected to drive increased tree mortality through drought, heat stress, and insect attacks, with manifold impacts on forest ecosystems. Yet, climate-induced tree mortality and biotic disturbance agents are largely absent from process-based ecosystem models. Using data sets from the western USA and associated studies, we present a framework for determining the relative contribution of drought stress, insect attack, and their interactions, which is critical for modeling mortality in future climates. We outline a simple approach that identifies the mechanisms associated with two guilds of insects – bark beetles and defoliators – which are responsible for substantial tree mortality. We then discuss cross-biome patterns of insect-driven tree mortality and draw upon available evidence contrasting the prevalence of insect outbreaks in temperate and tropical regions. We conclude with an overview of tools and promising avenues to address major challenges. Ultimately, a multitrophic approach that captures tree physiology, insect populations, and tree–insect interactions will better inform projections of forest ecosystem responses to climate change.

  4. Assessing Ecosystem Service Provision Under Climate Change to Support Conservation and Development Planning in Myanmar

    Science.gov (United States)

    Mandle, Lisa; Wolny, Stacie; Bhagabati, Nirmal; Helsingen, Hanna; Hamel, Perrine; Bartlett, Ryan; Dixon, Adam; Horton, Radley M.; Lesk, Corey; Manley, Danielle; hide

    2017-01-01

    Inclusion of ecosystem services (ES) information into national-scale development and climate adaptation planning has yet to become common practice, despite demand from decision makers. Identifying where ES originate and to whom the benefits flowunder current and future climate conditionsis especially critical in rapidly developing countries, where the risk of ES loss is high. Here, using Myanmar as a case study, we assess where and how ecosystems provide key benefits to the countrys people and infrastructure. We model the supply of and demand for sediment retention, dry-season baseflows, flood risk reduction and coastal storm protection from multiple beneficiaries. We find that locations currently providing the greatest amount of services are likely to remain important under the range of climate conditions considered, demonstrating their importance in planning for climate resilience. Overlap between priority areas for ES provision and biodiversity conservation is higher than expected by chance overall, but the areas important for multiple ES are underrepresented in currently designated protected areas and Key Biodiversity Areas. Our results are contributing to development planning in Myanmar, and our approach could be extended to other contexts where there is demand for national-scale natural capital information to shape development plans and policies

  5. Natural areas as a basis for assessing ecosystem vulnerability to climate change

    Science.gov (United States)

    Margaret H. Massie; Todd M. Wilson; Anita T. Morzillo; Emilie B. Henderson

    2016-01-01

    There are more than 580 natural areas in Oregon and Washington managed by 20 federal, state, local, and private agencies and organizations. This natural areas network is unparalleled in its representation of the diverse ecosystems found in the Pacific Northwest, and could prove useful for monitoring long-term ecological responses to climate change. Our objectives were...

  6. Downscaling Climate Projections to a Mountainous Landscape: A Climate Impact Assessment for the U.S. Northern Rockies Crown of the Continent Ecosystem

    Science.gov (United States)

    Oyler, J.; Anderson, R.; Running, S. W.

    2010-12-01

    In topographically complex landscapes, there is often a mismatch in scale between global climate model projections and more local climate-forcing factors and related ecological/hydrological processes. To overcome this limitation, the objective of this study was to downscale climate projections to the rugged Crown of the Continent Ecosystem (CCE) within the U.S. Northern Rockies and assess future impacts on water balances, vegetation dynamics, and carbon fluxes. A 40-year (1970-2009) spatial historical climate dataset (800m resolution, daily timestep) was generated for the CCE and modified for terrain influences. Regional climate projections were downscaled by applying them to the fine-scale historical dataset using a modified delta downscaling method and stochastic weather generator. The downscaled projections were used to drive the Biome-BGC ecosystem model. Overall CCE impacts included decreases in April 1 snow water equivalent, less days with snow on the ground, increased vegetation water stress, and increased growing degree days. The relaxing of temperature constraints increased annual net primary productivity (NPP) throughout most of the CCE landscape. However, an increase in water stress seems to have limited the growth in NPP and, in some areas, NPP actually decreased. Thus, CCE vegetation productivity trends under increasing temperatures will likely be determined by local changes in hydrologic function. Given the greater uncertainty in precipitation projections, future work should concentrate on determining thresholds in water constraints that greatly modify the magnitude and direction of carbon accumulation within the CCE under a warming climate.

  7. Global topics and novel approaches in the study of air pollution, climate change and forest ecosystems.

    Science.gov (United States)

    Sicard, Pierre; Augustaitis, Algirdas; Belyazid, Salim; Calfapietra, Carlo; de Marco, Alessandra; Fenn, Mark; Bytnerowicz, Andrzej; Grulke, Nancy; He, Shang; Matyssek, Rainer; Serengil, Yusuf; Wieser, Gerhard; Paoletti, Elena

    2016-06-01

    Research directions from the 27th conference for Specialists in Air Pollution and Climate Change Effects on Forest Ecosystems (2015) reflect knowledge advancements about (i) Mechanistic bases of tree responses to multiple climate and pollution stressors, in particular the interaction of ozone (O3) with nitrogen (N) deposition and drought; (ii) Linking genetic control with physiological whole-tree activity; (iii) Epigenetic responses to climate change and air pollution; (iv) Embedding individual tree performance into the multi-factorial stand-level interaction network; (v) Interactions of biogenic and anthropogenic volatile compounds (molecular, functional and ecological bases); (vi) Estimating the potential for carbon/pollution mitigation and cost effectiveness of urban and peri-urban forests; (vii) Selection of trees adapted to the urban environment; (viii) Trophic, competitive and host/parasite relationships under changing pollution and climate; (ix) Atmosphere-biosphere-pedosphere interactions as affected by anthropospheric changes; (x) Statistical analyses for epidemiological investigations; (xi) Use of monitoring for the validation of models; (xii) Holistic view for linking the climate, carbon, N and O3 modelling; (xiii) Inclusion of multiple environmental stresses (biotic and abiotic) in critical load determinations; (xiv) Ecological impacts of N deposition in the under-investigated areas; (xv) Empirical models for mechanistic effects at the local scale; (xvi) Broad-scale N and sulphur deposition input and their effects on forest ecosystem services; (xvii) Measurements of dry deposition of N; (xviii) Assessment of evapotranspiration; (xix) Remote sensing assessment of hydrological parameters; and (xx) Forest management for maximizing water provision and overall forest ecosystem services. Ground-level O3 is still the phytotoxic air pollutant of major concern to forest health. Specific issues about O3 are: (xxi) Developing dose-response relationships and

  8. Conservation of soil organic carbon, biodiversity and the provision of other ecosystem services along climatic gradients in West Africa

    Directory of Open Access Journals (Sweden)

    E. Marks

    2009-08-01

    Full Text Available Terrestrial carbon resources are major drivers of development in West Africa. The distribution of these resources co-varies with ecosystem type and rainfall along a strong Northeast-Southwest climatic gradient. Soil organic carbon, a strong indicator of soil quality, has been severely depleted in some areas by human activities, which leads to issues of soil erosion and desertification, but this trend can be altered with appropriate management. There is significant potential to enhance existing soil carbon stores in West Africa, with benefits at the global and local scale, for atmospheric CO2 mitigation as well as supporting and provisioning ecosystem services. Three key factors impacting carbon stocks are addressed in this review: climate, biotic factors, and human activities. Climate risks must be considered in a framework of global change, especially in West Africa, where landscape managers have few resources available to adapt to climatic perturbations. Among biotic factors, biodiversity conservation paired with carbon conservation may provide a pathway to sustainable development, and biodiversity conservation is also a global priority with local benefits for ecosystem resilience, biomass productivity, and provisioning services such as foodstuffs. Finally, human management has largely been responsible for reduced carbon stocks, but this trend can be reversed through the implementation of appropriate carbon conservation strategies in the agricultural sector, as shown by multiple studies. Owing to the strong regional climatic gradient, country-level initiatives will need to consider carbon sequestration approaches for multiple ecosystem types. Given the diversity of environments, global policies must be adapted and strategies developed at the national or sub-national levels to improve carbon storage above and belowground. Initiatives of this sort must act locally at farmer scale, and focus on ecosystem services rather than on carbon

  9. Final Scientific Report for "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall"

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, John C. H. [University of California, Berkeley, CA (United States); Wehner, Michael F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-29

    This is the final scientific report for grant DOE-FG02-08ER64588, "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall."The project investigates the role of the interhemispheric pattern in surface temperature – i.e. the contrast between the northern and southern temperature changes – in driving rapid changes to tropical rainfall changes over the 20th century and future climates. Previous observational and modeling studies have shown that the tropical rainband – the Intertropical Convergence Zone (ITCZ) over marine regions, and the summer monsoonal rainfall over land – are sensitive to the interhemispheric thermal contrast; but that the link between the two has not been applied to interpreting long-term tropical rainfall changes over the 20th century and future.The specific goals of the project were to i) develop dynamical mechanisms to explain the link between the interhemispheric pattern to abrupt changes of West African and Asian monsoonal rainfall; ii) Undertake a formal detection and attribution study on the interhemispheric pattern in 20th century climate; and iii) assess the likelihood of changes to this pattern in the future. In line with these goals, our project has produced the following significant results: 1.We have developed a case that suggests that the well-known abrupt weakening of the West African monsoon in the late 1960s was part of a wider co-ordinated weakening of the West African and Asian monsoons, and driven from an abrupt cooling in the high latitude North Atlantic sea surface temperature at the same time. Our modeling work suggests that the high-latitude North Atlantic cooling is effective in driving monsoonal weakening, through driving a cooling of the Northern hemisphere that is amplified by positive radiative feedbacks. 2.We have shown that anthropogenic sulfate aerosols may have partially contributed to driving a progressively southward displacement of the Atlantic Intertropical

  10. Climate bifurcation during the last deglaciation?

    Directory of Open Access Journals (Sweden)

    T. M. Lenton

    2012-07-01

    Full Text Available There were two abrupt warming events during the last deglaciation, at the start of the Bølling-Allerød and at the end of the Younger Dryas, but their underlying dynamics are unclear. Some abrupt climate changes may involve gradual forcing past a bifurcation point, in which a prevailing climate state loses its stability and the climate tips into an alternative state, providing an early warning signal in the form of slowing responses to perturbations, which may be accompanied by increasing variability. Alternatively, short-term stochastic variability in the climate system can trigger abrupt climate changes, without early warning. Previous work has found signals consistent with slowing down during the last deglaciation as a whole, and during the Younger Dryas, but with conflicting results in the run-up to the Bølling-Allerød. Based on this, we hypothesise that a bifurcation point was approached at the end of the Younger Dryas, in which the cold climate state, with weak Atlantic overturning circulation, lost its stability, and the climate tipped irreversibly into a warm interglacial state. To test the bifurcation hypothesis, we analysed two different climate proxies in three Greenland ice cores, from the Last Glacial Maximum to the end of the Younger Dryas. Prior to the Bølling warming, there was a robust increase in climate variability but no consistent slowing down signal, suggesting this abrupt change was probably triggered by a stochastic fluctuation. The transition to the warm Bølling-Allerød state was accompanied by a slowing down in climate dynamics and an increase in climate variability. We suggest that the Bølling warming excited an internal mode of variability in Atlantic meridional overturning circulation strength, causing multi-centennial climate fluctuations. However, the return to the Younger Dryas cold state increased climate stability. We find no consistent evidence for slowing down during the Younger Dryas, or in a longer

  11. Central Hardwoods ecosystem vulnerability assessment and synthesis: a report from the Central Hardwoods Climate Change Response Framework project

    Science.gov (United States)

    Leslie Brandt; Hong He; Louis Iverson; Frank R. Thompson; Patricia Butler; Stephen Handler; Maria Janowiak; P. Danielle Shannon; Chris Swanston; Matthew Albrecht; Richard Blume-Weaver; Paul Deizman; John DePuy; William D. Dijak; Gary Dinkel; Songlin Fei; D. Todd Jones-Farrand; Michael Leahy; Stephen Matthews; Paul Nelson; Brad Oberle; Judi Perez; Matthew Peters; Anantha Prasad; Jeffrey E. Schneiderman; John Shuey; Adam B. Smith; Charles Studyvin; John M. Tirpak; Jeffery W. Walk; Wen J. Wang; Laura Watts; Dale Weigel; Steve. Westin

    2014-01-01

    The forests in the Central Hardwoods Region will be affected directly and indirectly by a changing climate over the next 100 years. This assessment evaluates the vulnerability of terrestrial ecosystems in the Central Hardwoods Region of Illinois, Indiana, and Missouri to a range of future climates. Information on current forest conditions, observed climate trends,...

  12. Flow regime alterations under changing climate in two river basins: Implications for freshwater ecosystems

    Science.gov (United States)

    Gibson, C.A.; Meyer, J.L.; Poff, N.L.; Hay, L.E.; Georgakakos, A.

    2005-01-01

    We examined impacts of future climate scenarios on flow regimes and how predicted changes might affect river ecosystems. We examined two case studies: Cle Elum River, Washington, and Chattahoochee-Apalachicola River Basin, Georgia and Florida. These rivers had available downscaled global circulation model (GCM) data and allowed us to analyse the effects of future climate scenarios on rivers with (1) different hydrographs, (2) high future water demands, and (3) a river-floodplain system. We compared observed flow regimes to those predicted under future climate scenarios to describe the extent and type of changes predicted to occur. Daily stream flow under future climate scenarios was created by either statistically downscaling GCMs (Cle Elum) or creating a regression model between climatological parameters predicted from GCMs and stream flow (Chattahoochee-Apalachicola). Flow regimes were examined for changes from current conditions with respect to ecologically relevant features including the magnitude and timing of minimum and maximum flows. The Cle Elum's hydrograph under future climate scenarios showed a dramatic shift in the timing of peak flows and lower low flow of a longer duration. These changes could mean higher summer water temperatures, lower summer dissolved oxygen, and reduced survival of larval fishes. The Chattahoochee-Apalachicola basin is heavily impacted by dams and water withdrawals for human consumption; therefore, we made comparisons between pre-large dam conditions, current conditions, current conditions with future demand, and future climate scenarios with future demand to separate climate change effects and other anthropogenic impacts. Dam construction, future climate, and future demand decreased the flow variability of the river. In addition, minimum flows were lower under future climate scenarios. These changes could decrease the connectivity of the channel and the floodplain, decrease habitat availability, and potentially lower the ability

  13. Tropical and Highland Temperate Forest Plantations in Mexico: Pathways for Climate Change Mitigation and Ecosystem Services Delivery

    Directory of Open Access Journals (Sweden)

    Vidal Guerra-De la Cruz

    2017-12-01

    Full Text Available Forest plantations are a possible way of increasing forest productivity in temperate and tropical forests, and therefore also increasing above- and belowground carbon pools. In the context of climate change, monospecific plantations might become an alternative to mitigate global warming; however, their contribution to the structural complexity, complementarity, and biodiversity of forests has not been addressed. Mixed forest plantations can ensure that objectives of climate change mitigation are met through carbon sequestration, while also delivering anticipated ecosystem services (e.g., nutrient cycling, erosion control, and wildlife habitat. However, mixed forest plantations pose considerable operational challenges and research opportunities. For example, it is essential to know how many species or functional traits are necessary to deliver a set of benefits, or what mixture of species and densities are key to maintaining productive plantations and delivering multiple ecosystem services. At the same time, the establishment of forest plantations in Mexico should not be motivated solely by timber production. Forest plantations should also increase carbon sequestration, maintain biodiversity, and provide other ecosystem services. This article analyzes some matters that affect the development of planted forests in the Mexican national context, and presents alternatives for forest resources management through the recommendation of mixed forest plantations as a means of contributing to climate change mitigation and the delivery of ecosystem services.

  14. Going with the flow: the role of ocean circulation in global marine ecosystems under a changing climate.

    Science.gov (United States)

    van Gennip, Simon J; Popova, Ekaterina E; Yool, Andrew; Pecl, Gretta T; Hobday, Alistair J; Sorte, Cascade J B

    2017-07-01

    Ocean warming, acidification, deoxygenation and reduced productivity are widely considered to be the major stressors to ocean ecosystems induced by emissions of CO 2 . However, an overlooked stressor is the change in ocean circulation in response to climate change. Strong changes in the intensity and position of the western boundary currents have already been observed, and the consequences of such changes for ecosystems are beginning to emerge. In this study, we address climatically induced changes in ocean circulation on a global scale but relevant to propagule dispersal for species inhabiting global shelf ecosystems, using a high-resolution global ocean model run under the IPCC RCP 8.5 scenario. The ¼ degree model resolution allows improved regional realism of the ocean circulation beyond that of available CMIP5-class models. We use a Lagrangian approach forced by modelled ocean circulation to simulate the circulation pathways that disperse planktonic life stages. Based on trajectory backtracking, we identify present-day coastal retention, dominant flow and dispersal range for coastal regions at the global scale. Projecting into the future, we identify areas of the strongest projected circulation change and present regional examples with the most significant modifications in their dominant pathways. Climatically induced changes in ocean circulation should be considered as an additional stressor of marine ecosystems in a similar way to ocean warming or acidification. © 2017 John Wiley & Sons Ltd.

  15. An ecohydrological sketch of climate change impacts on water and natural ecosystems for the Netherlands: bridging the gap between science and society

    Directory of Open Access Journals (Sweden)

    J. P. M. Witte

    2012-11-01

    Full Text Available For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch map that indicates climate change effects on a number of ecosystems in the Netherlands. Soon after a first version of our sketch map was published by a Dutch professional journal, copies appeared in policy documents, and also in a commercial and popular atlas of the Netherlands. Moreover, the map led to a question in the Dutch parliament about the sustainability of bog reserves under the future climate. Apparently, there was an urgent need for the information provided by the map.

    The map shows that climate change will presumably have the largest influence on ecosystems in the Netherlands that depend on precipitation as the major water source, like heathlands, dry grasslands, rain-fed moorland pools and raised bogs. Also highly susceptible are fens in reserves surrounded by deeply drained polders, because such fens depend on the inlet of surface water, of which quality is likely to deteriorate upon climate change. While the map is indicative for directions of change, in view of the uncertainties of our study, no conclusions should be drawn that may have far-reaching consequences, such as giving up certain nature targets that might no longer be feasible in the future climate. Instead, we advise to anticipate the potential threats from climate change by taking a number of adaptation measures that enhance the robustness of nature reserves.

    To improve climate change projections on hydrology and ecosystems

  16. An ecohydrological sketch of climate change impacts on water and natural ecosystems for the Netherlands: bridging the gap between science and society

    Science.gov (United States)

    Witte, J. P. M.; Runhaar, J.; van Ek, R.; van der Hoek, D. C. J.; Bartholomeus, R. P.; Batelaan, O.; van Bodegom, P. M.; Wassen, M. J.; van der Zee, S. E. A. T. M.

    2012-11-01

    For policy making and spatial planning, information is needed about the impacts of climate change on natural ecosystems. To provide this information, commonly hydrological and ecological models are used. We give arguments for our assessment that modelling only is insufficient for determining the impacts of climate changes on natural ecosystems at regional scales. Instead, we proposed a combination of hydrological simulations, a literature review and process-knowledge on climate-hydrology-vegetation interactions, to compile a sketch map that indicates climate change effects on a number of ecosystems in the Netherlands. Soon after a first version of our sketch map was published by a Dutch professional journal, copies appeared in policy documents, and also in a commercial and popular atlas of the Netherlands. Moreover, the map led to a question in the Dutch parliament about the sustainability of bog reserves under the future climate. Apparently, there was an urgent need for the information provided by the map. The map shows that climate change will presumably have the largest influence on ecosystems in the Netherlands that depend on precipitation as the major water source, like heathlands, dry grasslands, rain-fed moorland pools and raised bogs. Also highly susceptible are fens in reserves surrounded by deeply drained polders, because such fens depend on the inlet of surface water, of which quality is likely to deteriorate upon climate change. While the map is indicative for directions of change, in view of the uncertainties of our study, no conclusions should be drawn that may have far-reaching consequences, such as giving up certain nature targets that might no longer be feasible in the future climate. Instead, we advise to anticipate the potential threats from climate change by taking a number of adaptation measures that enhance the robustness of nature reserves. To improve climate change projections on hydrology and ecosystems, future research should especially

  17. Ballast water management that adapts to climate changes and reduces harmful bio-invasions in marine eco-systems

    DEFF Research Database (Denmark)

    Rasmussen, Lauge Baungaard; Hansen, Mette Sanne

    2015-01-01

    food-webs and eco-systems. Economic impacts include reductions in fisheries production and algae blooms harmful for fish farms, tourism and human health. Due to the rising temperatures of the Oceans, organisms that prefer a warm climate may take roots in marine ecosystems that were previously too cold...... in marine ecosystem of changed factors in the shipping sector, for instance change of number, size, and design of vessels as well as treatment technologies of ballast water. New areas for shipping due to climate changes are also included. Our study would contribute to improve decision support tools, usable...... for them. In addition, future changes of temperature, storm patterns and sea-currents may also change shipping routes and ballast water management practices. Based on methods like stock taking, trend tracking and scenario modeling the paper aims to evaluate possible ecological and economic impacts...

  18. An ecosystem approach to climate policy : the role of rural renewable energy design

    International Nuclear Information System (INIS)

    Venema, H.D.

    2004-01-01

    Climate change provides renewed importance to the issues of rural energy and the task of providing modern, sustainable energy services to the 2 billion people around the world who rely on biomass energy. Impoverished countries are most vulnerable to the adverse affects of climate change. The author argues that energy deprivation must be addressed in order to alleviate poverty, and that increased energy provision to the world's poor is not a development option, rather a basic necessity. The choices made in how that energy is delivered can either intensify climate change or mitigate it. There are many changes that are transforming the power sector. Deregulation is providing new business opportunities for independent power producers and contributing to the break up of vertically integrated power utilities. Ecosystem and community-based methods to rural development are contributing to the application of decentralized renewable energy source development. In countries such as India, policy-makers have legislated decentralized renewable energy systems. This study addresses the fact that there are no appropriate design tools for ecosystem-oriented rural energy planning. The author therefore presents a newly developed ecosystem-based approach to rural energy systems design whose main components include the use of a complex adaptive system theory to establish rural energy system design principles; a human energetics model for studying the influence of bioenergy resource accessibility; and spatial optimization methods for rural biomass energy planning. The approach was refined to include landscape structure optimization for biodiversity objectives using landscape ecology concepts in subregions of India. It was then generalized for regional-scale distributed renewable energy system designs with integrated bioenergy, wind and solar resource assessment

  19. Climate Change Amplifications of Climate-Fire Teleconnections in the Southern Hemisphere

    Science.gov (United States)

    Mariani, Michela; Holz, Andrés.; Veblen, Thomas T.; Williamson, Grant; Fletcher, Michael-Shawn; Bowman, David M. J. S.

    2018-05-01

    Recent changes in trend and variability of the main Southern Hemisphere climate modes are driven by a variety of factors, including increasing atmospheric greenhouse gases, changes in tropical sea surface temperature, and stratospheric ozone depletion and recovery. One of the most important implications for climatic change is its effect via climate teleconnections on natural ecosystems, water security, and fire variability in proximity to populated areas, thus threatening human lives and properties. Only sparse and fragmentary knowledge of relationships between teleconnections, lightning strikes, and fire is available during the observed record within the Southern Hemisphere. This constitutes a major knowledge gap for undertaking suitable management and conservation plans. Our analysis of documentary fire records from Mediterranean and temperate regions across the Southern Hemisphere reveals a critical increased strength of climate-fire teleconnections during the onset of the 21st century including a tight coupling between lightning-ignited fire occurrences, the upward trend in the Southern Annular Mode, and rising temperatures across the Southern Hemisphere.

  20. Changing climate and endangered high mountain ecosystems in Colombia.

    Science.gov (United States)

    Ruiz, Daniel; Moreno, Hernán Alonso; Gutiérrez, María Elena; Zapata, Paula Andrea

    2008-07-15

    High mountain ecosystems are among the most sensitive environments to changes in climatic conditions occurring on global, regional and local scales. The article describes the changing conditions observed over recent years in the high mountain basin of the Claro River, on the west flank of the Colombian Andean Central mountain range. Local ground truth data gathered at 4150 m, regional data available at nearby weather stations, and satellite info were used to analyze changes in the mean and the variance, and significant trends in climatic time series. Records included minimum, mean and maximum temperatures, relative humidity, rainfall, sunshine, and cloud characteristics. In high levels, minimum and maximum temperatures during the coldest days increased at a rate of about 0.6 degrees C/decade, whereas maximum temperatures during the warmest days increased at a rate of about 1.3 degrees C/decade. Rates of increase in maximum, mean and minimum diurnal temperature range reached 0.6, 0.7, and 0.5 degrees C/decade. Maximum, mean and minimum relative humidity records showed reductions of about 1.8, 3.9 and 6.6%/decade. The total number of sunny days per month increased in almost 2.1 days. The headwaters exhibited no changes in rainfall totals, but evidenced an increased occurrence of unusually heavy rainfall events. Reductions in the amount of all cloud types over the area reached 1.9%/decade. In low levels changes in mean monthly temperatures and monthly rainfall totals exceeded + 0.2 degrees C and - 4% per decade, respectively. These striking changes might have contributed to the retreat of glacier icecaps and to the disappearance of high altitude water bodies, as well as to the occurrence and rapid spread of natural and man-induced forest fires. Significant reductions in water supply, important disruptions of the integrity of high mountain ecosystems, and dramatic losses of biodiversity are now a steady menu of the severe climatic conditions experienced by these

  1. Risk and contributing factors of ecosystem shifts over naturally vegetated land under climate change in China.

    Science.gov (United States)

    Yin, Yuanyuan; Tang, Qiuhong; Wang, Lixin; Liu, Xingcai

    2016-02-12

    Identifying the areas at risk of ecosystem transformation and the main contributing factors to the risk is essential to assist ecological adaptation to climate change. We assessed the risk of ecosystem shifts in China using the projections of four global gridded vegetation models (GGVMs) and an aggregate metric. The results show that half of naturally vegetated land surface could be under moderate or severe risk at the end of the 21(st) century under the middle and high emission scenarios. The areas with high risk are the Tibetan Plateau region and an area extended northeastward from the Tibetan Plateau to northeast China. With the three major factors considered, the change in carbon stocks is the main contributing factor to the high risk of ecosystem shifts. The change in carbon fluxes is another important contributing factor under the high emission scenario. The change in water fluxes is a less dominant factor except for the Tibetan Plateau region under the high emission scenario. Although there is considerable uncertainty in the risk assessment, the geographic patterns of the risk are generally consistent across different scenarios. The results could help develop regional strategies for ecosystem conservation to cope with climate change.

  2. Impacts of climate change and sea level rise to Danish near shore ecosystems

    International Nuclear Information System (INIS)

    Vestergaard, P.

    2001-01-01

    Salt marshes and sand dunes are important types of coastal, terrestrial nature, which like other terrestrial ecosystems will be sensible to the future changes in climate, which have been predicted. Due to the processes acting in their morphogenesis and in the development and composition of their ecosystems, they will not least be influenced by sea level rise. Especially a strong impact of a sea level rise of about 50 cm (midrange of the projected global sea level rise) for the next century can be expected on Danish salt marshes, considering their limited vertical range (50-100 cm). (LN)

  3. Interactions of Vegetation and Climate: Remote Observations, Earth System Models, and the Amazon Forest

    Science.gov (United States)

    Quetin, Gregory R.

    transitions in sign (greener when warmer or drier to greener when cooler or wetter) along an emergent line in climate space with a slope of about 59 mm/yr/°C, twice as steep as contours of aridity. The mismatch between these slopes is evidence at a global scale of the limitation of both water supply due to inefficiencies in plant access to rainfall, and plant physiological responses to atmospheric water demand. This empirical pattern can provide a functional constraint for process-based models, helping to improve predictions of the global-scale response of vegetation to a changing climate. In Chapter 2, we use observations of vegetation interaction with the physical environment to identify where ecosystem functioning is well simulated in an ensemble of Earth system models. We leverage this data-model comparison to hypothesize which physiological mechanisms--photosynthetic efficiency, respiration, water supply, atmospheric water demand, and sunlight availability--dominate the ecosystem response in places with different climates. The models are generally successful in reproducing the broad sign and shape of ecosystem function across climate space except for simulating generally lower leaf area during warmer years in places with hot wet climates. In addition, simulated ecosystem interaction with temperature is generally larger and changes more rapidly across a gradient of temperature than is observed. We hypothesize that the amplified interaction and change are both due to a lack of adaptation and acclimation in simulations. This discrepancy with observations suggests that simulated responses of vegetation to global warming, and feedbacks between vegetation and climate, are too strong in the models. Finally, models and observations share an abrupt threshold between dry regions and wet regions where strong positive vegetation response to precipitation falls to nearly zero in places receiving around 1000 mm/year. In Chapter 3, we investigate how ecoclimate interactions change

  4. Climate change impacts on U.S. coastal and marine ecosystems

    Science.gov (United States)

    Scavia, Donald; Field, John C.; Boesch, Donald F.; Buddemeier, Robert W.; Burkett, Virginia; Cayan, Daniel R.; Fogarty, Michael; Harwell, Mark A.; Howarth, Robert W.; Mason, Curt; Reed, Denise J.; Royer, Thomas C.; Sallenger, Asbury H.; Titus, James G.

    2002-01-01

    Increases in concentrations of greenhouse gases projected for the 21st century are expected to lead to increased mean global air and ocean temperatures. The National Assessment of Potential Consequences of Climate Variability and Change (NAST 2001) was based on a series of regional and sector assessments. This paper is a summary of the coastal and marine resources sector review of potential impacts on shorelines, estuaries, coastal wetlands, coral reefs, and ocean margin ecosystems. The assessment considered the impacts of several key drivers of climate change: sea level change; alterations in precipitation patterns and subsequent delivery of freshwater, nutrients, and sediment; increased ocean temperature; alterations in circulation patterns; changes in frequency and intensity of coastal storms; and increased levels of atmospheric CO2. Increasing rates of sea-level rise and intensity and frequency of coastal storms and hurricanes over the next decades will increase threats to shorelines, wetlands, and coastal development. Estuarine productivity will change in response to alteration in the timing and amount of freshwater, nutrients, and sediment delivery. Higher water temperatures and changes in freshwater delivery will alter estuarine stratification, residence time, and eutrophication. Increased ocean temperatures are expected to increase coral bleaching and higher CO2 levels may reduce coral calcification, making it more difficult for corals to recover from other disturbances, and inhibiting poleward shifts. Ocean warming is expected to cause poleward shifts in the ranges of many other organisms, including commercial species, and these shifts may have secondary effects on their predators and prey. Although these potential impacts of climate change and variability will vary from system to system, it is important to recognize that they will be superimposed upon, and in many cases intensify, other ecosystem stresses (pollution, harvesting, habitat destruction

  5. Protected area networks and savannah bird biodiversity in the face of climate change and land degradation.

    Science.gov (United States)

    Beale, Colin M; Baker, Neil E; Brewer, Mark J; Lennon, Jack J

    2013-08-01

    The extent to which climate change might diminish the efficacy of protected areas is one of the most pressing conservation questions. Many projections suggest that climate-driven species distribution shifts will leave protected areas impoverished and species inadequately protected while other evidence suggests that intact ecosystems within protected areas will be resilient to change. Here, we tackle this problem empirically. We show how recent changes in distribution of 139 Tanzanian savannah bird species are linked to climate change, protected area status and land degradation. We provide the first evidence of climate-driven range shifts for an African bird community. Our results suggest that the continued maintenance of existing protected areas is an appropriate conservation response to the challenge of climate and environmental change. © 2013 John Wiley & Sons Ltd/CNRS.

  6. Scenario and modelling uncertainty in global mean temperature change derived from emission driven Global Climate Models

    Science.gov (United States)

    Booth, B. B. B.; Bernie, D.; McNeall, D.; Hawkins, E.; Caesar, J.; Boulton, C.; Friedlingstein, P.; Sexton, D.

    2012-09-01

    We compare future changes in global mean temperature in response to different future scenarios which, for the first time, arise from emission driven rather than concentration driven perturbed parameter ensemble of a Global Climate Model (GCM). These new GCM simulations sample uncertainties in atmospheric feedbacks, land carbon cycle, ocean physics and aerosol sulphur cycle processes. We find broader ranges of projected temperature responses arising when considering emission rather than concentration driven simulations (with 10-90 percentile ranges of 1.7 K for the aggressive mitigation scenario up to 3.9 K for the high end business as usual scenario). A small minority of simulations resulting from combinations of strong atmospheric feedbacks and carbon cycle responses show temperature increases in excess of 9 degrees (RCP8.5) and even under aggressive mitigation (RCP2.6) temperatures in excess of 4 K. While the simulations point to much larger temperature ranges for emission driven experiments, they do not change existing expectations (based on previous concentration driven experiments) on the timescale that different sources of uncertainty are important. The new simulations sample a range of future atmospheric concentrations for each emission scenario. Both in case of SRES A1B and the Representative Concentration Pathways (RCPs), the concentration pathways used to drive GCM ensembles lies towards the lower end of our simulated distribution. This design decision (a legecy of previous assessments) is likely to lead concentration driven experiments to under-sample strong feedback responses in concentration driven projections. Our ensemble of emission driven simulations span the global temperature response of other multi-model frameworks except at the low end, where combinations of low climate sensitivity and low carbon cycle feedbacks lead to responses outside our ensemble range. The ensemble simulates a number of high end responses which lie above the CMIP5 carbon

  7. Scenario and modelling uncertainty in global mean temperature change derived from emission-driven global climate models

    Science.gov (United States)

    Booth, B. B. B.; Bernie, D.; McNeall, D.; Hawkins, E.; Caesar, J.; Boulton, C.; Friedlingstein, P.; Sexton, D. M. H.

    2013-04-01

    We compare future changes in global mean temperature in response to different future scenarios which, for the first time, arise from emission-driven rather than concentration-driven perturbed parameter ensemble of a global climate model (GCM). These new GCM simulations sample uncertainties in atmospheric feedbacks, land carbon cycle, ocean physics and aerosol sulphur cycle processes. We find broader ranges of projected temperature responses arising when considering emission rather than concentration-driven simulations (with 10-90th percentile ranges of 1.7 K for the aggressive mitigation scenario, up to 3.9 K for the high-end, business as usual scenario). A small minority of simulations resulting from combinations of strong atmospheric feedbacks and carbon cycle responses show temperature increases in excess of 9 K (RCP8.5) and even under aggressive mitigation (RCP2.6) temperatures in excess of 4 K. While the simulations point to much larger temperature ranges for emission-driven experiments, they do not change existing expectations (based on previous concentration-driven experiments) on the timescales over which different sources of uncertainty are important. The new simulations sample a range of future atmospheric concentrations for each emission scenario. Both in the case of SRES A1B and the Representative Concentration Pathways (RCPs), the concentration scenarios used to drive GCM ensembles, lies towards the lower end of our simulated distribution. This design decision (a legacy of previous assessments) is likely to lead concentration-driven experiments to under-sample strong feedback responses in future projections. Our ensemble of emission-driven simulations span the global temperature response of the CMIP5 emission-driven simulations, except at the low end. Combinations of low climate sensitivity and low carbon cycle feedbacks lead to a number of CMIP5 responses to lie below our ensemble range. The ensemble simulates a number of high-end responses which lie

  8. Scenario and modelling uncertainty in global mean temperature change derived from emission-driven global climate models

    Directory of Open Access Journals (Sweden)

    B. B. B. Booth

    2013-04-01

    Full Text Available We compare future changes in global mean temperature in response to different future scenarios which, for the first time, arise from emission-driven rather than concentration-driven perturbed parameter ensemble of a global climate model (GCM. These new GCM simulations sample uncertainties in atmospheric feedbacks, land carbon cycle, ocean physics and aerosol sulphur cycle processes. We find broader ranges of projected temperature responses arising when considering emission rather than concentration-driven simulations (with 10–90th percentile ranges of 1.7 K for the aggressive mitigation scenario, up to 3.9 K for the high-end, business as usual scenario. A small minority of simulations resulting from combinations of strong atmospheric feedbacks and carbon cycle responses show temperature increases in excess of 9 K (RCP8.5 and even under aggressive mitigation (RCP2.6 temperatures in excess of 4 K. While the simulations point to much larger temperature ranges for emission-driven experiments, they do not change existing expectations (based on previous concentration-driven experiments on the timescales over which different sources of uncertainty are important. The new simulations sample a range of future atmospheric concentrations for each emission scenario. Both in the case of SRES A1B and the Representative Concentration Pathways (RCPs, the concentration scenarios used to drive GCM ensembles, lies towards the lower end of our simulated distribution. This design decision (a legacy of previous assessments is likely to lead concentration-driven experiments to under-sample strong feedback responses in future projections. Our ensemble of emission-driven simulations span the global temperature response of the CMIP5 emission-driven simulations, except at the low end. Combinations of low climate sensitivity and low carbon cycle feedbacks lead to a number of CMIP5 responses to lie below our ensemble range. The ensemble simulates a number of high

  9. Integrating ecosystem services and climate change responses in coastal wetlands development plans for Bangladesh

    NARCIS (Netherlands)

    Sarwar, M.H.; Hein, L.G.; Rip, F.I.; Dearing, J.A.

    2015-01-01

    This study explores the integration of ecosystem services and climate change adaptation in development plans for coastal wetlands in Bangladesh. A new response framework for adaptation is proposed, based on an empirical analysis and consultations with stakeholders, using a modified version of the

  10. Effects on the function of Arctic ecosystems in the short- and long-term perspectives.

    Science.gov (United States)

    Callaghan, Terry V; Björn, Lars Olof; Chernov, Yuri; Chapin, Terry; Christensen, Torben R; Huntley, Brian; Ims, Rolf A; Johansson, Margareta; Jolly, Dyanna; Jonasson, Sven; Matveyeva, Nadya; Panikov, Nicolai; Oechel, Walter; Shaver, Gus

    2004-11-01

    incoming radiation, to summer when the ecosystem absorbs most incoming radiation. Vegetation profoundly influences the water and energy exchange of Arctic ecosystems. Albedo during the period of snow cover declines from tundra to forest tundra to deciduous forest to evergreen forest. Shrubs and trees increase snow depth which in turn increases winter soil temperatures. Future changes in vegetation driven by climate change are therefore, very likely to profoundly alter regional climate.

  11. Woody-plant ecosystems under climate change and air pollution-response consistencies across zonobiomes?

    Science.gov (United States)

    Matyssek, R; Kozovits, A R; Wieser, G; King, J; Rennenberg, H

    2017-06-01

    Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climate system, yet are threatened by climate change (CC) and associated air pollution (AP, highlighting ozone (O3) and nitrogen oxides (NOx)). We adopt the perspective that CC-AP drivers and physiological impacts are universal, resulting in consistent stress responses of forest ecosystems across zonobiomes. Evidence supporting this viewpoint is presented from the literature on ecosystem gross/net primary productivity and water cycling. Responses to CC-AP are compared across evergreen/deciduous foliage types, discussing implications of nutrition and resource turnover at tree and ecosystem scales. The availability of data is extremely uneven across zonobiomes, yet unifying patterns of ecosystem response are discernable. Ecosystem warming results in trade-offs between respiration and biomass production, affecting high elevation forests more than in the lowland tropics and low-elevation temperate zone. Resilience to drought is modulated by tree size and species richness. Elevated O3 tends to counteract stimulation by elevated carbon dioxide (CO2). Biotic stress and genomic structure ultimately determine ecosystem responsiveness. Aggrading early- rather than mature late-successional communities respond to CO2 enhancement, whereas O3 affects North American and Eurasian tree species consistently under free-air fumigation. Insect herbivory is exacerbated by CC-AP in biome-specific ways. Rhizosphere responses reflect similar stand-level nutritional dynamics across zonobiomes, but are modulated by differences in tree-soil nutrient cycling between deciduous and evergreen systems, and natural versus anthropogenic nitrogen (N) oversupply. The hypothesis of consistency of forest responses to interacting CC-AP is supported by currently available data, establishing the precedent for a global network of long-term coordinated research sites across zonobiomes to simultaneously advance both

  12. Ecosystem processes and human influences regulate streamflow response to climate change at long-term ecological research sites

    Science.gov (United States)

    Julia A. Jones; Irena F. Creed; Kendra L. Hatcher; Robert J. Warren; Mary Beth Adams; Melinda H. Benson; Emery Boose; Warren A. Brown; John L. Campbell; Alan Covich; David W. Clow; Clifford N. Dahm; Kelly Elder; Chelcy R. Ford; Nancy B. Grimm; Donald L Henshaw; Kelli L. Larson; Evan S. Miles; Kathleen M. Miles; Stephen D. Sebestyen; Adam T. Spargo; Asa B. Stone; James M. Vose; Mark W. Williams

    2012-01-01

    Analyses of long-term records at 35 headwater basins in the United States and Canada indicate that climate change effects on streamflow are not as clear as might be expected, perhaps because of ecosystem processes and human influences. Evapotranspiration was higher than was predicted by temperature in water-surplus ecosystems and lower than was predicted in water-...

  13. The economic value of the climate regulation ecosystem service provided by the Amazon rainforest

    Science.gov (United States)

    Heil Costa, Marcos; Pires, Gabrielle; Fontes, Vitor; Brumatti, Livia

    2017-04-01

    The rainy Amazon climate allowed important activities to develop in the region as large rainfed agricultural lands and hydropower plants. The Amazon rainforest is an important source of moisture to the regional atmosphere and helps regulate the local climate. The replacement of forest by agricultural lands decreases the flux of water vapor into the atmosphere and changes the precipitation patterns, which may severely affect such economic activities. Assign an economic value to this ecosystem service may emphasize the significance to preserve the Amazon rainforest. In this work, we provide a first approximation of the quantification of the climate regulation ecosystem service provided by the Amazon rainforest using the marginal production method. We use climate scenarios derived from Amazon deforestation scenarios as input to crop and runoff models to assess how land use change would affect agriculture and hydropower generation. The effects of forest removal on soybean production and on cattle beef production can both be as high as US 16 per year per ha deforested, and the effects on hydropower generation can be as high as US 8 per year per ha deforested. We consider this as a conservative estimate of a permanent service provided by the rainforest. Policy makers and other Amazon agriculture and energy businesses must be aware of these numbers, and consider them while planning their activities.

  14. Separating the Effects of Tropical Atlantic and Pacific SST-driven Climate Variability on Amazon Carbon Exchange

    Science.gov (United States)

    Liptak, J.; Keppel-Aleks, G.

    2016-12-01

    Amazon forests store an estimated 25% percent of global terrestrial carbon per year1, 2, but the responses of Amazon carbon uptake to climate change is highly uncertain. One source of this uncertainty is tropical sea surface temperature variability driven by teleconnections. El Nino-Southern Oscillation (ENSO) is a key driver of year-to-year Amazon carbon exchange, with associated temperature and precipitation changes favoring net carbon storage in La Nina years, and net carbon release during El Nino years3. To determine how Amazon climate and terrestrial carbon fluxes react to ENSO alone and in concert with other SST-driven teleconnections such as the Atlantic Multidecadal Oscillation (AMO), we force the atmosphere (CAM5) and land (CLM4) components of the CESM(BGC) with prescribed monthly SSTs over the period 1950—2014 in a Historical control simulation. We then run an experiment (PAC) with time-varying SSTs applied only to the tropical equatorial Pacific Ocean, and repeating SST seasonal cycle climatologies elsewhere. Limiting SST variability to the equatorial Pacific indicates that other processes enhance ENSO-driven Amazon climate anomalies. Compared to the Historical control simulation, warming, drying and terrestrial carbon loss over the Amazon during El Nino periods are lower in the PAC simulation, especially prior to 1990 during the cool phase of the AMO. Cooling, moistening, and net carbon uptake during La Nina periods are also reduced in the PAC simulation, but differences are greater after 1990 during the warm phase of the AMO. By quantifying the relationships among climate drivers and carbon fluxes in the Historical and PAC simulations, we both assess the sensitivity of these relationships to the magnitude of ENSO forcing and quantify how other teleconnections affect ENSO-driven Amazon climate feedbacks. We expect that these results will help us improve hypotheses for how Atlantic and Pacific climate trends will affect future Amazon carbon carbon

  15. Current and future carbon budget at Takayama site, Japan, evaluated by a regional climate model and a process-based terrestrial ecosystem model.

    Science.gov (United States)

    Kuribayashi, Masatoshi; Noh, Nam-Jin; Saitoh, Taku M; Ito, Akihiko; Wakazuki, Yasutaka; Muraoka, Hiroyuki

    2017-06-01

    Accurate projection of carbon budget in forest ecosystems under future climate and atmospheric carbon dioxide (CO 2 ) concentration is important to evaluate the function of terrestrial ecosystems, which serve as a major sink of atmospheric CO 2 . In this study, we examined the effects of spatial resolution of meteorological data on the accuracies of ecosystem model simulation for canopy phenology and carbon budget such as gross primary production (GPP), ecosystem respiration (ER), and net ecosystem production (NEP) of a deciduous forest in Japan. Then, we simulated the future (around 2085) changes in canopy phenology and carbon budget of the forest by incorporating high-resolution meteorological data downscaled by a regional climate model. The ecosystem model overestimated GPP and ER when we inputted low-resolution data, which have warming biases over mountainous landscape. But, it reproduced canopy phenology and carbon budget well, when we inputted high-resolution data. Under the future climate, earlier leaf expansion and delayed leaf fall by about 10 days compared with the present state was simulated, and also, GPP, ER and NEP were estimated to increase by 25.2%, 23.7% and 35.4%, respectively. Sensitivity analysis showed that the increase of NEP in June and October would be mainly caused by rising temperature, whereas that in July and August would be largely attributable to CO 2 fertilization. This study suggests that the downscaling of future climate data enable us to project more reliable carbon budget of forest ecosystem in mountainous landscape than the low-resolution simulation due to the better predictions of leaf expansion and shedding.

  16. Small changes in climate can profoundly alter the dynamics and ecosystem services of tropical crater lakes.

    Science.gov (United States)

    Saulnier-Talbot, Émilie; Gregory-Eaves, Irene; Simpson, Kyle G; Efitre, Jackson; Nowlan, Tobias E; Taranu, Zofia E; Chapman, Lauren J

    2014-01-01

    African tropical lakes provide vital ecosystem services including food and water to some of the fastest growing human populations, yet they are among the most understudied ecosystems in the world. The consequences of climate change and other stressors on the tropical lakes of Africa have been informed by long-term analyses, but these studies have largely focused on the massive Great Rift Valley lakes. Our objective was to evaluate how recent climate change has altered the functioning and services of smaller tropical lakes, which are far more abundant on the landscape. Based on a paired analysis of 20 years of high-resolution water column data and a paleolimnological record from a small crater lake in western Uganda, we present evidence that even a modest warming of the air (∼0.9°C increase over 20 years) and changes in the timing and intensity of rainfall can have significant consequences on the dynamics of this common tropical lake type. For example, we observed a significant nonlinear increase (R(2) adj  = 0.23, e.d.f. = 7, pdeterioration of fish habitat and appears to have abated primary production; processes that may impair ecosystem services for a vulnerable human population. This study on a system representative of small tropical crater lakes highlights the far-reaching effects of global climatic change on tropical waters. Increased research efforts into tropical aquatic ecosystem health and the development of sound management practices are necessary in order to strengthen adaptive capabilities in tropical regions.

  17. Impacts of air pollution and climate change on forest ecosystems - emerging research needs

    Science.gov (United States)

    Elena Paoletti; Bytnerowicz; Chris Andersen; Algirdas Augustaitis; Marco Ferretti; Nancy Grulke; Madeleine S. Gunthardt-goerg; John Innes; Dale Johnson; Dave Karnosky; Jessada Luangjame; Rainer Matyssek; Steven McNulty; Gerhard Muller-Starck; Robert Musselman; Kevin Percy

    2007-01-01

    Outcomes from the 22nd meeting for Specialists in Air Pollution Effects on Forest Ecosystems "Forests under Anthropogenic Pressure – Effects of Air Pollution, Climate Change and Urban Development", September 10–16, 2006, Riverside, CA, are summarized. Tropospheric or ground-level ozone (O3) is still the phytotoxic...

  18. The organic nature and atmosphere-climate dependency of nitrogen loss from forest watershed ecosystems

    OpenAIRE

    Brookshire, E. N. J.

    2006-01-01

    In this dissertation I describe how coupled internal cycling and external forcing from the atmosphere and climate can regulate the dynamics of nitrogen (N) loss from forest watersheds. I address three major gaps in our understanding of the global N cycle: 1) the role of dissolved organic N (DON) in internal N cycling in low-N ecosystems; 2) The influence of atmospheric pollution on DON production and loss from forests; and 3) the inherent climate sensitivity of forest N cycling and loss. In...

  19. Safeguarding Ecosystem Services: A Methodological Framework to Buffer the Joint Effect of Habitat Configuration and Climate Change.

    Directory of Open Access Journals (Sweden)

    Tereza C Giannini

    Full Text Available Ecosystem services provided by mobile agents are increasingly threatened by the loss and modification of natural habitats and by climate change, risking the maintenance of biodiversity, ecosystem functions, and human welfare. Research oriented towards a better understanding of the joint effects of land use and climate change over the provision of specific ecosystem services is therefore essential to safeguard such services. Here we propose a methodological framework, which integrates species distribution forecasts and graph theory to identify key conservation areas, which if protected or restored could improve habitat connectivity and safeguard ecosystem services. We applied the proposed framework to the provision of pollination services by a tropical stingless bee (Melipona quadrifasciata, a key pollinator of native flora from the Brazilian Atlantic Forest and important agricultural crops. Based on the current distribution of this bee and that of the plant species used to feed and nest, we projected the joint distribution of bees and plants in the future, considering a moderate climate change scenario (following IPPC. We then used this information, the bee's flight range, and the current mapping of Atlantic Forest remnants to infer habitat suitability and quantify local and regional habitat connectivity for 2030, 2050 and 2080. Our results revealed north to south and coastal to inland shifts in the pollinator distribution during the next 70 years. Current and future connectivity maps unraveled the most important corridors, which if protected or restored, could facilitate the dispersal and establishment of bees during distribution shifts. Our results also suggest that coffee plantations from eastern São Paulo and southern Minas Gerais States could suffer a pollinator deficit in the future, whereas pollination services seem to be secured in southern Brazil. Landowners and governmental agencies could use this information to implement new land use

  20. Safeguarding Ecosystem Services: A Methodological Framework to Buffer the Joint Effect of Habitat Configuration and Climate Change

    Science.gov (United States)

    Giannini, Tereza C.; Tambosi, Leandro R.; Acosta, André L.; Jaffé, Rodolfo; Saraiva, Antonio M.; Imperatriz-Fonseca, Vera L.; Metzger, Jean Paul

    2015-01-01

    Ecosystem services provided by mobile agents are increasingly threatened by the loss and modification of natural habitats and by climate change, risking the maintenance of biodiversity, ecosystem functions, and human welfare. Research oriented towards a better understanding of the joint effects of land use and climate change over the provision of specific ecosystem services is therefore essential to safeguard such services. Here we propose a methodological framework, which integrates species distribution forecasts and graph theory to identify key conservation areas, which if protected or restored could improve habitat connectivity and safeguard ecosystem services. We applied the proposed framework to the provision of pollination services by a tropical stingless bee (Melipona quadrifasciata), a key pollinator of native flora from the Brazilian Atlantic Forest and important agricultural crops. Based on the current distribution of this bee and that of the plant species used to feed and nest, we projected the joint distribution of bees and plants in the future, considering a moderate climate change scenario (following IPPC). We then used this information, the bee’s flight range, and the current mapping of Atlantic Forest remnants to infer habitat suitability and quantify local and regional habitat connectivity for 2030, 2050 and 2080. Our results revealed north to south and coastal to inland shifts in the pollinator distribution during the next 70 years. Current and future connectivity maps unraveled the most important corridors, which if protected or restored, could facilitate the dispersal and establishment of bees during distribution shifts. Our results also suggest that coffee plantations from eastern São Paulo and southern Minas Gerais States could suffer a pollinator deficit in the future, whereas pollination services seem to be secured in southern Brazil. Landowners and governmental agencies could use this information to implement new land use schemes

  1. Safeguarding Ecosystem Services: A Methodological Framework to Buffer the Joint Effect of Habitat Configuration and Climate Change.

    Science.gov (United States)

    Giannini, Tereza C; Tambosi, Leandro R; Acosta, André L; Jaffé, Rodolfo; Saraiva, Antonio M; Imperatriz-Fonseca, Vera L; Metzger, Jean Paul

    2015-01-01

    Ecosystem services provided by mobile agents are increasingly threatened by the loss and modification of natural habitats and by climate change, risking the maintenance of biodiversity, ecosystem functions, and human welfare. Research oriented towards a better understanding of the joint effects of land use and climate change over the provision of specific ecosystem services is therefore essential to safeguard such services. Here we propose a methodological framework, which integrates species distribution forecasts and graph theory to identify key conservation areas, which if protected or restored could improve habitat connectivity and safeguard ecosystem services. We applied the proposed framework to the provision of pollination services by a tropical stingless bee (Melipona quadrifasciata), a key pollinator of native flora from the Brazilian Atlantic Forest and important agricultural crops. Based on the current distribution of this bee and that of the plant species used to feed and nest, we projected the joint distribution of bees and plants in the future, considering a moderate climate change scenario (following IPPC). We then used this information, the bee's flight range, and the current mapping of Atlantic Forest remnants to infer habitat suitability and quantify local and regional habitat connectivity for 2030, 2050 and 2080. Our results revealed north to south and coastal to inland shifts in the pollinator distribution during the next 70 years. Current and future connectivity maps unraveled the most important corridors, which if protected or restored, could facilitate the dispersal and establishment of bees during distribution shifts. Our results also suggest that coffee plantations from eastern São Paulo and southern Minas Gerais States could suffer a pollinator deficit in the future, whereas pollination services seem to be secured in southern Brazil. Landowners and governmental agencies could use this information to implement new land use schemes. Overall

  2. Hydrological regulation drives regime shifts: evidence from paleolimnology and ecosystem modeling of a large shallow Chinese lake.

    Science.gov (United States)

    Kong, Xiangzhen; He, Qishuang; Yang, Bin; He, Wei; Xu, Fuliu; Janssen, Annette B G; Kuiper, Jan J; van Gerven, Luuk P A; Qin, Ning; Jiang, Yujiao; Liu, Wenxiu; Yang, Chen; Bai, Zelin; Zhang, Min; Kong, Fanxiang; Janse, Jan H; Mooij, Wolf M

    2017-02-01

    Quantitative evidence of sudden shifts in ecological structure and function in large shallow lakes is rare, even though they provide essential benefits to society. Such 'regime shifts' can be driven by human activities which degrade ecological stability including water level control (WLC) and nutrient loading. Interactions between WLC and nutrient loading on the long-term dynamics of shallow lake ecosystems are, however, often overlooked and largely underestimated, which has hampered the effectiveness of lake management. Here, we focus on a large shallow lake (Lake Chaohu) located in one of the most densely populated areas in China, the lower Yangtze River floodplain, which has undergone both WLC and increasing nutrient loading over the last several decades. We applied a novel methodology that combines consistent evidence from both paleolimnological records and ecosystem modeling to overcome the hurdle of data insufficiency and to unravel the drivers and underlying mechanisms in ecosystem dynamics. We identified the occurrence of two regime shifts: one in 1963, characterized by the abrupt disappearance of submerged vegetation, and another around 1980, with strong algal blooms being observed thereafter. Using model scenarios, we further disentangled the roles of WLC and nutrient loading, showing that the 1963 shift was predominantly triggered by WLC, whereas the shift ca. 1980 was attributed to aggravated nutrient loading. Our analysis also shows interactions between these two stressors. Compared to the dynamics driven by nutrient loading alone, WLC reduced the critical P loading and resulted in earlier disappearance of submerged vegetation and emergence of algal blooms by approximately 26 and 10 years, respectively. Overall, our study reveals the significant role of hydrological regulation in driving shallow lake ecosystem dynamics, and it highlights the urgency of using multi-objective management criteria that includes ecological sustainability perspectives when

  3. Sap-feeding insects on forest trees along latitudinal gradients in northern Europe: a climate-driven patterns.

    Science.gov (United States)

    Kozlov, Mikhail V; Stekolshchikov, Andrey V; Söderman, Guy; Labina, Eugenia S; Zverev, Vitali; Zvereva, Elena L

    2015-01-01

    Knowledge of the latitudinal patterns in biotic interactions, and especially in herbivory, is crucial for understanding the mechanisms that govern ecosystem functioning and for predicting their responses to climate change. We used sap-feeding insects as a model group to test the hypotheses that the strength of plant-herbivore interactions in boreal forests decreases with latitude and that this latitudinal pattern is driven primarily by midsummer temperatures. We used a replicated sampling design and quantitatively collected and identified all sap-feeding insects from four species of forest trees along five latitudinal gradients (750-1300 km in length, ten sites in each gradient) in northern Europe (59 to 70°N and 10 to 60°E) during 2008-2011. Similar decreases in diversity of sap-feeding insects with latitude were observed in all gradients during all study years. The sap-feeder load (i.e. insect biomass per unit of foliar biomass) decreased with latitude in typical summers, but increased in an exceptionally hot summer and was independent of latitude during a warm summer. Analysis of combined data from all sites and years revealed dome-shaped relationships between the loads of sap-feeders and midsummer temperatures, peaking at 17 °C in Picea abies, at 19.5 °C in Pinus sylvestris and Betula pubescens and at 22 °C in B. pendula. From these relationships, we predict that the losses of forest trees to sap-feeders will increase by 0-45% of the current level in southern boreal forests and by 65-210% in subarctic forests with a 1 °C increase in summer temperatures. The observed relationships between temperatures and the loads of sap-feeders differ between the coniferous and deciduous tree species. We conclude that climate warming will not only increase plant losses to sap-feeding insects, especially in subarctic forests, but can also alter plant-plant interactions, thereby affecting both the productivity and the structure of future forest ecosystems. © 2014

  4. New England and northern New York forest ecosystem vulnerability assessment and synthesis: a report from the New England Climate Change Response Framework project

    Science.gov (United States)

    Maria K. Janowiak; Anthony W. D' Amato; Christopher W. Swanston; Louis Iverson; Frank R. Thompson; William D. Dijak; Stephen Matthews; Matthew P. Peters; Anantha Prasad; Jacob S. Fraser; Leslie A. Brandt; Patricia Butler-Leopold; Stephen D. Handler; P. Danielle Shannon; Diane Burbank; John Campbell; Charles Cogbill; Matthew J. Duveneck; Marla R. Emery; Nicholas Fisichelli; Jane Foster; Jennifer Hushaw; Laura Kenefic; Amanda Mahaffey; Toni Lyn Morelli; Nicholas J. Reo; Paul G. Schaberg; K. Rogers Simmons; Aaron Weiskittel; Sandy Wilmot; David Hollinger; Erin Lane; Lindsey Rustad; Pamela H. Templer

    2018-01-01

    Forest ecosystems will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of forest ecosystems across the New England region (Connecticut, Maine, Massachusetts, New Hampshire, northern New York, Rhode Island, and Vermont) under a range of future climates. We synthesized and summarized information...

  5. Microbial ecology of mountain glacier ecosystems: biodiversity, ecological connections and implications of a warming climate.

    Science.gov (United States)

    Hotaling, Scott; Hood, Eran; Hamilton, Trinity L

    2017-08-01

    Glacier ecosystems are teeming with life on, beneath, and to a lesser degree, within their icy masses. This conclusion largely stems from polar research, with less attention paid to mountain glaciers that overlap environmentally and ecologically with their polar counterparts in some ways, but diverge in others. One difference lies in the susceptibility of mountain glaciers to the near-term threat of climate change, as they tend to be much smaller in both area and volume. Moreover, mountain glaciers are typically steeper, more dependent upon basal sliding for movement, and experience higher seasonal precipitation. Here, we provide a modern synthesis of the microbial ecology of mountain glacier ecosystems, and particularly those at low- to mid-latitudes. We focus on five ecological zones: the supraglacial surface, englacial interior, subglacial bedrock-ice interface, proglacial streams and glacier forefields. For each, we discuss the role of microbiota in biogeochemical cycling and outline ecological and hydrological connections among zones, underscoring the interconnected nature of these ecosystems. Collectively, we highlight the need to: better document the biodiversity and functional roles of mountain glacier microbiota; describe the ecological implications of rapid glacial retreat under climate change and resolve the relative contributions of ecological zones to broader ecosystem function. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Modeling the eco-hydrologic response of a Mediterranean type ecosystem to the combined impacts of projected climate change and altered fire frequencies

    DEFF Research Database (Denmark)

    Tague, Christina; Seaby, Lauren Paige; Hope, Allen

    2009-01-01

    Global Climate Models (GCMs) project moderate warming along with increases in atmospheric CO2 for California Mediterranean type ecosystems (MTEs). In water-limited ecosystems, vegetation acts as an important control on streamflow and responds to soil moisture availability. Fires are also key...... disturbances in semiarid environments, and few studies have explored the potential interactions among changes in climate, vegetation dynamics, hydrology, elevated atmospheric CO2 concentrations and fire. We model ecosystem productivity, evapotranspiration, and summer streamflow under a range of temperature...... climate scenarios, biomass in chaparral-dominated systems is likely to increase, leading to reductions in summer streamflow. However, within the range of GCM predictions, there are some scenarios in which vegetation may decrease, leading to higher summer streamflows. Changes due to increases in fire...

  7. A century of climate and ecosystem change in Western Montana: What do temperature trends portend?

    Science.gov (United States)

    Pederson, G.T.; Graumlich, L.J.; Fagre, D.B.; Kipfer, T.; Muhlfeld, C.C.

    2010-01-01

    The physical science linking human-induced increases in greenhouse gasses to the warming of the global climate system is well established, but the implications of this warming for ecosystem processes and services at regional scales is still poorly understood. Thus, the objectives of this work were to: (1) describe rates of change in temperature averages and extremes for western Montana, a region containing sensitive resources and ecosystems, (2) investigate associations between Montana temperature change to hemispheric and global temperature change, (3) provide climate analysis tools for land and resource managers responsible for researching and maintaining renewable resources, habitat, and threatened/endangered species and (4) integrate our findings into a more general assessment of climate impacts on ecosystem processes and services over the past century. Over 100 years of daily and monthly temperature data collected in western Montana, USA are analyzed for long-term changes in seasonal averages and daily extremes. In particular, variability and trends in temperature above or below ecologically and socially meaningful thresholds within this region (e.g., -17.8??C (0??F), 0??C (32??F), and 32.2??C (90??F)) are assessed. The daily temperature time series reveal extremely cold days (??? -17.8??C) terminate on average 20 days earlier and decline in number, whereas extremely hot days (???32??C) show a three-fold increase in number and a 24-day increase in seasonal window during which they occur. Results show that regionally important thresholds have been exceeded, the most recent of which include the timing and number of the 0??C freeze/thaw temperatures during spring and fall. Finally, we close with a discussion on the implications for Montana's ecosystems. Special attention is given to critical processes that respond non-linearly as temperatures exceed critical thresholds, and have positive feedbacks that amplify the changes. ?? Springer Science + Business Media B

  8. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody B.; Reed, Sasha C.

    2017-01-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  9. Albedo feedbacks to future climate via climate change impacts on dryland biocrusts

    Science.gov (United States)

    Rutherford, William A.; Painter, Thomas H.; Ferrenberg, Scott; Belnap, Jayne; Okin, Gregory S.; Flagg, Cody; Reed, Sasha C.

    2017-03-01

    Drylands represent the planet’s largest terrestrial biome and evidence suggests these landscapes have large potential for creating feedbacks to future climate. Recent studies also indicate that dryland ecosystems are responding markedly to climate change. Biological soil crusts (biocrusts) ‒ soil surface communities of lichens, mosses, and/or cyanobacteria ‒ comprise up to 70% of dryland cover and help govern fundamental ecosystem functions, including soil stabilization and carbon uptake. Drylands are expected to experience significant changes in temperature and precipitation regimes, and such alterations may impact biocrust communities by promoting rapid mortality of foundational species. In turn, biocrust community shifts affect land surface cover and roughness—changes that can dramatically alter albedo. We tested this hypothesis in a full-factorial warming (+4 °C above ambient) and altered precipitation (increased frequency of 1.2 mm monsoon-type watering events) experiment on the Colorado Plateau, USA. We quantified changes in shortwave albedo via multi-angle, solar-reflectance measurements. Warming and watering treatments each led to large increases in albedo (>30%). This increase was driven by biophysical factors related to treatment effects on cyanobacteria cover and soil surface roughness following treatment-induced moss and lichen mortality. A rise in dryland surface albedo may represent a previously unidentified feedback to future climate.

  10. Nonlinear dynamics in ecosystem response to climatic change: Case studies and policy implications

    Science.gov (United States)

    Burkett, Virginia R.; Wilcox, Douglas A.; Stottlemyer, Robert; Barrow, Wylie; Fagre, Dan; Baron, Jill S.; Price, Jeff; Nielsen, Jennifer L.; Allen, Craig D.; Peterson, David L.; Ruggerone, Greg; Doyle, Thomas

    2005-01-01

    Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among systems, precluding accurate modeling and prediction of system response to climate change. Ten case studies from North America illustrate how changes in climate can lead to rapid, threshold-type responses within ecological communities; the case studies also highlight the role of human activities that alter the rate or direction of system response to climate change. Understanding and anticipating nonlinear dynamics are important aspects of adaptation planning since responses of biological resources to changes in the physical climate system are not necessarily proportional and sometimes, as in the case of complex ecological systems, inherently nonlinear.

  11. Impacts of climate change under CMIP5 RCP scenarios on the streamflow in the Dinder River and ecosystem habitats in Dinder National Park, Sudan

    OpenAIRE

    A. K. Basheer; H. Lu; A. Omer; A. B. Ali; A. M. S. Abdelgader

    2016-01-01

    The fate of seasonal river ecosystem habitats under climate change essentially depends on the changes in annual recharge of the river, which are related to alterations in precipitation and evaporation over the river basin. Therefore, the change in climate conditions is expected to significantly affect hydrological and ecological components, particularly in fragmented ecosystems. This study aims to assess the impacts of climate change on the streamflow in the Dinder River bas...

  12. The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period

    Science.gov (United States)

    Sánchez Goñi, María Fernanda; Desprat, Stéphanie; Daniau, Anne-Laure; Bassinot, Frank C.; Polanco-Martínez, Josué M.; Harrison, Sandy P.; Allen, Judy R. M.; Anderson, R. Scott; Behling, Hermann; Bonnefille, Raymonde; Burjachs, Francesc; Carrión, José S.; Cheddadi, Rachid; Clark, James S.; Combourieu-Nebout, Nathalie; Mustaphi, Colin. J. Courtney; Debusk, Georg H.; Dupont, Lydie M.; Finch, Jemma M.; Fletcher, William J.; Giardini, Marco; González, Catalina; Gosling, William D.; Grigg, Laurie D.; Grimm, Eric C.; Hayashi, Ryoma; Helmens, Karin; Heusser, Linda E.; Hill, Trevor; Hope, Geoffrey; Huntley, Brian; Igarashi, Yaeko; Irino, Tomohisa; Jacobs, Bonnie; Jiménez-Moreno, Gonzalo; Kawai, Sayuri; Kershaw, A. Peter; Kumon, Fujio; Lawson, Ian T.; Ledru, Marie-Pierre; Lézine, Anne-Marie; Liew, Ping Mei; Magri, Donatella; Marchant, Robert; Margari, Vasiliki; Mayle, Francis E.; Merna McKenzie, G.; Moss, Patrick; Müller, Stefanie; Müller, Ulrich C.; Naughton, Filipa; Newnham, Rewi M.; Oba, Tadamichi; Pérez-Obiol, Ramón; Pini, Roberta; Ravazzi, Cesare; Roucoux, Katy H.; Rucina, Stephen M.; Scott, Louis; Takahara, Hikaru; Tzedakis, Polichronis C.; Urrego, Dunia H.; van Geel, Bas; Valencia, B. Guido; Vandergoes, Marcus J.; Vincens, Annie; Whitlock, Cathy L.; Willard, Debra A.; Yamamoto, Masanobu

    2017-09-01

    Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard-Oeschger (D-O) cycles during the last glacial period, which were sufficiently large to have had a potential feedback through changes in albedo and greenhouse gas emissions on climate. Previous reconstructions of vegetation and fire changes during the D-O cycles used independently constructed age models, making it difficult to compare the changes between different sites and regions. Here, we present the ACER (Abrupt Climate Changes and Environmental Responses) global database, which includes 93 pollen records from the last glacial period (73-15 ka) with a temporal resolution better than 1000 years, 32 of which also provide charcoal records. A harmonized and consistent chronology based on radiometric dating (14C, 234U/230Th, optically stimulated luminescence (OSL), 40Ar/39Ar-dated tephra layers) has been constructed for 86 of these records, although in some cases additional information was derived using common control points based on event stratigraphy. The ACER database compiles metadata including geospatial and dating information, pollen and charcoal counts, and pollen percentages of the characteristic biomes and is archived in Microsoft AccessTM at PANGAEA.870867" target="_blank">https://doi.org/10.1594/PANGAEA.870867.

  13. Ecosystem services in Mediterranean river basin: climate change impact on water provisioning and erosion control.

    Science.gov (United States)

    Bangash, Rubab F; Passuello, Ana; Sanchez-Canales, María; Terrado, Marta; López, Alfredo; Elorza, F Javier; Ziv, Guy; Acuña, Vicenç; Schuhmacher, Marta

    2013-08-01

    The Mediterranean basin is considered one of the most vulnerable regions of the world to climate change and such changes impact the capacity of ecosystems to provide goods and services to human society. The predicted future scenarios for this region present an increased frequency of floods and extended droughts, especially at the Iberian Peninsula. This paper evaluates the impacts of climate change on the water provisioning and erosion control services in the densely populated Mediterranean Llobregat river basin of. The assessment of ecosystem services and their mapping at the basin scale identify the current pressures on the river basin including the source area in the Pyrenees Mountains. Drinking water provisioning is expected to decrease between 3 and 49%, while total hydropower production will decrease between 5 and 43%. Erosion control will be reduced by up to 23%, indicating that costs for dredging the reservoirs as well as for treating drinking water will also increase. Based on these data, the concept for an appropriate quantification and related spatial visualization of ecosystem service is elaborated and discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Global Climate Change: Threat Multiplier for AFRICOM?

    National Research Council Canada - National Science Library

    Yackle, Terri A

    2007-01-01

    .... Whatever the catalyst for this abrupt climate change, stability for Africa hinges upon mitigating the effects of global climate change to prevent future conflicts such as Darfur, and the instability...

  15. A new method for large-scale assessment of change in ecosystem functioning in relation to land degradation

    Science.gov (United States)

    Horion, Stephanie; Ivits, Eva; Verzandvoort, Simone; Fensholt, Rasmus

    2017-04-01

    Ongoing pressures on European land are manifold with extreme climate events and non-sustainable use of land resources being amongst the most important drivers altering the functioning of the ecosystems. The protection and conservation of European natural capital is one of the key objectives of the 7th Environmental Action Plan (EAP). The EAP stipulates that European land must be managed in a sustainable way by 2020 and the UN Sustainable development goals define a Land Degradation Neutral world as one of the targets. This implies that land degradation (LD) assessment of European ecosystems must be performed repeatedly allowing for the assessment of the current state of LD as well as changes compared to a baseline adopted by the UNCCD for the objective of land degradation neutrality. However, scientifically robust methods are still lacking for large-scale assessment of LD and repeated consistent mapping of the state of terrestrial ecosystems. Historical land degradation assessments based on various methods exist, but methods are generally non-replicable or difficult to apply at continental scale (Allan et al. 2007). The current lack of research methods applicable at large spatial scales is notably caused by the non-robust definition of LD, the scarcity of field data on LD, as well as the complex inter-play of the processes driving LD (Vogt et al., 2011). Moreover, the link between LD and changes in land use (how land use changes relates to change in vegetation productivity and ecosystem functioning) is not straightforward. In this study we used the segmented trend method developed by Horion et al. (2016) for large-scale systematic assessment of hotspots of change in ecosystem functioning in relation to LD. This method alleviates shortcomings of widely used linear trend model that does not account for abrupt change, nor adequately captures the actual changes in ecosystem functioning (de Jong et al. 2013; Horion et al. 2016). Here we present a new methodology for

  16. Simulating the impacts of land use in northwest Europe on Net Ecosystem Exchange (NEE): the role of arable ecosystems, grasslands and forest plantations in climate change mitigation.

    Science.gov (United States)

    Abdalla, Mohamed; Saunders, Matthew; Hastings, Astley; Williams, Mike; Smith, Pete; Osborne, Bruce; Lanigan, Gary; Jones, Mike B

    2013-11-01

    In this study, we compared measured and simulated Net Ecosystem Exchange (NEE) values from three wide spread ecosystems in the southeast of Ireland (forest, arable and grassland), and investigated the suitability of the DNDC (the DeNitrification-DeComposition) model to estimate present and future NEE. Although, the field-DNDC version overestimated NEE at temperatures >5 °C, forest-DNDC under-estimated NEE at temperatures >5 °C. The results suggest that the field/forest DNDC models can successfully estimate changes in seasonal and annual NEE from these ecosystems. Differences in NEE were found to be primarily land cover specific. The annual NEE was similar for the grassland and arable sites, but due to the contribution of exported carbon, the soil carbon increased at the grassland site and decreased at the arable site. The NEE of the forest site was an order of magnitude larger than that of the grassland or arable ecosystems, with large amounts of carbon stored in woody biomass and the soil. The average annual NEE, GPP and Reco values over the measurement period were -904, 2379 and 1475 g C m(-2) (forest plantations), -189, 906 and 715 g C m(-2) (arable systems) and -212, 1653 and 1444 g C m(-2) (grasslands), respectively. The average RMSE values were 3.8 g C m(-2) (forest plantations), 0.12 g C m(-2) (arable systems) and 0.21 g C m(-2) (grasslands). When these models were run with climate change scenarios to 2060, predictions show that all three ecosystems will continue to operate as carbon sinks. Further, climate change may decrease the carbon sink strength in the forest plantations by up to 50%. This study supports the use of the DNDC model as a valid tool to predict the consequences of climate change on NEE from different ecosystems. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Small changes in climate can profoundly alter the dynamics and ecosystem services of tropical crater lakes.

    Directory of Open Access Journals (Sweden)

    Émilie Saulnier-Talbot

    Full Text Available African tropical lakes provide vital ecosystem services including food and water to some of the fastest growing human populations, yet they are among the most understudied ecosystems in the world. The consequences of climate change and other stressors on the tropical lakes of Africa have been informed by long-term analyses, but these studies have largely focused on the massive Great Rift Valley lakes. Our objective was to evaluate how recent climate change has altered the functioning and services of smaller tropical lakes, which are far more abundant on the landscape. Based on a paired analysis of 20 years of high-resolution water column data and a paleolimnological record from a small crater lake in western Uganda, we present evidence that even a modest warming of the air (∼0.9°C increase over 20 years and changes in the timing and intensity of rainfall can have significant consequences on the dynamics of this common tropical lake type. For example, we observed a significant nonlinear increase (R(2 adj  = 0.23, e.d.f. = 7, p<0.0001 in thermal stability over the past 20 years. This resulted in the expansion of anoxic waters and consequent deterioration of fish habitat and appears to have abated primary production; processes that may impair ecosystem services for a vulnerable human population. This study on a system representative of small tropical crater lakes highlights the far-reaching effects of global climatic change on tropical waters. Increased research efforts into tropical aquatic ecosystem health and the development of sound management practices are necessary in order to strengthen adaptive capabilities in tropical regions.

  18. A climate sensitive model of carbon transfer through atmosphere, vegetation and soil in managed forest ecosystems

    Science.gov (United States)

    Loustau, D.; Moreaux, V.; Bosc, A.; Trichet, P.; Kumari, J.; Rabemanantsoa, T.; Balesdent, J.; Jolivet, C.; Medlyn, B. E.; Cavaignac, S.; Nguyen-The, N.

    2012-12-01

    For predicting the future of the forest carbon cycle in forest ecosystems, it is necessary to account for both the climate and management impacts. Climate effects are significant not only at a short time scale but also at the temporal horizon of a forest life cycle e.g. through shift in atmospheric CO2 concentration, temperature and precipitation regimes induced by the enhanced greenhouse effect. Intensification of forest management concerns an increasing fraction of temperate and tropical forests and untouched forests represents only one third of the present forest area. Predicting tools are therefore needed to project climate and management impacts over the forest life cycle and understand the consequence of management on the forest ecosystem carbon cycle. This communication summarizes the structure, main components and properties of a carbon transfer model that describes the processes controlling the carbon cycle of managed forest ecosystems. The model, GO+, links three main components, (i) a module describing the vegetation-atmosphere mass and energy exchanges in 3D, (ii) a plant growth module and a (iii) soil carbon dynamics module in a consistent carbon scheme of transfer from atmosphere back into the atmosphere. It was calibrated and evaluated using observed data collected on coniferous and broadleaved forest stands. The model predicts the soil, water and energy balance of entire rotations of managed stands from the plantation to the final cut and according to a range of management alternatives. It accounts for the main soil and vegetation management operations such as soil preparation, understorey removal, thinnings and clearcutting. Including the available knowledge on the climatic sensitivity of biophysical and biogeochemical processes involved in atmospheric exchanges and carbon cycle of forest ecosystems, GO+ can produce long-term backward or forward simulations of forest carbon and water cycles under a range of climate and management scenarios. This

  19. On the data-driven inference of modulatory networks in climate science: an application to West African rainfall

    Science.gov (United States)

    González, D. L., II; Angus, M. P.; Tetteh, I. K.; Bello, G. A.; Padmanabhan, K.; Pendse, S. V.; Srinivas, S.; Yu, J.; Semazzi, F.; Kumar, V.; Samatova, N. F.

    2015-01-01

    Decades of hypothesis-driven and/or first-principles research have been applied towards the discovery and explanation of the mechanisms that drive climate phenomena, such as western African Sahel summer rainfall~variability. Although connections between various climate factors have been theorized, not all of the key relationships are fully understood. We propose a data-driven approach to identify candidate players in this climate system, which can help explain underlying mechanisms and/or even suggest new relationships, to facilitate building a more comprehensive and predictive model of the modulatory relationships influencing a climate phenomenon of interest. We applied coupled heterogeneous association rule mining (CHARM), Lasso multivariate regression, and dynamic Bayesian networks to find relationships within a complex system, and explored means with which to obtain a consensus result from the application of such varied methodologies. Using this fusion of approaches, we identified relationships among climate factors that modulate Sahel rainfall. These relationships fall into two categories: well-known associations from prior climate knowledge, such as the relationship with the El Niño-Southern Oscillation (ENSO) and putative links, such as North Atlantic Oscillation, that invite further research.

  20. Comparison of post-fire seedling establishment between scrub communities in mediterranean and non-mediterranean climate ecosystems

    Science.gov (United States)

    Carrington, M.E.; Keeley, J.E.

    1999-01-01

    I Both fire regimes and the conditions under which fires occur vary widely. Abiotic conditions (such as climate) in combination with fire season, frequency and intensity could influence vegetation responses to fire. A variety of adaptations facilitate post-fire recruitment in mediterranean climate ecosystems, but responses of other communities are less well known. We evaluated the importance of climate by comparing sites with mediterranean and subtropical climates. 2 We used paired burned and mature sites in chamise chaparral, mixed chaparral and coastal sage scrub (California), and rosemary scrub, sand pine scrub and sand-hill (Florida), to test whether (i) patterns of pre-fire and post-fire seedling recruitment are more similar between communities within a region than between regions, and (ii) post-fire stimulation of seedling establishment is greater in regions with marked fire-induced contrasts in abiotic site characteristics. 3 Post-fire seedling densities were more similar among sites within climatic regions than between regions. Both seedling densities and proportions of species represented by seedlings after fires were generally higher in California. 4 The only site characteristic showing a pre-fire-post-fire contrast was percentage open canopy, and the effect was greater in California than in Florida. Soil properties were unaffected by fire. 5 Mediterranean climate ecosystems in other regions have nutrient-poor soils similar to our subtropical Florida sites, but show post-fire seedling recruitment patterns more similar to the nutrient-rich sites in California. Climate therefore appears to play a more major role than soil characteristics.

  1. Using the Terrestrial Observation and Prediction System (TOPS) to Analyze Impacts of Climate Change on Ecosystems within Northern California Climate Regions

    Science.gov (United States)

    Pitts, K.; Little, M.; Loewenstein, M.; Iraci, L. T.; Milesi, C.; Schmidt, C.; Skiles, J. W.

    2011-12-01

    The projected impacts of climate change on Northern California ecosystems using model outputs from the Terrestrial Observation and Prediction System (TOPS) for the period 1950-2099 based on 1km downscaled climate data from the Geophysical Fluid Dynamics Laboratory (GFDL) model are analyzed in this study. The impacts are analyzed for the Special Report Emissions Scenarios (SRES) A1B and A2, both maintaining present levels of urbanization constant and under projected urban expansion. The analysis is in support of the Climate Adaptation Science Investigation at NASA Ames Research Center. A statistical analysis is completed for time series of temperature, precipitation, gross primary productivity (GPP), evapotranspiration, soil runoff, and vapor pressure deficit. Trends produced from this analysis show that increases in maximum and minimum temperatures lead to declines in peak GPP, length of growing seasons, and overall declines in runoff within the watershed. For Northern California, GPP is projected under the A2 scenario to decrease by 18-25% by the 2090 decade as compared to the 2000 decade. These trends indicate a higher risk to crop production and other ecosystem services, as conditions would be less hospitable to vegetation growth. The increase in dried out vegetation would then lead to a higher risk of wildfire and mudslides in the mountainous regions.

  2. Climate-induced changes in lake ecosystem structure inferred from coupled neo- and paleoecological approaches

    Science.gov (United States)

    Saros, Jasmine E.; Stone, Jeffery R.; Pederson, Gregory T.; Slemmons, Krista; Spanbauer, Trisha; Schliep, Anna; Cahl, Douglas; Williamson, Craig E.; Engstrom, Daniel R.

    2015-01-01

    Over the 20th century, surface water temperatures have increased in many lake ecosystems around the world, but long-term trends in the vertical thermal structure of lakes remain unclear, despite the strong control that thermal stratification exerts on the biological response of lakes to climate change. Here we used both neo- and paleoecological approaches to develop a fossil-based inference model for lake mixing depths and thereby refine understanding of lake thermal structure change. We focused on three common planktonic diatom taxa, the distributions of which previous research suggests might be affected by mixing depth. Comparative lake surveys and growth rate experiments revealed that these species respond to lake thermal structure when nitrogen is sufficient, with species optima ranging from shallower to deeper mixing depths. The diatom-based mixing depth model was applied to sedimentary diatom profiles extending back to 1750 AD in two lakes with moderate nitrate concentrations but differing climate settings. Thermal reconstructions were consistent with expected changes, with shallower mixing depths inferred for an alpine lake where treeline has advanced, and deeper mixing depths inferred for a boreal lake where wind strength has increased. The inference model developed here provides a new tool to expand and refine understanding of climate-induced changes in lake ecosystems.

  3. ÉCLAIRE - Effects of Climate Change on Air Pollution Impacts and Response Strategies for European Ecosystems - Key Messages for Policy Makers, Year 1

    OpenAIRE

    Sutton, Mark; Howard, Clare

    2013-01-01

    The central goal of ÉCLAIRE is to assess how future climate change may alter the extent to which air pollutants have adverse effects on terrestrial ecosystems. Based on the emerging activities of the first year, it is now hypothesized that, that climate change will worsen the threat of air pollutants on Europe’s ecosystems: Climate warming may cause an increase the emissions of many trace gases, such as biogenic volatile organic compounds (BVOCs), ammonia (NH3) and the soil component of nitro...

  4. Alpine ecosystems

    Science.gov (United States)

    P.W. Rundel; C.I. Millar

    2016-01-01

    Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

  5. Biodiversity, climate change, and ecosystem services

    CSIR Research Space (South Africa)

    Mooney, H

    2009-08-01

    Full Text Available of ecosystems, deepen our understanding of the biological underpinnings for ecosystem service delivery and develop new tools and techniques for maintaining and restoring resilient biological and social systems. We will be building on an ecosystem foundation...

  6. Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

    2016-06-01

    Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Capability-Driven Design of Business Service Ecosystem to Support Risk Governance in Regulatory Ecosystems

    Directory of Open Access Journals (Sweden)

    Christophe Feltus

    2017-04-01

    Full Text Available Risk-based regulation and risk governance gain momentum in most sectorial ecosystems, should they be the finance, the healthcare or the telecommunications ecosystems. Although there is a profusion of tools to address this issue at the corporate level, worth is to note that no solution fulfils this function at the ecosystem level yet. Therefore, in this article, the Business Service Ecosystem (BSE metamodel is semantically extended, considering the Capability as a Service (CaaS theory, in order to raise the enterprise risk management from the enterprise level up to the ecosystem level. This extension allows defining a concrete ecosystem metamodel which is afterwards mapped with an information system risk management model to support risk governance at the ecosystem level. This mapping is illustrated and validated on the basis of an application case for the Luxembourgish financial sector applied to the most important concepts from the BSE: capability, resource, service and goal.

  8. A Glacial Perspective on the Impact of Heinrich Stadials on North Atlantic Climate

    Science.gov (United States)

    Bromley, G. R.; Putnam, A. E.; Rademaker, K. M.; Balter, A.; Hall, B. L.

    2017-12-01

    The British Isles contain a rich geologic record of Late Pleistocene ice sheet behaviour in the NE North Atlantic basin. We are using cosmogenic 10Be surface-exposure dating, in conjunction with detailed glacial-geomorphic mapping, to reconstruct the timing and nature of cryospheric change - and thus climate variability - in northern Scotland since the Last Glacial Maximum. Our specific focus is Heinrich Stadial 1 (18,300-14,700 years ago), arguably the most significant abrupt climate event of the last glacial cycle and a major feature in global palaeoclimate records. Such constraint is needed because of currently conflicting models of how these events impact terrestrial environments and a recent hypothesis attributing this disparity to enhanced seasonality in the North Atlantic basin. To date, we have measured 10Be in > 30 samples from glacial erratics located on moraines deposited by the British Ice Sheet as it retreated from the continental shelf to its highland source regions. Our preliminary results indicate that the stadial was characterised by widespread deglaciation driven by atmospheric warming, a pattern that is suggestive of pronounced seasonality. Additionally, we report new exposure ages from moraines deposited during a subsequent phase of alpine glaciation (known locally as the Loch Lomond Readvance) that has long been attributed to the Younger Dryas stadial. With the growing focus on the full expression of stadials, and the inherent vulnerability of Europe to shifts in North Atlantic climate, developing the extant record of terrestrial glaciation and comparing these data to marine records is a critical step towards understanding the drivers of abrupt climate change.

  9. Both temperature fluctuations and East Asian monsoons have driven plant diversification in the karst ecosystems from southern China.

    Science.gov (United States)

    Kong, Hanghui; Condamine, Fabien L; Harris, A J; Chen, Junlin; Pan, Bo; Möller, Michael; Hoang, Van Sam; Kang, Ming

    2017-11-01

    Karst ecosystems in southern China are species-rich and have high levels of endemism, yet little is known regarding the evolutionary processes responsible for the origin and diversification of karst biodiversity. The genus Primulina (Gesneriaceae) comprises ca. 170 species endemic to southern China with high levels of ecological (edaphic) specialization, providing an exceptional model to study the plant diversification in karsts. We used molecular data from nine chloroplast and 11 nuclear regions and macroevolutionary analyses to assess the origin and cause of species diversification due to palaeoenvironmental changes and edaphic specialization in Primulina. We found that speciation was positively associated with changes in past temperatures and East Asian monsoons through the evolutionary history of Primulina. Climatic change around the mid-Miocene triggered an early burst followed by a slowdown of diversification rate towards the present with the climate cooling. We detected different speciation rates among edaphic types, and transitions among soil types were infrequently and did not impact the overall speciation rate. Our findings suggest that both global temperature changes and East Asian monsoons have played crucial roles in floristic diversification within the karst ecosystems in southern China, such that speciation was higher when climate was warmer and wetter. This is the first study to directly demonstrate that past monsoon activity is positively correlated with speciation rate in East Asia. This case study could motivate further investigations to assess the impacts of past environmental changes on the origin and diversification of biodiversity in global karst ecosystems, most of which are under threat. © 2017 John Wiley & Sons Ltd.

  10. Climate change drives a shift in peatland ecosystem plant community: implications for ecosystem function and stability.

    Science.gov (United States)

    Dieleman, Catherine M; Branfireun, Brian A; McLaughlin, James W; Lindo, Zoë

    2015-01-01

    The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO2 ), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO2 had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid-dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens. © 2014 John Wiley & Sons Ltd.

  11. Methane hydrates in quaternary climate change

    International Nuclear Information System (INIS)

    Kennett, J. P.; Hill, T. M.; Behl, R. J.

    2005-01-01

    The hydrate reservoir in marine sediments is known to contain a large volume of exchangeable carbon stored as solid methane hydrate and associated free gas. This reservoir has been shown to be potentially unstable in response to changing intermediate water temperature and sea level (pressure). Evidence continues to grow for past episodes of major methane release at times of climatic warming. Yet few studies of late Quaternary climate change include methane hydrates as an integral part of the global climate system, in spite of the largest known oscillations at this time in sea level and upper ocean temperature changes for the Cenozoic or earlier, conditions that favor instability of the methane hydrate reservoir. Abrupt increases in atmospheric methane recorded in polar ice cores are widely believed to have resulted, not from ocean-floor methane degassing, but instead from continental wetland activation, a hypothesis thus far unsupported by geological data. Furthermore, as part of this Wetland Methane Hypothesis, the abrupt methane increases have been seen as a response to climatic warming rather than contributing significantly to the change. An alternative view (formulated as the Clathrate Gun Hypothesis) is that the speed, magnitude and timing of abrupt climate change in the recent geologic past are consistent with the process of major degassing of methane hydrates. We summarize aspects of this hypothesis here and needs to test this hypothesis. (Author)

  12. Response of salt-marsh carbon accumulation to climate change.

    Science.gov (United States)

    Kirwan, Matthew L; Mudd, Simon M

    2012-09-27

    About half of annual marine carbon burial takes place in shallow water ecosystems where geomorphic and ecological stability is driven by interactions between the flow of water, vegetation growth and sediment transport. Although the sensitivity of terrestrial and deep marine carbon pools to climate change has been studied for decades, there is little understanding of how coastal carbon accumulation rates will change and potentially feed back on climate. Here we develop a numerical model of salt marsh evolution, informed by recent measurements of productivity and decomposition, and demonstrate that competition between mineral sediment deposition and organic-matter accumulation determines the net impact of climate change on carbon accumulation in intertidal wetlands. We find that the direct impact of warming on soil carbon accumulation rates is more subtle than the impact of warming-driven sea level rise, although the impact of warming increases with increasing rates of sea level rise. Our simulations suggest that the net impact of climate change will be to increase carbon burial rates in the first half of the twenty-first century, but that carbon-climate feedbacks are likely to diminish over time.

  13. Insects, Fires, and Climate Change: Implications for Snow Cover, Water Resources and Ecosystem Recovery in Western North America

    Science.gov (United States)

    Brooks, P. D.; Harpold, A. A.; Biederman, J. A.; Litvak, M. E.; Broxton, P. D.; Gochis, D.; Molotch, N. P.; Troch, P. A.; Ewers, B. E.

    2012-12-01

    Unprecedented levels of insect induced tree mortality and massive wildfires both have spread through the forests of Western North America over the last decade. Warming temperatures and increased drought stress have been implicated as major factors in the increasing spatial extent and frequency of these forest disturbances, but it is unclear how simultaneous changes in forest structure and climate will interact to affect either downstream water resources or the regeneration and recovery of forested ecosystems. Because both streamflow and ecosystem productivity depend on seasonal snowmelt, a critical knowledge gap exists in how these disturbances will interact with a changing climate to control to the amount, timing, and the partitioning of seasonal snow cover This presentation will address this knowledge gap by synthesizing recent work on snowpack dynamics and ecosystem productivity from seasonally snow-covered forests along a gradient of snow depth and duration from Arizona to Montana. These include undisturbed sites, recently burned forests, and areas of extensive insect-induced forest mortality. Both before-after and control-impacted studies of forest disturbance on snow accumulation and ablation suggest that the spatial scale of snow distribution increases following disturbance, but net snow water input likely will not increase under a warming climate. While forest disturbance changes spatial scale of snowpack partitioning, the amount and especially the timing of snow cover accumulation and ablation are strongly related to interannual variability in ecosystem productivity with both earlier snowmelt and later snow accumulation associated with decreased carbon uptake. These observations suggest that the ecosystem services of water provision and carbon storage may be very different in the forests that regenerate after disturbance.

  14. Ecosystem sentinels for climate change? Evidence of wetland cover changes over the last 30 years in the tropical Andes.

    Directory of Open Access Journals (Sweden)

    Olivier Dangles

    Full Text Available While the impacts of climate change on individual species and communities have been well documented there is little evidence on climate-mediated changes for entire ecosystems. Pristine alpine environments can provide unique insights into natural, physical and ecological response to climate change yet broad scale and long-term studies on these potential 'ecosystem sentinels' are scarce. We addressed this issue by examining cover changes of 1689 high-elevation wetlands (temporarily or perennial water-saturated grounds in the Bolivian Cordillera Real, a region that has experienced significant warming and glacier melting over the last 30 years. We combined high spatial resolution satellite images from PLEIADES with the long-term images archive from LANDSAT to 1 examine environmental factors (e.g., glacier cover, wetland and watershed size that affected wetland cover changes, and 2 identify wetlands' features that affect their vulnerability (using habitat drying as a proxy in the face of climate change. Over the (1984-2011 period, our data showed an increasing trend in the mean wetland total area and number, mainly related to the appearance of wet grassland patches during the wetter years. Wetland cover also showed high inter-annual variability and their area for a given year was positively correlated to precipitation intensities in the three months prior to the image date. Also, round wetlands located in highly glacierized catchments were less prone to drying, while relatively small wetlands with irregularly shaped contours suffered the highest rates of drying over the last three decades. High Andean wetlands can therefore be considered as ecosystem sentinels for climate change, as they seem sensitive to glacier melting. Beyond the specific focus of this study, our work illustrates how satellite-based monitoring of ecosystem sentinels can help filling the lack of information on the ecological consequences of current and changing climate conditions

  15. Comparing abrupt and gradual smoking cessation: a randomized trial.

    Science.gov (United States)

    Etter, Jean-François

    2011-11-01

    To compare abrupt and gradual smoking cessation. Randomized trial and observational study, Internet, 2007-2010. Smokers with no strong preference for abrupt or gradual quitting were randomly assigned to quitting immediately (n=472), or to gradually reducing their cigarette consumption over 2 weeks and then quit (n=502). Smokers who strongly preferred to quit abruptly were instructed to do so immediately (n=2456), those who strongly preferred gradual were instructed to reduce their cigarette consumption over 2 weeks, then quit (n=1801). Follow-up was conducted 4 weeks after target quit dates. Those who preferred abrupt quitting were the most motivated to quit and the most confident in their ability to quit. At follow-up, quit rates were 16% in those who preferred abrupt cessation, 7% in those who preferred gradual cessation and 9% in those who had no preference (pmotivation to quit and confidence in ability to quit: those who had low levels of motivation or low levels of confidence were more likely to quit at follow-up if they preferred and used abrupt rather than gradual. In those who had no strong preference for either method, abrupt and gradual produced similar results. Those who preferred and used the abrupt method were more likely to quit than those who preferred and used the gradual method, in particular when they had low motivation and confidence. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  16. Do Quercus ilex woodlands undergo abrupt non-linear functional changes in response to human disturbance along a climatic gradient?

    Science.gov (United States)

    Bochet, Esther; García-Fayos, Patricio; José Molina, Maria; Moreno de las Heras, Mariano; Espigares, Tíscar; Nicolau, Jose Manuel; Monleon, Vicente

    2017-04-01

    Theoretical models predict that drylands are particularly prone to suffer critical transitions with abrupt non-linear changes in their structure and functions as a result of the existing complex interactions between climatic fluctuations and human disturbances. However, so far, few studies provide empirical data to validate these models. We aim at determining how holm oak (Quercus ilex) woodlands undergo changes in their functions in response to human disturbance along an aridity gradient (from semi-arid to sub-humid conditions), in eastern Spain. For that purpose, we used (a) remote-sensing estimations of precipitation-use-efficiency (PUE) from enhanced vegetation index (EVI) observations performed in 231x231 m plots of the Moderate Resolution Imaging Spectroradiometer (MODIS); (b) biological and chemical soil parameter determinations (extracellular soil enzyme activity, soil respiration, nutrient cycling processes) from soil sampled in the same plots; (c) vegetation parameter determinations (ratio of functional groups) from vegetation surveys performed in the same plots. We analyzed and compared the shape of the functional change (in terms of PUE and soil and vegetation parameters) in response to human disturbance intensity for our holm oak sites along the aridity gradient. Overall, our results evidenced important differences in the shape of the functional change in response to human disturbance between climatic conditions. Semi-arid areas experienced a more accelerated non-linear decrease with an increasing disturbance intensity than sub-humid ones. The proportion of functional groups (herbaceous vs. woody cover) played a relevant role in the shape of the functional response of the holm oak sites to human disturbance.

  17. Climate warming and estuarine and marine coastal ecosystems

    International Nuclear Information System (INIS)

    Kennedy, V.S.

    1994-01-01

    Estuaries are physically controlled, resilient coastal ecosystems harboring environmentally tolerant species in diluted seawater. Marine coastal systems are less stressed physically and contain some environmentally less tolerant species. Both systems are biologically productive and economically significant. Because of their complex structure and function, it is difficult to predict accurately the effects of climate change, but some broad generalizations can be made. If climate warming occurs, it will raise sea-level, heat shallow waters, and modify precipitation, wind, and water circulation patterns. Rapid sea-level rise could cause the loss of salt marshes, mangrove swamps, and coral reefs, thus diminishing the ecological roles of these highly productive systems. Warmer waters could eliminate heat-sensitive species from part of their geographical range while allowing heat-tolerant species to expand their range, depending on their ability to disperse. Most thermally influenced losses of species will probably only be local, but changed distributions may lead to changed community function. It is more difficult to predict the effects of modified precipitation, wind, and water circulation patterns, but changes could affect organisms dependent on such patterns for food production (e.g., in upwelling regions) or for retention in estuaries. Aquacultural and fishery-related enterprises would be affected negatively in some regions and positively in others. 73 refs

  18. Life cycle ecophysiology of small pelagic fish and climate-driven changes in populations

    Science.gov (United States)

    Peck, Myron A.; Reglero, Patricia; Takahashi, Motomitsu; Catalán, Ignacio A.

    2013-09-01

    Due to their population characteristics and trophodynamic role, small pelagic fishes are excellent bio-indicators of climate-driven changes in marine systems world-wide. We argue that making robust projections of future changes in the productivity and distribution of small pelagics will require a cause-and-effect understanding of historical changes based upon physiological principles. Here, we reviewed the ecophysiology of small pelagic (clupeiform) fishes including a matrix of abiotic and biotic extrinsic factors (e.g., temperature, salinity, light, and prey characteristics) and stage-specific vital rates: (1) adult spawning, (2) survival and development of eggs and yolk sac larvae, and (3) feeding and growth of larvae, post-larvae and juveniles. Emphasis was placed on species inhabiting Northwest Pacific and Northeast Atlantic (European) waters for which summary papers are particularly scarce compared to anchovy and sardine in upwelling systems. Our review revealed that thermal niches (optimal and sub-optimal ranges in temperatures) were species- and stage-specific but that temperature effects only partly explained observed changes in the distribution and/or productivity of populations in the Northwest Pacific and Northeast Atlantic; changes in temperature may be necessary but not sufficient to induce population-level shifts. Prey availability during the late larval and early juvenile period was a common, density-dependent mechanism linked to fluctuations in populations but recruitment mechanisms were system-specific suggesting that generalizations of climate drivers across systems should be avoided. We identified gaps in knowledge regarding basic elements of the growth physiology of each life stage that will require additional field and laboratory study. Avenues of research are recommended that will aid the development of models that provide more robust, physiological-based projections of the population dynamics of these and other small pelagic fish. In our

  19. Climate change and ecosystem services: The contribution of and impacts on federal public lands in the United States

    Science.gov (United States)

    Valerie Esposito; Spencer Phillips; Roelof Boumans; Azur Moulaert; Jennifer Boggs

    2011-01-01

    The Intergovernmental Panel on Climate Change (IPCC) (2007) reports a likely 2 °C to 4.5 °C temperature rise in the upcoming decades. This warming is likely to affect ecosystems and their ability to provide services that benefit human well-being. Ecosystem services valuation (ESV), meanwhile, has emerged as a way to recognize the economic value embodied in these...

  20. Controls on the abruptness of gravel-sand transitions

    Science.gov (United States)

    Venditti, J. G.; Church, M. A.; Lamb, M. P.; Domarad, N.; Rennie, C. D.

    2014-12-01

    As gravel-bedded rivers fine downstream, they characteristically exhibit an abrupt transition from gravel- to sand-bed. This is the only abrupt transition in grain-size that occurs in the fluvial system and has attracted considerable attention. A number of competing theories have been proposed to account for the abruptness of the transition, including base-level control, attrition of ~10mm gravel to produce sand, and sediment sorting processes. The prevailing theory for the emergence of abrupt transitions is size selective sorting of bimodal sediment wherein gravel deposits due to downstream declining shear stress, fining the bedload until a sand-bed emerges. We explored this hypothesis by examining grain-size, shear stress, gravel mobility and sand suspension thresholds through the gravel-sand transition (GST) of the Fraser River, British Columbia. The Fraser GST is an arrested gravel wedge with patches of gravel downstream of the wedge forming a diffuse extension. There is an abrupt change in bed slope through the transition that leads to an abrupt change in shear stress. The GST, bed-slope change and backwater caused by the ocean are all coincident spatially, which enhances the sharpness of the GST. Interestingly, the bimodal reach of the river occurs downstream of the GST and exhibits no downstream gradients in shear stress, suspended sediment flux, gravel mobility or sand suspension thresholds. This calls into question the prevailing theory for the emergence of an abrupt GST by size selective sorting. We provide evidence, both empirical and theoretical, that suggests the emergence of an abrupt GST is caused by rapid deposition of sand when fine gravel deposits. We argue that the emergence of gravel-sand transitions is a consequence of gravel-bedded rivers adopting a steeper slope than sand-bedded rivers. The abruptness arises because the bed slope required to convey the gravel load fixes the distal location of a terminal gravel wedge, and once the river has

  1. Impacts of climate change under CMIP5 RCP scenarios on the streamflow in the Dinder River and ecosystem habitats in Dinder National Park, Sudan

    Science.gov (United States)

    Basheer, Amir K.; Lu, Haishen; Omer, Abubaker; Ali, Abubaker B.; Abdelgader, Abdeldime M. S.

    2016-04-01

    The fate of seasonal river ecosystem habitats under climate change essentially depends on the changes in annual recharge of the river, which are related to alterations in precipitation and evaporation over the river basin. Therefore, the change in climate conditions is expected to significantly affect hydrological and ecological components, particularly in fragmented ecosystems. This study aims to assess the impacts of climate change on the streamflow in the Dinder River basin (DRB) and to infer its relative possible effects on the Dinder National Park (DNP) ecosystem habitats in Sudan. Four global circulation models (GCMs) from Coupled Model Intercomparison Project Phase 5 and two statistical downscaling approaches combined with a hydrological model (SWAT - the Soil and Water Assessment Tool) were used to project the climate change conditions over the study periods 2020s, 2050s, and 2080s. The results indicated that the climate over the DRB will become warmer and wetter under most scenarios. The projected precipitation variability mainly depends on the selected GCM and downscaling approach. Moreover, the projected streamflow is quite sensitive to rainfall and temperature variation, and will likely increase in this century. In contrast to drought periods during the 1960s, 1970s, and 1980s, the predicted climate change is likely to affect ecosystems in DNP positively and promote the ecological restoration for the habitats of flora and fauna.

  2. Ecological grief as a mental health response to climate change-related loss

    Science.gov (United States)

    Cunsolo, Ashlee; Ellis, Neville R.

    2018-04-01

    Climate change is increasingly understood to impact mental health through multiple pathways of risk, including intense feelings of grief as people suffer climate-related losses to valued species, ecosystems and landscapes. Despite growing research interest, ecologically driven grief, or `ecological grief', remains an underdeveloped area of inquiry. We argue that grief is a natural and legitimate response to ecological loss, and one that may become more common as climate impacts worsen. Drawing upon our own research in Northern Canada and the Australian Wheatbelt, combined with a synthesis of the literature, we offer future research directions for the study of ecological grief.

  3. The ACER pollen and charcoal database: a global resource to document vegetation and fire response to abrupt climate changes during the last glacial period

    Directory of Open Access Journals (Sweden)

    M. F. Sánchez Goñi

    2017-09-01

    Full Text Available Quaternary records provide an opportunity to examine the nature of the vegetation and fire responses to rapid past climate changes comparable in velocity and magnitude to those expected in the 21st-century. The best documented examples of rapid climate change in the past are the warming events associated with the Dansgaard–Oeschger (D–O cycles during the last glacial period, which were sufficiently large to have had a potential feedback through changes in albedo and greenhouse gas emissions on climate. Previous reconstructions of vegetation and fire changes during the D–O cycles used independently constructed age models, making it difficult to compare the changes between different sites and regions. Here, we present the ACER (Abrupt Climate Changes and Environmental Responses global database, which includes 93 pollen records from the last glacial period (73–15 ka with a temporal resolution better than 1000 years, 32 of which also provide charcoal records. A harmonized and consistent chronology based on radiometric dating (14C, 234U∕230Th, optically stimulated luminescence (OSL, 40Ar∕39Ar-dated tephra layers has been constructed for 86 of these records, although in some cases additional information was derived using common control points based on event stratigraphy. The ACER database compiles metadata including geospatial and dating information, pollen and charcoal counts, and pollen percentages of the characteristic biomes and is archived in Microsoft AccessTM at https://doi.org/10.1594/PANGAEA.870867.

  4. Estuaries of the Greater Everglades Ecosystem: Laboratories of Long-term Change

    Science.gov (United States)

    Wingard, G.L.; Hudley, J.W.; Marshall, F.E.

    2010-01-01

    Restoring the greater Everglades ecosystem of south Florida is arguably the largest ecosystem restoration effort to date. A critical goal is to return more natural patterns of flow through south Florida wetlands and into the estuaries, but development of realistic targets requires acknowledgement that ecosystems are constantly evolving and changing in response to a variety of natural and human-driven stressors. Examination of ecosystems over long periods of time requires analysis of sedimentary records, such as those deposited in the wetlands and estuaries of south Florida. As sediment accumulates, it preserves information about the animals and plants that lived in the environment and the physical, chemical, and climatic conditions present. One of the methods used to interpret this information is paleoecology-the study of the ecology of previously living organisms. Paleoecologic investigations of south Florida estuaries provide quantitative data on historical variability of salinity and trends that may be applied to statistical models to estimate historical freshwater flow. These data provide a unique context to estimate future ecosystem response to changes related to restoration activities and predicted changes in sea level and temperature, thus increasing the likelihood of successful and sustainable ecosystem restoration.

  5. Novel approaches to study climate change effects on terrestrial ecosystems in the field

    DEFF Research Database (Denmark)

    Beier, C.; Emmett, B.; Gundersen, P.

    2004-01-01

    mimicked the way climate change, caused by increased cloudiness and increased greenhouse gas emissions, alters the heat balance of ecosystems. Drought conditions were created by automatically covering the vegetation with transparent curtains during rain events over a 2-5-month period. The experimental...... that the approach minimizes unintended artifacts with respect to water balance, moisture conditions, and light, while causing a small but significant reduction in wind speed by the curtains. Temperature measurements demonstrated that the edge effects associated with the treatments were small. Our method provides...... approach has been evaluated at four European sites across a climate gradient. All sites were dominated (more than 50%) by shrubs of the ericaceous family. Within each site, replicated 4-m X 5-m plots were established for control, warming, and drought treatments and the effect on climate variables recorded...

  6. Decade to centennial resolution hydrogen isotopic record of climate change from southern New England for the past 16 kyr: proxy validation and multi-proxy comparisons

    Science.gov (United States)

    Huang, Y.; Gao, L.; Hou, J.; Shuman, B. N.; Oswald, W.; Foster, D.

    2009-12-01

    Open system lakes in New England offer excellent archives of precipitation isotopic ratios that yield quantitative paleoclimate information. We have demonstrated previously from a lake sediment transect that hydrogen isotopic ratios of a middle-chain length fatty acid, behenic acid (BA), faithfully record precipitation isotopic ratios. We hypothesized that mid-chain n-alkyl lipids in these small lakes were primarily derived from aquatic plants that record lake water isotopic ratios. To test this hypothesis, we conducted systematic and extensive sampling of both terrestrial and aquatic plants over the past two years at two typical kettle hole lakes, Blood Pond and Rocky Pond, MA, and used a linear algebra approach to delineate percentage inputs of aquatic and terrestrial plant contributions to mid-chain n-alkyl lipids. Our results demonstrate that >92 % of the mid-chain n-alkyl lipids is derived from submerged and floating aquatic macrophytes. Our new data provide a solid basis for the application of behenic hydrogen isotopic ratios as a paleoclimate proxy from small lakes. We will present a decadal to centennial scale 16 kyr record of BA hydrogen isotopic ratios from Blood Pond, and will discuss the results in light of published pollen and lake level data. Overall, our hydrogen isotopic record is fully consistent with regional climate scenarios, including the distinctive warming at B-A events, abrupt cooling at YD event, and transition from glacial to Holcoene climate conditions. However, our high-solution isotopic data provides important new insights concerning abrupt regional climate variability. We demonstrate that the New England climate is exceptionally senstive to AMOC changes and solar forcing and that many of the abrupt climate fluctuations exert major impacts on terrestrial ecosystems, hydrology and lake levels.

  7. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    Science.gov (United States)

    Kok, Judith E.; Graham, Nicholas A. J.; Hoogenboom, Mia O.

    2016-06-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes ( Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.

  8. Asymmetrical Responses of Ecosystem Processes to Positive Versus Negative Precipitation Extremes: a Replicated Regression Experimental Approach

    Science.gov (United States)

    Felton, A. J.; Smith, M. D.

    2016-12-01

    Heightened climatic variability due to atmospheric warming is forecast to increase the frequency and severity of climate extremes. In particular, changes to interannual variability in precipitation, characterized by increases in extreme wet and dry years, are likely to impact virtually all terrestrial ecosystem processes. However, to date experimental approaches have yet to explicitly test how ecosystem processes respond to multiple levels of climatic extremity, limiting our understanding of how ecosystems will respond to forecast increases in the magnitude of climate extremes. Here we report the results of a replicated regression experimental approach, in which we imposed 9 and 11 levels of growing season precipitation amount and extremity in mesic grassland during 2015 and 2016, respectively. Each level corresponded to a specific percentile of the long-term record, which produced a large gradient of soil moisture conditions that ranged from extreme wet to extreme dry. In both 2015 and 2016, asymptotic responses to water availability were observed for soil respiration. This asymmetry was driven in part by transitions between soil moisture versus temperature constraints on respiration as conditions became increasingly dry versus increasingly wet. In 2015, aboveground net primary production (ANPP) exhibited asymmetric responses to precipitation that largely mirrored those of soil respiration. In total, our results suggest that in this mesic ecosystem, these two carbon cycle processes were more sensitive to extreme drought than to extreme wet years. Future work will assess ANPP responses for 2016, soil nutrient supply and physiological responses of the dominant plant species. Future efforts are needed to compare our findings across a diverse array of ecosystem types, and in particular how the timing and magnitude of precipitation events may modify the response of ecosystem processes to increasing magnitudes of precipitation extremes.

  9. Indications of anti-HY immunity in recurrent placental abruption

    DEFF Research Database (Denmark)

    Nielsen, Henriette Svarre; Mogensen, Marie; Steffensen, Rudi

    2007-01-01

    PROBLEM: Placental abruption is a potential life-threatening condition for both the fetus and the mother, being significantly more common in pregnancies with male fetuses. The pathogenesis of placental abruption remains unknown. However, some recent reports point toward a maternal immune response...... the fetus died. Seven patients (88%) had first-born boys, and 15 abruptions (68%) involved male fetuses. All patients with a first-born boy, except one, had HLA-class II alleles known to restrict CD4+ T-cell responses against male-specific minor histocompatibility (HY)-antigens (HLA-DRB1*15, HLA-DRB3...... abruption is exclusively almost preceded by the birth of a boy and the majority of patients have HLA-class II known to restrict CD4 T-cell reactions against HY-antigens. This indicates that maternal immunological responses against HY-antigens play a role in recurrent placental abruption. Udgivelsesdato...

  10. Assessing and comparing risk to climate changes among forested locations: implications for ecosystem services

    Science.gov (United States)

    Stephen N. Matthews; Louis R. Iverson; Matthew P. Peters; Anantha M. Prasad; Sakthi. Subburayalu

    2014-01-01

    Forests provide key ecosystem services (ES) and the extent to which the ES are realized varies spatially, with forest composition and cultural context, and in breadth, depending on the dominant tree species inhabiting an area. We address the question of how climate change may impact ES within the temperate and diverse forests of the eastern United States. We quantify...

  11. Grassland/atmosphere response to changing climate: Coupling regional and local scales

    International Nuclear Information System (INIS)

    Coughenour, M.B.; Kittel, T.G.F.; Pielke, R.A.; Eastman, J.

    1993-10-01

    The objectives of the study were: to evaluate the response of grassland ecosystems to atmospheric change at regional and site scales, and to develop multiscaled modeling systems to relate ecological and atmospheric models with different spatial and temporal resolutions. A menu-driven shell was developed to facilitate use of models at different temporal scales and to facilitate exchange information between models at different temporal scales. A detailed ecosystem model predicted that C 3 temperate grasslands wig respond more strongly to elevated CO 2 than temperate C 4 grasslands in the short-term while a large positive N-PP response was predicted for a C 4 Kenyan grassland. Long-term climate change scenarios produced either decreases or increases in Colorado plant productivity (NPP) depending on rainfall, but uniform increases in N-PP were predicted in Kenya. Elevated CO 2 is likely to have little effect on ecosystem carbon storage in Colorado while it will increase carbon storage in Kenya. A synoptic climate classification processor (SCP) was developed to evaluate results of GCM climate sensitivity experiments. Roughly 80% agreement was achieved with manual classifications. Comparison of lx and 2xCO 2 GCM Simulations revealed relatively small differences

  12. Effect of climate warming on the annual terrestrial net ecosystem CO2 exchange globally in the boreal and temperate regions.

    Science.gov (United States)

    Zhang, Zhiyuan; Zhang, Renduo; Cescatti, Alessandro; Wohlfahrt, Georg; Buchmann, Nina; Zhu, Juan; Chen, Guanhong; Moyano, Fernando; Pumpanen, Jukka; Hirano, Takashi; Takagi, Kentaro; Merbold, Lutz

    2017-06-08

    The net ecosystem CO 2 exchange is the result of the imbalance between the assimilation process (gross primary production, GPP) and ecosystem respiration (RE). The aim of this study was to investigate temperature sensitivities of these processes and the effect of climate warming on the annual terrestrial net ecosystem CO 2 exchange globally in the boreal and temperate regions. A database of 403 site-years of ecosystem flux data at 101 sites in the world was collected and analyzed. Temperature sensitivities of rates of RE and GPP were quantified with Q 10 , defined as the increase of RE (or GPP) rates with a temperature rise of 10 °C. Results showed that on the annual time scale, the intrinsic temperature sensitivity of GPP (Q 10sG ) was higher than or equivalent to the intrinsic temperature sensitivity of RE (Q 10sR ). Q 10sG was negatively correlated to the mean annual temperature (MAT), whereas Q 10sR was independent of MAT. The analysis of the current temperature sensitivities and net ecosystem production suggested that temperature rise might enhance the CO 2 sink of terrestrial ecosystems both in the boreal and temperate regions. In addition, ecosystems in these regions with different plant functional types should sequester more CO 2 with climate warming.

  13. When 1+1 can be >2: Uncertainties compound when simulating climate, fisheries and marine ecosystems

    Science.gov (United States)

    Evans, Karen; Brown, Jaclyn N.; Sen Gupta, Alex; Nicol, Simon J.; Hoyle, Simon; Matear, Richard; Arrizabalaga, Haritz

    2015-03-01

    Multi-disciplinary approaches that combine oceanographic, biogeochemical, ecosystem, fisheries population and socio-economic models are vital tools for modelling whole ecosystems. Interpreting the outputs from such complex models requires an appreciation of the many different types of modelling frameworks being used and their associated limitations and uncertainties. Both users and developers of particular model components will often have little involvement or understanding of other components within such modelling frameworks. Failure to recognise limitations and uncertainties associated with components and how these uncertainties might propagate throughout modelling frameworks can potentially result in poor advice for resource management. Unfortunately, many of the current integrative frameworks do not propagate the uncertainties of their constituent parts. In this review, we outline the major components of a generic whole of ecosystem modelling framework incorporating the external pressures of climate and fishing. We discuss the limitations and uncertainties associated with each component of such a modelling system, along with key research gaps. Major uncertainties in modelling frameworks are broadly categorised into those associated with (i) deficient knowledge in the interactions of climate and ocean dynamics with marine organisms and ecosystems; (ii) lack of observations to assess and advance modelling efforts and (iii) an inability to predict with confidence natural ecosystem variability and longer term changes as a result of external drivers (e.g. greenhouse gases, fishing effort) and the consequences for marine ecosystems. As a result of these uncertainties and intrinsic differences in the structure and parameterisation of models, users are faced with considerable challenges associated with making appropriate choices on which models to use. We suggest research directions required to address these uncertainties, and caution against overconfident predictions

  14. Carbon exchange between ecosystems and atmosphere in the Czech Republic is affected by climate factors.

    Science.gov (United States)

    Marek, Michal V; Janouš, Dalibor; Taufarová, Klára; Havránková, Kateřina; Pavelka, Marian; Kaplan, Věroslav; Marková, Irena

    2011-05-01

    By comparing five ecosystem types in the Czech Republic over several years, we recorded the highest carbon sequestration potential in an evergreen Norway spruce forest (100%) and an agroecosystem (65%), followed by European beech forest (25%) and a wetland ecosystem (20%). Because of a massive ecosystem respiration, the final carbon gain of the grassland was negative. Climate was shown to be an important factor of carbon uptake by ecosystems: by varying the growing season length (a 22-d longer season in 2005 than in 2007 increased carbon sink by 13%) or by the effect of short- term synoptic situations (e.g. summer hot and dry days reduced net carbon storage by 58% relative to hot and wet days). Carbon uptake is strongly affected by the ontogeny and a production strategy which is demonstrated by the comparison of seasonal course of carbon uptake between coniferous (Norway spruce) and deciduous (European beech) stands. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Historical and simulated ecosystem carbon dynamics in Ghana: land use, management, and climate

    Science.gov (United States)

    Tan, Z.; Tieszen, L. L.; Tachie-Obeng, E.; Liu, S.; Dieye, A. M.

    2009-01-01

    We used the General Ensemble biogeochemical Modeling System (GEMS) to simulate responses of natural and managed ecosystems to changes in land use and land cover, management, and climate for a forest/savanna transitional zone in central Ghana. Model results show that deforestation for crop production during the 20th century resulted in a substantial reduction in ecosystem carbon (C) stock from 135.4 Mg C ha-1 in 1900 to 77.0 Mg C ha-1 in 2000, and in soil organic C stock within the top 20 cm of soil from 26.6 Mg C ha-1 to 21.2 Mg C ha-1. If no land use change takes place from 2000 through 2100, low and high climate change scenarios (increase in temperature and decrease in precipitation over time) will result in losses of soil organic C stock by 16% and 20%, respectively. A low nitrogen (N) fertilization rate is the principal constraint on current crop production. An increase in N fertilization under the low climate change scenario would lead to an increase in the average crop yield by 21% with 30 kg N ha-1 and by 42% with 60 kg N ha-1 (varying with crop species), accordingly, the average soil C stock would decrease by 2% and increase by 17%, in all cropping systems by 2100. The results suggest that a reasonable N fertilization rate is critical to achieve food security and agricultural sustainability in the study area through the 21st century. Adaptation strategies for climate change in this study area require national plans to support policies and practices that provide adequate N fertilizers to sustain soil C and crop yields and to consider high temperature tolerant crop species if these temperature projections are exceeded.

  16. Assessing ecosystem response to multiple disturbances and climate change in South Africa using ground- and satellite-based measurements and model

    Science.gov (United States)

    Kutsch, W. L.; Falge, E. M.; Brümmer, C.; Mukwashi, K.; Schmullius, C.; Hüttich, C.; Odipo, V.; Scholes, R. J.; Mudau, A.; Midgley, G.; Stevens, N.; Hickler, T.; Scheiter, S.; Martens, C.; Twine, W.; Iiyambo, T.; Bradshaw, K.; Lück, W.; Lenfers, U.; Thiel-Clemen, T.; du Toit, J.

    2015-12-01

    Sub-Saharan Africa currently experiences rapidly growing human population, intrinsically tied to substantial changes in land use on shrubland, savanna and mixed woodland ecosystems due to over-exploitation. Significant conversions driving degradation, affecting fire frequency and water availability, and fueling climate change are expected to increase in the immediate future. However, measured data of greenhouse gas emissions as affected by land use change are scarce to entirely lacking from this region. The project 'Adaptive Resilience of Southern African Ecosystems' (ARS AfricaE) conducts research and develops scenarios of ecosystem development under climate change, for management support in conservation or for planning rural area development. This will be achieved by (1) creation of a network of research clusters (paired sites with natural and altered vegetation) along an aridity gradient in South Africa for ground-based micrometeorological in-situ measurements of energy and matter fluxes, (2) linking biogeochemical functions with ecosystem structure, and eco-physiological properties, (3) description of ecosystem disturbance (and recovery) in terms of ecosystem function such as carbon balance components and water use efficiency, (4) set-up of individual-based models to predict ecosystem dynamics under (post) disturbance managements, (5) combination with long-term landscape dynamic information derived from remote sensing and aerial photography, and (6) development of sustainable management strategies for disturbed ecosystems and land use change. Emphasis is given on validation (by a suite of field measurements) of estimates obtained from eddy covariance, model approaches and satellite derivations.

  17. Contribution of climate-driven change in continental water storage to recent sea-level rise

    Science.gov (United States)

    Milly, P. C. D.; Cazenave, A.; Gennero, C.

    2003-01-01

    Using a global model of continental water balance, forced by interannual variations in precipitation and near-surface atmospheric temperature for the period 1981–1998, we estimate the sea-level changes associated with climate-driven changes in storage of water as snowpack, soil water, and ground water; storage in ice sheets and large lakes is not considered. The 1981–1998 trend is estimated to be 0.12 mm/yr, and substantial interannual fluctuations are inferred; for 1993–1998, the trend is 0.25 mm/yr. At the decadal time scale, the terrestrial contribution to eustatic (i.e., induced by mass exchange) sea-level rise is significantly smaller than the estimated steric (i.e., induced by density changes) trend for the same period, but is not negligibly small. In the model the sea-level rise is driven mainly by a downtrend in continental precipitation during the study period, which we believe was generated by natural variability in the climate system. PMID:14576277

  18. Climate Change Transforms Fire Regimes but Does not Eliminate Forest Carbon Sequestration in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Henne, P. D.; Hawbaker, T. J.; Berryman, E.

    2017-12-01

    Annual area burned in the Rocky Mountains varies with climatic conditions. However, projecting long-term changes in wildfire presents an enduring challenge because climate also constrains vegetation and fuel availability. We combined an aridity-threshold fire model with the Landis-II dynamic landscape vegetation model (NECN extension) to project climate change impacts on vegetation, area burned, and ecosystem carbon balance in the Greater Yellowstone Ecosystem (GYE). We developed a fire model that relates drought stress to area burned by quantifying an aridity threshold separating large and small years in 15 ecoregions in the Intermountain West. A significant positive correlation (r2 = 0.97) exists between mean fire-season aridity and ecoregion-specific aridity thresholds. We simulated vegetation and fire dynamics in the GYE at 250 m spatial resolution with Landis-II, using projections from five climate models and two emissions scenarios for the period 1980-2100 AD. We determined if each simulation year exceeded the regional aridity threshold, then randomly drew the number of fires and size of individual fires from fire-size distributions from large or small fire years. Burned area increases dramatically in most climate scenarios, especially after 2060, when most years exceed the aridity threshold. Productivity gains due to rising temperatures partially offset biomass lost to fire, but C stocks plateau or decline after 2060 in most simulations as burned area increases, and drought stress causes post-fire regeneration to decline at low elevations. However, species level changes (e.g. expansion by drought-tolerant Pseuodotsuga menziesii) help maintain productivity in sites where water becomes limiting. Fire-adapted Pinus contorta occupies less total area, but a greater proportion of remaining forests, and Picea engelmannii and Abies lasiocarpa significantly decline. Although fire and climate change will alter species distributions and forest structure, our results

  19. Ecosystem service provision in a changing Europe: adapting to the impacts of combined climate and socio-economic change.

    Science.gov (United States)

    Dunford, Robert W; Smith, Alison C; Harrison, Paula A; Hanganu, Diana

    Future patterns of European ecosystem services provision are likely to vary significantly as a result of climatic and socio-economic change and the implementation of adaptation strategies. However, there is little research in mapping future ecosystem services and no integrated assessment approach to map the combined impacts of these drivers. Map changing patterns in ecosystem services for different European futures and (a) identify the role of driving forces; (b) explore the potential influence of different adaptation options. The CLIMSAVE integrated assessment platform is used to map spatial patterns in services (food, water and timber provision, atmospheric regulation, biodiversity existence/bequest, landscape experience and land use diversity) for a number of combined climatic and socio-economic scenarios. Eight adaptation strategies are explored within each scenario. Future service provision (particularly water provision) will be significantly impacted by climate change. Socio-economic changes shift patterns of service provision: more dystopian societies focus on food provision at the expense of other services. Adaptation options offer significant opportunities, but may necessitate trade-offs between services, particularly between agriculture- and forestry-related services. Unavoidable trade-offs between regions (particularly South-North) are also identified in some scenarios. Coordinating adaptation across regions and sectors will be essential to ensure that all needs are met: a factor that will become increasingly pressing under dystopian futures where inter-regional cooperation breaks down. Integrated assessment enables exploration of interactions and trade-offs between ecosystem services, highlighting the importance of taking account of complex cross-sectoral interactions under different future scenarios of planning adaptation responses.

  20. Collective behaviour of climate indices in the North Pacific air—sea system and its potential relationships with decadal climate changes

    International Nuclear Information System (INIS)

    Wang Xiao-Juan; Zhi Rong; He Wen-Ping; Gong Zhi-Qiang

    2012-01-01

    A climate network of six climate indices of the North Pacific air—sea system is constructed during the period of 1948–2009. In order to find out the inherent relationship between the intrinsic mechanism of climate index network and the important climate shift, the synchronization behaviour and the coupling behaviour of these indices are investigated. Results indicate that climate network synchronization happened around the beginning of the 1960s, in the middle of the 1970s and at the beginnings of the 1990s and the 2000s separately. These synchronization states were always followed by the decrease of the coupling coefficient. Each synchronization of the network was well associated with the abrupt phase or trend changes of annually accumulated abnormal values of North Pacific sea-surface temperature and 500-hPa height, among which the one that happened in the middle of the 1970s is the most noticeable climate shift. We can also obtain this mysterious shift from the first mode of the empirical orthogonal function of six indices. That is to say, abrupt climate shift in North Pacific air—sea system is not only shown by the phase or trend changes of climate indices, but also might be indicated by the synchronizing and the coupling of climate indices. Furthermore, at the turning point of 1975, there are also abrupt correlation changes in the yearly mode of spatial degree distribution of the sea surface temperature and 500-hPa height in the region of the North Pacific, which further proves the probability of climate index synchronization and coupling shift in air—sea systems. (geophysics, astronomy, and astrophysics)

  1. Collective behaviour of climate indices in the North Pacific air-sea system and its potential relationships with decadal climate changes

    Institute of Scientific and Technical Information of China (English)

    Wang Xiao-Juan; Zhi Rong; He Wen-Ping; Gong Zhi-Qiang

    2012-01-01

    A climate network of six climate indices of the North Pacific air-sea system is constructed during the period of 1948-2009.In order to find out the inherent relationship between the intrinsic mechanism of climate index network and the important climate shift,the synchronization behaviour and the coupling behaviour of these indices are investigated.Results indicate that climate network synchronization happened around the beginning of the 1960s,in the middle of the 1970s and at the beginnings of the 1990s and the 2000s separately.These synchronization states were always followed by the decrease of the coupling coefficient.Each synchronization of the network was well associated with the abrupt phase or trend changes of annually accumulated abnormal vaiues of North Pacific sea-surface temperature and 500-hPa height,among which the one that happened in the middle of the 1970s is the most noticeable climate shift.We can also obtain this mysterious shift from the first mode of the empirical orthogonal function of six indices.That is to say,abrupt climate shift in North Pacific air-sea system is not only shown by the phase or trend changes of climate indices,but also night be indicated by the synchronizing and the coupling of climate indices.Furthermore,at the turning point of 1975,there are also abrupt correlation changes in the yearly mode of spatial degree distribution of the sea surface temperature and 500-hPa height in the region of the North Pacific,which further proves the probability of climate index synchronization and coupling shift in air-sea systems.

  2. Data-driven nutrient analysis and reality check: Human inputs, catchment delivery and management effects

    Science.gov (United States)

    Destouni, G.

    2017-12-01

    Measures for mitigating nutrient loads to aquatic ecosystems should have observable effects, e.g, in the Baltic region after joint first periods of nutrient management actions under the Baltic Sea Action Plan (BASP; since 2007) and the EU Water Framework Directive (WFD; since 2009). Looking for such observable effects, all openly available water and nutrient monitoring data since 2003 are compiled and analyzed for Sweden as a case study. Results show that hydro-climatically driven water discharge dominates the determination of waterborne loads of both phosphorus and nitrogen. Furthermore, the nutrient loads and water discharge are all similarly well correlated with the ecosystem status classification of Swedish water bodies according to the WFD. Nutrient concentrations, which are hydro-climatically correlated and should thus reflect human effects better than loads, have changed only slightly over the study period (2003-2013) and even increased in moderate-to-bad status waters, where the WFD and BSAP jointly target nutrient decreases. These results indicate insufficient distinction and mitigation of human-driven nutrient components by the internationally harmonized applications of both the WFD and the BSAP. Aiming for better general identification of such components, nutrient data for the large transboundary catchments of the Baltic Sea and the Sava River are compared. The comparison shows cross-regional consistency in nutrient relationships to driving hydro-climatic conditions (water discharge) for nutrient loads, and socio-economic conditions (population density and farmland share) for nutrient concentrations. A data-driven screening methodology is further developed for estimating nutrient input and retention-delivery in catchments. Its first application to nested Sava River catchments identifies characteristic regional values of nutrient input per area and relative delivery, and hotspots of much larger inputs, related to urban high-population areas.

  3. Risk of placental abruption in relation to migraines and headaches

    Directory of Open Access Journals (Sweden)

    Ananth Cande V

    2010-10-01

    Full Text Available Abstract Background Migraine, a common chronic-intermittent disorder of idiopathic origin characterized by severe debilitating headaches and autonomic nervous system dysfunction, and placental abruption, the premature separation of the placenta, share many common pathophysiological characteristics. Moreover, endothelial dysfunction, platelet activation, hypercoagulation, and inflammation are common to both disorders. We assessed risk of placental abruption in relation to maternal history of migraine before and during pregnancy in Peruvian women. Methods Cases were 375 women with pregnancies complicated by placental abruption, and controls were 368 women without an abruption. During in-person interviews conducted following delivery, women were asked if they had physician-diagnosed migraine, and they were asked questions that allowed headaches and migraine to be classified according to criteria established by the International Headache Society. Logistic regression procedures were used to calculate odds ratios (aOR and 95% confidence intervals (CI adjusted for confounders. Results Overall, a lifetime history of any headaches or migraine was associated with an increased odds of placental abruption (aOR = 1.60; 95% CI 1.16-2.20. A lifetime history of migraine was associated with a 2.14-fold increased odds of placental abruption (aOR = 2.14; 95% CI 1.22-3.75. The odds of placental abruption was 2.11 (95% CI 1.00-4.45 for migraineurs without aura; and 1.59 (95% 0.70-3.62 for migraineurs with aura. A lifetime history of tension-type headache was also increased with placental abruption (aOR = 1.61; 95% CI 1.01-2.57. Conclusions This study adds placental abruption to a growing list of pregnancy complications associated with maternal headache/migraine disorders. Nevertheless, prospective cohort studies are needed to more rigorously evaluate the extent to which migraines and/or its treatments are associated with the occurrence of placental abruption.

  4. Effects of climatic changes on carbon dioxide and water vapor fluxes in boreal forest ecosystems of European part of Russia

    International Nuclear Information System (INIS)

    Olchev, A; Kurbatova, J; Novenko, E; Desherevskaya, O; Krasnorutskaya, K

    2009-01-01

    Effects of possible climatic and vegetation changes on H 2 O and CO 2 fluxes in boreal forest ecosystems of the central part of European Russia were quantified using modeling and experimental data. The future pattern of climatic conditions for the period up to 2100 was derived using the global climatic model ECHAM5 (Roeckner et al 2003 The Atmospheric General Circulation Model ECHAM 5. PART I: Model Description, Report 349 (Hamburg: Max-Planck Institute for Meteorology) p 127) with the A1B emission scenario. The possible trends of future vegetation changes were obtained by reconstructions of vegetation cover and paleoclimatic conditions in the Late Pleistocene and Holocene, as provided from pollen and plant macrofossil analysis of profiles in the Central Forest State Natural Biosphere Reserve (CFSNBR). Applying the method of paleoanalogues demonstrates that increasing the mean annual temperature, even by 1-2 deg. C, could result in reducing the proportion of spruce in boreal forest stands by up to 40%. Modeling experiments, carried out using a process-based Mixfor-SVAT model, show that the expected future climatic and vegetation changes lead to a significant increase of net ecosystem exchange (NEE) and gross primary productivity (GPP) of the boreal forests. Despite the expected warming and moistening of the climate, the modeling experiments indicate a relatively weak increase of annual evapotranspiration (ET) and even a reduction of transpiration (TR) rates of forest ecosystems compared to present conditions.

  5. Conditions for plasmoid penetration across abrupt magnetic barriers

    International Nuclear Information System (INIS)

    Brenning, Nils; Hurtig, Tomas; Raadu, Michael A.

    2005-01-01

    The penetration of plasma clouds, or plasmoids, across abrupt magnetic barriers (of the scale less than a few ion gyro radii, using the plasmoid directed velocity) is studied. The insight gained earlier, from detailed experimental and computer simulation investigations of a case study, is generalized into other parameter regimes. It is concluded for what parameters a plasmoid should be expected to penetrate the magnetic barrier through self-polarization, penetrate through magnetic expulsion, or be rejected from the barrier. The scaling parameters are n e , v 0 , B perpendicular , m i , T i , and the width w of the plasmoid. The scaling is based on a model for strongly driven, nonlinear magnetic field diffusion into a plasma which is a generalization of the earlier laboratory findings. The results are applied to experiments earlier reported in the literature, and also to the proposed application of impulsive penetration of plasmoids from the solar wind into the Earth's magnetosphere

  6. Potential effects of climate change on riparian areas, wetlands, and groundwater-dependent ecosystems in the Blue Mountains, Oregon, USA

    Directory of Open Access Journals (Sweden)

    Kathleen A. Dwire

    2018-04-01

    Full Text Available Riparian areas, wetlands, and groundwater-dependent ecosystems, which are found at all elevations throughout the Blue Mountains, comprise a small portion of the landscape but have high conservation value because they provide habitat for diverse flora and fauna. The effects of climate change on these special habitats may be especially profound, due to altered snowpack and hydrologic regimes predicted to occur in the near future. The functionality of many riparian areas is currently compromised by water diversions and livestock grazing, which reduces their resilience to additional stresses that a warmer climate may bring. Areas associated with springs and small streams will probably experience near-term changes, and some riparian areas and wetlands may decrease in size over time. A warmer climate and reduced soil moisture could lead to a transition from riparian hardwood species to more drought tolerant conifers and shrubs. Increased frequency and spatial extent of wildfire spreading from upland forests could also affect riparian species composition. The specific effects of climate change will vary, depending on local hydrology (especially groundwater, topography, streamside microclimates, and current conditions and land use. Keywords: Climate change, Groundwater-dependent ecosystems, Riparian areas, Springs, Wetlands

  7. Sources and Impacts of Modeled and Observed Low-Frequency Climate Variability

    Science.gov (United States)

    Parsons, Luke Alexander

    Here we analyze climate variability using instrumental, paleoclimate (proxy), and the latest climate model data to understand more about the sources and impacts of low-frequency climate variability. Understanding the drivers of climate variability at interannual to century timescales is important for studies of climate change, including analyses of detection and attribution of climate change impacts. Additionally, correctly modeling the sources and impacts of variability is key to the simulation of abrupt change (Alley et al., 2003) and extended drought (Seager et al., 2005; Pelletier and Turcotte, 1997; Ault et al., 2014). In Appendix A, we employ an Earth system model (GFDL-ESM2M) simulation to study the impacts of a weakening of the Atlantic meridional overturning circulation (AMOC) on the climate of the American Tropics. The AMOC drives some degree of local and global internal low-frequency climate variability (Manabe and Stouffer, 1995; Thornalley et al., 2009) and helps control the position of the tropical rainfall belt (Zhang and Delworth, 2005). We find that a major weakening of the AMOC can cause large-scale temperature, precipitation, and carbon storage changes in Central and South America. Our results suggest that possible future changes in AMOC strength alone will not be sufficient to drive a large-scale dieback of the Amazonian forest, but this key natural ecosystem is sensitive to dry-season length and timing of rainfall (Parsons et al., 2014). In Appendix B, we compare a paleoclimate record of precipitation variability in the Peruvian Amazon to climate model precipitation variability. The paleoclimate (Lake Limon) record indicates that precipitation variability in western Amazonia is 'red' (i.e., increasing variability with timescale). By contrast, most state-of-the-art climate models indicate precipitation variability in this region is nearly 'white' (i.e., equally variability across timescales). This paleo-model disagreement in the overall

  8. Testing Paradigms of Ecosystem Change under Climate Warming in Antarctica

    Science.gov (United States)

    Melbourne-Thomas, Jessica; Constable, Andrew; Wotherspoon, Simon; Raymond, Ben

    2013-01-01

    Antarctic marine ecosystems have undergone significant changes as a result of human activities in the past and are now responding in varied and often complicated ways to climate change impacts. Recent years have seen the emergence of large-scale mechanistic explanations–or “paradigms of change”–that attempt to synthesize our understanding of past and current changes. In many cases, these paradigms are based on observations that are spatially and temporally patchy. The West Antarctic Peninsula (WAP), one of Earth’s most rapidly changing regions, has been an area of particular research focus. A recently proposed mechanistic explanation for observed changes in the WAP region relates changes in penguin populations to variability in krill biomass and regional warming. While this scheme is attractive for its simplicity and chronology, it may not account for complex spatio-temporal processes that drive ecosystem dynamics in the region. It might also be difficult to apply to other Antarctic regions that are experiencing some, though not all, of the changes documented for the WAP. We use qualitative network models of differing levels of complexity to test paradigms of change for the WAP ecosystem. Importantly, our approach captures the emergent effects of feedback processes in complex ecological networks and provides a means to identify and incorporate uncertain linkages between network elements. Our findings highlight key areas of uncertainty in the drivers of documented trends, and suggest that a greater level of model complexity is needed in devising explanations for ecosystem change in the Southern Ocean. We suggest that our network approach to evaluating a recent and widely cited paradigm of change for the Antarctic region could be broadly applied in hypothesis testing for other regions and research fields. PMID:23405116

  9. Climate-driven polar motion

    Science.gov (United States)

    Celaya, Michael A.; Wahr, John M.; Bryan, Frank O.

    1999-06-01

    The output of a coupled climate system model provides a synthetic climate record with temporal and spatial coverage not attainable with observational data, allowing evaluation of climatic excitation of polar motion on timescales of months to decades. Analysis of the geodetically inferred Chandler excitation power shows that it has fluctuated by up to 90% since 1900 and that it has characteristics representative of a stationary Gaussian process. Our model-predicted climate excitation of the Chandler wobble also exhibits variable power comparable to the observed. Ocean currents and bottom pressure shifts acting together can alone drive the 14-month wobble. The same is true of the excitation generated by the combined effects of barometric pressure and winds. The oceanic and atmospheric contributions are this large because of a relatively high degree of constructive interference between seafloor pressure and currents and between atmospheric pressure and winds. In contrast, excitation by the redistribution of water on land appears largely insignificant. Not surprisingly, the full climate effect is even more capable of driving the wobble than the effects of the oceans or atmosphere alone are. Our match to the observed annual excitation is also improved, by about 17%, over previous estimates made with historical climate data. Efforts to explain the 30-year Markowitz wobble meet with less success. Even so, at periods ranging from months to decades, excitation generated by a model of a coupled climate system makes a close approximation to the amplitude of what is geodetically observed.

  10. A population-based study of race-specific risk for placental abruption

    Directory of Open Access Journals (Sweden)

    Stamilio David M

    2008-09-01

    Full Text Available Abstract Background Efforts to elucidate risk factors for placental abruption are imperative due to the severity of complications it produces for both mother and fetus, and its contribution to preterm birth. Ethnicity-based differences in risk of placental abruption and preterm birth have been reported. We tested the hypotheses that race, after adjusting for other factors, is associated with the risk of placental abruption at specific gestational ages, and that there is a greater contribution of placental abruption to the increased risk of preterm birth in Black mothers, compared to White mothers. Methods We conducted a population-based cohort study using the Missouri Department of Health's maternally-linked database of all births in Missouri (1989–1997 to assess racial effects on placental abruption and the contribution of placental abruption to preterm birth, at different gestational age categories (n = 664,303. Results Among 108,806 births to Black mothers and 555,497 births to White mothers, 1.02% (95% CI 0.96–1.08 of Black births were complicated by placental abruption, compared to 0.71% (95% CI 0.69–0.73 of White births (aOR 1.32, 95% CI 1.22–1.43. The magnitude of risk of placental abruption for Black mothers, compared to White mothers, increased with younger gestational age categories. The risk of placental abruption resulting in term and extreme preterm births ( Conclusion Black women have an increased risk of placental abruption compared to White women, even when controlling for known coexisting risk factors. This risk increase is greatest at the earliest preterm gestational ages when outcomes are the poorest. The relative contribution of placental abruption to term births was greater in Black women, whereas the relative contribution of placental abruption to preterm birth was greater in White women.

  11. Ecosystem stewardship: sustainability strategies for a rapidly changing planet

    Science.gov (United States)

    F. Stuart Chapin; Stephen R. Carpenter; Gary P. Kofinas; Carl Folke; Nick Abel; William C. Clark; Per Olsson; D. Mark Stafford Smith; Brian Walker; Oran R. Young; Fikret Berkes; Reinette Biggs; J. Morgan Grove; Rosamond L. Naylor; Evelyn Pinkerton; Will Steffen; Frederick J. Swanson

    2010-01-01

    Ecosystem stewardship is an action-oriented framework intended to foster the social-ecological sustainability of a rapidly changing planet. Recent developments identify three strategies that make optimal use of current understanding in an environment of inevitable uncertainty and abrupt change: reducing the magnitude of, and exposure and sensitivity to, known stresses...

  12. Forest ecosystems: Vegetation, disturbance, and economics: Chapter 5

    Science.gov (United States)

    Littell, Jeremy S.; Hicke, Jeffrey A.; Shafer, Sarah L.; Capalbo, Susan M.; Houston, Laurie L.; Glick, Patty

    2013-01-01

    Forests cover about 47% of the Northwest (NW–Washington, Oregon, and Idaho) (Smith et al. 2009, fig. 5.1, table 5.1). The impacts of current and future climate change on NW forest ecosystems are a product of the sensitivities of ecosystem processes to climate and the degree to which humans depend on and interact with those systems. Forest ecosystem structure and function, particularly in relatively unmanaged forests where timber harvest and other land use have smaller effects, is sensitive to climate change because climate has a strong influence on ecosystem processes. Climate can affect forest structure directly through its control of plan physiology and life history (establishment, individual growth, productivity, and morality) or indirectly through its control of disturbance (fire, insects, disease). As climate changes, many forest processes will be affected, altering ecosystem services such as timber production and recreation. These changes have socioeconomic implications (e.g. for timber economies) and will require changes to current management of forests. Climate and management will interact to determine the forests of the future, and the scientific basis for adaptation to climate change in forests thus depends significantly on how forests will be affected.

  13. Detecting ecosystem performance anomalies for land management in the upper colorado river basin using satellite observations, climate data, and ecosystem models

    Science.gov (United States)

    Gu, Yingxin; Wylie, B.K.

    2010-01-01

    This study identifies areas with ecosystem performance anomalies (EPA) within the Upper Colorado River Basin (UCRB) during 2005-2007 using satellite observations, climate data, and ecosystem models. The final EPA maps with 250-m spatial resolution were categorized as normal performance, underperformance, and overperformance (observed performance relative to weather-based predictions) at the 90% level of confidence. The EPA maps were validated using "percentage of bare soil" ground observations. The validation results at locations with comparable site potential showed that regions identified as persistently underperforming (overperforming) tended to have a higher (lower) percentage of bare soil, suggesting that our preliminary EPA maps are reliable and agree with ground-based observations. The 3-year (2005-2007) persistent EPA map from this study provides the first quantitative evaluation of ecosystem performance anomalies within the UCRB and will help the Bureau of Land Management (BLM) identify potentially degraded lands. Results from this study can be used as a prototype by BLM and other land managers for making optimal land management decisions. ?? 2010 by the authors.

  14. Drought-associated changes in climate and their relevance for ecosystem experiments and models

    Directory of Open Access Journals (Sweden)

    H. J. De Boeck

    2011-05-01

    Full Text Available Drought periods can have important impacts on plant productivity and ecosystem functioning, but climatic conditions other than the lack of precipitation during droughts have never been quantified and have therefore not been considered explicitly in both experimental and modeling studies. Here, we identify which climatic characteristics deviate from normal during droughts and how these deviations could affect plant responses. Analysis of 609 years of daily data from nine Western European meteorological stations reveals that droughts in the studied region are consistently associated with more sunshine (+45 %, increased mean (+1.6 °C and maximum (+2.8 °C air temperatures and vapour pressure deficits that were 51 % higher than under normal conditions. These deviations from normal increase significantly as droughts progress. Using the process-model ORCHIDEE, we simulated droughts consistent with the results of the dataset analysis and compared water and carbon exchange of three different vegetation types during such natural droughts and droughts in which only the precipitation was affected. The comparison revealed contrasting responses: carbon loss was higher under natural drought in grasslands, while increased carbon uptake was found especially in decidious forests. This difference was attributed to better access to water reserves in forest ecosystems which prevented drought stress. This demonstrates that the warmer and sunnier conditions naturally associated with droughts can either improve growth or aggravate drought-related stress, depending on water reserves. As the impacts of including or excluding climatic parameters that correlate with drought are substantial, we propose that both experimental and modeling efforts should take into account other environmental factors than merely precipitation.

  15. Slow Onsets, Abrupt Changes, and Fast Reflexes: Learning from Climate Hazards in a Changing World

    Science.gov (United States)

    Pulwarty, R. S.

    2016-12-01

    Adaptation is higher than ever before on the global agenda. Awareness of risks across the weather-climate continuum has increased pressure for information to support planning under changing rates and emergence of multiple hazards (e.g. drought, heat waves, floods). In recognition of this demand, the global community is developing a Global Framework for Climate Services, implementing the Sendai Framework on disaster risk reduction, and formulating climate-sensitive development and research initiatives aimed at nations and communities. The gap between conceptual feasibility and practical implementation remains immense. One of Gilbert White's many important contributions was in developing a framework for structuring adjustment decisions in the context of longer-term risks. The physical environment at a given stage of technology sets the theoretical range of choice while the practical range of choice is set by culture, capacity and institutions. These factors facilitate or impede efficient and equitable responses, with the latter being key in the underestimation of the complexities of adaptation. This presentation will focus on the scientific research, monitoring and information needed to address challenges in (1) Understanding thresholds in the relationship between physical and social changes, including those in connected systems such as water, food and energy, (2) Designing and diffusion of decision support tools and smart practices, and (3) Understanding the links between capacity-building and implementation, including the need to focus researchers and institutions on improving decision quality (not just meeting "user needs"). The author will engage the audience in a discussion of the drivers of social transitions and transformations, drawing on cases from around the world. Key questions, include "What leads to proactive collaboration and action?"; "How often should we revise our assumptions about the direction and magnitude of changes as events unfold?"; and "What

  16. Climate change and the Delta

    Science.gov (United States)

    Dettinger, Michael; Anderson, Jamie; Anderson, Michael L.; Brown, Larry R.; Cayan, Daniel; Maurer, Edwin P.

    2016-01-01

    Anthropogenic climate change amounts to a rapidly approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in different ways that are characterized by different levels of uncertainty. For example, there is high certainty that climate will warm by about 2°C more (than late-20th-century averages) by mid-century and about 4°C by end of century, if greenhouse-gas emissions continue their current rates of acceleration. Future precipitation changes are much less certain, with as many climate models projecting wetter conditions as drier. However, the same projections agree that precipitation will be more intense when storms do arrive, even as more dry days will separate storms. Warmer temperatures will likely enhance evaporative demands and raise water temperatures. Consequently, climate change is projected to yield both more extreme flood risks and greater drought risks. Sea level rise (SLR) during the 20th century was about 22cm, and is projected to increase by at least 3-fold this century. SLR together with land subsidence threatens the Delta with greater vulnerabilities to inundation and salinity intrusion. Effects on the Delta ecosystem that are traceable to warming include SLR, reduced snowpack, earlier snowmelt and larger storm-driven streamflows, warmer and longer summers, warmer summer water temperatures, and water-quality changes. These changes and their uncertainties will challenge the operations of water projects and uses throughout the Delta’s watershed and delivery areas. Although the effects of climate change on Delta ecosystems may be profound, the end results are difficult to predict, except that native species will fare worse than invaders. Successful

  17. Ecosystem services and climate change: Understanding the differences and identifying opportunities for forest carbon

    Science.gov (United States)

    Robert L. Deal; Crystal Raymond; David L. Peterson; Cindy. Glick

    2010-01-01

    There are a number of misunderstandings about “ecosystem services” and “climate change” and these terms are often used incorrectly to describe different concepts. These concepts address different issues and objectives but have some important integrating themes relating to carbon and carbon sequestration. In this paper, we provide definitions and distinctions between...

  18. Impacts of droughts and extreme-temperature events on gross primary production and ecosystem respiration: a systematic assessment across ecosystems and climate zones

    Science.gov (United States)

    von Buttlar, Jannis; Zscheischler, Jakob; Rammig, Anja; Sippel, Sebastian; Reichstein, Markus; Knohl, Alexander; Jung, Martin; Menzer, Olaf; Altaf Arain, M.; Buchmann, Nina; Cescatti, Alessandro; Gianelle, Damiano; Kiely, Gerard; Law, Beverly E.; Magliulo, Vincenzo; Margolis, Hank; McCaughey, Harry; Merbold, Lutz; Migliavacca, Mirco; Montagnani, Leonardo; Oechel, Walter; Pavelka, Marian; Peichl, Matthias; Rambal, Serge; Raschi, Antonio; Scott, Russell L.; Vaccari, Francesco P.; van Gorsel, Eva; Varlagin, Andrej; Wohlfahrt, Georg; Mahecha, Miguel D.

    2018-03-01

    Extreme climatic events, such as droughts and heat stress, induce anomalies in ecosystem-atmosphere CO2 fluxes, such as gross primary production (GPP) and ecosystem respiration (Reco), and, hence, can change the net ecosystem carbon balance. However, despite our increasing understanding of the underlying mechanisms, the magnitudes of the impacts of different types of extremes on GPP and Reco within and between ecosystems remain poorly predicted. Here we aim to identify the major factors controlling the amplitude of extreme-event impacts on GPP, Reco, and the resulting net ecosystem production (NEP). We focus on the impacts of heat and drought and their combination. We identified hydrometeorological extreme events in consistently downscaled water availability and temperature measurements over a 30-year time period. We then used FLUXNET eddy covariance flux measurements to estimate the CO2 flux anomalies during these extreme events across dominant vegetation types and climate zones. Overall, our results indicate that short-term heat extremes increased respiration more strongly than they downregulated GPP, resulting in a moderate reduction in the ecosystem's carbon sink potential. In the absence of heat stress, droughts tended to have smaller and similarly dampening effects on both GPP and Reco and, hence, often resulted in neutral NEP responses. The combination of drought and heat typically led to a strong decrease in GPP, whereas heat and drought impacts on respiration partially offset each other. Taken together, compound heat and drought events led to the strongest C sink reduction compared to any single-factor extreme. A key insight of this paper, however, is that duration matters most: for heat stress during droughts, the magnitude of impacts systematically increased with duration, whereas under heat stress without drought, the response of Reco over time turned from an initial increase to a downregulation after about 2 weeks. This confirms earlier theories that

  19. Spatially explicit integrated modeling and economic valuation of climate driven land use change and its indirect effects.

    OpenAIRE

    Bateman, Ian; Agarwala, M.; Binner, A.; Coombes, E.; Day, B.; Ferrini, Silvia; Fezzi, C.; Hutchins, M.; Lovett, A.; Posen, P.

    2016-01-01

    We present an integrated model of the direct consequences of climate change on land use, and the indirect effects of induced land use change upon the natural environment. The model predicts climate-driven shifts in the profitability of alternative uses of agricultural land. Both the direct impact of climate change and the induced shift in land use patterns will cause secondary effects on the water environment, for which agriculture is the major source of diffuse pollution. We model the impact...

  20. Future C loss in mid-latitude mineral soils: climate change exceeds land use mitigation potential in France

    OpenAIRE

    Meersmans, Jeroen; Arrouays, Dominique; Van Rompaey, Anton J. J.; Pag?, Christian; De Baets, Sarah; Quine, Timothy A.

    2016-01-01

    Many studies have highlighted significant interactions between soil C reservoir dynamics and global climate and environmental change. However, in order to estimate the future soil organic carbon sequestration potential and related ecosystem services well, more spatially detailed predictions are needed. The present study made detailed predictions of future spatial evolution (at 250 m resolution) of topsoil SOC driven by climate change and land use change for France up to the year 2100 by takin...