WorldWideScience

Sample records for warmer climate growth

  1. Potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types.

    Directory of Open Access Journals (Sweden)

    Alison Jones

    Full Text Available One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change.

  2. Potential Costs of Acclimatization to a Warmer Climate: Growth of a Reef Coral with Heat Tolerant vs. Sensitive Symbiont Types

    Science.gov (United States)

    Jones, Alison; Berkelmans, Ray

    2010-01-01

    One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change. PMID:20454653

  3. Potential costs of acclimatization to a warmer climate: growth of a reef coral with heat tolerant vs. sensitive symbiont types.

    Science.gov (United States)

    Jones, Alison; Berkelmans, Ray

    2010-05-03

    One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Keppel Islands in the southern Great Barrier Reef this species naturally harbors nrDNA ITS1 thermally sensitive type C2 or thermally tolerant type D zooxanthellae of the genus Symbiodinium and can change dominant type following bleaching. We show that under controlled conditions, corals with type D symbionts grow 29% slower than those with type C2 symbionts. In the field, type D colonies grew 38% slower than C2 colonies. These results demonstrate the magnitude of trade-offs likely to be experienced by this species as they acclimatize to warmer conditions by changing to more thermally tolerant type D zooxanthellae. Irrespective of symbiont genotype, corals were affected to an even greater degree by the stress of a bleaching event which reduced growth by more than 50% for up to 18 months compared to pre-bleaching rates. The processes of symbiont change and acute thermal stress are likely to act in concert on coral growth as reefs acclimatize to more stressful warmer conditions, further compromising their regeneration capacity following climate change.

  4. Potential Costs of Acclimatization to a Warmer Climate: Growth of a Reef Coral with Heat Tolerant vs. Sensitive Symbiont Types

    OpenAIRE

    Jones, Alison; Berkelmans, Ray

    2010-01-01

    One of the principle ways in which reef building corals are likely to cope with a warmer climate is by changing to more thermally tolerant endosymbiotic algae (zooxanthellae) genotypes. It is highly likely that hosting a more heat-tolerant algal genotype will be accompanied by tradeoffs in the physiology of the coral. To better understand one of these tradeoffs, growth was investigated in the Indo-Pacific reef-building coral Acropora millepora in both the laboratory and the field. In the Kepp...

  5. WARMER URBAN CLIMATES FOR DEVELOPMENT OF GREEN SPACES IN NORTHERN SIBERIAN CITIES

    Directory of Open Access Journals (Sweden)

    Igor Esau

    2016-01-01

    Full Text Available Modern human societies have accumulated considerable power to modify their environment and the earth’s system climate as the whole. The most significant environmental changes are found in the urbanized areas. This study considers coherent changes in vegetation productivity and land surface temperature (LST around four northern West Siberian cities, namely, Tazovsky, Nadym, Noyabrsk and Megion. These cities are located in tundra, forest-tundra, northern taiga and middle taiga bioclimatic zones correspondingly. Our analysis of 15 years (2000–2014 Moderate Resolution Imaging Spectroradiometer (MODIS data revealed significantly (1.3 °C to 5.2 °C warmer seasonally averaged LST within the urbanized territories than those of the surrounding landscapes. The magnitude of the urban LST anomaly corresponds to climates found 300–600 km to the South. In the climate change perspective, this magnitude corresponds to the expected regional warming by the middle or the end of the 21st century. Warmer urban climates, and specifically warmer upper soil layers, can support re-vegetation of the disturbed urban landscapes with more productive trees and tall shrubs. This afforestation is welcome by the migrant city population as it is more consistent with their traditional ecological knowledge. Survival of atypical, southern plant species encourages a number of initiatives and investment to introduce even broader spectrum of temperate blossoming trees and shrubs in urban landscapes. The unintended changes of the urban micro-climates in combination with knowledgeable urban planning could transform the Siberian pioneer settlements into places of belonging.

  6. Modeling lodgepole pine radial growth relative to climate and genetics using universal growth-trend response functions.

    Science.gov (United States)

    McLane, Sierra C; LeMay, Valerie M; Aitken, Sally N

    2011-04-01

    Forests strongly affect Earth's carbon cycles, making our ability to forecast forest-productivity changes associated with rising temperatures and changes in precipitation increasingly critical. In this study, we model the influence of climate on annual radial growth using lodgepole pine (Pinus contorta) trees grown for 34 years in a large provenance experiment in western Canada. We use a random-coefficient modeling approach to build universal growth-trend response functions that simultaneously incorporate the impacts of different provenance and site climates on radial growth trends under present and future annual (growth-year), summer, and winter climate regimes. This approach provides new depth to traditional quantitative genetics population response functions by illustrating potential changes in population dominance over time, as well as indicating the age and size at which annual growth begins declining for any population growing in any location under any present or future climate scenario within reason, given the ages and climatic conditions sampled. Our models indicate that lodgepole pine radial-growth levels maximize between 3.9 degrees and 5.1 degrees C mean growth-year temperature. This translates to productivity declining by the mid-21st century in southern and central British Columbia (BC), while increasing beyond the 2080s in northern BC and Yukon, as temperatures rise. Relative to summer climate indices, productivity is predicted to decline continuously through the 2080s in all locations, while relative to winter climate variables, the opposite trend occurs, with the growth increases caused by warmer winters potentially offsetting the summer losses. Trees from warmer provenances, i.e., from the center of the species range, perform best in nearly all of our present and future climate-scenario models. We recommend that similar models be used to analyze population growth trends relative to annual and intra-annual climate in other large-scale provenance

  7. Climate threats on growth of rear-edge European beech peripheral populations in Spain

    Science.gov (United States)

    Dorado-Liñán, I.; Akhmetzyanov, L.; Menzel, A.

    2017-12-01

    European beech ( Fagus sylvatica L.) forests in the Iberian Peninsula are a clear example of a temperate forest tree species at the rear edge of its large distribution area in Europe. The expected drier and warmer climate may alter tree growth and species distribution. Consequently, the peripheral populations will most likely be the most threatened ones. Four peripheral beech forests in the Iberian Peninsula were studied in order to assess the climate factors influencing tree growth for the last six decades. The analyses included an individual tree approach in order to detect not only the changes in the sensitivity to climate but also the potential size-mediated sensitivity to climate. Our results revealed a dominant influence of previous and current year summer on tree growth during the last six decades, although the analysis in two equally long periods unveiled changes and shifts in tree sensitivity to climate. The individual tree approach showed that those changes in tree response to climate are not size dependent in most of the cases. We observed a reduced negative effect of warmer winter temperatures at some sites and a generalized increased influence of previous year climatic conditions on current year tree growth. These results highlight the crucial role played by carryover effects and stored carbohydrates for future tree growth and species persistence.

  8. Adapting to warmer climate through prolonged maize grain filling period in the US Midwest

    Science.gov (United States)

    Zhu, P.; Zhuang, Q.; Jin, Z.

    2017-12-01

    Climate warming is expected to negatively impact the US food productivity. How to adapt to the future warmer environment and meet the rising food requirement becomes unprecedented urgent. Continuous satellite observational data provides an opportunity to examine the historic responses of crop plants to climate variation. Here 16 years crop growing phases information across US Midwest is generated based on satellite observations. We found a prolonged grain-filling period during 2000-2015, which could partly explain the increasing trend in Midwest maize yield. This longer grain-filling period might be resulted from the adoption of longer maturity group varieties or more resistant varieties to temperature variation. Other management practice changes like advance in planting date could be also an effective way of adapting future warmer climate through lowering the possibility of exposure to heat and drought stresses. If the progress in breeding technology enables the maize grain-filling period to prolong with the current rate, the maize grain filling length could be longer and maize yield in Midwest could adapt to future climate despite of the warming.

  9. Recent climate warming forces contrasting growth responses of white spruce at treeline in Alaska through temperature thresholds

    Science.gov (United States)

    Martin Wilmking; Glenn P. Juday; Valerie A. Barber; Harold S.J. Zald

    2004-01-01

    Northern and high-latitude alpine treelines are generally thought to be limited by available warmth. Most studies of tree-growth-climate interaction at treeline as well as climate reconstructions using dendrochronology report positive growth response of treeline trees to warmer temperatures. However, population-wide responses of treeline trees to climate remain largely...

  10. Life on a warmer earth: possible climatic consequences of man made global warming

    Energy Technology Data Exchange (ETDEWEB)

    Flohn, H

    1981-01-01

    The interaction between energy and climate is explored, including the impact on global climate of three main energy sources: solar, nuclear and fossil fuels. The global warming problem is introduced. Comprehensive analogies with warmer times are made. From the best models available, the future global average surface temperature is found and modified, describing the global warming effects caused by greenhouse effect caused by gases other than carbon dioxide, released into the atmosphere by man, i.e. nitrous oxide, methane, ammonia, and the chlorofluoromethanes. Paleoclimatic scenarios are reviewed, showing possible effects of global warming. An 800 to 1100 ppm CO/sub 2/ concentration causes irreversible Arctic melting, leading to displacement of present climatic zones by 400 to 800 km.

  11. Growth tradeoffs associated with thermotolerant symbionts in the coral Pocillopora damicornis are lost in warmer oceans

    Science.gov (United States)

    Cunning, R.; Gillette, P.; Capo, T.; Galvez, K.; Baker, A. C.

    2015-03-01

    The growth and survival of reef corals are influenced by their symbiotic algal partners ( Symbiodinium spp.), which may be flexible in space and time. Tradeoffs among partnerships exist such that corals with thermotolerant symbionts (e.g., clade D) resist bleaching but grow more slowly, making the long-term ecosystem-level impacts of different host-symbiont associations uncertain. However, much of this uncertainty is due to limited data regarding these tradeoffs and particularly how they are mediated by the environment. To address this knowledge gap, we measured growth and survival of Pocillopora damicornis with thermally sensitive (clade C) or tolerant (clade D) symbionts at three temperatures over 18-55 weeks. Warming reduced coral growth overall, but altered the tradeoffs associated with symbiont type. While clade D corals grew 35-40 % slower than clade C corals at cooler temperatures (26 °C), warming of 1.5-3 °C reduced and eliminated this growth disadvantage. These results suggest that although warmer oceans will negatively impact corals, clade D may enhance survival at no cost to growth relative to clade C. Understanding these genotype-environment interactions can help improve modeling efforts and conservation strategies for reefs under global climate change.

  12. Forest structure, stand composition, and climate-growth response in montane forests of Jiuzhaigou National Nature Reserve, China.

    Directory of Open Access Journals (Sweden)

    Mark W Schwartz

    Full Text Available Montane forests of western China provide an opportunity to establish baseline studies for climate change. The region is being impacted by climate change, air pollution, and significant human impacts from tourism. We analyzed forest stand structure and climate-growth relationships from Jiuzhaigou National Nature Reserve in northwestern Sichuan province, along the eastern edge of the Tibetan plateau. We conducted a survey to characterize forest stand diversity and structure in plots occurring between 2050 and 3350 m in elevation. We also evaluated seedling and sapling recruitment and tree-ring data from four conifer species to assess: 1 whether the forest appears in transition toward increased hardwood composition; 2 if conifers appear stressed by recent climate change relative to hardwoods; and 3 how growth of four dominant species responds to recent climate. Our study is complicated by clear evidence of 20(th century timber extraction. Focusing on regions lacking evidence of logging, we found a diverse suite of conifers (Pinus, Abies, Juniperus, Picea, and Larix strongly dominate the forest overstory. We found population size structures for most conifer tree species to be consistent with self-replacement and not providing evidence of shifting composition toward hardwoods. Climate-growth analyses indicate increased growth with cool temperatures in summer and fall. Warmer temperatures during the growing season could negatively impact conifer growth, indicating possible seasonal climate water deficit as a constraint on growth. In contrast, however, we found little relationship to seasonal precipitation. Projected warming does not yet have a discernible signal on trends in tree growth rates, but slower growth with warmer growing season climates suggests reduced potential future forest growth.

  13. Climate threats on growth of rear-edge European beech peripheral populations in Spain

    NARCIS (Netherlands)

    Dorado-Liñán, I.; Akhmetzyanov, L.; Menzel, A.

    2017-01-01

    European beech (Fagus sylvatica L.) forests in the Iberian Peninsula are a clear example of a temperate forest tree species at the rear edge of its large distribution area in Europe. The expected drier and warmer climate may alter tree growth and species distribution. Consequently, the peripheral

  14. Subtropical Low Cloud Response to a Warmer Climate in an Superparameterized Climate Model: Part I. Regime Sorting and Physical Mechanisms

    Directory of Open Access Journals (Sweden)

    Peter N Blossey

    2009-07-01

    Full Text Available The subtropical low cloud response to a climate with SST uniformly warmed by 2 K is analyzed in the SP- CAM superparameterized climate model, in which each grid column is replaced by a two-dimensional cloud-resolving model (CRM. Intriguingly, SP-CAM shows substantial low cloud increases over the subtropical oceans in the warmer climate. The paper aims to understand the mechanism for these increases. The subtropical low cloud increase is analyzed by sorting grid-column months of the climate model into composite cloud regimes using percentile ranges of lower tropospheric stability (LTS. LTS is observed to be well correlated to subtropical low cloud amount and boundary layer vertical structure. The low cloud increase in SP-CAM is attributed to boundary-layer destabilization due to increased clear-sky radiative cooling in the warmer climate. This drives more shallow cumulus convection and a moister boundary layer, inducing cloud increases and further increasing the radiative cooling. The boundary layer depth does not change substantially, due to compensation between increased radiative cooling (which promotes more turbulent mixing and boundary-layer deepening and slight strengthening of the boundary-layer top inversion (which inhibits turbulent entrainment and promotes a shallower boundary layer. The widespread changes in low clouds do not appear to be driven by changes in mean subsidence.
    In a companion paper we use column-mode CRM simulations based on LTS-composite profiles to further study the low cloud response mechanisms and to explore the sensitivity of low cloud response to grid resolution in SP-CAM.

  15. Tracking an atmospheric river in a warmer climate: from water vapor to economic impacts

    Science.gov (United States)

    Dominguez, Francina; Dall'erba, Sandy; Huang, Shuyi; Avelino, Andre; Mehran, Ali; Hu, Huancui; Schmidt, Arthur; Schick, Lawrence; Lettenmaier, Dennis

    2018-03-01

    Atmospheric rivers (ARs) account for more than 75 % of heavy precipitation events and nearly all of the extreme flooding events along the Olympic Mountains and western Cascade Mountains of western Washington state. In a warmer climate, ARs in this region are projected to become more frequent and intense, primarily due to increases in atmospheric water vapor. However, it is unclear how the changes in water vapor transport will affect regional flooding and associated economic impacts. In this work we present an integrated modeling system to quantify the atmospheric-hydrologic-hydraulic and economic impacts of the December 2007 AR event that impacted the Chehalis River basin in western Washington. We use the modeling system to project impacts under a hypothetical scenario in which the same December 2007 event occurs in a warmer climate. This method allows us to incorporate different types of uncertainty, including (a) alternative future radiative forcings, (b) different responses of the climate system to future radiative forcings and (c) different responses of the surface hydrologic system. In the warming scenario, AR integrated vapor transport increases; however, these changes do not translate into generalized increases in precipitation throughout the basin. The changes in precipitation translate into spatially heterogeneous changes in sub-basin runoff and increased streamflow along the entire Chehalis main stem. Economic losses due to stock damages increase moderately, but losses in terms of business interruption are significant. Our integrated modeling tool provides communities in the Chehalis region with a range of possible future physical and economic impacts associated with AR flooding.

  16. Enhanced growth of Juniperus thurifera under a warmer climate is explained by a positive carbon gain under cold and drought.

    Science.gov (United States)

    Gimeno, Teresa E; Camarero, J Julio; Granda, Elena; Pías, Beatriz; Valladares, Fernando

    2012-03-01

    Juniperus thurifera L. is an endemic conifer of the western Mediterranean Basin where it is subjected to a severe climatic stress characterized by low winter temperatures and summer drought. Given the trend of increased warming-induced drought stress in this area and the climatic sensitivity of this species, we expect a negative impact of climate change on growth and ecophysiological performance of J. thurifera in the harsh environments where it dominates. To evaluate this, we measured long- and short-term radial growth using dendrochronology, photosynthesis and water-use efficiency in males, females and juveniles in three sites in Central Spain. Climate was monitored and completed with historical records. Mean annual temperature has increased +0.2 °C per decade in the study area, and the main warming trends corresponded to spring (+0.2 °C per decade) and summer (+0.3 °C per decade). Radial growth and maximum photosynthesis peaked in spring and autumn. Positive photosynthetic rates were maintained all year long, albeit at reduced rates in winter and summer. Radial growth was enhanced by wet conditions in the previous autumn and by warm springs and high precipitation in summer of the year of tree-ring formation. Cloud cover during the summer increased growth, while cloudy winters led to impaired carbon gain and reduced growth in the long term. We argue that maintenance of carbon gain under harsh conditions (low winter temperatures and dry summer months) and plastic xylogenesis underlie J. thurifera's ability to profit from changing climatic conditions such as earlier spring onset and erratic summer rainfall. Our results highlight that not only the magnitude but also the sign of the impact of climate change on growth and persistence of Mediterranean trees is species specific.

  17. Tracking an atmospheric river in a warmer climate: from water vapor to economic impacts

    Directory of Open Access Journals (Sweden)

    F. Dominguez

    2018-03-01

    Full Text Available Atmospheric rivers (ARs account for more than 75 % of heavy precipitation events and nearly all of the extreme flooding events along the Olympic Mountains and western Cascade Mountains of western Washington state. In a warmer climate, ARs in this region are projected to become more frequent and intense, primarily due to increases in atmospheric water vapor. However, it is unclear how the changes in water vapor transport will affect regional flooding and associated economic impacts. In this work we present an integrated modeling system to quantify the atmospheric–hydrologic–hydraulic and economic impacts of the December 2007 AR event that impacted the Chehalis River basin in western Washington. We use the modeling system to project impacts under a hypothetical scenario in which the same December 2007 event occurs in a warmer climate. This method allows us to incorporate different types of uncertainty, including (a alternative future radiative forcings, (b different responses of the climate system to future radiative forcings and (c different responses of the surface hydrologic system. In the warming scenario, AR integrated vapor transport increases; however, these changes do not translate into generalized increases in precipitation throughout the basin. The changes in precipitation translate into spatially heterogeneous changes in sub-basin runoff and increased streamflow along the entire Chehalis main stem. Economic losses due to stock damages increase moderately, but losses in terms of business interruption are significant. Our integrated modeling tool provides communities in the Chehalis region with a range of possible future physical and economic impacts associated with AR flooding.

  18. Assessing forest vulnerability to climate warming using a process-based model of tree growth: bad prospects for rear-edges.

    Science.gov (United States)

    Sánchez-Salguero, Raúl; Camarero, Jesus Julio; Gutiérrez, Emilia; González Rouco, Fidel; Gazol, Antonio; Sangüesa-Barreda, Gabriel; Andreu-Hayles, Laia; Linares, Juan Carlos; Seftigen, Kristina

    2017-07-01

    Growth models can be used to assess forest vulnerability to climate warming. If global warming amplifies water deficit in drought-prone areas, tree populations located at the driest and southernmost distribution limits (rear-edges) should be particularly threatened. Here, we address these statements by analyzing and projecting growth responses to climate of three major tree species (silver fir, Abies alba; Scots pine, Pinus sylvestris; and mountain pine, Pinus uncinata) in mountainous areas of NE Spain. This region is subjected to Mediterranean continental conditions, it encompasses wide climatic, topographic and environmental gradients, and, more importantly, it includes rear-edges of the continuous distributions of these tree species. We used tree-ring width data from a network of 110 forests in combination with the process-based Vaganov-Shashkin-Lite growth model and climate-growth analyses to forecast changes in tree growth during the 21st century. Climatic projections were based on four ensembles CO 2 emission scenarios. Warm and dry conditions during the growing season constrain silver fir and Scots pine growth, particularly at the species rear-edge. By contrast, growth of high-elevation mountain pine forests is enhanced by climate warming. The emission scenario (RCP 8.5) corresponding to the most pronounced warming (+1.4 to 4.8 °C) forecasted mean growth reductions of -10.7% and -16.4% in silver fir and Scots pine, respectively, after 2050. This indicates that rising temperatures could amplify drought stress and thus constrain the growth of silver fir and Scots pine rear-edge populations growing at xeric sites. Contrastingly, mountain pine growth is expected to increase by +12.5% due to a longer and warmer growing season. The projections of growth reduction in silver fir and Scots pine portend dieback and a contraction of their species distribution areas through potential local extinctions of the most vulnerable driest rear-edge stands. Our modeling

  19. Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions.

    Science.gov (United States)

    Fraga, Helder; Malheiro, Aureliano C; Moutinho-Pereira, José; Cardoso, Rita M; Soares, Pedro M M; Cancela, Javier J; Pinto, Joaquim G; Santos, João A

    2014-01-01

    The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

  20. Growth Rate Potential of Juvenile Sockeye Salmon in Warmer and Cooler Years on the Eastern Bering Sea Shelf

    Directory of Open Access Journals (Sweden)

    Edward V. Farley

    2009-01-01

    Full Text Available A spatially explicit bioenergetics model was used to predict juvenile sockeye salmon Oncorhynchus nerka growth rate potential (GRP on the eastern Bering Sea shelf during years with cooler and warmer spring sea surface temperatures (SSTs. Annual averages of juvenile sockeye salmon GRP were generally lower among years with cooler SSTs and generally higher in offshore than nearshore regions of the eastern Bering Sea shelf during years with warmer SSTs. Juvenile sockeye salmon distribution was significantly (P<.05 related to GRP and their prey densities were positively related to spring SST (P<.05. Juvenile sockeye salmon GRP was more sensitive to changes in prey density and observed SSTs during years when spring SSTs were warmer (2002, 2003, and 2005. Our results suggest that the pelagic productivity on the eastern Bering Sea shelf was higher during years with warmer spring SSTs and highlight the importance of bottom-up control on the eastern Bering Sea ecosystem.

  1. Impact of Climate Trends and Drought Events on the Growth of Oaks (Quercus robur L. and Quercus petraea (Matt. Liebl. within and beyond Their Natural Range

    Directory of Open Access Journals (Sweden)

    Diana Perkins

    2018-02-01

    Full Text Available Due to predicted climate change, it is important to know to what extent trees and forests will be impacted by chronic and episodic drought stress. As oaks play an important role in European forestry, this study focuses on the growth response of sessile oak (Quercus petraea (Matt. Liebl. and pedunculate oak (Quercus robur (L. under contrasting climatic conditions. Analyses cover both site conditions of their natural occurrence (Southern Germany and Northeast Italy and site conditions beyond their natural range (South Africa. The sites beyond their natural range represent possible future climate conditions. Tree-ring series from three different sites were compared and analysed using dendrochronological methods. The long-term growth development of oak trees appears to be similar across the sites, yet the growth level over time is higher in the drier and warmer climate than in the temperate zone. When compared with previous growth periods, growth models reveal that oak trees grew more than expected during the last decades. A recent setback in growth can be observed, although growth is still higher than the model predicts. By focusing on the short-term reactions of the trees, distinct drought events and periods were discovered. In each climatic region, similar growth reactions developed after drought periods. A decline in growth rate occurred in the second or third year after the drought event. Oaks in South Africa are currently exposed to a warmer climate with more frequent drought events. This climatic condition is a future prediction also for Europe. In view of this climate change, we discuss the consequences of the long- and short- term growth behaviour of oaks grown in the climate of South Africa for a tree species selection that naturally occurs in Europe.

  2. Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions.

    Directory of Open Access Journals (Sweden)

    Helder Fraga

    Full Text Available The Iberian viticultural regions are convened according to the Denomination of Origin (DO and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

  3. Global climate change and California agriculture

    International Nuclear Information System (INIS)

    Lewis, L.; Rains, W.; Kennedy, L.

    1991-01-01

    This paper has highlighted some of the impacts that a warmer climate may have on agriculture in California. Because of the state's diverse geomorphology it is difficult to predict what crops will grow in which locations under future climate regimes. However, the potential interactions between warmer temperatures, higher CO 2 concentrations, and the factors that affect plant and animal growth may have major consequences for the competitive position of the state's agriculture. Forward-thinking research and public policies are required to assure that responses to climate change will optimize production systems under future constraints

  4. [Responses of Pinus sylvestris var. mongolica radial growth to climate warming in Great Xing' an Mountins: a case study in Mangui].

    Science.gov (United States)

    Zhang, Xing-Liang; He, Xing-Yuan; Chen, Zhen-Ju; Cui, Ming-Xing; Li, Na

    2011-12-01

    Based on the theory and methodology of dendrochronology, the tree ring width chronology of Pinus sylvestris var. mongolica in Mangui of Great Xing' an Mountains was developed, and the relationships between the standardized tree ring width chronology and local climate factors (temperature and precipitation) as well as the effects of climate factors on the P. sylvestris var. mongolica radial growth were analyzed. In this region, the mean monthly temperature in April-August of current year was the main factor limiting the radial growth, and the increasing mean monthly temperature from April to August had negative effects to the radial growth. The simulation of the variations of the radial growth by the mean monthly temperature change in April-August showed that the radial growth of P. sylvestris var. mongolica would present a declining trend accompanied with the warmer and drier regional climate condition.

  5. More Intense Mega Heat Waves in the Warmer World

    Science.gov (United States)

    Choi, G.; Robinson, D. A.

    2017-12-01

    In this study, changes in the occurrences of heat waves on the globe since the mid- 20th century and the synoptic characteristics of mega heat waves at regional scales in the warmer climate are examined. The NCEP-NCAR reanalysis surface data show that there have been no obvious linear changes in the heat wave frequencies at the continental scales since the mid-20th century, but amplified interdecadal variations led to unprecedented intense heat waves in the recent decades at the regional scales. Such mega heat waves have been more frequently observed in the poleward subtropical climate belts as well as in the interior region of continents. According to the analyses of upper tropospheric data, the occurrences of more intense mega heat waves since the late 20th century may be associated with the expansion of subtropical high pressures. These results suggest that populous cities near the subtropical climate zones should provide proactive mega heat wave warning systems for residents due to their vulnerability to the sudden attack of human lives harvest by mega heat waves in the warmer 21st century.

  6. Climatic limits on foliar growth during major droughts in the southwestern USA

    Science.gov (United States)

    Weiss, Jeremy L.; Betancourt, Julio L.; Overpeck, Jonathan T.

    2012-09-01

    Pronounced droughts during the 1950s and 2000s in the American Southwest provide an opportunity to compare mesoscale ecosystem responses to anomalously dry conditions before and during the regional warming that started in the late 1970s. This year-round warming has produced fewer cool season freezes, losses in regional snowpack, an 8-10 day advance in spring onset, and hotter summers, all of which should affect vegetation differently across seasons and elevations. Here, we examine indices that represent climatic limits on foliar growth for both drought periods and evaluate these indices for areas that experienced tree mortality during the 2000s drought. Relative to the 1950s drought, warmer conditions during the 2000s drought decreased the occurrence of temperatures too low for foliar growth at lower elevations in winter and higher elevations in summer. Higher vapor pressure deficits (VPDs), largely driven by warmer temperatures in the more recent drought, were more limiting to foliar growth from spring through summer at lower and middle elevations. At many locations where tree mortality occurred during the 2000s drought, low-temperature constraints on foliar growth were extremely unlimiting, whereas VPD constraints were extremely limiting from early spring through late autumn. Our analysis shows that in physiographically complex regions such as the Southwest, seasonality and elevational gradients are important for understanding vegetative responses to warming. It also suggests that continued warming will both increase the degree to which VPD limits foliar growth during future droughts and expand its reach to higher elevations and other seasons.

  7. Climate extremes and predicted warming threaten Mediterranean Holocene firs forests refugia.

    Science.gov (United States)

    Sánchez-Salguero, Raúl; Camarero, J Julio; Carrer, Marco; Gutiérrez, Emilia; Alla, Arben Q; Andreu-Hayles, Laia; Hevia, Andrea; Koutavas, Athanasios; Martínez-Sancho, Elisabet; Nola, Paola; Papadopoulos, Andreas; Pasho, Edmond; Toromani, Ervin; Carreira, José A; Linares, Juan C

    2017-11-21

    Warmer and drier climatic conditions are projected for the 21st century; however, the role played by extreme climatic events on forest vulnerability is still little understood. For example, more severe droughts and heat waves could threaten quaternary relict tree refugia such as Circum-Mediterranean fir forests (CMFF). Using tree-ring data and a process-based model, we characterized the major climate constraints of recent (1950-2010) CMFF growth to project their vulnerability to 21st-century climate. Simulations predict a 30% growth reduction in some fir species with the 2050s business-as-usual emission scenario, whereas growth would increase in moist refugia due to a longer and warmer growing season. Fir populations currently subjected to warm and dry conditions will be the most vulnerable in the late 21st century when climatic conditions will be analogous to the most severe dry/heat spells causing dieback in the late 20th century. Quantification of growth trends based on climate scenarios could allow defining vulnerability thresholds in tree populations. The presented predictions call for conservation strategies to safeguard relict tree populations and anticipate how many refugia could be threatened by 21st-century dry spells.

  8. Thermal physiology of native cool-climate, and non-native warm-climate Pumpkinseed sunfish raised in a common environment.

    Science.gov (United States)

    Rooke, Anna C; Burness, Gary; Fox, Michael G

    2017-02-01

    Contemporary evolution of thermal physiology has the potential to help limit the physiological stress associated with rapidly changing thermal environments; however it is unclear if wild populations can respond quickly enough for such changes to be effective. We used native Canadian Pumpkinseed (Lepomis gibbosus) sunfish, and non-native Pumpkinseed introduced into the milder climate of Spain ~100 years ago, to assess genetic differences in thermal physiology in response to the warmer non-native climate. We compared temperature performance reaction norms of two Canadian and two Spanish Pumpkinseed populations born and raised within a common environment. We found that Canadian Pumpkinseed had higher routine metabolic rates when measured at seasonally high temperatures (15°C in winter, 30°C in summer), and that Spanish Pumpkinseed had higher critical thermal maxima when acclimated to 30°C in the summer. Growth rates were not significantly different among populations, however Canadian Pumpkinseed tended to have faster growth at the warmest temperatures measured (32°C). The observed differences in physiology among Canadian and Spanish populations at the warmest acclimation temperatures are consistent with the introduced populations being better suited to the warmer non-native climate than native populations. The observed differences could be the result of either founder effects, genetic drift, and/or contemporary adaptive evolution in the warmer non-native climate. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Air quality in Europe during the summer of 2003 as a prototype of air quality in a warmer climate

    International Nuclear Information System (INIS)

    Vautard, R.; Beekmann, M.; Desplat, J.; Morel, S.; Hodzic, A.

    2007-01-01

    The extremely warm summer of 2003, with its August heat wave, is taken as a prototype of future summer weather in Europe. The stagnant circulation led to accumulation of heat and pollutants, increased forest fires, and induced high ozone and particulate matter levels. After a description of the meteorological conditions encountered, we review here the effects of the heat-wave meteorology on photochemistry, wild fires, and particulate matter, at the continental and urban scales. We discuss the extent to which this special summer can be taken for projecting air quality in a future warmer climate, especially in the perspective of changes in regional and global emissions. For ozone, the effect of regional reduction of emissions will dominate over summer climate change, but the increase in baseline ozone should significantly raise the mean ozone levels. (authors)

  10. Linking wood anatomy and xylogenesis allows pinpointing of climate and drought influences on growth of coexisting conifers in continental Mediterranean climate.

    Science.gov (United States)

    Pacheco, Arturo; Camarero, J Julio; Carrer, Marco

    2016-04-01

    Forecasted warmer and drier conditions will probably lead to reduced growth rates and decreased carbon fixation in long-term woody pools in drought-prone areas. We therefore need a better understanding of how climate stressors such as drought constrain wood formation and drive changes in wood anatomy. Drying trends could lead to reduced growth if they are more intense in spring, when radial growth rates of conifers in continental Mediterranean climates peak. Since tree species from the aforementioned areas have to endure dry summers and also cold winters, we chose two coexisting species: Aleppo pine (Pinus halepensisMill., Pinaceae) and Spanish juniper (Juniperus thuriferaL., Cupressaceae) (10 randomly selected trees per species), to analyze how growth (tree-ring width) and wood-anatomical traits (lumen transversal area, cell-wall thickness, presence of intra-annual density fluctuations-IADFs-in the latewood) responded to climatic variables (minimum and maximum temperatures, precipitation, soil moisture deficit) calculated for different time intervals. Tree-ring width and mean lumen area showed similar year-to-year variability, which indicates that they encoded similar climatic signals. Wet and cool late-winter to early-spring conditions increased lumen area expansion, particularly in pine. In juniper, cell-wall thickness increased when early summer conditions became drier and the frequency of latewood IADFs increased in parallel with late-summer to early-autumn wet conditions. Thus, latewood IADFs of the juniper capture increased water availability during the late growing season, which is reflected in larger tracheid lumens. Soil water availability was one of the main drivers of wood formation and radial growth for the two species. These analyses allow long-term (several decades) growth and wood-anatomical responses to climate to be inferred at intra-annual scales, which agree with the growing patterns already described by xylogenesis approaches for the same

  11. Climate change. Climate in Medieval time.

    Science.gov (United States)

    Bradley, Raymond S; Hughes, Malcolm K; Diaz, Henry F

    2003-10-17

    Many papers have referred to a "Medieval Warm Period." But how well defined is climate in this period, and was it as warm as or warmer than it is today? In their Perspective, Bradley et al. review the evidence and conclude that although the High Medieval (1100 to 1200 A.D.) was warmer than subsequent centuries, it was not warmer than the late 20th century. Moreover, the warmest Medieval temperatures were not synchronous around the globe. Large changes in precipitation patterns are a particular characteristic of "High Medieval" time. The underlying mechanisms for such changes must be elucidated further to inform the ongoing debate on natural climate variability and anthropogenic climate change.

  12. Western forests, fire risk, and climate change.

    Science.gov (United States)

    Valerie. Rapp

    2004-01-01

    Climate warming may first show up in forests as increased growth, which occurs as warmer temperatures, increased carbon dioxide, and more precipitation encourage higher rates of photosynthesis. The second way that climate change may show up in forests is through changes in disturbance regimes—the long-term patterns of fire, drought, insects, and diseases that are basic...

  13. Western forest, fire risk, and climate change

    Science.gov (United States)

    Valerie Rapp

    2004-01-01

    Climate warming may first show up in forests as increased growth, which occurs as warmer temperatures, increased carbon dioxide, and more precipitation encourage higher rates of photosynthesis. The second way that climate change may show up in forests is through changes in disturbance regimes—the long-term patterns of fire, drought, insects, and diseases that are basic...

  14. Stand competition determines how different tree species will cope with a warming climate.

    Directory of Open Access Journals (Sweden)

    Laura Fernández-de-Uña

    Full Text Available Plant-plant interactions influence how forests cope with climate and contribute to modulate species response to future climate scenarios. We analysed the functional relationships between growth, climate and competition for Pinus sylvestris, Quercus pyrenaica and Quercus faginea to investigate how stand competition modifies forest sensitivity to climate and simulated how annual growth rates of these species with different drought tolerance would change throughout the 21st century. Dendroecological data from stands subjected to thinning were modelled using a novel multiplicative nonlinear approach to overcome biases related to the general assumption of a linear relationship between covariates and to better mimic the biological relationships involved. Growth always decreased exponentially with increasing competition, which explained more growth variability than climate in Q. faginea and P. sylvestris. The effect of precipitation was asymptotic in all cases, while the relationship between growth and temperature reached an optimum after which growth declined with warmer temperatures. Our growth projections indicate that the less drought-tolerant P. sylvestris would be more negatively affected by climate change than the studied sub-Mediterranean oaks. Q. faginea and P. sylvestris mean growth would decrease under all the climate change scenarios assessed. However, P. sylvestris growth would decline regardless of the competition level, whereas this decrease would be offset by reduced competition in Q. faginea. Conversely, Q. pyrenaica growth would remain similar to current rates, except for the warmest scenario. Our models shed light on the nature of the species-specific interaction between climate and competition and yield important implications for management. Assuming that individual growth is directly related to tree performance, trees under low competition would better withstand the warmer conditions predicted under climate change scenarios but in

  15. Budgets and balances in a warmer world

    International Nuclear Information System (INIS)

    Boer, G.J.

    1994-01-01

    Potential climate warming is studied by performing the open-quotes first standard CO2 experimentclose quotes which consists of coupling a comparatively sophisticated atmospheric general circulation model to a thermodynamically, but not dynamically, active ocean/ice model. The differences in the equilibrium climates simulated for the current or 1xCO2 case and for the new equilibrium climate that results with twice that amount of CO2 are investigated. Results indicate that although the dynamical consequences of greenhouse gas warming are not as marked nor statistically significant as the thermodynamical changes, they display an intriguing rearrangement of flow structures which take advantage of the altered thermodynamic structures in the atmosphere that occur. Since the overall forcing does not change appreciably, the poleward transport of energy remains the same but this is accomplished by an increase in latent energy transport associated with a warmer and moister lower troposphere which balances a decrease in internal and potential energy transport associated with weaker temperature gradients in this region

  16. Sensitivity of peak flow to the change of rainfall temporal pattern due to warmer climate

    Science.gov (United States)

    Fadhel, Sherien; Rico-Ramirez, Miguel Angel; Han, Dawei

    2018-05-01

    The widely used design storms in urban drainage networks has different drawbacks. One of them is that the shape of the rainfall temporal pattern is fixed regardless of climate change. However, previous studies have shown that the temporal pattern may scale with temperature due to climate change, which consequently affects peak flow. Thus, in addition to the scaling of the rainfall volume, the scaling relationship for the rainfall temporal pattern with temperature needs to be investigated by deriving the scaling values for each fraction within storm events, which is lacking in many parts of the world including the UK. Therefore, this study analysed rainfall data from 28 gauges close to the study area with a 15-min resolution as well as the daily temperature data. It was found that, at warmer temperatures, the rainfall temporal pattern becomes less uniform, with more intensive peak rainfall during higher intensive times and weaker rainfall during less intensive times. This is the case for storms with and without seasonal separations. In addition, the scaling values for both the rainfall volume and the rainfall fractions (i.e. each segment of rainfall temporal pattern) for the summer season were found to be higher than the corresponding results for the winter season. Applying the derived scaling values for the temporal pattern of the summer season in a hydrodynamic sewer network model produced high percentage change of peak flow between the current and future climate. This study on the scaling of rainfall fractions is the first in the UK, and its findings are of importance to modellers and designers of sewer systems because it can provide more robust scenarios for flooding mitigation in urban areas.

  17. Epidemic malaria and warmer temperatures in recent decades in an East African highland

    NARCIS (Netherlands)

    Alonso, David; Bouma, Menno J.; Pascual, Mercedes

    2011-01-01

    Climate change impacts on malaria are typically assessed with scenarios for the long-term future. Here we focus instead on the recent past (1970-2003) to address whether warmer temperatures have already increased the incidence of malaria in a highland region of East Africa. Our analyses rely on a

  18. Tropical cyclones in a stabilized 1.5 and 2 degree warmer world.

    Science.gov (United States)

    Wehner, M. F.; Stone, D. A.; Loring, B.; Krishnan, H.

    2017-12-01

    We present an ensemble of very high resolution global climate model simulations of a stabilized 1.5oC and 2oC warmer climate as envisioned by the Paris COP21 agreement. The resolution of this global climate model (25km) permits simulated tropical cyclones up to Category Five on the Saffir-Simpson scale Projected changes in tropical cyclones are significant. Tropical cyclones in the two stabilization scenarios are less frequent but more intense than in simulations of the present. Output data from these simulations is freely available to all interested parties and should prove a useful resource to those interested in studying the impacts of stabilized global warming.

  19. Composition and carbon dynamics of forests in northeastern North America in a future, warmer world

    International Nuclear Information System (INIS)

    Mohan, J.E.; Georgia Univ., Athens, GA; Cox, R.M.; Iverson, L.R.

    2009-01-01

    This article provided a synthesis of modelling and scientific DNA which indicated that tree migrations since the last glaciation period were slower than current and predicted climatic warming trends. Air pollution is now offsetting carbon dioxide (CO 2 ) gains in biomass and will predispose many trees to other stresses. Nitrogen and sulfate deposition in the northeastern United States is changing forest nutrient availability, and is reducing the reproductive success and frost hardiness of some species. Acid deposition is also causing physical damage to leaves and changing the behaviour of pests and diseases. It is expected that the interacting stresses will cause declines in tree populations as well as ecosystem disturbances during the transition to warmer climates. Modelling studies have predicted that the warmer climates will increase habitats for most tree species in the northeastern United States. Species with declining habitats in the United States and Canada may migrate northwards. Paleo-ecological studies suggest that local edaphic factors will negatively impact current and future recruitment successes, but may also combine with climatic effect to cause sudden large shifts in vegetation. 83 refs., 2 tabs., 3 figs

  20. A 2 °C warmer world is not safe for ecosystem services in the European Alps.

    Science.gov (United States)

    Elkin, Ché; Gutiérrez, Alvaro G; Leuzinger, Sebastian; Manusch, Corina; Temperli, Christian; Rasche, Livia; Bugmann, Harald

    2013-06-01

    Limiting the increase in global average temperature to 2 °C is the objective of international efforts aimed at avoiding dangerous climate impacts. However, the regional response of terrestrial ecosystems and the services that they provide under such a scenario are largely unknown. We focus on mountain forests in the European Alps and evaluate how a range of ecosystem services (ES) are projected to be impacted in a 2 °C warmer world, using four novel regional climate scenarios. We employ three complementary forest models to assess a wide range of ES in two climatically contrasting case study regions. Within each climate scenario we evaluate if and when ES will deviate beyond status quo boundaries that are based on current system variability. Our results suggest that the sensitivity of mountain forest ES to a 2 °C warmer world depends heavily on the current climatic conditions of a region, the strong elevation gradients within a region, and the specific ES in question. Our simulations project that large negative impacts will occur at low and intermediate elevations in initially warm-dry regions, where relatively small climatic shifts result in negative drought-related impacts on forest ES. In contrast, at higher elevations, and in regions that are initially cool-wet, forest ES will be comparatively resistant to a 2 °C warmer world. We also found considerable variation in the vulnerability of forest ES to climate change, with some services such as protection against rockfall and avalanches being sensitive to 2 °C global climate change, but other services such as carbon storage being reasonably resistant. Although our results indicate a heterogeneous response of mountain forest ES to climate change, the projected substantial reduction of some forest ES in dry regions suggests that a 2 °C increase in global mean temperature cannot be seen as a universally 'safe' boundary for the maintenance of mountain forest ES. © 2013 Blackwell Publishing Ltd.

  1. Contrasting environmental drivers of adult and juvenile growth in a marine fish: implications for the effects of climate change.

    Science.gov (United States)

    Ong, Joyce Jia Lin; Rountrey, Adam Nicholas; Meeuwig, Jessica Jane; Newman, Stephen John; Zinke, Jens; Meekan, Mark Gregory

    2015-06-08

    Many marine fishes have life history strategies that involve ontogenetic changes in the use of coastal habitats. Such ontogenetic shifts may place these species at particular risk from climate change, because the successive environments they inhabit can differ in the type, frequency and severity of changes related to global warming. We used a dendrochronology approach to examine the physical and biological drivers of growth of adult and juvenile mangrove jack (Lutjanus argentimaculatus) from tropical north-western Australia. Juveniles of this species inhabit estuarine environments and adults reside on coastal reefs. The Niño-4 index, a measure of the status of the El Niño-Southern Oscillation (ENSO) had the highest correlation with adult growth chronologies, with La Niña years (characterised by warmer temperatures and lower salinities) having positive impacts on growth. Atmospheric and oceanographic phenomena operating at ocean-basin scales seem to be important correlates of the processes driving growth in local coastal habitats. Conversely, terrestrial factors influencing precipitation and river runoff were positively correlated with the growth of juveniles in estuaries. Our results show that the impacts of climate change on these two life history stages are likely to be different, with implications for resilience and management of populations.

  2. Impacts of simulated climate change and fungal symbionts on survival and growth of a foundation species in sand dunes.

    Science.gov (United States)

    Emery, Sarah M; Rudgers, Jennifer A

    2013-12-01

    For many ecosystems, one of the primary avenues of climate impact may be through changes to foundation species, which create habitats and sustain ecosystem services. For plants, microbial symbionts can often act as mutualists under abiotic stress and may mediate foundational plant responses to climate change. We manipulated the presence of endophytes in Ammophila breviligulata, a foundational sand dune species, to evaluate their potential to influence plant responses to climate change. We simulated projected climate change scenarios for temperature and precipitation using a growth chamber experiment. A 5 °C increase in temperature relative to current climate in northern Michigan reduced A. breviligulata survival by 45 %. Root biomass of A. breviligulata, which is critical to dune stabilization, was also strongly reduced by temperature. Plants inoculated with the endophyte had 14 % higher survival than endophyte-free plants. Contrary to our prediction, endophyte symbiosis did not alter the magnitude or direction of the effects of climate manipulations on A. breviligulata survival. However, in the absence of the endophyte, an increase in temperature increased the number of sand grains bound by roots by 80 %, while in symbiotic plants sand adherence did not significantly respond to temperature. Thus, plant-endophyte symbiosis actually negated the benefits in ecosystem function gained under a warmer climate. This study suggests that heat stress related to climate change in the Great Lakes may compromise the ability of A. breviligulata to stabilize dune ecosystems and reduce carbon storage and organic matter build-up in these early-successional systems due to reduced plant survival and root growth.

  3. Carbon assimilation and transfer through kelp forests in the NE Atlantic is diminished under a warmer ocean climate.

    Science.gov (United States)

    Pessarrodona, Albert; Moore, Pippa J; Sayer, Martin D J; Smale, Dan A

    2018-06-03

    Global climate change is affecting carbon cycling by driving changes in primary productivity and rates of carbon fixation, release and storage within Earth's vegetated systems. There is, however, limited understanding of how carbon flow between donor and recipient habitats will respond to climatic changes. Macroalgal-dominated habitats, such as kelp forests, are gaining recognition as important carbon donors within coastal carbon cycles, yet rates of carbon assimilation and transfer through these habitats are poorly resolved. Here, we investigated the likely impacts of ocean warming on coastal carbon cycling by quantifying rates of carbon assimilation and transfer in Laminaria hyperborea kelp forests-one of the most extensive coastal vegetated habitat types in the NE Atlantic-along a latitudinal temperature gradient. Kelp forests within warm climatic regimes assimilated, on average, more than three times less carbon and donated less than half the amount of particulate carbon compared to those from cold regimes. These patterns were not related to variability in other environmental parameters. Across their wider geographical distribution, plants exhibited reduced sizes toward their warm-water equatorward range edge, further suggesting that carbon flow is reduced under warmer climates. Overall, we estimated that Laminaria hyperborea forests stored ~11.49 Tg C in living biomass and released particulate carbon at a rate of ~5.71 Tg C year -1 . This estimated flow of carbon was markedly higher than reported values for most other marine and terrestrial vegetated habitat types in Europe. Together, our observations suggest that continued warming will diminish the amount of carbon that is assimilated and transported through temperate kelp forests in NE Atlantic, with potential consequences for the coastal carbon cycle. Our findings underline the need to consider climate-driven changes in the capacity of ecosystems to fix and donate carbon when assessing the impacts of

  4. Assessment of irrigated maize yield response to climate change scenarios in Portugal

    NARCIS (Netherlands)

    Yang, Chenyao; Fraga, Helder; Ieperen, van W.; Andrade Santos, João

    2017-01-01

    Maize is an important crop for the Portuguese agricultural sector. Future climate change, with warmer and dryer conditions in this Mediterranean environment, will challenge this high-water demanding crop. The present study aims at assessing the response of maize yield, growth cycle, seasonal water

  5. Global drought and severe drought-affected populations in 1.5 and 2 °C warmer worlds

    Science.gov (United States)

    Liu, Wenbin; Sun, Fubao; Lim, Wee Ho; Zhang, Jie; Wang, Hong; Shiogama, Hideo; Zhang, Yuqing

    2018-03-01

    The 2015 Paris Agreement proposed a more ambitious climate change mitigation target on limiting global warming to 1.5 °C instead of 2 °C above preindustrial levels. Scientific investigations on environmental risks associated with these warming targets are necessary to inform climate policymaking. Based on the Coupled Model Intercomparison Project phase 5 (CMIP5) climate models, we present the first risk-based assessment of changes in global drought and the impact of severe drought on populations from additional 1.5 and 2 °C warming conditions. Our results highlight the risk of drought on a global scale and in several hotspot regions such as the Amazon, northeastern Brazil, southern Africa and Central Europe at both 1.5 and 2 °C global warming relative to the historical period, showing increases in drought durations from 2.9 to 3.2 months. Correspondingly, more total and urban populations would be exposed to severe droughts globally (+132.5 ± 216.2 million and +194.5 ± 276.5 million total population and +350.2 ± 158.8 million and +410.7 ± 213.5 million urban populations in 1.5 and 2 °C warmer worlds) and regionally (e.g., East Africa, West Africa and South Asia). Less rural populations (-217.7 ± 79.2 million and -216.2 ± 82.4 million rural populations in 1.5 and 2 °C warmer worlds) would be exposed to severe drought globally under climate warming, population growth and especially the urbanization-induced population migration. By keeping global warming at 1.5 °C above the preindustrial levels instead of 2 °C, there is a decrease in drought risks (i.e., less drought duration, less drought intensity and severity but relatively more frequent drought) and the affected total, urban and rural populations would decrease globally and in most regions. While challenging for both East Africa and South Asia, the benefits of limiting warming to below 1.5 °C in terms of global drought risk and impact reduction are significant.

  6. Tree- and Stand-Level Thinning Effects on Growth of European Beech (Fagus sylvatica L. on a Northeast- and a Southwest-Facing Slope in Southwest Germany

    Directory of Open Access Journals (Sweden)

    Daniela Diaconu

    2015-09-01

    Full Text Available Anticipated changes in climate and research findings on the drought sensitivity of beech have triggered controversial discussions about the future of European beech. We investigated the growth response of beech on the tree- and stand-level in mature stands to three different thinning intensities (no thinning, strong thinning, very strong thinning on a northeast- and southwest-facing slope in Southwest Germany. Linear mixed-effects models were formulated to describe effects on growth parameters on the tree- and stand-level (diameter, height, basal area, volume. At the stand-level, the stand basal area increment and stand volume increment were lower on the thinned plots. At the tree-level, the basal area increment significantly increased with increasing thinning intensity. The growth of individual trees was also influenced by initial tree size, the size-related rank of the tree within a stand, and by the aspect of the site. Our data indicate that growth of European beech is impaired on the southwest-facing slope with a warmer and drier climate and that a very strong thinning regime applied at advanced age can accelerate growth of European beech trees even on the warmer and drier site. Our findings, therefore, imply that in a warmer climate intensive thinning may also represent an important adaptive forest management measure in European beech stands.

  7. Adaptive and plastic responses of Quercus petraea populations to climate across Europe

    DEFF Research Database (Denmark)

    Sáenz-Romero, Cuauhtémoc; Lamy, Jean-Baptiste; Ducousso, Alexis

    2017-01-01

    geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (i) to identify the source......How temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150 000 trees sourced from 116...... of differential population responses to climate (genetic differentiation due to past divergent climatic selection vs. plastic responses to ongoing climate change) and (ii) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled...

  8. Short-term acclimation to warmer temperatures accelerates leaf carbon exchange processes across plant types.

    Science.gov (United States)

    Smith, Nicholas G; Dukes, Jeffrey S

    2017-11-01

    While temperature responses of photosynthesis and plant respiration are known to acclimate over time in many species, few studies have been designed to directly compare process-level differences in acclimation capacity among plant types. We assessed short-term (7 day) temperature acclimation of the maximum rate of Rubisco carboxylation (V cmax ), the maximum rate of electron transport (J max ), the maximum rate of phosphoenolpyruvate carboxylase carboxylation (V pmax ), and foliar dark respiration (R d ) in 22 plant species that varied in lifespan (annual and perennial), photosynthetic pathway (C 3 and C 4 ), and climate of origin (tropical and nontropical) grown under fertilized, well-watered conditions. In general, acclimation to warmer temperatures increased the rate of each process. The relative increase in different photosynthetic processes varied by plant type, with C 3 species tending to preferentially accelerate CO 2 -limited photosynthetic processes and respiration and C 4 species tending to preferentially accelerate light-limited photosynthetic processes under warmer conditions. R d acclimation to warmer temperatures caused a reduction in temperature sensitivity that resulted in slower rates at high leaf temperatures. R d acclimation was similar across plant types. These results suggest that temperature acclimation of the biochemical processes that underlie plant carbon exchange is common across different plant types, but that acclimation to warmer temperatures tends to have a relatively greater positive effect on the processes most limiting to carbon assimilation, which differ by plant type. The acclimation responses observed here suggest that warmer conditions should lead to increased rates of carbon assimilation when water and nutrients are not limiting. © 2017 John Wiley & Sons Ltd.

  9. Climate changes, economy and growth: political relationships

    International Nuclear Information System (INIS)

    Alex, Bastien

    2017-03-01

    The author addresses the relationships which may exist between climate change and economic growth, by discussing and criticising some common ideas, and the role of the economic parameter in the position of states within negotiations. These common ideas are: the struggle against climate change impedes economic growth, and green economy provides new growth levers. The author also discusses the fact that some countries may feel they have to slow down their growth because emerging countries are facing a strong development and thus have a strong impact on climate changes. He also outlines that political forces which are presently in power, tend to have a critical approach and speech on mitigation measures

  10. Variable effects of climate on forest growth in relation to climate extremes, disturbance, and forest dynamics.

    Science.gov (United States)

    Itter, Malcolm S; Finley, Andrew O; D'Amato, Anthony W; Foster, Jane R; Bradford, John B

    2017-06-01

    Changes in the frequency, duration, and severity of climate extremes are forecast to occur under global climate change. The impacts of climate extremes on forest productivity and health remain difficult to predict due to potential interactions with disturbance events and forest dynamics-changes in forest stand composition, density, size and age structure over time. Such interactions may lead to non-linear forest growth responses to climate involving thresholds and lag effects. Understanding how forest dynamics influence growth responses to climate is particularly important given stand structure and composition can be modified through management to increase forest resistance and resilience to climate change. To inform such adaptive management, we develop a hierarchical Bayesian state space model in which climate effects on tree growth are allowed to vary over time and in relation to past climate extremes, disturbance events, and forest dynamics. The model is an important step toward integrating disturbance and forest dynamics into predictions of forest growth responses to climate extremes. We apply the model to a dendrochronology data set from forest stands of varying composition, structure, and development stage in northeastern Minnesota that have experienced extreme climate years and forest tent caterpillar defoliation events. Mean forest growth was most sensitive to water balance variables representing climatic water deficit. Forest growth responses to water deficit were partitioned into responses driven by climatic threshold exceedances and interactions with insect defoliation. Forest growth was both resistant and resilient to climate extremes with the majority of forest growth responses occurring after multiple climatic threshold exceedances across seasons and years. Interactions between climate and disturbance were observed in a subset of years with insect defoliation increasing forest growth sensitivity to water availability. Forest growth was particularly

  11. Variable effects of climate on forest growth in relation to climate extremes, disturbance, and forest dynamics

    Science.gov (United States)

    Itter, Malcolm S.; Finley, Andrew O.; D'Amato, Anthony W.; Foster, Jane R.; Bradford, John B.

    2017-01-01

    Changes in the frequency, duration, and severity of climate extremes are forecast to occur under global climate change. The impacts of climate extremes on forest productivity and health remain difficult to predict due to potential interactions with disturbance events and forest dynamics—changes in forest stand composition, density, size and age structure over time. Such interactions may lead to non-linear forest growth responses to climate involving thresholds and lag effects. Understanding how forest dynamics influence growth responses to climate is particularly important given stand structure and composition can be modified through management to increase forest resistance and resilience to climate change. To inform such adaptive management, we develop a hierarchical Bayesian state space model in which climate effects on tree growth are allowed to vary over time and in relation to past climate extremes, disturbance events, and forest dynamics. The model is an important step toward integrating disturbance and forest dynamics into predictions of forest growth responses to climate extremes. We apply the model to a dendrochronology data set from forest stands of varying composition, structure, and development stage in northeastern Minnesota that have experienced extreme climate years and forest tent caterpillar defoliation events. Mean forest growth was most sensitive to water balance variables representing climatic water deficit. Forest growth responses to water deficit were partitioned into responses driven by climatic threshold exceedances and interactions with insect defoliation. Forest growth was both resistant and resilient to climate extremes with the majority of forest growth responses occurring after multiple climatic threshold exceedances across seasons and years. Interactions between climate and disturbance were observed in a subset of years with insect defoliation increasing forest growth sensitivity to water availability. Forest growth was particularly

  12. On climate change and economic growth

    International Nuclear Information System (INIS)

    Fankhauser, Samuel; Tol, Richard S.J.

    2005-01-01

    The economic impact of climate change is usually measured as the extent to which the climate of a given period affects social welfare in that period. This static approach ignores the dynamic effects through which climate change may affect economic growth and hence future welfare. In this paper we take a closer look at these dynamic effects, in particular saving and capital accumulation. With a constant savings rate, a lower output due to climate change will lead to a proportionate reduction in investment which in turn will depress future production (capital accumulation effect) and, in almost all cases, future consumption per capita. If the savings rate is endogenous, forward looking agents would change their savings behavior to accommodate the impact of future climate change. This suppresses growth prospects in absolute and per capita terms (savings effect). In an endogenous growth context, these two effects may be exacerbated through changes in labour productivity and the rate of technical progress. Simulations using a simple climate-economy model suggest that the capital accumulation effect is important, especially if technological change is endogenous, and may be larger than the direct impact of climate change. The savings effect is less pronounced. The dynamic effects are more important, relative to the direct effects, if climate change impacts are moderate overall. This suggests that they are more of a concern in developed countries, which are believed to be less vulnerable to climate change. The magnitude of dynamic effects is not sensitive to the choice of discount rate

  13. Elevated temperature is more effective than elevated [CO2 ] in exposing genotypic variation in Telopea speciosissima growth plasticity: implications for woody plant populations under climate change.

    Science.gov (United States)

    Huang, Guomin; Rymer, Paul D; Duan, Honglang; Smith, Renee A; Tissue, David T

    2015-10-01

    Intraspecific variation in phenotypic plasticity is a critical determinant of plant species capacity to cope with climate change. A long-standing hypothesis states that greater levels of environmental variability will select for genotypes with greater phenotypic plasticity. However, few studies have examined how genotypes of woody species originating from contrasting environments respond to multiple climate change factors. Here, we investigated the main and interactive effects of elevated [CO2 ] (CE ) and elevated temperature (TE ) on growth and physiology of Coastal (warmer, less variable temperature environment) and Upland (cooler, more variable temperature environment) genotypes of an Australian woody species Telopea speciosissima. Both genotypes were positively responsive to CE (35% and 29% increase in whole-plant dry mass and leaf area, respectively), but only the Coastal genotype exhibited positive growth responses to TE . We found that the Coastal genotype exhibited greater growth response to TE (47% and 85% increase in whole-plant dry mass and leaf area, respectively) when compared with the Upland genotype (no change in dry mass or leaf area). No intraspecific variation in physiological plasticity was detected under CE or TE , and the interactive effects of CE and TE on intraspecific variation in phenotypic plasticity were also largely absent. Overall, TE was a more effective climate factor than CE in exposing genotypic variation in our woody species. Our results contradict the paradigm that genotypes from more variable climates will exhibit greater phenotypic plasticity in future climate regimes. © 2015 John Wiley & Sons Ltd.

  14. Teleconnections in a warmer climate: the pliocene perspective

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Sonali P. [Columbia University, Deptartment of Earth and Environmental Sciences and the NASA Goddard Institute for Space Studies, New York, NY (United States); Chandler, Mark A.; Sohl, Linda E.; Jonas, Jeff; Lerner, Jean [Columbia University, Center for Climate Systems Research, New York, NY (United States); Rind, David [National Aeronautics and Space Administration, Goddard Institute for Space Studies, New York, NY (United States)

    2011-11-15

    Migrations toward altered sea surface temperature (SST) patterns in the Indo-Pacific region are present in the recent observational record and in future global warming projections. These SSTs are in the form of ''permanent'' El Nino-like (herein termed ''El Padre'') and Indian Ocean Dipole (IOD)-like patterns. The Early Pliocene Warm Period, which bears similarity to future warming projections, may have also exhibited these Indo-Pacific SST patterns, as suggested by regional terrestrial paleo-climatic data and general circulation model studies. The ability to corroborate this assessment with paleo-data reconstructions is an advantage of the warm Pliocene period that is not afforded by future warming scenarios. Thus, the Pliocene period provides us with a warm-climate perspective and test bed for understanding potential changes to future atmospheric interactions given these altered SST states. This study specifically assesses how atmospheric teleconnections from El Padre/IOD SST patterns are generated and propagate to create the regional climate signals of the Pliocene period, as these signals may be representative of future regional climatic changes as well. To do this, we construct a holistic diagnostic rubric that allows us to examine atmospheric teleconnections, both energetically and dynamically, as produced by a general circulation model. We incorporate KE', a diagnostic adapted from the eddy kinetic energy generation field, to assess the available energy transferred to these teleconnections. Using this methodology, we found that relative to our Modern Control experiments, weaker atmospheric teleconnections prevail under warm Pliocene conditions, although pathways of propagation still appear directed toward the southwestern United States from our tropical Pacific sector forcing. Propagation directly emanating from the Indian Ocean forcing sector appears to be largely blocked, although indirect teleconnective

  15. Will the warmer temperature bring the more intensity precipitation?

    Science.gov (United States)

    Yutong, Z., II; Wang, T.

    2017-12-01

    Will the warmer temperature bring the more intensity precipitation?Over the past several decades, changes in climate are amplified over the Tibetan Plateau(TP), with warming trend almost being twice as large as the global average. In sharp contrast, there is a large spatial discrepancy of the variations in precipitation extremes, with increasing trends found in the southern and decreasing trends in central TP. These features motivate are urgent need for an observation-based understanding of how precipitation extremes respond to climate change. Here we examine the relation between precipitation intensity with atmospheric temperature, dew point temperature (Td) and convective available potential energy (CAPE) in Tibet Plateau. Owing to the influences of the westerlies and Indian monsoon on Tibetan climate, the stations can be divided into three sub-regions in TP: the westerlies region (north of 35°N, N = 28), the monsoon region (south of 30°N in TP, N = 31), and the transition region (located between 30°N and 35°N, N = 48). We found that the intensity precipitation does not follow the C-C relation and there is a mix of positive and negative slope. To better understand why different scaling occurs with temperature in district region, using the dew point temperature replace the temperature, although there is significant variability in relative humidity values, at most stations, there appears to be a general increase in relative humidity associated. It is likely that the observed rise in relative humidity can assist in explaining the negative scaling of extreme precipitation at westerlies domain and monsoon domain, with the primary reason why precipitation extremes expected to increase follows from the fact that a warmer atmosphere can "hold" more moisture. This suggests that not only on how much the moisture the atmosphere can hold, but on how much moisture exits in atmosphere. To understand the role of dynamic on extreme precipitation, we repeat the precipitation

  16. Prolonged limitation of tree growth due to warmer spring in semi-arid mountain forests of Tianshan, northwest China

    International Nuclear Information System (INIS)

    Wu Xiuchen; Liu Hongyan; Wang Yufu; Deng Minghua

    2013-01-01

    Based on radial tree growth measurements in nine plots of area 625 m 2 (369 trees in total) and climate data, we explored the possibly changing effects of climate on regional tree growth in the temperate continental semi-arid mountain forests in the Tianshan Mountains in northwest China during 1933–2005. Tree growth in our study region is generally limited by the soil water content of pre- and early growing season (February–July). Remarkably, moving correlation functions identified a clear temporal change in the relationship between tree growth and mean April temperature. Tree growth showed a significant (p < 0.05) and negative relationship to mean April temperature since approximately the beginning of the 1970s, which indicated that the semi-arid mountain forests are suffering a prolonged growth limitation in recent years accompanying spring warming. This prolonged limitation of tree growth was attributed to the effects of soil water limitation in early spring (March–April) caused by the rapid spring warming. Warming-induced prolonged drought stress contributes, to a large part, to the marked reduction of regional basal area increment (BAI) in recent years and a much slower growth rate in young trees. Our results highlight that the increasing water limitation induced by spring warming on tree growth most likely aggravated the marked reduction in tree growth. This work provides a better understanding of the effects of spring warming on tree growth in temperate continental semi-arid forests. (letter)

  17. Winter climate limits subantarctic low forest growth and establishment.

    Science.gov (United States)

    Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

  18. Climate, Tree Growth, Forest Drought Stress, and Tree Mortality in Forests of Western North America: Long-Term Patterns and Recent Trends

    Science.gov (United States)

    Allen, C. D.; Williams, P.

    2012-12-01

    Ongoing climate changes are increasingly affecting the world's forests, particularly including high latitude and high elevation coniferous forests. Although forest growth has improved in some regions due to greater growing season length and warmth (perhaps along with increased atmospheric CO2 or N), large growth declines or increased mortality from droughts or hotter temperatures also are being observed. We present and interpret information on regional variation in climate-tree growth relationships and trends, and on patterns and trends of climate-related forest disturbances, from western North America. From 235 tree-ring chronologies in the Southwest US we show that tree-ring growth records from warmer southwestern sites are more sensitive to temperature than tree-ring growth records from cooler southwestern sites. Assessment of 59 tree-ring records from 11 species in the Cascade Mountains of the Pacific Northwest shows that trees growing in cool places respond positively to increased temperature and trees in warm places respond negatively, implying that trees historically not sensitive to temperature may become sensitive as mean temperatures warm. An analysis of 59 white spruce populations in Alaska supports the hypothesis that warming has caused tree growth to lose sensitivity to cold temperatures. Comparing ring widths to temperature during just the coldest 50% of years during the 20th century, tree growth was sensitive to cold temperatures, and this effect was strongest at the coldest sites; whereas during the warmest 50% of years, trees were not at all sensitive to cold temperatures, even at the cold sites. Drought and vapor pressure deficit are among the variables that emerge as being increasingly important to these Alaska boreal forests as mean temperatures rise. Most recently, from 346 tree-ring chronologies in the Southwest US we establish a tree-ring-based Forest Drought Stress Index (FDSI) for the three most widespread conifer species (Pinus edulis

  19. Winter climate limits subantarctic low forest growth and establishment.

    Directory of Open Access Journals (Sweden)

    Melanie A Harsch

    Full Text Available Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E is oceanic (Conrad Index of Continentality  =  -5 with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C, dry winters (total winter precipitation <400 mm. Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

  20. Winter Climate Limits Subantarctic Low Forest Growth and Establishment

    Science.gov (United States)

    Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

  1. Intensification of extreme European summer precipitation in a warmer climate

    DEFF Research Database (Denmark)

    Christensen, O. B.; Christensen, J. H.

    2004-01-01

    Heavy and/or extended precipitation episodes with subsequent surface runoff can inflict catastrophic property damage and loss of human life. Thus, it is important to determine how the character of such events could change in response to greenhouse gas-induced global warming. Impacts of climate...... warming on severe precipitation events in Europe on a diurnal time scale were investigated with a high-resolution regional climate model for two of the greenhouse gas emission scenarios constructed by the Intergovernmental Panel on Climate Change (IPCC; Nakicenovic, N., et al., 2000, IPCC special report...... models both originating from fully transient climate change simulations. Here, we show that although the summer time precipitation decreases over a substantial part of Europe in the scenarios analysed, an increase in the amount of precipitation exceeding the present-day 99th and in most cases even the 95...

  2. Methane Feedbacks to the Global Climate System in a Warmer World

    Science.gov (United States)

    Dean, Joshua F.; Middelburg, Jack J.; Röckmann, Thomas; Aerts, Rien; Blauw, Luke G.; Egger, Matthias; Jetten, Mike S. M.; de Jong, Anniek E. E.; Meisel, Ove H.; Rasigraf, Olivia; Slomp, Caroline P.; in't Zandt, Michiel H.; Dolman, A. J.

    2018-03-01

    Methane (CH4) is produced in many natural systems that are vulnerable to change under a warming climate, yet current CH4 budgets, as well as future shifts in CH4 emissions, have high uncertainties. Climate change has the potential to increase CH4 emissions from critical systems such as wetlands, marine and freshwater systems, permafrost, and methane hydrates, through shifts in temperature, hydrology, vegetation, landscape disturbance, and sea level rise. Increased CH4 emissions from these systems would in turn induce further climate change, resulting in a positive climate feedback. Here we synthesize biological, geochemical, and physically focused CH4 climate feedback literature, bringing together the key findings of these disciplines. We discuss environment-specific feedback processes, including the microbial, physical, and geochemical interlinkages and the timescales on which they operate, and present the current state of knowledge of CH4 climate feedbacks in the immediate and distant future. The important linkages between microbial activity and climate warming are discussed with the aim to better constrain the sensitivity of the CH4 cycle to future climate predictions. We determine that wetlands will form the majority of the CH4 climate feedback up to 2100. Beyond this timescale, CH4 emissions from marine and freshwater systems and permafrost environments could become more important. Significant CH4 emissions to the atmosphere from the dissociation of methane hydrates are not expected in the near future. Our key findings highlight the importance of quantifying whether CH4 consumption can counterbalance CH4 production under future climate scenarios.

  3. Economic Growth, Climate Change, and Obesity.

    Science.gov (United States)

    Minos, Dimitrios; Butzlaff, Iris; Demmler, Kathrin Maria; Rischke, Ramona

    2016-12-01

    Human and planetary health as well as economic growth are firmly interlinked and subject to complex interaction effects. In this paper, we provide an overview of interlinkages between economic growth, climate change, and obesity focusing on recent advances in the literature. In addition to empirical findings, we discuss different theoretical frameworks used to conceptualize these complex links and highlight policy options and challenges. We conclude that policies addressing both climate change and obesity simultaneously are particularly promising and often suitable for ensuring sustainable development.

  4. Pan-Tropical Analysis of Climate Effects on Seasonal Tree Growth

    Science.gov (United States)

    Wagner, Fabien; Rossi, Vivien; Aubry-Kientz, Mélaine; Bonal, Damien; Dalitz, Helmut; Gliniars, Robert; Stahl, Clément; Trabucco, Antonio; Hérault, Bruno

    2014-01-01

    Climate models predict a range of changes in tropical forest regions, including increased average temperatures, decreased total precipitation, reduced soil moisture and alterations in seasonal climate variations. These changes are directly related to the increase in anthropogenic greenhouse gas concentrations, primarily CO2. Assessing seasonal forest growth responses to climate is of utmost importance because woody tissues, produced by photosynthesis from atmospheric CO2, water and light, constitute the main component of carbon sequestration in the forest ecosystem. In this paper, we combine intra-annual tree growth measurements from published tree growth data and the corresponding monthly climate data for 25 pan-tropical forest sites. This meta-analysis is designed to find the shared climate drivers of tree growth and their relative importance across pan-tropical forests in order to improve carbon uptake models in a global change context. Tree growth reveals significant intra-annual seasonality at seasonally dry sites or in wet tropical forests. Of the overall variation in tree growth, 28.7% was explained by the site effect, i.e. the tree growth average per site. The best predictive model included four climate variables: precipitation, solar radiation (estimated with extrasolar radiation reaching the atmosphere), temperature amplitude and relative soil water content. This model explained more than 50% of the tree growth variations across tropical forests. Precipitation and solar radiation are the main seasonal drivers of tree growth, causing 19.8% and 16.3% of the tree growth variations. Both have a significant positive association with tree growth. These findings suggest that forest productivity due to tropical tree growth will be reduced in the future if climate extremes, such as droughts, become more frequent. PMID:24670981

  5. Douglas-fir displays a range of growth responses to ...

    Science.gov (United States)

    Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) growth in the Pacific Northwest is affected by climatic, edaphic factors and Swiss needle cast (SNC) disease. We examine Douglas-fir growth responses to temperature, dewpoint deficit (DPD), soil moisture, and SNC using time series intervention analysis of intra-annual tree-ring width data collected at nine forest stands in western Oregon, USA. The effects of temperature and SNC were similar in importance on tree growth at all sites. Previous-year DPD during the annual drought period was a key factor limiting growth regionally. Winter temperature was more important at high elevation cool sites, whereas summer temperature was more important at warm and dry sites. Growth rate increased with summer temperature to an optimum (Topt) then decreased at higher temperatures. At drier sites, temperature and water affected growth interactively such that Topt decreased with decreasing summer soil moisture. With climate change, growth rates increased at high elevation sites and declined at mid-elevation inland sites since ~1990. Growth response to climate is masked by SNC regionally. We conclude that as temperature rises and precipitation patterns shift towards wetter winters and drier summers, Douglas-fir will experience greater temperature and water stress and an increase in severity of SNC. By the end of the 21st century, climate models predict hotter, drier summers and warmer, wetter winters in the Pac

  6. Global drought and severe drought-affected populations in 1.5 and 2 °C warmer worlds

    Directory of Open Access Journals (Sweden)

    W. Liu

    2018-03-01

    Full Text Available The 2015 Paris Agreement proposed a more ambitious climate change mitigation target on limiting global warming to 1.5 °C instead of 2 °C above preindustrial levels. Scientific investigations on environmental risks associated with these warming targets are necessary to inform climate policymaking. Based on the Coupled Model Intercomparison Project phase 5 (CMIP5 climate models, we present the first risk-based assessment of changes in global drought and the impact of severe drought on populations from additional 1.5 and 2 °C warming conditions. Our results highlight the risk of drought on a global scale and in several hotspot regions such as the Amazon, northeastern Brazil, southern Africa and Central Europe at both 1.5 and 2 °C global warming relative to the historical period, showing increases in drought durations from 2.9 to 3.2 months. Correspondingly, more total and urban populations would be exposed to severe droughts globally (+132.5 ± 216.2 million and +194.5 ± 276.5 million total population and +350.2 ± 158.8 million and +410.7 ± 213.5 million urban populations in 1.5 and 2 °C warmer worlds and regionally (e.g., East Africa, West Africa and South Asia. Less rural populations (−217.7 ± 79.2 million and −216.2 ± 82.4 million rural populations in 1.5 and 2 °C warmer worlds would be exposed to severe drought globally under climate warming, population growth and especially the urbanization-induced population migration. By keeping global warming at 1.5 °C above the preindustrial levels instead of 2 °C, there is a decrease in drought risks (i.e., less drought duration, less drought intensity and severity but relatively more frequent drought and the affected total, urban and rural populations would decrease globally and in most regions. While challenging for both East Africa and South Asia, the benefits of limiting warming to below 1.5 °C in terms of global drought risk

  7. The analysis of Last Interglacial (MIS 5e) relative sea-level indicators: Reconstructing sea-level in a warmer world

    NARCIS (Netherlands)

    Rovere, A.; Raymo, M.E.; Vacchi, M.; Lorscheid, T; Stocchi, P.; Gómez-Pujolf, L.; Harris, D.L.; Casella, E.; O'Leary, M.J.; Hearty, P.J.

    2016-01-01

    The Last Interglacial (MIS 5e, 128–116 ka) is among the most studied past periods in Earth's history. The climate at that time was warmer than today, primarily due to different orbital conditions, with smaller ice sheets and higher sea-level. Field evidence for MIS 5e sea-level was reported from

  8. Will a warmer and wetter future cause extinction of native Hawaiian forest birds?

    Science.gov (United States)

    Liao, Wei; Timm, Oliver Elison; Zhang, Chunxi; Atkinson, Carter T.; LaPointe, Dennis; Samuel, Michael D.

    2015-01-01

    Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate future bird-mosquito-malaria dynamics in response to alternative climate projections from the Coupled Model Intercomparison Project (CMIP). Climate changes during the second half of the century accelerate malaria transmission and cause a dramatic decline in bird abundance. Different temperature and precipitation patterns produce divergent trajectories where native birds persist with low malaria infection under a warmer and dryer projection (RCP4.5), but suffer high malaria infection and severe reductions under hot and dry (RCP8.5) or warm and wet (A1B) futures. We conclude that future global climate change will cause significant decreases in the abundance and diversity of remaining Hawaiian bird communities. Because these effects appear unlikely before mid-century, natural resource managers have time to implement conservation strategies to protect this unique avifauna from further decimation. Similar climatic drivers for avian and human malaria suggest that mitigation strategies for Hawai'i have broad application to human health.

  9. Tree growth and climate in the Pacific Northwest, North America: a broad-scale analysis of changing growth environments

    Science.gov (United States)

    Whitney L. Albright; David L. Peterson

    2013-01-01

    Climate change in the 21st century will affect tree growth in the Pacific Northwest region of North America, although complex climate–growth relationships make it difficult to identify how radial growth will respond across different species distributions. We used a novel method to examine potential growth responses to climate change at a broad geographical scale with a...

  10. Climate sensitivity of shrub growth across the tundra biome

    DEFF Research Database (Denmark)

    Myers-Smith, Isla H.; Elmendorf, Sarah C.; Beck, Pieter S.A.

    2015-01-01

    Rapid climate warming in the tundra biome has been linked to increasing shrub dominance1–4. Shrub expansion can modify climate by altering surface albedo, energy and water balance, and permafrost2,5–8, yet the drivers of shrub growth remain poorly understood. Dendroecological data consisting...... of multi-decadal time series of annual shrub growth provide an underused resource to explore climate–growth relationships. Here, we analyse circumpolar data from 37 Arctic and alpine sites in 9 countries, including 25 species, and 42,000 annual growth records from 1,821 individuals. Our analyses...... demonstrate that the sensitivity of shrub growth to climate was: (1) heterogeneous, with European sites showing greater summer temperature sensitivity than North American sites, and (2) higher at sites with greater soil moisture and for taller shrubs (for example, alders and willows) growing at their northern...

  11. Climate challenge 2012: growth and climate change - Socio-economical impacts of climate change. Conference proceedings

    International Nuclear Information System (INIS)

    Orange-Louboutin, Mylene; Robinet, Olivier; Delalande, Daniel; Reysset, Bertrand; De Perthuis, Christian; Le Treut, Herve; Cottenceau, Jean-Baptiste; Ayong, Alain; Daubaire, Aurelien; Gaudin, Thomas

    2012-01-01

    The contributions of this conference session proposed comments and discussion on the relationship between climate change and 'green' growth, on the status of scientific knowledge on climate change (from global to local), on the way to perform carbon print assessment and to decide which actions to implement, on the costs and opportunity of impacts of climate change, on the economy of adaptation, on the benefits and costs of the adaptation policy, and on impacts of climate change on employment in quantitative terms and in terms of profession types

  12. Will seabass (Dicentrarchus labrax) quality change in a warmer ocean?

    Science.gov (United States)

    Barbosa, Vera; Maulvault, Ana Luísa; Alves, Ricardo N; Anacleto, Patrícia; Pousão-Ferreira, Pedro; Carvalho, Maria Luísa; Nunes, Maria Leonor; Rosa, Rui; Marques, António

    2017-07-01

    The impacts of climate change on seafood quality, safety and human health are still unknown. The present study investigated the effect of warming on fatty acids and elements content in two tissues (muscle and liver) of the relevant commercial seabass species (Dicentrarchus labrax). After exposing fish to increased seawater temperature for a period of 60days, higher saturated fatty acid (SFA) levels were observed in fish muscle (2.16% increase); whereas lower SFA levels were observed in fish liver (5.42% decrease). On the other hand, monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) contents decreased in both muscle (1.77% and 0.39%, respectively) and liver (10.54% and 8.11%, respectively) of fish subjected to warmer conditions. Additionally, warming promoted changes in fish elemental profiles, leading to significantly higher levels of Cl in the muscle and lower levels of Rb in the liver. Overall, data showed that fatty acids and elemental contents were affected by temperature, though representing small implications to human health. Moreover, this preliminary study highlights the importance of conducting further seafood risk-benefit assessments under climate change contexts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Impacts of northern climate changes on Arctic engineering practice

    International Nuclear Information System (INIS)

    Esch, D.C.

    1993-01-01

    Potential impacts of climate changes on engineering design practices in the Arctic are discussed with reference to permafrost engineering aspects, hydrology, and coastal and sea ice processes. Permafrost generally remains thermally stable only when mean annual air temperature remains 2-4 degrees below zero and the original surface conditions remain unchanged. It has been demonstrated that a temperature rise of only 1-2 degrees is very critical. The many different climate change forecasts make it difficult to design structures in permafrost with definite levels of confidence over a project's lifetime (i.e. up to 50 years). Consequences of climate warming on transportation-related structures can be estimated to a certain degree by examining experience with natural permafrost surfaces affected by land clearing or with structures built in permafrost. Melting of permafrost will be accompanied by surface settlements, slumping of slopes and banks, and creation of thaw pits and ponds, with eventual distress to many surface structures such as pavements and foundations. Designing for a warmer climate is illustrated for the case of the Bethel Highway, the first in Alaska to be designed for a progressively warmer climate. Increased water flows both from ice melting and increased precipitation in a warmer climate will make forecasting of discharge levels in drainage basins a difficult task. Of great concern to engineers is the potential for increased erosion and sediment loadings in streams. In coastal engineering, the effects of rising sea levels, increased open-water areas, and more severe storms foreseen in a warmer climate will require heavier and more elevated shore protection. On the other hand, shipping and offshore operations will be made easier. 9 refs., 4 figs

  14. Geographical differences in maternal basking behaviour and offspring growth rate in a climatically widespread viviparous reptile.

    Science.gov (United States)

    Cadby, Chloé D; Jones, Susan M; Wapstra, Erik

    2014-04-01

    In reptiles, the thermal environment during embryonic development affects offspring phenotypic traits and potentially offspring fitness. In viviparous species, mothers can potentially manipulate the embryonic thermal environment through their basking behaviour and, thus, may be able to manipulate offspring phenotype and increase offspring fitness. One way in which mothers can maximise offspring phenotype (and thus potentially affect offspring fitness) is by fine-tuning their basking behaviour to the environment in order to buffer the embryo from deleterious developmental temperatures. In widespread species, it is unclear whether populations that have evolved under different climatic conditions will exhibit different maternal behaviours and/or thermal effects on offspring phenotype. To test this, we provided extended or reduced basking opportunity to gravid spotted skinks (Niveoscincus ocellatus) and their offspring from two populations at the climatic extremes of the species' distribution. Gravid females fine-tuned their basking behaviour to the basking opportunity, which allowed them to buffer their embryos from potentially negative thermal effects. This fine-tuning of female basking behaviour appears to have led to the expression of geographical differences in basking behaviour, with females from the cold alpine regions being more opportunistic in their basking behaviour than females from the warmer regions. However, those differences in maternal behaviour did not preclude the evolution of geographic differences in thermal effects: offspring growth varied between populations, potentially suggesting local adaptation to basking conditions. Our results demonstrate that maternal effects and phenotypic plasticity can play a significant role in allowing species to cope in changing environmental conditions, which is particularly relevant in the context of climate change.

  15. Urban climate modifies tree growth in Berlin

    Science.gov (United States)

    Dahlhausen, Jens; Rötzer, Thomas; Biber, Peter; Uhl, Enno; Pretzsch, Hans

    2018-05-01

    Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees ( Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of increment cores, we are able to trace back their growth for the last 50 to 100 years. A general growth trend can be shown by comparing recent basal area growth with estimates from extrapolating a growth function that had been fitted with growth data from earlier years. Estimating a linear model, we show that air temperature and precipitation significantly influence tree growth within the last 20 years. Under consideration of housing density, the results reveal that higher air temperature and less precipitation led to higher growth rates in high-dense areas, but not in low-dense areas. In addition, our data reveal a significantly higher variance of the ring width index in areas with medium housing density compared to low housing density, but no temporal trend. Transferring the results to forest stands, climate change is expected to lead to higher tree growth rates.

  16. Urban climate modifies tree growth in Berlin

    Science.gov (United States)

    Dahlhausen, Jens; Rötzer, Thomas; Biber, Peter; Uhl, Enno; Pretzsch, Hans

    2017-12-01

    Climate, e.g., air temperature and precipitation, differs strongly between urban and peripheral areas, which causes diverse life conditions for trees. In order to compare tree growth, we sampled in total 252 small-leaved lime trees (Tilia cordata Mill) in the city of Berlin along a gradient from the city center to the surroundings. By means of increment cores, we are able to trace back their growth for the last 50 to 100 years. A general growth trend can be shown by comparing recent basal area growth with estimates from extrapolating a growth function that had been fitted with growth data from earlier years. Estimating a linear model, we show that air temperature and precipitation significantly influence tree growth within the last 20 years. Under consideration of housing density, the results reveal that higher air temperature and less precipitation led to higher growth rates in high-dense areas, but not in low-dense areas. In addition, our data reveal a significantly higher variance of the ring width index in areas with medium housing density compared to low housing density, but no temporal trend. Transferring the results to forest stands, climate change is expected to lead to higher tree growth rates.

  17. Competition amplifies drought stress in forests across broad climatic and compositional gradients

    Science.gov (United States)

    Gleason, Kelly; Bradford, John B.; Bottero, Alessandra; D'Amato, Tony; Fraver, Shawn; Palik, Brian J.; Battaglia, Michael; Iverson, Louis R.; Kenefic, Laura; Kern, Christel C.

    2017-01-01

    Forests around the world are experiencing increasingly severe droughts and elevated competitive intensity due to increased tree density. However, the influence of interactions between drought and competition on forest growth remains poorly understood. Using a unique dataset of stand-scale dendrochronology sampled from 6405 trees, we quantified how annual growth of entire tree populations responds to drought and competition in eight, long-term (multi-decadal), experiments with replicated levels of density (e.g., competitive intensity) arrayed across a broad climatic and compositional gradient. Forest growth (cumulative individual tree growth within a stand) declined during drought, especially during more severe drought in drier climates. Forest growth declines were exacerbated by high density at all sites but one, particularly during periods of more severe drought. Surprisingly, the influence of forest density was persistent overall, but these density impacts were greater in the humid sites than in more arid sites. Significant density impacts occurred during periods of more extreme drought, and during warmer temperatures in the semi-arid sites but during periods of cooler temperatures in the humid sites. Because competition has a consistent influence over growth response to drought, maintaining forests at lower density may enhance resilience to drought in all climates.

  18. The effect of the pathway to a two degrees warmer world on the regional temperature change of Europe

    Directory of Open Access Journals (Sweden)

    Cathrine Fox Maule

    2017-08-01

    Full Text Available The purpose of this study is to investigate if the pathway to reach a 2 degree warmer world influences the regional climate in Europe at the time of 2 degrees of global warming above the pre-industrial level. We have investigated this using climate change data from ensembles of both Global Climate Models and Regional Climate Models. We compare the change of regional temperature in Europe to the global temperature change for different emission scenarios, following the IPCC Representative Concentration Pathways (RCP, to see if the pathway has any influence. We find that there is a small but significant difference in the regional temperature change, but the effect is small compared to internal variability on the timescales involved in reaching +2 degrees for the investigated emission scenarios. From an adaptation point of view, reaching +2 degrees as slowly as possible will obviously allow for a longer time period to implement adaptation measures to mitigate the effect of climate change.

  19. Growth-climate relationships across topographic gradients in the northern Great Lakes

    Science.gov (United States)

    S.F. Dymond; A.W. D' Amato; Randy Kolka; P.V. Bolstad; Stephen Sebestyen; J.B. Bradford

    2016-01-01

    Climatic conditions exert important control over the growth, productivity, and distribution of forests, and characterizing these relationships is essential for understanding how forest ecosystems will respond to climate change. We used dendrochronological methods to develop climate–growth relationships for two dominant species, Populus tremuloides...

  20. Methane feedbacks to the global climate system in a warmer world

    NARCIS (Netherlands)

    Dean, Joshua F.; Middelburg, Jack J.; Röckmann, Thomas; Aerts, Rien; Blauw, Luke G.; Egger, Matthias; Jetten, Mike S.M.; de Jong, Anniek E.E.; Meisel, Ove H.; Rasigraf, Olivia; Slomp, Caroline P.; in't Zandt, Michiel H.; Dolman, A. J.

    Methane (CH4) is produced in many natural systems that are vulnerable to change under a warming climate, yet current CH4 budgets, as well as future shifts in CH4 emissions, have high uncertainties. Climate change has the potential to increase CH4 emissions from critical systems such as wetlands,

  1. Geoengineering: Direct Mitigation of Climate Warming

    Science.gov (United States)

    For Frank Princiotta’s book, Global Climate Change—The Technology Challenge With the concentrations of atmospheric greenhouse gases (GHGs) rising to levels unprecedented in the current glacial epoch, the earth’s climate system appears to be rapidly shifting into a warmer regime....

  2. Interactive effects of ozone and climate on water use, soil moisture content and streamflow in a southern Appalachian forest in the USA

    Science.gov (United States)

    S.B. McLaughlin; S.D. Wullschleger; G. Sun; M. Nosal

    2007-01-01

    Documentation of the degree and direction of effects of ozone on transpiration of canopies of mature forest trees is critically needed to model ozone effects on forest water use and growth in a warmer future climate.Patterns of sap flow in stems and soil moisture in the rooting zones of mature trees, coupled with late-season...

  3. Regional patterns of increasing Swiss needle cast impacts on Douglas-fir growth with warming temperatures.

    Science.gov (United States)

    Lee, E Henry; Beedlow, Peter A; Waschmann, Ronald S; Tingey, David T; Cline, Steven; Bollman, Michael; Wickham, Charlotte; Carlile, Cailie

    2017-12-01

    The fungal pathogen, Phaeocryptopus gaeumannii , causing Swiss needle cast (SNC) occurs wherever Douglas-fir is found but disease damage is believed to be limited in the U.S. Pacific Northwest (PNW) to the Coast Range of Oregon and Washington (Hansen et al., Plant Disease , 2000, 84 , 773; Rosso & Hansen, Phytopathology , 2003, 93 , 790; Shaw, et al., Journal of Forestry , 2011, 109 , 109). However, knowledge remains limited on the history and spatial distribution of SNC impacts in the PNW. We reconstructed the history of SNC impacts on mature Douglas-fir trees based on tree-ring width chronologies from western Oregon. Our findings show that SNC impacts on growth occur wherever Douglas-fir is found and is not limited to the coastal fog zone. The spatiotemporal patterns of growth impact from SNC disease were synchronous across the region, displayed periodicities of 12-40 years, and strongly correlated with winter and summer temperatures and summer precipitation. The primary climatic factor limiting pathogen dynamics varied spatially by location, topography, and elevation. SNC impacts were least severe in the first half of the 20th century when climatic conditions during the warm phase of the Pacific Decadal Oscillation (1924-1945) were less conducive to pathogen development. At low- to mid-elevations, SNC impacts were most severe in 1984-1986 following several decades of warmer winters and cooler, wetter summers including a high summer precipitation anomaly in 1983. At high elevations on the west slope of the Cascade Range, SNC impacts peaked several years later and were the greatest in the 1990s, a period of warmer winter temperatures. Climate change is predicted to result in warmer winters and will likely continue to increase SNC severity at higher elevations, north along the coast from northern Oregon to British Columbia, and inland where low winter temperatures currently limit growth of the pathogen. Our findings indicate that SNC may become a significant

  4. Building when the climate gets warmer

    International Nuclear Information System (INIS)

    Brunner, C. U.; Steinemann, U.; Nipkow, J.

    2007-01-01

    This final report for the Swiss Federal Office of Energy (SFOE), takes a look at how the building process will have to take account of climate change with higher summer temperatures in Switzerland. The authors consider the situation as being in strong contrast to the past in Switzerland, when attention was devoted to energy demand in buildings during the winter. Today there is a new focus with the anticipation of increasingly frequent, extended hot spells in summer. The goal of this investigation is to analyse and present economic measures to assure a high level of summer comfort with a reduced demand for electricity under these changing conditions. Strategies with respect to construction, technology and operation are addressed. The current spread of technically questionable and inefficient room air conditioning units in residential and commercial buildings is considered as being strongly reminiscent of a dangerous, analogous case in the past, when small electric heaters became widespread. A largely untapped potential exists for increasing the efficiency of air conditioning and chiller technologies for both central systems and room units by the careful use of small temperature differences. Several new and unconventional solution paths are discussed, including high-efficiency room air conditioners, solar cooling equipment, balanced mechanical ventilation, phase-change materials, thermal storage, etc., all aimed at reducing electricity consumption. The expected additional electricity demand of around 1.9 TWh annually for ventilation and air conditioning is commented on.

  5. Future wheat yields in Western Australia under a warmer and drier climate

    International Nuclear Information System (INIS)

    Farre, Imma; Foster, Ian; Charles, Steve

    2007-01-01

    Full text: Full text: Climate change projections for the mid 21st century for southern Western Australia indicate an increase in temperatures, a decrease in rainfall and higher C02 concentrations. These changes could have adverse impacts on some agricultural systems, but they may also offer new opportunities (i.e. in areas where the risk of waterlogging may be reduced). In this paper we studied the potential impacts of climate change on wheat production by combining three modelling systems. Daily climate data for current and future conditions from the CCAM climate model was statistically downscaled to individual locations in the Western Australia wheatbelt. This climate data was then input to the APSIM-Wheat simulation model to evaluate yields and phenology under current and future climate for several soil types. The aim was to investigate the usefulness of such a modelling cascade in defining key risks to wheat cropping from projected climate change. In an earlier stage of the project, we compared climate simulation from several climate models (CSIRO Mk3, CCAM, ECHAM and HADCM), and selected the CCAM model as best representing the climate of southern Western Australia. This was used for a more detailed study of the impacts on wheat cropping. The APSIM model simulates crop development, yield, water uptake and nitrogen accumulation in response to temperature, radiation, C02 level, water and nitrogen supply. It offers a framework for investigating interactions and testing some simple adaptation options. The CCAM model simulated total annual rainfall reductions of 5-11% for 2050 across the locations studied (consistent with other model projections). Total annual rainfall reductions tended to be higher in the high-rainfall locations than in the low- or medium-rainfall locations. The highest seasonal rainfall reduction was predicted for April-June, resulting in later sowing opportunities and decreasing expected yields. The impacts of climate change varied depending on

  6. Reduced Urban Heat Island intensity under warmer conditions

    Science.gov (United States)

    Scott, Anna A.; Waugh, Darryn W.; Zaitchik, Ben F.

    2018-06-01

    The Urban Heat Island (UHI), the tendency for urban areas to be hotter than rural regions, represents a significant health concern in summer as urban populations are exposed to elevated temperatures. A number of studies suggest that the UHI increases during warmer conditions, however there has been no investigation of this for a large ensemble of cities. Here we compare urban and rural temperatures in 54 US cities for 2000–2015 and show that the intensity of the Urban Heat Island, measured here as the differences in daily-minimum or daily-maximum temperatures between urban and rural stations or ΔT, in fact tends to decrease with increasing temperature in most cities (38/54). This holds when investigating daily variability, heat extremes, and variability across climate zones and is primarily driven by changes in rural areas. We relate this change to large-scale or synoptic weather conditions, and find that the lowest ΔT nights occur during moist weather conditions. We also find that warming cities have not experienced an increasing Urban Heat Island effect.

  7. Growth-climate relationships across topographic gradients in the northern Great Lakes

    Science.gov (United States)

    Dymond, S.F.; D'Amato, A.W.; Kolka, R.K.; Bolstad, P.V.; Sebestyen, S.D.; Bradford, John B.

    2016-01-01

    Climatic conditions exert important control over the growth, productivity, and distribution of forests, and characterizing these relationships is essential for understanding how forest ecosystems will respond to climate change. We used dendrochronological methods to develop climate–growth relationships for two dominant species, Populus tremuloides (quaking aspen) and Pinus resinosa (red pine), in the upper Great Lakes region to understand how climate and water availability influence annual forest productivity. Trees were sampled along a topographic gradient at the Marcell Experimental Forest (Minnesota, USA) to assess growth response to variations in temperature and different water availability metrics (precipitation, potential evapotranspiration (PET), cumulative moisture index (CMI), and soil water storage). Climatic variables were able to explain 33–58% of the variation in annual growth (as measured by ring-width increment) for quaking aspen and 37–74% of the variation for red pine. Climate–growth relationships were influenced by topography for quaking aspen but not for red pine. Annual ring growth for quaking aspen decreased with June CMI on ridges, decreased with temperature in the November prior to the growing season on sideslopes, and decreased with June PET on toeslopes. Red pine growth increased with increasing July PET across all topographic positions. These results indicate the sensitivity of both quaking aspen and red pine to local climate and show several vulnerabilities of these species to shifts in water supply and temperature because of climate change.

  8. Climate Change Indicators: Health and Society

    Science.gov (United States)

    ... chapter looks at some of the ways that climate change is affecting human health and society, including changes in Lyme disease, West ... health effects. Why does it matter? Changes in climate affect the ... to human health and welfare. Warmer average temperatures will likely lead ...

  9. The time scales of the climate-economy feedback and the climatic cost of growth

    Energy Technology Data Exchange (ETDEWEB)

    Hallegatte, Stephane [CIRED - CNRM, Nogent-sur-Marne (France)

    2005-04-01

    This paper is based on the perception that the inertia of climate and socio-economic systems are key parameters in the climate change issue. In a first part, it develops and implements a new approach based on a simple integrated model with a particular focus on an innovative transient impact and adaptation modelling. In a second part, a climate-economy feedback is defined and characterized. It is found that: (i) it has a 70-year characteristic time, which is long when compared to the system's other time-scales, and it cannot act as a natural damping process of climate change; (ii) mitigation has to be anticipated since the feedback of an emission reduction on the economy is significant only after a 20-year delay and really efficient after a one-century delay; (iii) the IPCC methodology, that neglects the feedback from impacts to emissions, is acceptable up to 2100, whatever is the level of impacts. This analysis allows also to define a climatic cost of growth as the additional climate change damages due to the additional emissions linked to economic growth. Usefully, this metric for climate change damages is particularly independent of the baseline scenario. (orig.)

  10. The time scales of the climate-economy feedback and the climatic cost of growth

    International Nuclear Information System (INIS)

    Hallegatte, Stephane

    2005-04-01

    This paper is based on the perception that the inertia of climate and socio-economic systems are key parameters in the climate change issue. In a first part, it develops and implements a new approach based on a simple integrated model with a particular focus on an innovative transient impact and adaptation modelling. In a second part, a climate-economy feedback is defined and characterized. It is found that: (i) it has a 70-year characteristic time, which is long when compared to the system's other time-scales, and it cannot act as a natural damping process of climate change; (ii) mitigation has to be anticipated since the feedback of an emission reduction on the economy is significant only after a 20-year delay and really efficient after a one-century delay; (iii) the IPCC methodology, that neglects the feedback from impacts to emissions, is acceptable up to 2100, whatever is the level of impacts. This analysis allows also to define a climatic cost of growth as the additional climate change damages due to the additional emissions linked to economic growth. Usefully, this metric for climate change damages is particularly independent of the baseline scenario. (orig.)

  11. Orographic cirrus in a future climate

    Directory of Open Access Journals (Sweden)

    H. Joos

    2009-10-01

    Full Text Available A cloud resolving model (CRM is used to investigate the formation of orographic cirrus clouds in the current and future climate. The formation of cirrus clouds depends on a variety of dynamical and thermodynamical processes, which act on different scales. First, the capability of the CRM in realistically simulating orographic cirrus clouds has been tested by comparing the simulated results to aircraft measurements of an orographic cirrus cloud. The influence of a warmer climate on the microphysical and optical properties of cirrus clouds has been investigated by initializing the CRM with vertical profiles of horizontal wind, potential temperature and equivalent potential temperature, respectively. The vertical profiles are extracted from IPCC A1B simulations for the current climate and for the period 2090–2099 for two regions representative for North and South America. The influence of additional moisture in a future climate on the propagation of gravity waves and the formation of orographic cirrus could be estimated. In a future climate, the increase in moisture dampens the vertical propagation of gravity waves and the occurring vertical velocities in the moist simulations. Together with higher temperatures fewer ice crystals nucleate homogeneously. Assuming that the relative humidity does not change in a warmer climate the specific humidity in the model is increased. This increase in specific humidity in a warmer climate results in a higher ice water content. The net effect of a reduced ice crystal number concentration and a higher ice water content is an increased optical depth. However, in some moist simulations dynamical changes contribute to changes in the ice water content, ice crystal number concentration and optical depth. For the corresponding dry simulations dynamical changes are more pronounced leading to a decreased optical depth in a future climate in some cases.

  12. Scariest thing about climate change: climate flips

    International Nuclear Information System (INIS)

    Beaulieu, P.

    1997-01-01

    The idea that an increase in greenhouse gases will cause the global average temperature to rise slowly over the next decades was discussed. Studies of ice core from Greenland have shown that in the past climate shifts seem to have happened quickly. Some scientists fear that increasingly frequent extreme weather events could be a sign that the climate system is nearing its threshold and a rapid climate flip may be just ahead. In the case of global climatic system, the danger is that stresses from greenhouse gas effects are pushing the present system over the threshold where it must flip into a new warmer system that will be stable, but different from the climate on which our agriculture, economy, settlements and lives depend. 4 refs

  13. Green growth in the post-Copenhagen climate

    International Nuclear Information System (INIS)

    Sterner, Thomas; Damon, Maria

    2011-01-01

    Global climate change stands out from most environmental problems because it will span generations and force us to think in new ways about intergenerational fairness. It involves the delicate problem of complex coordination between countries on a truly global scale. As long as fossil fuels are too cheap, climate change policy will engage all major economies. The costs are high enough to make efficiency a priority, which means striving toward a single market for carbon-plus tackling the thorny issues of fairness. Hopes for a grand deal were mercilessly shattered at Copenhagen in December 2009 and in other recent UNFCCC meetings, with the result that 'green growth' is promoted as an alternative path. Indeed, green growth is clearly the goal, but it is no magic bullet. The world economy will require clear and rather tough policy instruments for growth to be green-and it is naive to think otherwise. Growth, green or not, will boost demand for energy and coal is normally the cheapest source. The magnitude of the challenge is greater if we also consider the problems related to nuclear (fission) energy and, in some instances, to bioenergy (such as its competition for land that may be essential for the poor). This paper discusses some necessary ingredients for a long-term global climate strategy. As we wait for the final (and maybe elusive) worldwide treaty, we must find a policy that makes sense and is not only compatible with, but facilitates the development of such a treaty. - Highlights: → Climate mitigation will be expensive so we must use market based instruments to deal with it efficiently. → All countries need to be involved but many will hesitate. → MBIs require us to deal with problems of fairness in allocation. → Some countries see grandfathering as fair others prefer equal per capita allocation. → Green growth is a necessity but no panacea.

  14. Climate-mediated competition in a high-elevation salamander community

    Science.gov (United States)

    Dallalio, Eric A.; Brand, Adrianne B,; Grant, Evan H. Campbell

    2017-01-01

    The distribution of the federally endangered Shenandoah Salamander (Plethodon shenandoah) is presumed to be limited by competition with the Red-backed Salamander (Plethodon cinereus). In particular, the current distribution of P. shenandoah is understood to be restricted to warmer and drier habitats because of interspecific interactions. These habitats may be particularly sensitive to climate change, though the influence of competition may also be affected by temperature and relative humidity. We investigated the response of P. shenandoah to competition with P. cinereus under four climate scenarios in 3-dimensional mesocosms. The results suggest that, although climate change may alleviate competitive pressure from P. cinereus, warmer temperatures may also significantly influence the persistence of the species across its known range.

  15. Adaptive and plastic responses of Quercus petraea populations to climate across Europe.

    Science.gov (United States)

    Sáenz-Romero, Cuauhtémoc; Lamy, Jean-Baptiste; Ducousso, Alexis; Musch, Brigitte; Ehrenmann, François; Delzon, Sylvain; Cavers, Stephen; Chałupka, Władysław; Dağdaş, Said; Hansen, Jon Kehlet; Lee, Steve J; Liesebach, Mirko; Rau, Hans-Martin; Psomas, Achilleas; Schneck, Volker; Steiner, Wilfried; Zimmermann, Niklaus E; Kremer, Antoine

    2017-07-01

    How temperate forests will respond to climate change is uncertain; projections range from severe decline to increased growth. We conducted field tests of sessile oak (Quercus petraea), a widespread keystone European forest tree species, including more than 150 000 trees sourced from 116 geographically diverse populations. The tests were planted on 23 field sites in six European countries, in order to expose them to a wide range of climates, including sites reflecting future warmer and drier climates. By assessing tree height and survival, our objectives were twofold: (i) to identify the source of differential population responses to climate (genetic differentiation due to past divergent climatic selection vs. plastic responses to ongoing climate change) and (ii) to explore which climatic variables (temperature or precipitation) trigger the population responses. Tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071-2100, using two greenhouse gas concentration trajectory scenarios each. Overall, results indicated a moderate response of tree height and survival to climate variation, with changes in dryness (either annual or during the growing season) explaining the major part of the response. While, on average, populations exhibited local adaptation, there was significant clinal population differentiation for height growth with winter temperature at the site of origin. The most moderate climate model (HIRHAM5-EC; rcp4.5) predicted minor decreases in height and survival, while the most extreme model (CCLM4-GEM2-ES; rcp8.5) predicted large decreases in survival and growth for southern and southeastern edge populations (Hungary and Turkey). Other nonmarginal populations with continental climates were predicted to be severely and negatively affected (Bercé, France), while populations at the contemporary northern limit (colder and humid maritime regions; Denmark and Norway) will

  16. Arctic Climate and Climate Change with a Focus on Greenland

    DEFF Research Database (Denmark)

    Stendel, Martin; Christensen, Jens Hesselbjerg; Petersen, Dorthe

    2008-01-01

    Paleoclimatic evidence suggests that the Arctic presently is warmer than during the last 125,000 years, and it is very likely11The term "likelihood" is used here as in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4). According to the definition in this rep...... Ice Sheet, the fate of arctic sea ice and a possible weakening of the thermohaline circulation (THC) under future warming conditions have led to increased research activities, including an assessment of arctic climate and climate change (ACIA, 2005), the fourth assessment report (AR4...

  17. Parthenium weed (Parthenium hysterophorus L.) and climate change: the effect of CO2 concentration, temperature, and water deficit on growth and reproduction of two biotypes.

    Science.gov (United States)

    Nguyen, Thi; Bajwa, Ali Ahsan; Navie, Sheldon; O'Donnell, Chris; Adkins, Steve

    2017-04-01

    Climate change will have a considerable impact upon the processes that moderate weed invasion, in particular to that of parthenium weed (Parthenium hysterophorus L.). This study evaluated the performance of two Australian biotypes of parthenium weed under a range of environmental conditions including soil moisture (100 and 50% of field capacity), atmospheric carbon dioxide (CO 2 ) concentration (390 and 550 ppm), and temperature (35/20 and 30/15 °C/day/night). Measurements were taken upon growth, reproductive output, seed biology (fill, viability and dormancy) and soil seed longevity. Parthenium weed growth and seed output were significantly increased under the elevated CO 2 concentration (550 ppm) and in the cooler (30/15 °C) and wetter (field capacity) conditions. However, elevated CO 2 concentration could not promote growth or seed output when the plants were grown under the warmer (35/20 °C) and wetter conditions. Warm temperatures accelerated the growth of parthenium weed, producing plants with greater height biomass but with a shorter life span. Warm temperatures also affected the reproductive output by promoting both seed production and fill, and promoting seed longevity. Dryer soil conditions (50% of field capacity) also promoted the reproductive output, but did not retain high seed fill or promote seed longevity. Therefore, the rising temperatures, the increased atmospheric CO 2 concentration and the longer periods of drought predicted under climate change scenarios are likely to substantially enhance the growth and reproductive output of these two Australian parthenium weed biotypes. This may facilitate the further invasion of this noxious weed in tropical and sub-tropical natural and agro-ecosystems.

  18. Precipitation variability increases in a warmer climate.

    Science.gov (United States)

    Pendergrass, Angeline G; Knutti, Reto; Lehner, Flavio; Deser, Clara; Sanderson, Benjamin M

    2017-12-21

    Understanding changes in precipitation variability is essential for a complete explanation of the hydrologic cycle's response to warming and its impacts. While changes in mean and extreme precipitation have been studied intensively, precipitation variability has received less attention, despite its theoretical and practical importance. Here, we show that precipitation variability in most climate models increases over a majority of global land area in response to warming (66% of land has a robust increase in variability of seasonal-mean precipitation). Comparing recent decades to RCP8.5 projections for the end of the 21 st century, we find that in the global, multi-model mean, precipitation variability increases 3-4% K -1 globally, 4-5% K -1 over land and 2-4% K -1 over ocean, and is remarkably robust on a range of timescales from daily to decadal. Precipitation variability increases by at least as much as mean precipitation and less than moisture and extreme precipitation for most models, regions, and timescales. We interpret this as being related to an increase in moisture which is partially mitigated by weakening circulation. We show that changes in observed daily variability in station data are consistent with increased variability.

  19. Phenological cues drive an apparent trade-off between freezing tolerance and growth in the family Salicaceae.

    Science.gov (United States)

    Savage, Jessica A; Cavender-Bares, Jeannine

    2013-08-01

    With increasing concern about the ecological consequences of global climate change, there has been renewed interest in understanding the processes that determine species range limits. We tested a long-hypothesized trade-off between freezing tolerance and growth rate that is often used to explain species range limits. We grew 24 willow and poplar species (family Salicaceae) collected from across North America in a greenhouse common garden under two climate treatments. Maximum entropy models were used to describe species distributions and to estimate species-specific climate parameters. A range of traits related to freezing tolerance, including senescence, budburst, and susceptibility to different temperature minima during and after acclimation were measured. As predicted, species from colder climates exhibited higher freezing tolerance and slower growth rates than species from warmer climates under certain environmental conditions. However, the average relative growth rate (millimeters per meter per day) of northern species markedly increased when a subset of species was grown under a long summer day length (20.5 h), indicating that genetically based day-length cues are required for growth regulation in these species. We conclude that the observed relationship between freezing tolerance and growth rate is not driven by differences in species' intrinsic growth capacity but by differences in the environmental cues that trigger growth. We propose that the coordinated evolution of freezing tolerance and growth phenology could be important in circumscribing willow and poplar range limits and may have important implications for species' current and future distributions.

  20. 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.

  1. Extreme weather events in Iran under a changing climate

    Science.gov (United States)

    Alizadeh-Choobari, Omid; Najafi, M. S.

    2018-01-01

    Observations unequivocally show that Iran has been rapidly warming over recent decades, which in sequence has triggered a wide range of climatic impacts. Meteorological records of several ground stations across Iran with daily temporal resolution for the period 1951-2013 were analyzed to investigate the climate change and its impact on some weather extremes. Iran has warmed by nearly 1.3 °C during the period 1951-2013 (+0.2 °C per decade), with an increase of the minimum temperature at a rate two times that of the maximum. Consequently, an increase in the frequency of heat extremes and a decrease in the frequency of cold extremes have been observed. The annual precipitation has decreased by 8 mm per decade, causing an expansion of Iran's dry zones. Previous studies have pointed out that warming is generally associated with more frequent heavy precipitation because a warmer air can hold more moisture. Nevertheless, warming in Iran has been associated with more frequent light precipitation, but less frequent moderate, heavy and extremely heavy precipitation. This is because in the subtropical dry zones, a longer time is required to recharge the atmosphere with water vapour in a warmer climate, causing more water vapour to be transported from the subtropics to high latitudes before precipitations forms. In addition, the altitude of the condensation level increases in a warmer climate in subtropical regions, causing an overall decrease of precipitation. We argue that changing in the frequency of heavy precipitation in response to warming varies depending on the geographical location. Warming over the dry subtropical regions is associated with a decrease in the frequency of heavy precipitation, while an increase is expected over both subpolar and tropical regions. The warmer climate has also led to the increase in the frequency of both thunderstorms (driven by convective heating) and dust events over Iran.

  2. Quantifying climate-growth relationships at the stand level in a mature mixed-species conifer forest.

    Science.gov (United States)

    Teets, Aaron; Fraver, Shawn; Weiskittel, Aaron R; Hollinger, David Y

    2018-03-11

    A range of environmental factors regulate tree growth; however, climate is generally thought to most strongly influence year-to-year variability in growth. Numerous dendrochronological (tree-ring) studies have identified climate factors that influence year-to-year variability in growth for given tree species and location. However, traditional dendrochronology methods have limitations that prevent them from adequately assessing stand-level (as opposed to species-level) growth. We argue that stand-level growth analyses provide a more meaningful assessment of forest response to climate fluctuations, as well as the management options that may be employed to sustain forest productivity. Working in a mature, mixed-species stand at the Howland Research Forest of central Maine, USA, we used two alternatives to traditional dendrochronological analyses by (1) selecting trees for coring using a stratified (by size and species), random sampling method that ensures a representative sample of the stand, and (2) converting ring widths to biomass increments, which once summed, produced a representation of stand-level growth, while maintaining species identities or canopy position if needed. We then tested the relative influence of seasonal climate variables on year-to-year variability in the biomass increment using generalized least squares regression, while accounting for temporal autocorrelation. Our results indicate that stand-level growth responded most strongly to previous summer and current spring climate variables, resulting from a combination of individualistic climate responses occurring at the species- and canopy-position level. Our climate models were better fit to stand-level biomass increment than to species-level or canopy-position summaries. The relative growth responses (i.e., percent change) predicted from the most influential climate variables indicate stand-level growth varies less from to year-to-year than species-level or canopy-position growth responses. By

  3. Climate Change and Flood Operations in the Sacramento Basin, California

    Directory of Open Access Journals (Sweden)

    Ann D. Willis

    2011-07-01

    Full Text Available Ann D. Willis, Jay R. Lund, Edwin S. Townsley, and Beth A. Faberdoi: http://dx.doi.org/10.15447/sfews.2014v9iss2art3Climate warming is likely to challenge many current conceptions and regulatory policies, particularly for water management. A warmer climate is likely to hinder flood operations in California’s Sacramento Valley by decreasing snowpack storage and increasing the rain fraction of major storms. This work examines how a warmer climate would change flood peaks and volumes for nine major historical floods entering Shasta, Oroville, and New Bullards Bar reservoirs, using current flood flow forecast models and current flood operating rules. Shasta and Oroville have dynamic flood operation curves that accommodate many climate-warming scenarios. New Bullards Bar’s more static operating rule performs poorly for these conditions. Revisiting flood operating rules is an important adaptation for climate warming.

  4. Environmental effects on growth phenology of co-occurring Eucalyptus species.

    Science.gov (United States)

    Rawal, Deepa S; Kasel, Sabine; Keatley, Marie R; Aponte, Cristina; Nitschke, Craig R

    2014-05-01

    Growth is one of the most important phenological cycles in a plant's life. Higher growth rates increase the competitive ability, survival and recruitment and can provide a measure of a plant's adaptive capacity to climate variability and change. This study identified the growth relationship of six Eucalyptus species to variations in temperature, soil moisture availability, photoperiod length and air humidity over 12 months. The six species represent two naturally co-occurring groups of three species each representing warm-dry and the cool-moist sclerophyll forests, respectively. Warm-dry eucalypts were found to be more tolerant of higher temperatures and lower air humidity than the cool-moist eucalypts. Within groups, species-specific responses were detected with Eucalyptus microcarpa having the widest phenological niche of the warm-dry species, exhibiting greater resistance to high temperature and lower air humidity. Temperature dependent photoperiodic responses were exhibited by all the species except Eucalyptus tricarpa and Eucalyptus sieberi, which were able to maintain growth as photoperiod shortened but temperature requirements were fulfilled. Eucalyptus obliqua exhibited a flexible growth rate and tolerance to moisture limitation which enables it to maintain its growth rate as water availability changes. The wider temperature niche exhibited by E. sieberi compared with E. obliqua and Eucalyptus radiata may improve its competitive ability over these species where winters are warm and moisture does not limit growth. With climate change expected to result in warmer and drier conditions in south-east Australia, the findings of this study suggest all cool-moist species will likely suffer negative effects on growth while the warm-dry species may still maintain current growth rates. Our findings highlight that climate driven shifts in growth phenology will likely occur as climate changes and this may facilitate changes in tree communities by altering inter

  5. Relationships between climate and growth of Gymnocypris selincuoensis in the Tibetan Plateau.

    Science.gov (United States)

    Tao, Juan; Chen, Yifeng; He, Dekui; Ding, Chengzhi

    2015-04-01

    The consequences of climate change are becoming increasingly evident in the Tibetan Plateau, represented by glaciers retreating and lakes expanding, but the biological response to climate change by plateau-lake ecosystems is poorly known. In this study, we applied dendrochronology methods to develop a growth index chronology with otolith increment widths of Selincuo naked carp (Gymnocypris selincuoensis), which is an endemic species in Lake Selincuo (4530 m), and investigated the relationships between fish growth and climate variables (regional and global) in the last three decades. A correlation analysis and principle component regression analysis between regional climate factors and the growth index chronology indicated that the growth of G. selincuoensis was significantly and positively correlated with length of the growing season and temperature-related variables, particularly during the growing season. Most of global climate variables, which are relevant to the Asian monsoon and the midlatitude westerlies, such as El Nino Southern Oscillation Index, the Arctic Oscillation, North Atlantic Oscillation, and North America Pattern, showed negative but not significant correlations with the annual growth of Selincuo naked carp. This may have resulted from the high elevation of the Tibetan Plateau and the high mountains surrounding this area. In comparison, the Pacific Decade Oscillation (PDO) negatively affected the growth of G. selincuoensis. The reason maybe that enhancement of the PDO can lead to cold conditions in this area. Taken together, the results indicate that the Tibetan Plateau fish has been affected by global climate change, particularly during the growing season, and global climate change likely has important effects on productivity of aquatic ecosystems in this area.

  6. A warmer policy for a colder climate: Can China both reduce poverty and cap carbon emissions?

    International Nuclear Information System (INIS)

    Glomsrød, Solveig; Wei, Taoyuan; Aamaas, Borgar; Lund, Marianne T.; Samset, Bjørn H.

    2016-01-01

    Reducing global carbon dioxide (CO_2) emissions is often thought to be at odds with economic growth and poverty reduction. Using an integrated assessment modeling approach, we find that China can cap CO_2 emissions at 2015 level while sustaining economic growth and reducing the urban-rural income gap by a third by 2030. As a result, the Chinese economy becomes less dependent on exports and investments, as household consumption emerges as a driver behind economic growth, in line with current policy priorities. The resulting accumulated greenhouse gas emissions reduction 2016–2030 is about 60 billion ton (60 Mg) CO_2e. A CO_2 tax combined with income re-distribution initially leads to a modest warming due to reduction in sulfur dioxide (SO_2) emissions. However, the net effect is eventually cooling when the effect of reduced CO_2 emissions dominates due to the long-lasting climate response of CO_2. The net reduction in global temperature for the remaining part of this century is about 0.03 ± 0.02 °C, corresponding in magnitude to the cooling from avoiding one year of global CO_2 emissions. - Highlights: • China can cap CO_2-emissions at 2015 level without harming economic growth. • Poverty reduction is compatible with policy to cap CO_2 emissions. • Rural poverty reduction financed by CO_2 tax revenue increases domestic consumption. • One year of the global emissions is avoided. • The global mean temperature is reduced by 0.03 (± 0.02) °C.

  7. Climate-growth relationships of Abies spectabilis in a central Himalayan treeline ecotone

    Science.gov (United States)

    Schwab, Niels; Kaczka, Ryszard J.; Schickhoff, Udo

    2017-04-01

    Climate warming is expected to induce treelines to advance to higher elevations. Empirical studies in diverse mountain ranges, however, give evidence of both advancing alpine treelines as well as rather insignificant responses. The large spectrum of responses is not fully understood. In the framework of investigating the sensitivity and response of a near-natural treeline ecotone in Rolwaling Himal, Nepal, to climate warming we present results from dendroclimatological analyses of Abies spectabilis (Himalayan Fir) increment cores. Tree ring width was measured and cross-dated. After standardization, the chronology was correlated with temperature and precipitation variables. Preliminary results point to positive correlations with autumn temperature and precipitation. We will present improved climate-growth relationships. The resulting climate - tree growth relationships may be used as an indication of future growth patterns and treeline dynamics under climate change conditions.

  8. Projections of European summer tourism demand at a +2 degrees warmer climate.

    Science.gov (United States)

    Grillakis, Manolis; Koutroulis, Aristeidis; Tsanis, Ioannis; Jacob, Daniela

    2015-04-01

    Tourism is a billion euros industry for Europe and especially for the southern countries for which summer tourism is an important contribution to their GDP. It is highly dependent on the climate and any future changes will alter the favorability of European destinations. The impact of a potential global temperature increase of 1.5 and 2 degrees on European tourism was investigated in the frame of IMPACT2C FP7 project. Climate information from four ENSEMBLES and five Euro-CORDEX RCMs were used to estimate the Tourism Climatic Index (TCI) under the A1B, RCP4.5 and RCP8.5 scenarios. The monthly averages of the historical TCI estimates were correlated to the recorded monthly averages of overnight stays for all considered NUTS3 regions in Europe. The correlation proved to be significantly high for the majority of these regions with higher values for the European South, while the lowest correlation was attained for Sweden Denmark and Austria. The correlation estimates was then used to provide information about the change in tourism activity due to changes in the future climate favorability through the TCI. The results show that for the May to October "summer tourism" season, and under +1.5 and +2 degrees climate the potential overnight stays are projected to increase in average in almost the entire European domain, except Cyprus which exhibits a consistent decrease, robust across all scenarios. In contrast, for the peak of the summer season between June and August, it is projected that the European south will potentially exhibit decrease in the overnight stays to as high as 20% and for some cases to even higher than 30% (Greece). Key strength of the results are the correlation of measured tourism indicators to a conceptual index, which gives the ability to quantify the change in the tourism indicator, rather than investigating the coarser concept of climate risk.

  9. Wild Apple Growth and Climate Change in Southeast Kazakhstan

    Directory of Open Access Journals (Sweden)

    Irina P. Panyushkina

    2017-10-01

    Full Text Available Wild populations of Malus sieversii [Ldb.] M. Roem are valued genetic and watershed resources in Inner Eurasia. These populations are located in a region that has experienced rapid and on-going climatic change over the past several decades. We assess relationships between climate variables and wild apple radial growth with dendroclimatological techniques to understand the potential of a changing climate to influence apple radial growth. Ring-width chronologies spanning 48 to 129 years were developed from 12 plots in the Trans-Ili Alatau and Jungar Alatau ranges of Tian Shan Mountains, southeastern Kazakhstan. Cluster analysis of the plot-level chronologies suggests different temporal patterns of growth variability over the last century in the two mountain ranges studied. Changes in the periodicity of annual ring-width variability occurred ca. 1970 at both mountain ranges, with decadal-scale variability supplanted by quasi-biennial variation. Seascorr correlation analysis of primary and secondary weather variables identified negative growth associations with spring precipitation and positive associations with cooler fall-winter temperatures, but the relative importance of these relationships varied spatially and temporally, with a shift in the relative importance of spring precipitation ca. 1970 at Trans-Ili Alatau. Altered apple tree radial growth patterns correspond to altered climatology in the Lake Balkhash Basin driven by unprecedented intensified Arctic Oscillations after the late 1970s.

  10. 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

  11. A Novel Modelling Approach for Predicting Forest Growth and Yield under Climate Change.

    Directory of Open Access Journals (Sweden)

    M Irfan Ashraf

    Full Text Available Global climate is changing due to increasing anthropogenic emissions of greenhouse gases. Forest managers need growth and yield models that can be used to predict future forest dynamics during the transition period of present-day forests under a changing climatic regime. In this study, we developed a forest growth and yield model that can be used to predict individual-tree growth under current and projected future climatic conditions. The model was constructed by integrating historical tree growth records with predictions from an ecological process-based model using neural networks. The new model predicts basal area (BA and volume growth for individual trees in pure or mixed species forests. For model development, tree-growth data under current climatic conditions were obtained using over 3000 permanent sample plots from the Province of Nova Scotia, Canada. Data to reflect tree growth under a changing climatic regime were projected with JABOWA-3 (an ecological process-based model. Model validation with designated data produced model efficiencies of 0.82 and 0.89 in predicting individual-tree BA and volume growth. Model efficiency is a relative index of model performance, where 1 indicates an ideal fit, while values lower than zero means the predictions are no better than the average of the observations. Overall mean prediction error (BIAS of basal area and volume growth predictions was nominal (i.e., for BA: -0.0177 cm(2 5-year(-1 and volume: 0.0008 m(3 5-year(-1. Model variability described by root mean squared error (RMSE in basal area prediction was 40.53 cm(2 5-year(-1 and 0.0393 m(3 5-year(-1 in volume prediction. The new modelling approach has potential to reduce uncertainties in growth and yield predictions under different climate change scenarios. This novel approach provides an avenue for forest managers to generate required information for the management of forests in transitional periods of climate change. Artificial intelligence

  12. The last interglacial climate

    DEFF Research Database (Denmark)

    Pedersen, Rasmus A.; Langen, Peter L.; Vinther, Bo M.

    2017-01-01

    The last interglacial climate was influenced by substantial changes in the annual insolation cycle that led to a warmer climate state with pronounced high northern latitude warming. We analyze the impact of the insolation changes 125,000 years before present using an equilibrium snapshot simulation...... with the EC-Earth coupled climate model at high spatial resolution. Using additional atmosphere-only simulations, we separate the direct impact from the changed insolation from the secondary contribution from changed sea surface conditions. These simulations are forced with a combination of last interglacial...

  13. Global warming: Climate scenarios and international agriculture

    International Nuclear Information System (INIS)

    Downing, T.E.; Parry, M.L.

    1991-01-01

    The potential impacts of climatic change on international agriculture are summarized, drawing on results from the Intergovernmental Panel on Climate Change impacts working group. The four different climate change scenarios used for investigating impacts: historical studies, artificial scenarios, analogues, and general circulation models, are briefly reviewed. Climate change will affect agriculture in three ways: direct effects of increased carbon dioxide concentration, effects of altered weather patterns, and secondary effects on social and economic situations. The effect of increased carbon dioxide concentration is uncertain, but potentially will enhance plant growth and water use efficiency. The sensitivity of grain maize to incremental changes in annual temperature is described, with the suitable zone expanding from the middle of Europe to southern Scandinavia. Potential damage from insect pests may increase under warmer climates, with northerly movement of insect breeding grounds. Temperature increases are likely to lengthen the growing season where temperature is a limiting factor, especially at higher lattitudes in the Northern Hemisphere. Higher temperatures, shorter periods of grain filling, and reduced winter chilling will reduce potential yields in current core grain-growing areas, and changing moisture regimes will shift agricultural patterns. The horn of Africa and parts of western Africa are likely to suffer enhanced food supply vulnerability. 16 refs., 4 figs

  14. A warmer policy for a colder climate: Can China both reduce poverty and cap carbon emissions?

    Energy Technology Data Exchange (ETDEWEB)

    Glomsrød, Solveig; Wei, Taoyuan, E-mail: taoyuan.wei@cicero.uio.no; Aamaas, Borgar; Lund, Marianne T.; Samset, Bjørn H.

    2016-10-15

    Reducing global carbon dioxide (CO{sub 2}) emissions is often thought to be at odds with economic growth and poverty reduction. Using an integrated assessment modeling approach, we find that China can cap CO{sub 2} emissions at 2015 level while sustaining economic growth and reducing the urban-rural income gap by a third by 2030. As a result, the Chinese economy becomes less dependent on exports and investments, as household consumption emerges as a driver behind economic growth, in line with current policy priorities. The resulting accumulated greenhouse gas emissions reduction 2016–2030 is about 60 billion ton (60 Mg) CO{sub 2}e. A CO{sub 2} tax combined with income re-distribution initially leads to a modest warming due to reduction in sulfur dioxide (SO{sub 2}) emissions. However, the net effect is eventually cooling when the effect of reduced CO{sub 2} emissions dominates due to the long-lasting climate response of CO{sub 2}. The net reduction in global temperature for the remaining part of this century is about 0.03 ± 0.02 °C, corresponding in magnitude to the cooling from avoiding one year of global CO{sub 2} emissions. - Highlights: • China can cap CO{sub 2}-emissions at 2015 level without harming economic growth. • Poverty reduction is compatible with policy to cap CO{sub 2} emissions. • Rural poverty reduction financed by CO{sub 2} tax revenue increases domestic consumption. • One year of the global emissions is avoided. • The global mean temperature is reduced by 0.03 (± 0.02) °C.

  15. Growth and reproduction respond differently to climate in three Neotropical tree species.

    Science.gov (United States)

    Alfaro-Sánchez, Raquel; Muller-Landau, Helene C; Wright, S Joseph; Camarero, J Julio

    2017-06-01

    The response of tropical forests to anthropogenic climate change is critically important to future global carbon budgets, yet remains highly uncertain. Here, we investigate how precipitation, temperature, solar radiation and dry- and wet-season lengths are related to annual tree growth, flower production, and fruit production in three moist tropical forest tree species using long-term datasets from tree rings and litter traps in central Panama. We also evaluated how growth, flower, and fruit production were interrelated. We found that growth was positively correlated with wet-season precipitation in all three species: Jacaranda copaia (r = 0.63), Tetragastris panamensis (r = 0.39) and Trichilia tuberculata (r = 0.39). Flowering and fruiting in Jacaranda were negatively related to current-year dry-season rainfall and positively related to prior-year dry-season rainfall. Flowering in Tetragastris was negatively related to current-year annual mean temperature while Trichilia showed no significant relationships of reproduction with climate. Growth was significantly related to reproduction only in Tetragastris, where it was positively related to previous year fruiting. Our results suggest that tree growth in moist tropical forest tree species is generally reduced by drought events such as those associated with strong El Niño events. In contrast, interannual variation in reproduction is not generally associated with growth and has distinct and species-specific climate responses, with positive effects of El Niño events in some species. Understanding these contrasting climate effects on tree growth and reproduction is critical to predicting changes in tropical forest dynamics and species composition under climate change.

  16. Elevated CO2, warmer temperatures and soil water deficit affect plant growth, physiology and water use of cotton (Gossypium hirsutum L.)

    Science.gov (United States)

    Changes in temperature, atmospheric [CO2] and precipitation under the scenarios of projected climate change present a challenge to crop production, and may have significant impacts on the physiology, growth and yield of cotton (Gossypium hirsutum L.). A glasshouse experiment explored the early growt...

  17. Climate-change adaptation on rangelands: Linking regional exposure with diverse adaptive capacity

    Science.gov (United States)

    David D. Briske; Linda A. Joyce; H. Wayne Polley; Joel R. Brown; Klaus Wolter; Jack A. Morgan; Bruce A. McCarl; Derek W. Bailey

    2015-01-01

    The ecological consequences of climate change are predicted to vary greatly throughout US rangelands. Projections show warming and drying in the southern Great Plains and the Southwest, warmer and drier summers with reduced winter snowpack in the Northwest, and warmer and wetter conditions in the northern Great Plains. Primarily through their combined effects on soil...

  18. Darcy’s law predicts widespread forest mortality under climate warming

    Science.gov (United States)

    McDowell, Nate G.; Allen, Craig D.

    2015-01-01

    Drought and heat-induced tree mortality is accelerating in many forest biomes as a consequence of a warming climate, resulting in a threat to global forests unlike any in recorded history. Forests store the majority of terrestrial carbon, thus their loss may have significant and sustained impacts on the global carbon cycle. We use a hydraulic corollary to Darcy’s law, a core principle of vascular plant physiology, to predict characteristics of plants that will survive and die during drought under warmer future climates. Plants that are tall with isohydric stomatal regulation, low hydraulic conductance, and high leaf area are most likely to die from future drought stress. Thus, tall trees of old-growth forests are at the greatest risk of loss, which has ominous implications for terrestrial carbon storage. This application of Darcy’s law indicates today’s forests generally should be replaced by shorter and more xeric plants, owing to future warmer droughts and associated wildfires and pest attacks. The Darcy’s corollary also provides a simple, robust framework for informing forest management interventions needed to promote the survival of current forests. Given the robustness of Darcy’s law for predictions of vascular plant function, we conclude with high certainty that today’s forests are going to be subject to continued increases in mortality rates that will result in substantial reorganization of their structure and carbon storage.

  19. Climate Response of Tree Radial Growth at Different Timescales in the Qinling Mountains.

    Directory of Open Access Journals (Sweden)

    Changfeng Sun

    Full Text Available The analysis of the tree radial growth response to climate is crucial for dendroclimatological research. However, the response relationships between tree-ring indices and climatic factors at different timescales are not yet clear. In this study, the tree-ring width of Huashan pine (Pinus armandii from Huashan in the Qinling Mountains, north-central China, was used to explore the response differences of tree growth to climatic factors at daily, pentad (5 days, dekad (10 days and monthly timescales. Correlation function and linear regression analysis were applied in this paper. The tree-ring width showed a more sensitive response to daily and pentad climatic factors. With the timescale decreasing, the absolute value of the maximum correlation coefficient between the tree-ring data and precipitation increases as well as temperature (mean, minimum and maximum temperature. Compared to the other three timescales, pentad was more suitable for analysing the response of tree growth to climate. Relative to the monthly climate data, the association between the tree-ring data and the pentad climate data was more remarkable and accurate, and the reconstruction function based on the pentad climate was also more reliable and stable. We found that the major climatic factor limiting Huashan pine growth was the precipitation of pentads 20-35 (from April 6 to June 24 rather than the well-known April-June precipitation. The pentad was also proved to be a better timescale for analysing the climate and tree growth in the western and eastern Qinling Mountains. The formation of the earlywood density of Chinese pine (Pinus tabulaeformis from Shimenshan in western Qinling was mainly affected by the maximum temperature of pentads 28-32 (from May 16 to June 9. The maximum temperature of pentads 28-33 (from May 16 to June 14 was the major factor affecting the ring width of Chinese pine from Shirenshan in eastern Qinling.

  20. Wild apple growth and climate change in southeast Kazakhstan

    Science.gov (United States)

    Irina P. Panyushkina; Nurjan S. Mukhamadiev; Ann M. Lynch; Nursagim A. Ashikbaev; Alexis H. Arizpe; Christopher D. O' Connor; Danyar Abjanbaev; Gulnaz Z. Mengdbayeva; Abay O. Sagitov

    2017-01-01

    Wild populations of Malus sieversii [Ldb.] M. Roem are valued genetic and watershed resources in Inner Eurasia. These populations are located in a region that has experienced rapid and on-going climatic change over the past several decades. We assess relationships between climate variables and wild apple radial growth with dendroclimatological techniques to understand...

  1. Climate change in the Netherlands : Challenges for a safe and attractive urban environment

    NARCIS (Netherlands)

    Döpp, S.P.; Bosch, P.R.; Deelen, C.L. van

    2009-01-01

    Climate change in cities has so far been underexposed in Dutch research on climate change adaptation. High population density and high economic values make Dutch urban areas nevertheless vulnerable to climate change. Even with stringent mitigation policies Dutch cities will be subject to warmer

  2. Both life-history plasticity and local adaptation will shape range-wide responses to climate warming in the tundra plant Silene acaulis.

    Science.gov (United States)

    Peterson, Megan L; Doak, Daniel F; Morris, William F

    2018-04-01

    Many predictions of how climate change will impact biodiversity have focused on range shifts using species-wide climate tolerances, an approach that ignores the demographic mechanisms that enable species to attain broad geographic distributions. But these mechanisms matter, as responses to climate change could fundamentally differ depending on the contributions of life-history plasticity vs. local adaptation to species-wide climate tolerances. In particular, if local adaptation to climate is strong, populations across a species' range-not only those at the trailing range edge-could decline sharply with global climate change. Indeed, faster rates of climate change in many high latitude regions could combine with local adaptation to generate sharper declines well away from trailing edges. Combining 15 years of demographic data from field populations across North America with growth chamber warming experiments, we show that growth and survival in a widespread tundra plant show compensatory responses to warming throughout the species' latitudinal range, buffering overall performance across a range of temperatures. However, populations also differ in their temperature responses, consistent with adaptation to local climate, especially growing season temperature. In particular, warming begins to negatively impact plant growth at cooler temperatures for plants from colder, northern populations than for those from warmer, southern populations, both in the field and in growth chambers. Furthermore, the individuals and maternal families with the fastest growth also have the lowest water use efficiency at all temperatures, suggesting that a trade-off between growth and water use efficiency could further constrain responses to forecasted warming and drying. Taken together, these results suggest that populations throughout species' ranges could be at risk of decline with continued climate change, and that the focus on trailing edge populations risks overlooking the largest

  3. Mixed precipitation occurrences over southern Québec, Canada, under warmer climate conditions using a regional climate model

    Science.gov (United States)

    Matte, Dominic; Thériault, Julie M.; Laprise, René

    2018-05-01

    Winter weather events with temperatures near 0°C are often associated with freezing rain. They can have major impacts on the society by causing power outages and disruptions to the transportation networks. Despite the catastrophic consequences of freezing rain, very few studies have investigated how their occurrences could evolve under climate change. This study aims to investigate the change of freezing rain and ice pellets over southern Québec using regional climate modeling at high resolution. The fifth-generation Canadian Regional Climate Model with climate scenario RCP 8.5 at 0.11° grid mesh was used. The precipitation types such as freezing rain, ice pellets or their combination are diagnosed using five methods (Cantin and Bachand, Bourgouin, Ramer, Czys and, Baldwin). The occurrences of the diagnosed precipitation types for the recent past (1980-2009) are found to be comparable to observations. The projections for the future scenario (2070-2099) suggested a general decrease in the occurrences of mixed precipitation over southern Québec from October to April. This is mainly due to a decrease in long-duration events (≥6 h ). Overall, this study contributes to better understand how the distribution of freezing rain and ice pellets might change in the future using high-resolution regional climate model.

  4. Araucaria growth response to solar and climate variability in South Brazil

    Science.gov (United States)

    Prestes, Alan; Klausner, Virginia; Rojahn da Silva, Iuri; Ojeda-González, Arian; Lorensi, Caren

    2018-05-01

    In this work, the Sun-Earth-climate relationship is studied using tree growth rings of Araucaria angustifolia (Bertol.) O. Kuntze collected in the city of Passo Fundo, located in the state of Rio Grande do Sul (RS), Brazil. These samples were previously studied by Rigozo et al. (2008); however, their main interest was to search for the solar periodicities in the tree-ring width mean time series without interpreting the rest of the periodicities found. The question arises as to what are the drivers related to those periodicities. For this reason, the classical method of spectral analysis by iterative regression and wavelet methods are applied to find periodicities and trends present in each tree-ring growth, in Southern Oscillation Index (SOI), and in annual mean temperature anomaly between the 24 and 44° S. In order to address the aforementioned question, this paper discusses the correlation between the growth rate of the tree rings with temperature and SOI. In each tree-ring growth series, periods between 2 and 7 years were found, possibly related to the El Niño/La Niña phenomena, and a ˜ 23-year period was found, which may be related to temperature variation. These novel results might represent the tree-ring growth response to local climate conditions during its lifetime, and to nonlinear coupling between the Sun and the local climate variability responsible to the regional climate variations.

  5. Quantifying impacts of historical climate change in American River basin

    Science.gov (United States)

    Sultana, R.

    2017-12-01

    There is a near consensus among scientists that climate has been changing for the last few decades in different parts of the world. Some regions are already experiencing the impacts of these changes. Warmer climate can alter the hydrology and water resources around the globe. Historical data shows the temperature has been rising in California and affecting California's water resource by reducing snowfall and snowmelt runoff during spring season. In this study, Soil and Water Assessment Tool (SWAT) model is used to simulate the historical climate in American River basin, a mountainous watershed in California. The results show that warmer climate in the recent decades (1995-2014) have already have affected streamflow characteristics of the watershed. Compared to the 1965-1974, the mean annual streamflow has decreased more than 6% and the peak streamflow has shifted from May to April. Understanding the changes will assist the water resource managers with valuable insight on the effectiveness of mitigation strategies considered as of now.

  6. The importance of mixed-phase clouds for climate sensitivity in the global aerosol-climate model ECHAM6-HAM2

    OpenAIRE

    Lohmann, Ulrike; Neubauer, David

    2018-01-01

    Clouds are important in the climate system because of their large influence on the radiation budget. On the one hand, they scatter solar radiation and with that cool the climate. On the other hand, they absorb and re-emit terrestrial radiation, which causes a warming. How clouds change in a warmer climate is one of the largest uncertainties for the equilibrium climate sensitivity (ECS). While a large spread in the cloud feedback arises from low-level clouds, it was recently shown that also mi...

  7. The Future of Tourism: Can Tourism Growth and Climate Policy be Reconciled? A Climate Change Mitigation Perspective

    NARCIS (Netherlands)

    Gössling, S.; Hall, C.M.; Peeters, P.M.; Scott, D.

    2010-01-01

    Tourism is an increasingly significant contributor to greenhouse gas (GHG) emissions. Emissions growth in the sector is in substantial conflict with global climate policy goals that seek to mitigate climate change through deep emission reductions. This article discusses the role of various tourism

  8. Possible changes in climate constraints and consequences on tree growth

    International Nuclear Information System (INIS)

    Breda, Nathalie; Granier, Andre; Aussenac, Gilbert

    2000-01-01

    The probable consequences of changes in the major climate variables (rainfall, temperature, potential evapotranspiration) on growth and die back of forest trees are analysed for the range of variations forecasted by global climate change models. The sensitivity of phenology (temperature effects) and levels of water constraints during the growing season (change in rainfall and potential evapotranspiration) are developed. On the basis of the relations established by a retrospective dendro-climatological approach between radial increment and climate, the consequences of climate variations on the radial increment of beech and on oak mortality are discussed. (authors)

  9. A climate trend analysis of Ethiopia

    Science.gov (United States)

    Funk, Christopher C.; Rowland, Jim; Eilerts, Gary; Kebebe, Emebet; Biru, Nigist; White, Libby; Galu, Gideon

    2012-01-01

    This brief report, drawing from a multi-year effort by the U.S. Agency for International Development (USAID) Famine Early Warning Systems Network (FEWS NET), examines recent trends in March-June, June-September, and March-September rainfall and temperature, identifying significant reductions in rainfall and increases in temperature over time in many areas of Ethiopia. Conclusions: * Spring and summer rains in parts of Ethiopia have declined by 15-20 percent since the mid-1970s. * Substantial warming across the entire country has exacerbated the dryness.* An important pattern of observed existing rainfall declines coincides with heavily populated areas of the Rift Valley in south-central Ethiopia, and is likely already adversely affecting crop yields and pasture conditions. * Rapid population growth and the expansion of farming and pastoralism under a drier, warmer climate regime could dramatically increase the number of at-risk people in Ethiopia during the next 20 years.* Many areas of Ethiopia will maintain moist climate conditions, and agricultural development in these areas could help offset rainfall declines and reduced production in other areas.

  10. Observed forest sensitivity to climate implies large changes in 21st century North American forest growth.

    Science.gov (United States)

    Charney, Noah D; Babst, Flurin; Poulter, Benjamin; Record, Sydne; Trouet, Valerie M; Frank, David; Enquist, Brian J; Evans, Margaret E K

    2016-09-01

    Predicting long-term trends in forest growth requires accurate characterisation of how the relationship between forest productivity and climatic stress varies across climatic regimes. Using a network of over two million tree-ring observations spanning North America and a space-for-time substitution methodology, we forecast climate impacts on future forest growth. We explored differing scenarios of increased water-use efficiency (WUE) due to CO2 -fertilisation, which we simulated as increased effective precipitation. In our forecasts: (1) climate change negatively impacted forest growth rates in the interior west and positively impacted forest growth along the western, southeastern and northeastern coasts; (2) shifting climate sensitivities offset positive effects of warming on high-latitude forests, leaving no evidence for continued 'boreal greening'; and (3) it took a 72% WUE enhancement to compensate for continentally averaged growth declines under RCP 8.5. Our results highlight the importance of locally adapted forest management strategies to handle regional differences in growth responses to climate change. © 2016 John Wiley & Sons Ltd/CNRS.

  11. Life in Europe under climate change

    DEFF Research Database (Denmark)

    Alcamo, J.; Olesen, Jørgen E

    Life in Europe will indeed go on as the climate changes, but not in the same way as before. The air will be warmer, winds will change, patterns of rainfall and snowfall will alter, and sea level is likely to rise. These phenomena are already being seen. Europe will in the future experience marked...... changes in vegetation cover, increased floods along rivers and coastlines as well as more frequent droughts and forest fires, often leading to large societal costs. The changes will be minor in some cases, profound in others, but in any case, pervasive.......Life in Europe will indeed go on as the climate changes, but not in the same way as before. The air will be warmer, winds will change, patterns of rainfall and snowfall will alter, and sea level is likely to rise. These phenomena are already being seen. Europe will in the future experience marked...

  12. Change in Vegetation Growth and Its Feedback to Climate in the Tibet Plateau

    Science.gov (United States)

    Piao, S.

    2015-12-01

    Vegetation growth is strongly influenced by climate and climate change and can affect the climate system through a number of bio-physical processes. As a result, monitoring, understanding and predicting the response of vegetation growth to global change has been a central activity in Earth system science during the past two decades. The Tibetan Plateau (TP) has experienced a pronounced warming over recent decades. The warming rate of the TP over the period 1960-2009 was about twice the global average warming rate, yet with heterogeneous patterns. In this study, we use satellite derived NDVI data to investigate spatio-temporal change in vegetation growth over the last three decades.

  13. Radial growth of Qilian juniper on the Northeast Tibetan Plateau and potential climate associations.

    Directory of Open Access Journals (Sweden)

    Chun Qin

    Full Text Available There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110-2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes.

  14. Radial growth of Qilian juniper on the Northeast Tibetan Plateau and potential climate associations.

    Science.gov (United States)

    Qin, Chun; Yang, Bao; Melvin, Thomas M; Fan, Zexin; Zhao, Yan; Briffa, Keith R

    2013-01-01

    There is controversy regarding the limiting climatic factor for tree radial growth at the alpine treeline on the northeastern Tibetan Plateau. In this study, we collected 594 increment cores from 331 trees, grouped within four altitude belts spanning the range 3550 to 4020 m.a.s.l. on a single hillside. We have developed four equivalent ring-width chronologies and shown that there are no significant differences in their growth-climate responses during 1956 to 2011 or in their longer-term growth patterns during the period AD 1110-2011. The main climate influence on radial growth is shown to be precipitation variability. Missing ring analysis shows that tree radial growth at the uppermost treeline location is more sensitive to climate variation than that at other elevations, and poor tree radial growth is particularly linked to the occurrence of serious drought events. Hence water limitation, rather than temperature stress, plays the pivotal role in controlling the radial growth of Sabina przewalskii Kom. at the treeline in this region. This finding contradicts any generalisation that tree-ring chronologies from high-elevation treeline environments are mostly indicators of temperature changes.

  15. Rapid climate variability during warm and cold periods in polar regions and Europe

    DEFF Research Database (Denmark)

    Masson-Delmotte, V.; Landais, A.; Combourieu-Nebout, N.

    2005-01-01

    Typical rapid climate events punctuating the last glacial period in Greenland, Europe and Antarctica are compared to two rapid events occurring under warmer conditions: (i) Dansgaard-Oeschger event 25, the first abrupt warming occurring during last glacial inception; (ii) 8.2 ka BP event, the only...... rapid cooling recorded during the Holocene in Greenland ice cores and in Ammersee, Germany. The rate of warming during previous warmer interglacial periods is estimated from polar ice cores to 1.5 °C per millennium, without abrupt changes. Climate change expected for the 21st century should however...

  16. Recent widespread tree growth decline despite increasing atmospheric CO2.

    Science.gov (United States)

    Silva, Lucas C R; Anand, Madhur; Leithead, Mark D

    2010-07-21

    The synergetic effects of recent rising atmospheric CO(2) and temperature are expected to favor tree growth in boreal and temperate forests. However, recent dendrochronological studies have shown site-specific unprecedented growth enhancements or declines. The question of whether either of these trends is caused by changes in the atmosphere remains unanswered because dendrochronology alone has not been able to clarify the physiological basis of such trends. Here we combined standard dendrochronological methods with carbon isotopic analysis to investigate whether atmospheric changes enhanced water use efficiency (WUE) and growth of two deciduous and two coniferous tree species along a 9 degrees latitudinal gradient across temperate and boreal forests in Ontario, Canada. Our results show that although trees have had around 53% increases in WUE over the past century, growth decline (measured as a decrease in basal area increment--BAI) has been the prevalent response in recent decades irrespective of species identity and latitude. Since the 1950s, tree BAI was predominantly negatively correlated with warmer climates and/or positively correlated with precipitation, suggesting warming induced water stress. However, where growth declines were not explained by climate, WUE and BAI were linearly and positively correlated, showing that declines are not always attributable to warming induced stress and additional stressors may exist. Our results show an unexpected widespread tree growth decline in temperate and boreal forests due to warming induced stress but are also suggestive of additional stressors. Rising atmospheric CO2 levels during the past century resulted in consistent increases in water use efficiency, but this did not prevent growth decline. These findings challenge current predictions of increasing terrestrial carbon stocks under climate change scenarios.

  17. Comparison of injury incidences between football teams playing in different climatic regions

    Science.gov (United States)

    Orchard, John W; Waldén, Markus; Hägglund, Martin; Orchard, Jessica J; Chivers, Ian; Seward, Hugh; Ekstrand, Jan

    2013-01-01

    Australian Football League (AFL) teams in northern (warmer) areas generally have higher rates of injury than those in southern (cooler) areas. Conversely, in soccer (football) in Europe, teams in northern (cooler) areas have higher rates of injury than those in southern (warmer) areas, with an exception being knee anterior cruciate ligament (ACL) injuries, which are more common in the southern (warmer) parts of Europe. This study examined relative injury incidence in the AFL comparing 9,477 injuries over 229,827 player-weeks from 1999–2012. There was a slightly higher injury incidence for teams from warmer parts of Australia (relative risk [RR] 1.05, 95% confidence interval [CI] 1.01–1.10) with quadriceps strains (RR 1.32, 95% CI 1.10–1.58), knee cartilage injuries (RR 1.42, 95% CI 1.16–1.74), and ankle sprains (RR 1.17, 95% CI 1.00–1.37) all being more likely in warmer region teams. Achilles injuries followed a reverse pattern, tending to be more common in cooler region teams (RR 0.70, 95% CI 0.47–1.03). In conclusion, common findings from the AFL and European soccer are that ankle sprains and ACL injuries are generally more likely in teams playing in warmer climate zones, whereas Achilles tendinopathy may be more likely in teams playing in cooler zones. These injuries may have climate or surface risk factors (possibly related to types and structure of grass and shoe-surface traction) that are universal across different football codes. PMID:24379731

  18. The Impact of Urban Growth and Climate Change on Heat Stress in an Australian City

    Science.gov (United States)

    Chapman, S.; Mcalpine, C. A.; Thatcher, M. J.; Salazar, A.; Watson, J. R.

    2017-12-01

    Over half of the world's population lives in urban areas. Most people will therefore be exposed to climate change in an urban environment. One of the climate risks facing urban residents is heat stress, which can lead to illness and death. Urban residents are at increased risk of heat stress due to the urban heat island effect. The urban heat island is a modification of the urban environment and increases temperatures on average by 2°C, though the increase can be much higher, up to 8°C when wind speeds and cloud cover are low. The urban heat island is also expected to increase in the future due to urban growth and intensification, further exacerbating urban heat stress. Climate change alters the urban heat island due to changes in weather (wind speed and cloudiness) and evapotranspiration. Future urban heat stress will therefore be affected by urban growth and climate change. The aim of this study was to examine the impact of urban growth and climate change on the urban heat island and heat stress in Brisbane, Australia. We used CCAM, the conformal cubic atmospheric model developed by the CSIRO, to examine temperatures in Brisbane using scenarios of urban growth and climate change. We downscaled the urban climate using CCAM, based on bias corrected Sea Surface Temperatures from the ACCESS1.0 projection of future climate. We used Representative Concentration Pathway (RCP) 8.5 for the periods 1990 - 2000, 2049 - 2060 and 2089 - 2090 with current land use and an urban growth scenario. The present day climatology was verified using weather station data from the Australian Bureau of Meteorology. We compared the urban heat island of the present day with the urban heat island with climate change to determine if climate change altered the heat island. We also calculated heat stress using wet-bulb globe temperature and apparent temperature for the climate change and base case scenarios. We found the urban growth scenario increased present day temperatures by 0.5°C in the

  19. Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

    Science.gov (United States)

    Kerhoulas, Lucy P; Kane, Jeffrey M

    2012-01-01

    Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

  20. Population differentiation in tree-ring growth response of white fir (Abies concolor) to climate: Implications for predicting forest responses to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Deborah Bowne [Univ. of California, Berkeley, CA (United States)

    1993-01-01

    Forest succession models and correlative models have predicted 200--650 kilometer shifts in the geographic range of temperate forests and forest species as one response to global climate change. Few studies have investigated whether population differences may effect the response of forest species to climate change. This study examines differences in tree-ring growth, and in the phenotypic plasticity of tree-ring growth in 16-year old white fir, Abies concolor, from ten populations grown in four common gardens in the Sierra Nevada of California. For each population, tree-ring growth was modelled as a function of precipitation and degree-day sums. Tree-ring growth under three scenarios of doubled CO2 climates was estimated.

  1. Who is the new sheriff in town regulating boreal forest growth?

    Science.gov (United States)

    Park Williams, A.; Xu, Chonggang; McDowell, Nate G.

    2011-12-01

    Climate change appears to be altering boreal forests. One recently observed symptom of these changes has been an apparent weakening of the positive relationship between high-latitude boreal tree growth and temperature at some sites (D'Arrigo et al 2008). This phenomenon is referred to as the 'divergence problem' or 'divergence effect' and is thought to reflect a non-linear relationship between temperature and tree growth, where recent warming has allowed other factors besides growing-season temperature to emerge as dominant regulators of annual growth rates. Figure 1 demonstrates this divergence phenomenon with records of tree-ring widths collected from 59 populations of white spruce in Alaska 1. Key tendencies among these populations include: (1) growth is most sensitive to temperature during relatively cold growing seasons (figure 1(a)), (2) populations at colder sites are more sensitive to temperature than those at warmer sites are (figure 1(a)), and (3) growth at warmer sites may respond negatively to increased temperature beyond some optimal growing-season temperature (figure 1(b)). Since temperature is rising rapidly at high latitudes, one interpretation of figures 1(a) and (b) is that warming has promoted increased growth at colder sites, but caused growth to plateau or slow at warmer sites. Corroborating this interpretation, satellite imagery and tree-ring data indicate increasing vegetation productivity near the forest-tundra boundary but declining productivity in warmer regions within forest interiors (e.g., Bunn and Goetz 2006, Beck and Goetz 2011, Beck et al 2011, Berner et al 2011). Will continued warming cause a northward migration of boreal forests, with mortality in the warmer, southern locations and expansion into the colder tundra? This question is difficult to answer because many factors besides temperature influence boreal forest dynamics. Widespread productivity declines within interior boreal forests appear to be related to warming

  2. Response of Vegetation to Climate Change in the Drylands of East Asia

    International Nuclear Information System (INIS)

    Dai, L; Wang, K; Wang, R L; Zhang, L

    2014-01-01

    Over the past 25 years, global climate and environmental changes have caused an unprecedented rate of vegetation change, as exemplified in the drylands of East Asia. In this study, we investigated the spatio-temporal changes of vegetation in this region and analysed their relationship with climate data. Our results show that vegetation productivity significantly increased from 1982 to 2006. This increasing trend was observed for most of the region, particularly for northwest Mongolia and central Inner Mongolia. Grasslands, croplands, forests, and shrublands, all exhibited this trend. The annual growth rate of the grasslands determined using the Normalized Difference Vegetation Index (NDVI) was the largest observed change; reaching 0.07% p.a, followed by shrublands (0.06%), croplands (0.03%), and forests (0.02%). In the different geographic regions, the roles of temperature and precipitation on vegetation growth were shown to be different. Temperature was the dominant factor for the observed NDVI increase in northwest Mongolia and the centre of Inner Mongolia. The combined influences of temperature and precipitation changes have resulted in the promotion of vegetation growth, as seen in eastern GanSu. Temperature change is the primary factor for initiating vegetation growth in spring and autumn because warmer temperatures increase the length of the growing season, and are thus evaluated as an increased NDVI value. Increased precipitation has been shown to play a positive role on vegetation growth during summer

  3. Variations in the Sensitivity of Shrub Growth to Climate Change along Arctic Environmental and Biotic Gradients

    Science.gov (United States)

    Beck, P. S. A.; Myers-Smith, I. H.; Elmendorf, S.; Georges, D.

    2015-12-01

    Despite evidence of rapid shrub expansion at many Arctic sites and the profound effects this has on ecosystem structure, biogeochemical cycling, and land-atmosphere feedbacks in the Arctic, the drivers of shrub growth remain poorly understood. The compilation of 41,576 annual shrub growth measurements made around the Arctic, allowed for the first systematic evaluation of the climate sensitivity of Arctic shrub growth, i.e. the strength of the relationship between annual shrub growth and monthly climate variables. The growth measurements were taken on 1821 plants of 25 species at 37 arctic and alpine sites, either as annual ring widths or as stem increments. We evaluated climate sensitivity of shrub growth for each genus-by-site combination in this data set based on the performance and parameters of linear mixed models that used CRU TS3.21 climate data as predictors of shrub growth between 1950 and 2010. 76% of genus-by-site combinations showed climate sensitive growth, but climate-growth relationships varied with soil moisture, species canopy height, and geographic position within the species ranges. Shrubs growing at sites with more soil moisture showed greater climate sensitivity, suggesting that water availability might limit shrub growth if continued warming isn't matched by a steady increase in soil moisture. Tall shrub species growing at their northern range limit were particularly climate sensitive causing climate sensitivity of shrubs to peak at the transition between Low and High Arctic, where carbon storage in permafrost is greatest. Local and regional studies have documented matching spatial and temporal patterns in dendrochronological measurements and satellite observations of vegetation indices both in boreal and Arctic regions. Yet the circumarctic comparison of patterns in dendrochronological and remote sensing data sets yielded poor levels of agreement. In much of the Arctic, steep environmental gradients generate fine spatial patterns of vegetation

  4. Severe Autumn storms in future Western Europe with a warmer Atlantic Ocean

    Science.gov (United States)

    Baatsen, Michiel; Haarsma, Reindert J.; Van Delden, Aarnout J.; de Vries, Hylke

    2015-08-01

    Simulations with a very high resolution (~25 km) global climate model indicate that more severe Autumn storms will impact Europe in a warmer future climate. The observed increase is mainly attributed to storms with a tropical origin, especially in the later part of the twentyfirst century. As their genesis region expands, tropical cyclones become more intense and their chances of reaching Europe increase. This paper investigates the properties and evolution of such storms and clarifies the future changes. The studied tropical cyclones feature a typical evolution of tropical development, extratropical transition and a re-intensification. A reduction of the transit area between regions of tropical and extratropical cyclogenesis increases the probability of re-intensification. Many of the modelled storms exhibit hybrid properties in a considerable part of their life cycle during which they exhibit the hazards of both tropical and extratropical systems. In addition to tropical cyclones, other systems such as cold core extratropical storms mainly originating over the Gulf Stream region also increasingly impact Western Europe. Despite their different history, all of the studied storms have one striking similarity: they form a warm seclusion. The structure, intensity and frequency of storms in the present climate are compared to observations using the MERRA and IBTrACS datasets. Damaging winds associated with the occurrence of a sting jet are observed in a large fraction of the cyclones during their final stage. Baroclinic instability is of great importance for the (re-)intensification of the storms. Furthermore, so-called atmospheric rivers providing tropical air prove to be vital for the intensification through diabatic heating and will increase considerably in strength in the future, as will the associated flooding risks.

  5. Climate Change, Growth, and Poverty in Ethiopia

    Science.gov (United States)

    2013-06-01

    intergration Tests 8 Empirical Strategy 8 Discussion of Estimation Results 9 Climate Change and Economic Growth...production and marketing (Parry, 2007; Barrios et al , 2004), the impact of which can easily be transmitted to Ethiopia through trade channels with...Ethiopia and other developing countries to depend particularly on expensive cereal imports, worsening the trade balance in these countries However

  6. Climate change

    International Nuclear Information System (INIS)

    2006-01-01

    This paper presented indicators of climate change for British Columbia (BC) with an emphasis on the coastal region. An overview of global effects of climate change was presented, as well as details of BC's current climate change action plan. Indicators examined in the paper for the BC coastal region included long-term trends in air temperature; long-term trends in precipitation; coastal ocean temperatures; sea levels on the BC coast; and the sensitivity of the BC coast to sea level rise and erosion. Data suggested that average air temperatures have become higher in many areas, and that Springtime temperatures have become warmer over the whole province. Winters have become drier in many areas of the province. Sea surface temperature has risen over the entire coast, with the North Coast and central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in 5 inlets on the South Coast. Results suggested that the direction and spatial pattern of the climate changes reported for British Columbia are consistent with broader trends in North America and the type of changes predicted by climate models for the region. Climate change will likely result in reduced snow-pack in southern BC. An earlier spring freshet on many snow-dominated river systems is anticipated as well as glacial retreat and disappearance. Warmer temperatures in some lakes and rivers are expected, as well as the increased frequency and severity of natural disturbances such as the pine mountain beetle. Large-scale shifts in ecosystems and the loss of certain ecosystems may also occur. BC's current climate plan includes cost effective actions that address GHG emissions and support efficient infrastructure and opportunities for innovation. Management programs for forest and agricultural lands have been initiated, as well as programs to reduce emissions from government operations. Research is also being conducted to understand the impacts of climate change on water

  7. Phenology and growth of European trees in relation to climate change

    NARCIS (Netherlands)

    Kramer, K.

    1996-01-01

    Research topics

    The relationships between climate and both phenology and growth of some important European tree species were studied to evaluate the potential impacts of climate change on trees and forests in Europe. In order to make such assessments, insight is

  8. Partnering for climate change adaptations by Dutch housing associations

    OpenAIRE

    Roders, M.J.

    2015-01-01

    Introduction Climate change can no longer be ignored. It is globally recognised that the evidence for climate change is unequivocal and that action needs to be taken in order to address its negative effects. These effects, such as warmer and drier summers and more extreme rainfall, may threaten the quality of life of those living in urban environments. To limit these threats, a number of climate change adaptation measures can be taken to pre-empt the negative effects of climate chan...

  9. Rapid climatic changes recorded in loess successions

    NARCIS (Netherlands)

    Vandenberghe, J.; Nugteren, G.D.

    2001-01-01

    Detailed grain-size analyses, both in China and western Europe, indicate the occurrence of short climatic cycles during loess deposition of the last glacial. Cold episodes coincided with enhanced deposition of relatively coarse loess and alternated with relatively warmer episodes with decreased

  10. Last Interglacial climate and sea-level evolution from a coupled ice sheet-climate model

    NARCIS (Netherlands)

    Goelzer, Heiko; Huybrechts, Philippe; Marie-France, Loutre; Fichefet, Thierry

    2016-01-01

    As the most recent warm period in Earth's history with a sea-level stand higher than present, the Last Interglacial (LIG, ∼130 to 115kyrgBP) is often considered a prime example to study the impact of a warmer climate on the two polar ice sheets remaining today. Here we simulate the Last Interglacial

  11. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches

    International Nuclear Information System (INIS)

    Manninen, S.; Huttunen, S.; Vanhatalo, M.; Pakonen, T.; Haemaelaeinen, A.

    2009-01-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O 3 ) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O 3 , i.e. O 3 levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O 3 and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels. - Northern birches are responsive to ambient ozone levels.

  12. Inter- and intra-specific responses to elevated ozone and chamber climate in northern birches.

    Science.gov (United States)

    Manninen, S; Huttunen, S; Vanhatalo, M; Pakonen, T; Hämäläinen, A

    2009-05-01

    We studied the responses of micropropagated, northern provenances of downy, mountain and silver birches to elevated ozone (O(3)) and changing climate using open-top chambers (OTCs). Contrary to our hypothesis, northern birches were sensitive to O(3), i.e. O(3) levels of 31-36 ppb reduced the leaf and root biomasses by -10%, whereas wood biomass was affected to a lesser extent. The warmer and drier OTC climate enhanced growth in general, though there were differences among the species and clones, e.g. in bud burst and biomass production. Inter- and intra-specific responses to O(3) and changing climate relate to traits such as allocation patterns between the above- and belowground parts (i.e. root/shoot ratio), which further relate to nutrient and water economy. Our experiments may have mimicked future conditions quite well, but only long-term field studies can yield the information needed to forecast responses at both tree and ecosystem levels.

  13. CLIMATE CHANGES: CAUSES AND IMPACT

    Directory of Open Access Journals (Sweden)

    Camelia Slave

    2013-07-01

    Full Text Available Present brings several environmental problems for people. Many of these are closely related, but by far the most important problem is the climate change. In the course of Earth evolution, climate has changed many times, sometimes dramatically. Warmer eras always replaced and were in turn replaced by glacial ones. However, the climate of the past almost ten thousand years has been very stable. During this period human civilization has also developed. In the past nearly 100 years - since the beginning of industrialization - the global average temperature has increased by approx. 0.6 ° C (after IPCC (Intergovernmental Panel on Climate Change, faster than at any time in the last 1000 years.

  14. Tree growth-climate relationships in a forest-plot network on Mediterranean mountains.

    Science.gov (United States)

    Fyllas, Nikolaos M; Christopoulou, Anastasia; Galanidis, Alexandros; Michelaki, Chrysanthi Z; Dimitrakopoulos, Panayiotis G; Fulé, Peter Z; Arianoutsou, Margarita

    2017-11-15

    In this study we analysed a novel tree-growth dataset, inferred from annual ring-width measurements, of 7 forest tree species from 12 mountain regions in Greece, in order to identify tree growth - climate relationships. The tree species of interest were: Abies cephalonica, Abies borisii-regis, Picea abies, Pinus nigra, Pinus sylvestris, Fagus sylvatica and Quercus frainetto growing across a gradient of climate conditions with mean annual temperature ranging from 5.7 to 12.6°C and total annual precipitation from 500 to 950mm. In total, 344 tree cores (one per tree) were analysed across a network of 20 study sites. We found that water availability during the summer period (May-August) was a strong predictor of interannual variation in tree growth for all study species. Across species and sites, annual tree growth was positively related to summer season precipitation (P SP ). The responsiveness of annual growth to P SP was tightly related to species and site specific measurements of instantaneous photosynthetic water use efficiency (WUE), suggesting that the growth of species with efficient water use is more responsive to variations in precipitation during the dry months of the year. Our findings support the importance of water availability for the growth of mountainous Mediterranean tree species and highlight that future reductions in precipitation are likely to lead to reduced tree-growth under climate change conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Climate of origin affects tick (Ixodes ricinus) host-seeking behavior in response to temperature: implications for resilience to climate change?

    Science.gov (United States)

    Gilbert, Lucy; Aungier, Jennifer; Tomkins, Joseph L

    2014-04-01

    Climate warming is changing distributions and phenologies of many organisms and may also impact on vectors of disease-causing pathogens. In Europe, the tick Ixodes ricinus is the primary vector of medically important pathogens (e.g., Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis). How might climate change affect I. ricinus host-seeking behavior (questing)? We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. We predicted that ticks from cooler climates quest at cooler temperatures than those from warmer climates. This would suggest that I. ricinus can adapt and therefore have the potential to be resilient to climate change. I. ricinus were collected from a cline of climates using a latitudinal gradient (northeast Scotland, North Wales, South England, and central France). Under laboratory conditions, ticks were subjected to temperature increases of 1°C per day, from 6 to 15°C. The proportion of ticks questing was recorded five times per temperature (i.e., per day). The theoretical potential to quest was then estimated for each population over the year for future climate change projections. As predicted, more ticks from cooler climates quested at lower temperatures than did ticks from warmer climates. The proportion of ticks questing was strongly associated with key climate parameters from each location. Our projections, based on temperature alone, suggested that populations could advance their activity season by a month under climate change, which has implications for exposure periods of hosts to tick-borne pathogens. Our findings suggest that I. ricinus have adapted their behavior in response to climate, implying some potential to adapt to climate change. Predictive models of I. ricinus dynamics and disease risk over continental scales would benefit from knowledge of these differences between populations.

  16. Climate interacts with soil to produce beta diversity in Californian plant communities.

    Science.gov (United States)

    Fernandez-Going, B M; Harrison, S P; Anacker, B L; Safford, H D

    2013-09-01

    Spatially distinct communities can arise through interactions and feedbacks between abiotic and biotic factors. We suggest that, for plants, patches of infertile soils such as serpentine may support more distinct communities from those in the surrounding non-serpentine matrix in regions where the climate is more productive (i.e., warmer and/or wetter). Where both soil fertility and climatic productivity are high, communities may be dominated by plants with fast-growing functional traits, whereas where either soils or climate impose low productivity, species with stress-tolerant functional traits may predominate. As a result, both species and functional composition may show higher dissimilarity between patch and matrix in productive climates. This pattern may be reinforced by positive feedbacks, in which higher plant growth under favorable climate and soil conditions leads to higher soil fertility, further enhancing plant growth. For 96 pairs of sites across a 200-km latitudinal gradient in California, we found that the species and functional dissimilarities between communities on infertile serpentine and fertile non-serpentine soils were higher in more productive (wetter) regions. Woody species had more stress-tolerant functional traits on serpentine than non-serpentine soil, and as rainfall increased, woody species functional composition changed toward fast-growing traits on non-serpentine, but not on serpentine soils. Soil organic matter increased with rainfall, but only on non-serpentine soils, and the difference in organic matter between soils was positively correlated with plant community dissimilarity. These results illustrate a novel mechanism wherein climatic productivity is associated with higher species, functional, and landscape-level dissimilarity (beta diversity).

  17. Pressure Infusion Cuff and Blood Warmer during Massive Transfusion: An Experimental Study About Hemolysis and Hypothermia.

    Science.gov (United States)

    Poder, Thomas G; Pruneau, Denise; Dorval, Josée; Thibault, Louis; Fisette, Jean-François; Bédard, Suzanne K; Jacques, Annie; Beauregard, Patrice

    2016-01-01

    Blood warmers were developed to reduce the risk of hypothermia associated with the infusion of cold blood products. During massive transfusion, these devices are used with compression sleeve, which induce a major stress to red blood cells. In this setting, the combination of blood warmer and compression sleeve could generate hemolysis and harm the patient. We conducted this study to compare the impact of different pressure rates on the hemolysis of packed red blood cells and on the outlet temperature when a blood warmer set at 41.5°C is used. Pressure rates tested were 150 and 300 mmHg. Ten packed red blood cells units were provided by Héma-Québec and each unit was sequentially tested. We found no increase in hemolysis either at 150 or 300 mmHg. By cons, we found that the blood warmer was not effective at warming the red blood cells at the specified temperature. At 150 mmHg, the outlet temperature reached 37.1°C and at 300 mmHg, the temperature was 33.7°C. To use a blood warmer set at 41.5°C in conjunction with a compression sleeve at 150 or 300 mmHg does not generate hemolysis. At 300 mmHg a blood warmer set at 41.5°C does not totally avoid a risk of hypothermia.

  18. Water temperature and fish growth: otoliths predict growth patterns of a marine fish in a changing climate.

    Science.gov (United States)

    Rountrey, Adam N; Coulson, Peter G; Meeuwig, Jessica J; Meekan, Mark

    2014-08-01

    Ecological modeling shows that even small, gradual changes in body size in a fish population can have large effects on natural mortality, biomass, and catch. However, efforts to model the impact of climate change on fish growth have been hampered by a lack of long-term (multidecadal) data needed to understand the effects of temperature on growth rates in natural environments. We used a combination of dendrochronology techniques and additive mixed-effects modeling to examine the sensitivity of growth in a long-lived (up to 70 years), endemic marine fish, the western blue groper (Achoerodus gouldii), to changes in water temperature. A multi-decadal biochronology (1952-2003) of growth was constructed from the otoliths of 56 fish collected off the southwestern coast of Western Australia, and we tested for correlations between the mean index chronology and a range of potential environmental drivers. The chronology was significantly correlated with sea surface temperature in the region, but common variance among individuals was low. This suggests that this species has been relatively insensitive to past variations in climate. Growth increment and age data were also used in an additive mixed model to predict otolith growth and body size later this century. Although growth was relatively insensitive to changes in temperature, the model results suggested that a fish aged 20 in 2099 would have an otolith about 10% larger and a body size about 5% larger than a fish aged 20 in 1977. Our study shows that species or populations regarded as relatively insensitive to climate change could still undergo significant changes in growth rate and body size that are likely to have important effects on the productivity and yield of fisheries. © 2014 John Wiley & Sons Ltd.

  19. Climate change and human health

    International Nuclear Information System (INIS)

    Sanderson, G.

    1991-01-01

    Changes in the earth's climate, stemming from the greenhouse effect, are highly likely to damage human health. As well as the disruptions to food and fresh water supplies, there is the prospect of major diseases flourishing in warmer conditions, in addition the decrease in the ozone layer is causing an increased incidence of skin cancer

  20. Major Changes in Growth Rate and Growth Variability of Beech (Fagus sylvatica L. Related to Soil Alteration and Climate Change in Belgium

    Directory of Open Access Journals (Sweden)

    Nicolas Latte

    2016-08-01

    Full Text Available Global change—particularly climate change, forest management, and atmospheric deposition—has significantly altered forest growing conditions in Europe. The influences of these changes on beech growth (Fagus sylvatica L. were investigated for the past 80 years in Belgium, using non-linear mixed effects models on ring-width chronologies of 149 mature and dominant beech trees (87–186 years old. The effects of the developmental stage (i.e., increasing tree size were filtered out in order to focus on time-dependent growth changes. Beech radial growth was divided into a low-frequency signal (=growth rate, mainly influenced by forest management and atmospheric deposition, and into a high-frequency variability (≈mean sensitivity, mainly influenced by climate change. Between 1930 and 2008, major long-term and time-dependent changes were highlighted. The beech growth rate has decreased by about 38% since the 1950–1960s, and growth variability has increased by about 45% since the 1970–1980s. Our results indicate that (1 before the 1980s, beech growth rate was not predominantly impacted by climate change but rather by soil alteration (i.e., soil compaction and/or nitrogen deposition; and (2 since the 1980s, climate change induced more frequent and intense yearly growth reductions that amplified the growth rate decrease. The highlighted changes were similar in the two ecoregions of Belgium, although more pronounced in the lowlands than in the uplands.

  1. Solar cycles and climate variations

    International Nuclear Information System (INIS)

    Chistyakov, V.F.

    1990-01-01

    Climate oscillations with 100-, 200- and 300-year periods are positively correlated with solar activity oscillations: the higher is solar activity the warmer is climate. According to geological data (varved clays) it is determined, that length of cycles has decreased from 23.4 up to 11 years during latter 2.5 billion years. 12-year cycles occurred during the great glaciation periods, while 10-year cycles occurred during interglaciation periods. It is suggested, that these oscillations are related with variations of the solar activity and luminescence

  2. Warmer weather linked to tick attack and emergence of severe rickettsioses.

    Directory of Open Access Journals (Sweden)

    Philippe Parola

    Full Text Available The impact of climate on the vector behaviour of the worldwide dog tick Rhipicephalus sanguineus is a cause of concern. This tick is a vector for life-threatening organisms including Rickettsia rickettsii, the agent of Rocky Mountain spotted fever, R. conorii, the agent of Mediterranean spotted fever, and the ubiquitous emerging pathogen R. massiliae. A focus of spotted fever was investigated in France in May 2007. Blood and tissue samples from two patients were tested. An entomological survey was organised with the study of climatic conditions. An experimental model was designed to test the affinity of Rh. sanguineus for biting humans in variable temperature conditions. Serological and/or molecular tools confirmed that one patient was infected by R. conorii, whereas the other was infected by R. massiliae. Dense populations of Rh. sanguineus were found. They were infected with new genotypes of clonal populations of either R. conorii (24/133; 18% or R. massiliae (13/133; 10%. April 2007 was the warmest since 1950, with summer-like temperatures. We show herein that the human affinity of Rh. sanguineus was increased in warmer temperatures. In addition to the originality of theses cases (ophthalmic involvements, the second reported case of R. massiliae infection, we provide evidence that this cluster of cases was related to a warming-mediated increase in the aggressiveness of Rh. sanguineus, leading to increased human attacks. From a global perspective, we predict that as a result of globalisation and warming, more pathogens transmitted by the brown dog tick may emerge in the future.

  3. 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.

  4. The growth of finfish in global open-ocean aquaculture under climate change.

    Science.gov (United States)

    Klinger, Dane H; Levin, Simon A; Watson, James R

    2017-10-11

    Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon ( Salmo salar ), gilthead seabream ( Sparus aurata ) and cobia ( Rachycentron canadum )-is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses. © 2017 The Author(s).

  5. Influences of climate on the radial growth of lodgepole pine in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Chhin, S.; Lieffers, V.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Renewable Resources; Hogg, E.H. [Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, AB (Canada); Huang, S. [Alberta Sustainable Resource Development, Edmonton, AB (Canada). Forest Management Branch

    2008-02-15

    The forests of the Cordilleran region were used to document past relationships between tree growth and climate. Radial growth and climate relationships of lodgepole pines were examined across a network of 17 sites in Alberta over a distance of 1100 km. Pine sites were selected from a permanent plot database covering the predominant latitudinal and elevational range of lodgepole pines. An average of 21 dominant and co-dominant trees were sampled in a 50 m buffer zone. Ring-width series were detrended in 3 stages using negative exponential curves, linear regression, and low frequency standardized series (LFS). Each LFS series was detrended with a cubic-smoothing spline. Autocorrelation in each series was removed via autoregressive (AR) modelling resulting in high frequency residual series. High frequency residual (HFR) site chronologies were constructed by averaging HFR series developed at each site. Primary climate variables included mean daily minimum and maximum temperatures for each month and total monthly precipitation. Relationships between the different chronology types were then examined. Results of the study demonstrated that cool and moist conditions during the later summer months led to improved radial growth levels during the following years. Warm, dry winters and warm conditions during the autumn of the year in which the ring was formed also promoted tree growth. Results suggested that climatic warming and drying have opposing effects. It was concluded that future impacts on lodgepole pine radial growth will depend on the pattern and magnitude of changes in temperature and precipitation in each season. 55 refs., 3 tabs., 8 figs.

  6. Impacts and adaptation for climate change in urban forests

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, M. [Saskatchewan Research Council, Saskatoon, SK (Canada)

    2006-07-01

    Changes to urban trees as a result of climate change were reviewed in order to aid urban forest managers in the development of adaptive climate change strategies. Various climate change models have predicted that winter and spring temperatures will increase. Higher amounts of precipitation are also anticipated. Higher temperatures will results in evapotranspiration, which will cause soil moisture levels to decline. Climatologists have also suggested that very hot days, winter storms and high rainfall events will increase in frequency. In addition, higher levels of atmospheric carbon dioxide (CO{sub 2}) will affect photosynthesis, with associated impacts on urban tree growth. Higher temperatures and longer growing seasons will allow insect populations to build up to higher levels, and warmer and dryer summers are likely to bring longer fire seasons and more severe fires. Urban trees under stress from drought and higher temperatures will be increasingly vulnerable to existing urban stressors such as air pollution and soil compaction. However, the ecological services provided by trees will become more valuable under future climate change regimes, particularly for shading and space cooling, as well as soil aeration and stabilization and the uptake of storm water. It was suggested that future tree growth may be enhanced on sites with adequate water and nutrients, but will probably decline in areas that are already marginal. It was recommended that urban forest managers assess the present vulnerability of trees to climate-related events in order to prepare for future change. Managers should also assess their capacity to implement various strategies through municipal and provincial partnerships. It was observed that decisions taken now about forest management will play out over several decades. It was concluded that maintaining a flexible and resilient urban forest management system is the best defence, as specific climate change impacts cannot be predicted. 18 refs., 4

  7. A hypothesis and a case-study projection of an influence of MJO modulation on boreal-summer tropical cyclogenesis in a warmer climate with a global non-hydrostatic model: a transition toward the central Pacific?

    Directory of Open Access Journals (Sweden)

    KAZUYOSHI eOOUCHI

    2014-02-01

    Full Text Available The eastward shift of the enhanced activity of tropical cyclone to the central Pacific is a robust projection result for a future warmer climate, and is shared by most of the state-of-the-art climate models. The shift has been argued to originate from the underlying El-Ñino like sea-surface temperature (SST forcing. This study explores the possibility that the change of the activity of the Madden-Julian Oscillation (MJO can be an additional, if not alternative, contributor to the shift, using the dataset of Yamada et al. (2010 from a global non-hydrostatic 14-km grid mesh time-slice experiment for a boreal-summer case. Within the case-study framework, we develop the hypothesis that an eastward shift of the high-activity area of the MJO, as manifested itself as the significant intra-seasonal modulation of the enhanced precipitation, is associated with the increased tropical cyclogenesis potential over the North central Pacific by regulating cyclonic relative vorticity and vertical shear. In contrast, the North Indian Ocean and maritime continent undergo relatively diminished genesis potential. An implication is that uncertainty in the future tropical cyclogenesis in some part of the Pacific and other ocean basins could be reduced if projection of the MJO and its connection with the underlying SST environment can be better understood and constrained by the improvement of climate models.

  8. The Science of Climate Change

    Science.gov (United States)

    Oppenheimer, Michael; Anttila-Hughes, Jesse K.

    2016-01-01

    Michael Oppenheimer and Jesse Anttila-Hughes begin with a primer on how the greenhouse effect works, how we know that Earth is rapidly getting warmer, and how we know that the recent warming is caused by human activity. They explain the sources of scientific knowledge about climate change as well as the basis for the models scientists use to…

  9. Costs of climate impacts

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, W O

    1980-03-01

    The surest prospect for future world climate patterns is that they will differ from present ones. What is uncertain is how much, and exactly in what way in different geographical regions. The anthropogenic CO/sub 2/ increase will probably exceed the unknown forcing functions of natural climate change within 30 to 60 years. It is not unlikely that by AD 2040 the world's climate, driven by the CO/sub 2/ increase, will enter a domain warmer than any within the past few million years. The costs of averting this climate change or of absorbing its impact are likely to be huge, even though today imponderable. Not least among these are intangible and unquantifiable costs associated with changes in human values and the quality of everyday life for future generations.

  10. Ecotypic differentiation between urban and rural populations of the grasshopper Chorthippus brunneus relative to climate and habitat fragmentation.

    Science.gov (United States)

    San Martin Y Gomez, Gilles; Van Dyck, Hans

    2012-05-01

    Urbanization alters environmental conditions in multiple ways and offers an ecological or evolutionary challenge for organisms to cope with. Urban areas typically have a warmer climate and strongly fragmented herbaceous vegetation; the urban landscape matrix is often assumed to be hostile for many organisms. Here, we addressed the issue of evolutionary differentiation between urban and rural populations of an ectotherm insect, the grasshopper Chorthippus brunneus. We compared mobility-related morphology and climate-related life history traits measured on the first generation offspring of grasshoppers from urban and rural populations reared in a common garden laboratory experiment. We predicted (1) the urban phenotype to be more mobile (i.e., lower mass allocation to the abdomen, longer relative femur and wing lengths) than the rural phenotype; (2) the urban phenotype to be more warm adapted (e.g., higher female body mass); and (3) further evidence of local adaptation in the form of significant interaction effects between landscape of origin and breeding temperature. Both males and females of urban origin had significantly longer relative femur and wing lengths and lower mass allocation to the abdomen (i.e., higher investment in thorax and flight muscles) relative to individuals of rural origin. The results were overall significant but small (2-4%). Body mass and larval growth rate were much higher (+10%) in females of urban origin. For the life history traits, we did not find evidence for significant interaction effects between the landscape of origin and the two breeding temperatures. Our results point to ecotypic differentiation with urbanization for mobility-related morphology and climate-related life history traits. We argue that the warmer urban environment has an indirect effect through longer growth season rather than direct effects on the development.

  11. Variations of Climate-Growth Response of Major Conifers at Upper Distributional Limits in Shika Snow Mountain, Northwestern Yunnan Plateau, China

    Directory of Open Access Journals (Sweden)

    Yun Zhang

    2017-10-01

    Full Text Available Improved understanding of climate-growth relationships of multiple species is fundamental to understanding and predicting the response of forest growth to future climate change. Forests are mainly composed of conifers in Northwestern Yunnan Plateau, but variations of growth response to climate conditions among the species are not well understood. To detect the growth response of multiple species to climate change, we developed residual chronologies of four major conifers, i.e., George’s fir (Abies georgei Orr, Likiang spruce (Picea likiangensis (Franch. E.Pritz., Gaoshan pine (Pinus densata Mast. and Chinese larch (Larix potaninii Batalin at the upper distributional limits in Shika Snow Mountain. Using the dendroclimatology method, we analyzed correlations between the residual chronologies and climate variables. The results showed that conifer radial growth was influenced by both temperature and precipitation in Shika Snow Mountain. Previous November temperature, previous July temperature, and current May precipitation were the common climatic factors that had consistent influences on radial growth of the four species. Temperature in the previous post-growing season (September–October and moisture conditions in the current growing season (June–August were the common climatic factors that had divergent impacts on the radial growth of the four species. Based on the predictions of climate models and our understanding of the growth response of four species to climate variables, we may understand the growth response to climate change at the species level. It is difficult to predict future forest growth in the study area, since future climate change might cause both increases and decreases for the four species and indirect effects of climate change on forests should be considered.

  12. Warmer winters modulate life history and energy storage but do not affect sensitivity to a widespread pesticide in an aquatic insect.

    Science.gov (United States)

    Arambourou, Hélène; Stoks, Robby

    2015-10-01

    Despite the increased attention for the effects of pesticides under global warming no studies tested how winter warming affects subsequent sensitivity to pesticides. Winter warming is expected to cause delayed negative effects when it increases metabolic rates and thereby depletes energy reserves. Using a common-garden experiment, we investigated the combined effect of a 4 °C increase in winter temperature and subsequent exposure to chlorpyrifos in the aquatic larvae of replicated low- and high-latitude European populations of the damselfly Ischnura elegans. The warmer winter (8 °C) resulted in a higher winter survival and higher growth rates compared to the cold winter (4 °C) commonly experienced by European high-latitude populations. Low-latitude populations were better at coping with the warmer winter, indicating thermal adaptation to the local winter temperatures. Subsequent chlorpyrifos exposure at 20 °C induced strong negative effects on survival, growth rate, lipid content and acetylcholinesterase activity while phenoloxidase activity increased. These pesticide effects were not affected by winter warming. Our results suggest that for species where winter warming has positive effects on life history, no delayed effects on the sensitivity to subsequent pesticide exposure should be expected. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Comparison of injury incidences between football teams playing in different climatic regions

    Directory of Open Access Journals (Sweden)

    Orchard JW

    2013-12-01

    Full Text Available John W Orchard,1 Markus Waldén,2 Martin Hägglund,3 Jessica J Orchard,1 Ian Chivers,4 Hugh Seward,5 Jan Ekstrand21School of Public Health, University of Sydney, Sydney, NSW, Australia; 2Department of Medical and Health Sciences, Division of Community Medicine, Linköping University, Linköping, Sweden; 3Department of Medical and Health Sciences, Division of Physiotherapy, Linköping University, Linköping, Sweden; 4Native Seeds, Cheltenham, VIC, Australia; 5Australian Football League Medical Officers Association, Melbourne, VIC, AustraliaAbstract: Australian Football League (AFL teams in northern (warmer areas generally have higher rates of injury than those in southern (cooler areas. Conversely, in soccer (football in Europe, teams in northern (cooler areas have higher rates of injury than those in southern (warmer areas, with an exception being knee anterior cruciate ligament (ACL injuries, which are more common in the southern (warmer parts of Europe. This study examined relative injury incidence in the AFL comparing 9,477 injuries over 229,827 player-weeks from 1999–2012. There was a slightly higher injury incidence for teams from warmer parts of Australia (relative risk [RR] 1.05, 95% confidence interval [CI] 1.01–1.10 with quadriceps strains (RR 1.32, 95% CI 1.10–1.58, knee cartilage injuries (RR 1.42, 95% CI 1.16–1.74, and ankle sprains (RR 1.17, 95% CI 1.00–1.37 all being more likely in warmer region teams. Achilles injuries followed a reverse pattern, tending to be more common in cooler region teams (RR 0.70, 95% CI 0.47–1.03. In conclusion, common findings from the AFL and European soccer are that ankle sprains and ACL injuries are generally more likely in teams playing in warmer climate zones, whereas Achilles tendinopathy may be more likely in teams playing in cooler zones. These injuries may have climate or surface risk factors (possibly related to types and structure of grass and shoe-surface traction that are

  14. Evaluating within-population variability in behavior and demography for the adaptive potential of a dispersal-limited species to climate change

    Science.gov (United States)

    Muñoz, David J.; Miller Hesed, Kyle; Grant, Evan H. Campbell; Miller, David A.W.

    2016-01-01

    Multiple pathways exist for species to respond to changing climates. However, responses of dispersal-limited species will be more strongly tied to ability to adapt within existing populations as rates of environmental change will likely exceed movement rates. Here, we assess adaptive capacity in Plethodon cinereus, a dispersal-limited woodland salamander. We quantify plasticity in behavior and variation in demography to observed variation in environmental variables over a 5-year period. We found strong evidence that temperature and rainfall influence P. cinereus surface presence, indicating changes in climate are likely to affect seasonal activity patterns. We also found that warmer summer temperatures reduced individual growth rates into the autumn, which is likely to have negative demographic consequences. Reduced growth rates may delay reproductive maturity and lead to reductions in size-specific fecundity, potentially reducing population-level persistence. To better understand within-population variability in responses, we examined differences between two common color morphs. Previous evidence suggests that the color polymorphism may be linked to physiological differences in heat and moisture tolerance. We found only moderate support for morph-specific differences for the relationship between individual growth and temperature. Measuring environmental sensitivity to climatic variability is the first step in predicting species' responses to climate change. Our results suggest phenological shifts and changes in growth rates are likely responses under scenarios where further warming occurs, and we discuss possible adaptive strategies for resulting selective pressures.

  15. Climate-driven speedup of alpine treeline forest growth in the Tianshan Mountains, Northwestern China.

    Science.gov (United States)

    Qi, Zhaohuan; Liu, Hongyan; Wu, Xiuchen; Hao, Qian

    2015-02-01

    Forest growth is sensitive to interannual climatic change in the alpine treeline ecotone (ATE). Whether the alpine treeline ecotone shares a similar pattern of forest growth with lower elevational closed forest belt (CFB) under changing climate remains unclear. Here, we reported an unprecedented acceleration of Picea schrenkiana forest growth since 1960s in the ATE of Tianshan Mountains, northwestern China by a stand-total sampling along six altitudinal transects with three plots in each transect: one from the ATE between the treeline and the forest line, and the other two from the CFB. All the sampled P. schrenkiana forest patches show a higher growth speed after 1960 and, comparatively, forest growth in the CFB has sped up much slower than that in the ATE. The speedup of forest growth at the ATE is mainly accounted for by climate factors, with increasing temperature suggested to be the primary driver. Stronger water deficit as well as more competition within the CFB might have restricted forest growth there more than that within the ATE, implying biotic factors were also significant for the accelerated forest growth in the ATE, which should be excluded from simulations and predictions of warming-induced treeline dynamics. © 2014 John Wiley & Sons Ltd.

  16. Table of Policy Options for Smart Growth Fixes for Climate Adaptation and Resilience

    Science.gov (United States)

    Sortable table of policy options discussed in the publication Smart Growth Fixes for Climate Adaptation and Resilience, which can help local governments prepare for climate change while gaining other environmental, economic, health, and social benefits

  17. Climatic warming destabilizes forest ant communities.

    Science.gov (United States)

    Diamond, Sarah E; Nichols, Lauren M; Pelini, Shannon L; Penick, Clint A; Barber, Grace W; Cahan, Sara Helms; Dunn, Robert R; Ellison, Aaron M; Sanders, Nathan J; Gotelli, Nicholas J

    2016-10-01

    How will ecological communities change in response to climate warming? Direct effects of temperature and indirect cascading effects of species interactions are already altering the structure of local communities, but the dynamics of community change are still poorly understood. We explore the cumulative effects of warming on the dynamics and turnover of forest ant communities that were warmed as part of a 5-year climate manipulation experiment at two sites in eastern North America. At the community level, warming consistently increased occupancy of nests and decreased extinction and nest abandonment. This consistency was largely driven by strong responses of a subset of thermophilic species at each site. As colonies of thermophilic species persisted in nests for longer periods of time under warmer temperatures, turnover was diminished, and species interactions were likely altered. We found that dynamical (Lyapunov) community stability decreased with warming both within and between sites. These results refute null expectations of simple temperature-driven increases in the activity and movement of thermophilic ectotherms. The reduction in stability under warming contrasts with the findings of previous studies that suggest resilience of species interactions to experimental and natural warming. In the face of warmer, no-analog climates, communities of the future may become increasingly fragile and unstable.

  18. Assessing climate change effects on European crop yields using the Crop Growth

    NARCIS (Netherlands)

    Supit, I.; Diepen, van C.A.; Wit, de A.J.W.; Wolf, J.; Kabat, P.; Baruth, B.; Ludwig, F.

    2012-01-01

    Climate change impacts on potential and rainfed crop yields on the European continent were studied using output of three General Circulation Models and the Crop Growth Monitoring System in combination with a weather generator. Climate change impacts differ per crop type and per CO2 emission

  19. Life on a warmer earth: possible climatic consequences of man-made global warming. [Monograph

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    A summary of research conducted by the International Institute for Applied Systems Analysis (IIASA) and published by H. Flohn in 1977 updates the original data to March 1980. The work explores the interaction between energy and climate, including the impact on the global climate of three main energy sources: solar, nuclear, and fossil fuels. Its findings describe the global warming effects caused by carbon dioxide released by burning fossil fuels and by other trace gases released into the atmosphere. The approach is paleoclimatic in that it gains insights into what global warming will produce by considering what is known about past periods of the earth's history when the global average surface temperature was higher than it is now. Although paleoclimatic knowledge is limited, no complete model of the climatic system is available. This research uses both approaches, combining the two to some extent. 10 figures.

  20. Low climate stabilisation under diverse growth and convergence scenarios

    International Nuclear Information System (INIS)

    Markandya, A.; González-Eguino, M.; Criqui, P.; Mima, S.

    2014-01-01

    In the last decade a number of papers have analysed the consequences of achieving the greenhouse gas concentration levels necessary to maintain global temperature increases below 2 °C above preindustrial levels. Most models and scenarios assume that future trends in global GDP will be similar to the growth experienced in the past century, which would imply multiplying current output by about 19 times in the 21st century. However, natural resource and environmental constraints suggest that future global economic growth may not be so high. Furthermore, the environmental implications of such growth depend on how it is distributed across countries. This paper studies the implications on GHG abatement policies of low global GDP growth and high convergence levels in GDP per capita across countries. A partial equilibrium model (POLES) of the world's energy system is used to provide detailed projections up to 2050 for the different regions of the world. The results suggest that while low stabilisation could be technically feasible and economically viable for the world in all the scenarios considered, it is more likely to occur with more modest global growth. However, that will imply higher global abatement costs relative to GDP. Convergence in living standards on the other hand places greater pressures in terms of the required reduction in emissions. In general we find that there are major differences between regions in terms of the size and the timing of abatement costs and economic impact. - Highlights: • We study the implications of GDP growth and convergence on climate stabilisation. • A partial equilibrium model (POLES) of the world's energy system is used. • Low climate stabilisation is technically feasible and economically viable. • Low stabilisation is more likely to occur with more modest global growth. • Convergence places pressure in terms of the required reduction in emissions

  1. Climate Change in Voyageurs National Park

    Science.gov (United States)

    Seeley, M. W.

    2011-12-01

    Voyageurs National Park was created in 1975. This beautifully forested and lake-dominated landscape shared between Minnesota and Canada has few roads and must be seen by water. The islands and Kabetogama Peninsula are part of the Canadian Shield, some of the oldest exposed rock in the world. Voyageurs National Park boasts many unique landscape and climatic attributes, and like most mid-latitude regions of the northern hemisphere climate change is in play there. The statistical signals of change in the climate record are evident from both temperature and precipitation measurements. The history of these measurements goes back over 100 years. Additionally, studies and measurements of the lakes and general ecosystem already show some consequences of these climate changes. Mean temperature measurements are generally warmer than they once were, most notably in the winter season. Minimum temperatures have changed more than maximum temperatures. Precipitation has trended upward, but has also changed in character with greater frequency and contribution from thunderstorm rainfalls across the park. In addition variability in annual precipitation has become more amplified, as the disparity between wet and dry years has grown wider. Some changes are already in evidence in terms of bird migration patterns, earlier lake ice-out dates, warmer water temperatures with more algal blooms, decline in lake clarity, and somewhat longer frost-free seasons. Climate change will continue to have impacts on Voyageurs National Park, and likely other national parks across the nation. Furthermore scientists may find that the study, presentation, and discussion about climate impacts on our national parks is a particularly engaging way to educate citizens and improve climate literacy as we contemplate what adaptation and mitigation policies should be enacted to preserve the quality of our national parks for future generations.

  2. Disentangling the climate-driven bimodal growth pattern in coastal and continental Mediterranean pine stands.

    Science.gov (United States)

    Pacheco, Arturo; Camarero, J Julio; Ribas, Montse; Gazol, Antonio; Gutierrez, E; Carrer, Marco

    2018-02-15

    Mediterranean climate promotes two distinct growth peaks separated by summer quiescence in trees. This bimodal pattern has been associated to favourable growing conditions during spring and autumn when mild temperatures and soil-water availability enhance cambial activity. Climatic models predict progressive warming and drying for the Mediterranean Basin, which could shorten or shift the spring and autumn growing seasons. We explored this idea by comparing two sites with different Mediterranean climate types (continental/dry and coastal/wet) and studied how climate drives the bimodal growth pattern in Aleppo pine (Pinus halepensis). Specifically we investigated the intra-annual changes in wood anatomy and the corresponding formation of density fluctuations (IADF). Trees on both sites were analyzed by dendrometer monitoring and by developing chronologies of wood anatomical traits. Radial-increment dynamics followed a similar bimodal pattern in both sites but coastal trees showed higher increments during the spring and autumn growth peaks, especially in autumn. The summer rest of cambium activity occurs almost one month earlier in the coastal than in the inland site. Lumen area and cell-wall thickness were significantly smaller in the continental site, while the increment rate of cell-wall thickness during an IADF event was much higher in the coastal pines. The accumulated soil moisture deficit was the main climatic constraint of tracheid enlargement in continental pines. Intra-annual density fluctuations were more frequent in the coastal trees where wood anatomy features recover to average values after such events, meanwhile inland trees presented a much lower recovery rate. Growth bimodality and the formation of density fluctuations were linked, but mild climate of the coastal site allows a longer growing season, which explains why trees in this area showed higher and more variable growth rates. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Climate change leads to decreasing bird migration distances

    NARCIS (Netherlands)

    Visser, M.E.; Perdeck, A.C.; van Balen, J.H.; Both, C.

    2009-01-01

    Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

  4. Climate change leads to decreasing bird migration distances

    NARCIS (Netherlands)

    Visser, Marcel E.; Perdeck, Albert C.; van Balen, Johan H.; Both, Christiaan

    Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

  5. Rapid warming forces contrasting growth trends of subalpine fir ( Abies fabri ) at higher- and lower-elevations in the eastern Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenzhi; Jia, Min; Wang, Genxu; Zhu, Wanze; McDowell, Nate G.

    2017-10-01

    Tree radial growth is expected to increase at higher elevations under climate warming, while lower elevation tree growth is expected to decline. However, numerous studies have found tree radial growth responds consistently to climate along elevational gradients. Here, we sampled five plots across the subalpine Abies fabri forest belt on Gongga Mountain in the eastern Tibetan Plateau to determine tree radial growth trends and responses to climate. Three commonly used detrending methods all consistently showed that tree radial growth at high elevation (> 3100 m) increased, while tree growth declined at the lower elevations (2700 m–2900 m) over the last three decades. Increasing late-growing season temperature positively (p < 0.05) correlated to tree radial growth at higher elevations, but the sign of this relationship reversed to become negative at lower elevations. Moving-window correlation analyses indicated the difference between high and low elevations response to temperature variation increased strongly with warming. Placing our result into the global context, 62% of 39 published studies found that trees along elevation gradients respond divergently to warming, and that these are located in warmer and wetter regions of the Earth. Notably, 28% of studies found non-significant responses to temperature at both high and low elevations. Our findings in the subalpine mountain forest in the eastern Tibetan Plateau were consistent with the majority of published datasets, and imply increasing temperature benefit for tree populations at higher elevation, while warming dampens growth at lower elevations.

  6. Human health impacts in a changing South African climate

    CSIR Research Space (South Africa)

    Wright, CY

    2014-08-01

    Full Text Available Climate change is projected to lead to warmer temperatures, especially in southern Africa, where the warming is predicted to be 2°C higher than the global increase. Given the high burden of disease already associated with environmental factors...

  7. Contrasting growth forecasts across the geographical range of Scots pine due to altitudinal and latitudinal differences in climatic sensitivity.

    Science.gov (United States)

    Matías, Luis; Linares, Juan C; Sánchez-Miranda, Ángela; Jump, Alistair S

    2017-10-01

    Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of a species' geographical distribution, where differences in growth or population dynamics may result in range expansions or contractions. Understanding population responses to different climatic drivers along wide latitudinal and altitudinal gradients is necessary in order to gain a better understanding of plant responses to ongoing increases in global temperature and drought severity. We selected Scots pine (Pinus sylvestris L.) as a model species to explore growth responses to climatic variability (seasonal temperature and precipitation) over the last century through dendrochronological methods. We developed linear models based on age, climate and previous growth to forecast growth trends up to year 2100 using climatic predictions. Populations were located at the treeline across a latitudinal gradient covering the northern, central and southernmost populations and across an altitudinal gradient at the southern edge of the distribution (treeline, medium and lower elevations). Radial growth was maximal at medium altitude and treeline of the southernmost populations. Temperature was the main factor controlling growth variability along the gradients, although the timing and strength of climatic variables affecting growth shifted with latitude and altitude. Predictive models forecast a general increase in Scots pine growth at treeline across the latitudinal distribution, with southern populations increasing growth up to year 2050, when it stabilizes. The highest responsiveness appeared at central latitude, and moderate growth increase is projected at the northern limit. Contrastingly, the model forecasted growth declines at lowland-southern populations, suggesting an upslope range displacement over the coming decades. Our results give insight into the geographical responses of tree species to climate change

  8. Adapting silviculture to a changing climate in the southern United States

    Science.gov (United States)

    James M. Guldin

    2014-01-01

    Questions about how forests might respond to climate change are often addressed through planning, prediction, and modeling at the landscape scale. A recent synthesis of climate-change impacts on forest management and policy found that the earth is warmer than it has been in the recent past, and that 11 of the last 12 years rank among the 12 warmest since 1850 (Solomon...

  9. The influence of recent climate change on tree height growth differs with species and spatial environment.

    Science.gov (United States)

    Messaoud, Yassine; Chen, Han Y H

    2011-02-16

    Tree growth has been reported to increase in response to recent global climate change in controlled and semi-controlled experiments, but few studies have reported response of tree growth to increased temperature and atmospheric carbon dioxide (CO₂) concentration in natural environments. This study addresses how recent global climate change has affected height growth of trembling aspen (Populus tremuloides Michx) and black spruce (Picea mariana Mill B.S.) in their natural environments. We sampled 145 stands dominated by aspen and 82 dominated by spruce over the entire range of their distributions in British Columbia, Canada. These stands were established naturally after fire between the 19th and 20th centuries. Height growth was quantified as total heights of sampled dominant and co-dominant trees at breast-height age of 50 years. We assessed the relationships between 50-year height growth and environmental factors at both spatial and temporal scales. We also tested whether the tree growth associated with global climate change differed with spatial environment (latitude, longitude and elevation). As expected, height growth of both species was positively related to temperature variables at the regional scale and with soil moisture and nutrient availability at the local scale. While height growth of trembling aspen was not significantly related to any of the temporal variables we examined, that of black spruce increased significantly with stand establishment date, the anomaly of the average maximum summer temperature between May-August, and atmospheric CO₂ concentration, but not with the Palmer Drought Severity Index. Furthermore, the increase of spruce height growth associated with recent climate change was higher in the western than in eastern part of British Columbia. This study demonstrates that the response of height growth to recent climate change, i.e., increasing temperature and atmospheric CO₂ concentration, did not only differ with tree species, but

  10. 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...

  11. Physical and economic consequences of climate change in Europe.

    Science.gov (United States)

    Ciscar, Juan-Carlos; Iglesias, Ana; Feyen, Luc; Szabó, László; Van Regemorter, Denise; Amelung, Bas; Nicholls, Robert; Watkiss, Paul; Christensen, Ole B; Dankers, Rutger; Garrote, Luis; Goodess, Clare M; Hunt, Alistair; Moreno, Alvaro; Richards, Julie; Soria, Antonio

    2011-02-15

    Quantitative estimates of the economic damages of climate change usually are based on aggregate relationships linking average temperature change to loss in gross domestic product (GDP). However, there is a clear need for further detail in the regional and sectoral dimensions of impact assessments to design and prioritize adaptation strategies. New developments in regional climate modeling and physical-impact modeling in Europe allow a better exploration of those dimensions. This article quantifies the potential consequences of climate change in Europe in four market impact categories (agriculture, river floods, coastal areas, and tourism) and one nonmarket impact (human health). The methodology integrates a set of coherent, high-resolution climate change projections and physical models into an economic modeling framework. We find that if the climate of the 2080s were to occur today, the annual loss in household welfare in the European Union (EU) resulting from the four market impacts would range between 0.2-1%. If the welfare loss is assumed to be constant over time, climate change may halve the EU's annual welfare growth. Scenarios with warmer temperatures and a higher rise in sea level result in more severe economic damage. However, the results show that there are large variations across European regions. Southern Europe, the British Isles, and Central Europe North appear most sensitive to climate change. Northern Europe, on the other hand, is the only region with net economic benefits, driven mainly by the positive effects on agriculture. Coastal systems, agriculture, and river flooding are the most important of the four market impacts assessed.

  12. Quantifying the health impacts of air pollution under a changing climate-a review of approaches and methodology.

    Science.gov (United States)

    Sujaritpong, Sarunya; Dear, Keith; Cope, Martin; Walsh, Sean; Kjellstrom, Tord

    2014-03-01

    Climate change has been predicted to affect future air quality, with inevitable consequences for health. Quantifying the health effects of air pollution under a changing climate is crucial to provide evidence for actions to safeguard future populations. In this paper, we review published methods for quantifying health impacts to identify optimal approaches and ways in which existing challenges facing this line of research can be addressed. Most studies have employed a simplified methodology, while only a few have reported sensitivity analyses to assess sources of uncertainty. The limited investigations that do exist suggest that examining the health risk estimates should particularly take into account the uncertainty associated with future air pollution emissions scenarios, concentration-response functions, and future population growth and age structures. Knowledge gaps identified for future research include future health impacts from extreme air pollution events, interactions between temperature and air pollution effects on public health under a changing climate, and how population adaptation and behavioural changes in a warmer climate may modify exposure to air pollution and health consequences.

  13. Chemical Hand Warmer Packet Ingestion: A Case of Elemental Iron Exposure.

    Science.gov (United States)

    Weiland, Jessica L; Sherrow, Leighanne K; Jayant, Deepak A; Katz, Kenneth D

    2017-09-01

    For individuals who work outdoors in the winter or play winter sports, chemical hand warmers are becoming increasingly more commonplace because of their convenience and effectiveness. A 32-year-old woman with a history of chronic pain and bipolar disorder presented to the emergency department complaining of a "warm sensation" in her mouth and epigastrium after reportedly ingesting the partial contents of a chemical hand warmer packet containing between 5 and 8 g of elemental iron. She had been complaining of abdominal pain for approximately 1 month and was prescribed unknown antibiotics the previous day. The patient denied ingestion of any other product or medication other than what was prescribed. A serum iron level obtained approximately 6 hours after ingestion measured 235 micrograms/dL (reference range 40-180 micrograms/dL). As the patient demonstrated no new abdominal complaints and no evidence of systemic iron toxicity, she was discharged uneventfully after education. However, the potential for significant iron toxicity exists depending on the extent of exposure to this or similar products. Treatment for severe iron toxicity may include fluid resuscitation, whole bowel irrigation, and iron chelation therapy with deferoxamine. Physicians should become aware of the toxicity associated with ingestion of commercially available hand warmers. Consultation with a medical toxicologist is recommended. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  14. Linkages between Alaskan sockeye salmon abundance, growth at sea, and climate, 1955-2002

    Science.gov (United States)

    Ruggerone, G.T.; Nielsen, J.L.; Bumgarner, J.

    2007-01-01

    We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976-1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976-1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean. ?? 2007 Elsevier Ltd. All rights reserved.

  15. Are whooping cranes destined for extinction? Climate change imperils recruitment and population growth.

    Science.gov (United States)

    Butler, Matthew J; Metzger, Kristine L; Harris, Grant M

    2017-04-01

    Identifying climatic drivers of an animal population's vital rates and locating where they operate steers conservation efforts to optimize species recovery. The population growth of endangered whooping cranes ( Grus americana ) hinges on juvenile recruitment. Therefore, we identify climatic drivers (solar activity [sunspots] and weather) of whooping crane recruitment throughout the species' life cycle (breeding, migration, wintering). Our method uses a repeated cross-validated absolute shrinkage and selection operator approach to identify drivers of recruitment. We model effects of climate change on those drivers to predict whooping crane population growth given alternative scenarios of climate change and solar activity. Years with fewer sunspots indicated greater recruitment. Increased precipitation during autumn migration signified less recruitment. On the breeding grounds, fewer days below freezing during winter and more precipitation during breeding suggested less recruitment. We predicted whooping crane recruitment and population growth may fall below long-term averages during all solar cycles when atmospheric CO 2 concentration increases, as expected, to 500 ppm by 2050. Species recovery during a typical solar cycle with 500 ppm may require eight times longer than conditions without climate change and the chance of population decline increases to 31%. Although this whooping crane population is growing and may appear secure, long-term threats imposed by climate change and increased solar activity may jeopardize its persistence. Weather on the breeding grounds likely affects recruitment through hydrological processes and predation risk, whereas precipitation during autumn migration may influence juvenile mortality. Mitigating threats or abating climate change should occur within ≈30 years or this wild population of whooping cranes may begin declining.

  16. Inconclusive Predictions and Contradictions: A Lack of Consensus on Seed Germination Response to Climate Change at High Altitude and High Latitude

    Directory of Open Access Journals (Sweden)

    Ganesh K. Jaganathan

    2016-01-01

    Full Text Available Climate change directly affects arctic-alpine plants and acute responses to increased temperatures may be seen in their reproductive fitness and germination ability. However, uncertainties prevail in predicting whether a future warmer climate favors or hampers seed germination in high latitude and high altitude soils and seed germination research in such systems has not been able to provide generalizable patterns of response. The available literature on this subject has been conducted at various locations contributing to difficulties in predicting the response of arctic-alpine seeds to climate change. Here, we show that discrepancies in seed collection, dormancy breaking treatments, and germination conditions found in the published literature are possible reasons for our inability to draw large scale conclusions. We explore how these factors influence the results and highlight the fact that many of the previous investigations have reported the effects of warmer temperature, rather than a warmer climate and all the associated complex environmental interactions, on seed germination. We recommend that long-term monitoring of seed response to treatments that mimic the present and future alpine climate is likely to produce more ecologically meaningful insights and suggest several practical steps that researchers can take that would facilitate greater coherence between studies.

  17. Interspecific variation in growth responses to tree size, competition and climate of western Canadian boreal mixed forests.

    Science.gov (United States)

    Jiang, Xinyu; Huang, Jian-Guo; Cheng, Jiong; Dawson, Andria; Stadt, Kenneth J; Comeau, Philip G; Chen, Han Y H

    2018-08-01

    Tree growth of boreal forest plays an important role on global carbon (C) cycle, while tree growth in the western Canadian boreal mixed forests has been predicted to be negatively affected by regional drought. Individual tree growth can be controlled by many factors, such as competition, climate, tree size and age. However, information about contributions of different factors to tree growth is still limited in this region. In order to address this uncertainty, tree rings of two dominant tree species, trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca (Moench.) Voss), were sampled from boreal mixed forest stands distributed across Alberta, Canada. Tree growth rates over different time intervals (10years interval, 1998-2007; 20years interval, 1988-2007; 30years interval, 1978-2007) were calculated to study the effects of different factors (tree size, competition, climate, and age) on tree growth. Results indicated that tree growth of two species were both primarily affected by competition or tree size, while climatic indices showed less effects on tree growth. Growth of trembling aspen was significantly affected by inter- and intraspecific competition, while growth of white spruce was primarily influenced by tree size, followed by competition. Positive relationship was found between growth of white spruce and competition index of coniferous group, suggesting an intraspecific mutualism mechanism within coniferous group. Our results further suggested that competition driven succession was the primary process of forest composition shift in the western Canadian boreal mixed forest. Although drought stress increased tree mortality, decline of stem density under climate change released competition stress of surviving trees, which in turn sustained growth of surviving trees. Therefore, climatic indices showed fewer effects on growth of dominant tree species compared to other factors in our study. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Phenological Shifts in Animals Under Contemporary Climate Change

    NARCIS (Netherlands)

    Visser, M.E.; Roitberg, Bernard D.

    2017-01-01

    One of the best documented impacts of climate change has been on the seasonal timing, or phenology, of species. There are clear shifts in all taxonomic groups in terrestrial, aquatic, and marine environments. There is, however, ample variation in the rate at which species shift in response to warmer

  19. A farm-level analysis of economic and agronomic impacts of gradual climate warming

    International Nuclear Information System (INIS)

    Kaiser, H.M.; Sampath, R.; Riha, S.J.; Wilks, D.S.; Rossiter, D.G.

    1993-01-01

    The potential economic and agronomic impacts of gradual climate warming are examined at the farm level. Three models of the relevant climatic, agronomic, and economic processes are developed and linked to address climate change impacts and agricultural adaptability. Several climate warming severity. The results indicate that grain farmers in southern Minnesota can effectively adapt to a gradually changing climate (warmer and either wetter or drier) by adopting later maturing cultivars, changing crop mix, and altering the timing of field operations to take advantage of a longer growing season resulting from climate warming

  20. Fine-scale variability in growth-climate relationships of Douglas-fir, North Cascade Range, Washington.

    Science.gov (United States)

    Michael J. Case; David L. Peterson

    2005-01-01

    Information about the sensitivity to climate of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is valuable because it will allow forest managers to maximize growth, better understand how carbon sequestration may change over time, and better model and predict future ecosystem responses to climatic change. We examined the effects of climatic...

  1. A risk assessment of climate change and the impact of forest diseases on forest ecosystems in the Western United States and Canada

    Science.gov (United States)

    John T. Kliejunas

    2011-01-01

    This risk assessment projects the effects of eight forest diseases under two climate-change scenarios (warmer and drier, warmer and wetter). Examples are used to describe how various types of forest diseases may respond to environmental changes. Forest diseases discussed in this report include foliar diseases, Phytophthora diseases, stem rusts,...

  2. Health effects of a warmer climate - a knowledge review; Haelsopaaverkan av ett varmare klimat - en kunskapsoeversikt

    Energy Technology Data Exchange (ETDEWEB)

    Rockloev, Joacim; Hurtig, Anna-Karin; Forsberg, Bertil [Umeaa Univ. (SE). Dept. of Public Health and Clinical Medicine

    2008-01-15

    Global warming has caused changes that can already be seen and that motivates considerations of the possible adaptation measures needed to protect people and public health. Expert bodies such as the United Nations International Panel on Climate Change (IPCC) now conduct model simulations on how the world's climate is expected to change depending on, for example, the emission of greenhouse gases. The Swedish SMHI has provided scenarios for how the future climate in Sweden may develop. These assume an increase in the winter temperature of 3-8 deg C in winter and 1-5 deg C during summer, compared to the period 1961-1990. In addition, these scenarios indicate increased precipitation especially in northern Sweden, a greater risk of drought in Skaane during summer, as well as an increased risk of extreme events such as storms, heavy rainfall and heat waves. The climate change may affect health and its determinants in a number of different ways. The effects may be direct, as in extreme weather conditions, and also indirect, such as the influence of changes in climate and the environment on the spread of infectious diseases as well as the far-reaching effects of changes in other parts of the world. The aim of this overview report is to briefly present our current understanding of how health risks and public health may be affected. The presentations of potential consequences are partly built using knowledge of the associations between climate and health in various regions to draw analogies for areas expected to undergo changes that will make their climate more similar to current conditions in other regions. Distribution of vector-borne diseases can be determined by the type of climate a certain mosquito can survive. In the future we may face outbreaks of diseases that are new to us. Another way of making predictions is to use the observations of how health effects relate to weather variations in one place, for example, temperature fluctuations. In this regard we already

  3. Health effects of a warmer climate - a knowledge review; Haelsopaaverkan av ett varmare klimat - en kunskapsoeversikt

    Energy Technology Data Exchange (ETDEWEB)

    Rockloev, Joacim; Hurtig, Anna-Karin; Forsberg, Bertil (Umeaa Univ. (SE). Dept. of Public Health and Clinical Medicine)

    2008-01-15

    Global warming has caused changes that can already be seen and that motivates considerations of the possible adaptation measures needed to protect people and public health. Expert bodies such as the United Nations International Panel on Climate Change (IPCC) now conduct model simulations on how the world's climate is expected to change depending on, for example, the emission of greenhouse gases. The Swedish SMHI has provided scenarios for how the future climate in Sweden may develop. These assume an increase in the winter temperature of 3-8 deg C in winter and 1-5 deg C during summer, compared to the period 1961-1990. In addition, these scenarios indicate increased precipitation especially in northern Sweden, a greater risk of drought in Skaane during summer, as well as an increased risk of extreme events such as storms, heavy rainfall and heat waves. The climate change may affect health and its determinants in a number of different ways. The effects may be direct, as in extreme weather conditions, and also indirect, such as the influence of changes in climate and the environment on the spread of infectious diseases as well as the far-reaching effects of changes in other parts of the world. The aim of this overview report is to briefly present our current understanding of how health risks and public health may be affected. The presentations of potential consequences are partly built using knowledge of the associations between climate and health in various regions to draw analogies for areas expected to undergo changes that will make their climate more similar to current conditions in other regions. Distribution of vector-borne diseases can be determined by the type of climate a certain mosquito can survive. In the future we may face outbreaks of diseases that are new to us. Another way of making predictions is to use the observations of how health effects relate to weather variations in one place, for example, temperature fluctuations. In this regard we

  4. Response of northern hemisphere environmental and atmospheric conditions to climate changes using Greenland aerosol records from the Eemian to the Holocene

    Science.gov (United States)

    Fischer, H.

    2017-12-01

    The Northern Hemisphere experienced dramatic climate changes over the last glacial cycle, including vast ice sheet expansion and frequent abrupt climate events. Moreover, high northern latitudes during the last interglacial (Eemian) were warmer than today and may provide guidance for future climate change scenarios. However, little evidence exists regarding the environmental alterations connected to these climate changes. Using aerosol concentration records in decadal resolution from the North Greenland Eemian Ice Drilling (NEEM) over the last 128,000 years we extract quantitative information on environmental changes, including the first comparison of northern hemisphere environmental conditions between the warmer than present Eemian and the early Holocene. Separating source changes from transport effects, we find that changes in the ice concentration greatly overestimate the changes in atmospheric concentrations in the aerosol source region, the latter mirroring changes in aerosol emissions. Glacial times were characterized by a strong reduction in terrestrial biogenic emissions (only 10-20% of the early Holocene value) reflecting the net loss of vegetated area in mid to high latitudes, while rapid climate changes during the glacial had essentially no effect on terrestrial biogenic aerosol emissions. An increase in terrestrial dust emissions of approximately a factor of eight during peak glacial and cold stadial intervals indicates higher aridity and dust storm activity in Asian deserts. Glacial sea salt aerosol emissions increased only moderately (by approximately 50%), likely due to sea ice expansion, while marked stadial/interstadial variations in sea salt concentrations in the ice reflect mainly changes in wet deposition en route. Eemian ice contains lower aerosol concentrations than ice from the early Holocene, due to shortened atmospheric residence time during the warmer Eemian, suggesting that generally 2°C warmer climate in high northern latitudes did not

  5. Live Fast, Die Young: Experimental Evidence of Population Extinction Risk due to Climate Change

    Science.gov (United States)

    Bestion, Elvire; Teyssier, Aimeric; Richard, Murielle; Clobert, Jean; Cote, Julien

    2015-01-01

    Evidence has accumulated in recent decades on the drastic impact of climate change on biodiversity. Warming temperatures have induced changes in species physiology, phenology, and have decreased body size. Such modifications can impact population dynamics and could lead to changes in life cycle and demography. More specifically, conceptual frameworks predict that global warming will severely threaten tropical ectotherms while temperate ectotherms should resist or even benefit from higher temperatures. However, experimental studies measuring the impacts of future warming trends on temperate ectotherms' life cycle and population persistence are lacking. Here we investigate the impacts of future climates on a model vertebrate ectotherm species using a large-scale warming experiment. We manipulated climatic conditions in 18 seminatural populations over two years to obtain a present climate treatment and a warm climate treatment matching IPCC predictions for future climate. Warmer temperatures caused a faster body growth, an earlier reproductive onset, and an increased voltinism, leading to a highly accelerated life cycle but also to a decrease in adult survival. A matrix population model predicts that warm climate populations in our experiment should go extinct in around 20 y. Comparing our experimental climatic conditions to conditions encountered by populations across Europe, we suggest that warming climates should threaten a significant number of populations at the southern range of the distribution. Our findings stress the importance of experimental approaches on the entire life cycle to more accurately predict population and species persistence in future climates. PMID:26501958

  6. Impact of population growth and population ethics on climate change mitigation policy.

    Science.gov (United States)

    Scovronick, Noah; Budolfson, Mark B; Dennig, Francis; Fleurbaey, Marc; Siebert, Asher; Socolow, Robert H; Spears, Dean; Wagner, Fabian

    2017-11-14

    Future population growth is uncertain and matters for climate policy: higher growth entails more emissions and means more people will be vulnerable to climate-related impacts. We show that how future population is valued importantly determines mitigation decisions. Using the Dynamic Integrated Climate-Economy model, we explore two approaches to valuing population: a discounted version of total utilitarianism (TU), which considers total wellbeing and is standard in social cost of carbon dioxide (SCC) models, and of average utilitarianism (AU), which ignores population size and sums only each time period's discounted average wellbeing. Under both approaches, as population increases the SCC increases, but optimal peak temperature decreases. The effect is larger under TU, because it responds to the fact that a larger population means climate change hurts more people: for example, in 2025, assuming the United Nations (UN)-high rather than UN-low population scenario entails an increase in the SCC of 85% under TU vs. 5% under AU. The difference in the SCC between the two population scenarios under TU is comparable to commonly debated decisions regarding time discounting. Additionally, we estimate the avoided mitigation costs implied by plausible reductions in population growth, finding that large near-term savings ($billions annually) occur under TU; savings under AU emerge in the more distant future. These savings are larger than spending shortfalls for human development policies that may lower fertility. Finally, we show that whether lowering population growth entails overall improvements in wellbeing-rather than merely cost savings-again depends on the ethical approach to valuing population. Copyright © 2017 the Author(s). Published by PNAS.

  7. Climate change alters the reproductive phenology and investment of a lacustrine fish, the three-spine stickleback.

    Science.gov (United States)

    Hovel, Rachel A; Carlson, Stephanie M; Quinn, Thomas P

    2017-06-01

    High-latitude lakes are particularly sensitive to the effects of global climate change, demonstrating earlier ice breakup, longer ice-free seasons, and increased water temperatures. Such physical changes have implications for diverse life-history traits in taxa across entire lake food webs. Here, we use a five-decade time series from an Alaskan lake to explore effects of climate change on growth and reproduction of a widely distributed lacustrine fish, the three-spine stickleback (Gasterosteus aculeatus). We used multivariate autoregressive state-space (MARSS) models to describe trends in the mean length for multiple size classes and to explore the influence of physical (date of ice breakup, surface water temperature) and biological (density of con- and heterospecifics) factors. As predicted, mean size of age 1 and older fish at the end of the growing season increased across years with earlier ice breakup and warmer temperatures. In contrast, mean size of age 0 fish decreased over time. Overall, lower fish density and warmer water temperatures were associated with larger size for all cohorts. Earlier ice breakup was associated with larger size for age 1 and older fish but, paradoxically, with smaller size of age 0 fish. To explore this latter result, we used mixing models on age 0 size distributions, which revealed an additional cohort in years with early ice breakup, lowering the mean size of age 0 fish. Moreover, early ice breakup was associated with earlier breeding, evidenced by earlier capture of age 0 fish. Our results suggest that early ice breakup altered both timing and frequency of breeding; three-spine stickleback spawned earlier and more often in response to earlier ice breakup date. While previous studies have shown the influence of changing conditions in northern lakes on breeding timing and growth, this is the first to document increased breeding frequency, highlighting another pathway by which climate change can alter the ecology of northern lakes

  8. Difference in tree growth responses to climate at the upper treeline: Qilian Juniper in the Anyemaqen Mountains.

    Science.gov (United States)

    Peng, Jianfeng; Gou, Xiaohua; Chen, Fahu; Li, Jinbao; Liu, Puxing; Zhang, Yong; Fang, Keyan

    2008-08-01

    Three ring-width chronologies were developed from Qilian Juniper (Sabina przewalskii Kom.) at the upper treeline along a west-east gradient in the Anyemaqen Mountains. Most chronological statistics, except for mean sensitivity (MS), decreased from west to east. The first principal component (PC1) loadings indicated that stands in a similar climate condition were most important to the variability of radial growth. PC2 loadings decreased from west to east, suggesting the difference of tree-growth between eastern and western Anyemaqen Mountains. Correlations between standard chronologies and climatic factors revealed different climatic influences on radial growth along a west-east gradient in the study area. Temperature of warm season (July-August) was important to the radial growth at the upper treeline in the whole study area. Precipitation of current May was an important limiting factor of tree growth only in the western (drier) upper treeline, whereas precipitation of current September limited tree growth in the eastern (wetter) upper treeline. Response function analysis results showed that there were regional differences between tree growth and climatic factors in various sampling sites of the whole study area. Temperature and precipitation were the important factors influencing tree growth in western (drier) upper treeline. However, tree growth was greatly limited by temperature at the upper treeline in the middle area, and was more limited by precipitation than temperature in the eastern (wetter) upper treeline.

  9. Suitability of European climate for the Asian tiger mosquito Aedes albopictus: recent trends and future scenarios

    Science.gov (United States)

    Caminade, Cyril; Medlock, Jolyon M.; Ducheyne, Els; McIntyre, K. Marie; Leach, Steve; Baylis, Matthew; Morse, Andrew P.

    2012-01-01

    The Asian tiger mosquito (Aedes albopictus) is an invasive species that has the potential to transmit infectious diseases such as dengue and chikungunya fever. Using high-resolution observations and regional climate model scenarios for the future, we investigated the suitability of Europe for A. albopictus using both recent climate and future climate conditions. The results show that southern France, northern Italy, the northern coast of Spain, the eastern coast of the Adriatic Sea and western Turkey were climatically suitable areas for the establishment of the mosquito during the 1960–1980s. Over the last two decades, climate conditions have become more suitable for the mosquito over central northwestern Europe (Benelux, western Germany) and the Balkans, while they have become less suitable over southern Spain. Similar trends are likely in the future, with an increased risk simulated over northern Europe and slightly decreased risk over southern Europe. These distribution shifts are related to wetter and warmer conditions favouring the overwintering of A. albopictus in the north, and drier and warmer summers that might limit its southward expansion. PMID:22535696

  10. RELATIONSHIP BETWEEN CLIMATE VARIABLES, TRUNK GROWTH RATE AND WOOD DENSITY OF Eucalyptus grandis W. Mill ex Maiden TREES

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Sette Jr

    2016-04-01

    Full Text Available ABSTRACT Climatic conditions stimulates the cambial activity of plants, and cause significant changes in trunk diameter growth and wood characteristics. The objective of this study was to evaluate the influence of climate variables in the diameter growth rate of the stem and the wood density of Eucalyptus grandis trees in different classes of the basal area. A total of 25 Eucalyptus trees at 22 months of age were selected according to the basal area distribution. Dendrometer bands were installed at the height of 1.30 meters (DBH to monitor the diameter growth every 14 days, for 26 months. After measuring growth, the trees were felled and wood discs were removed at the DBH level to determine the radial density profile through x-ray microdensitometry and then re-scale the average values every 14 days. Climatic variables for the monitoring period were obtained and grouped every 14 days. The effect of the climate variables was determined by maximum and minimum growth periods in assessing trunk growth. These growth periods were related with precipitation, average temperature and relative air humidity. The re-scaled wood density values, calculated using the radial growth of the tree trunks measured accurately with steel dendrometers, enabled the determination of the relationship of small changes in wood density and the effect of the climatic variations and growth rate of eucalyptus tree trunks. A high sensitivity of the wood density to variation in precipitation levels was found.

  11. Vascular plant-mediated controls on atmospheric carbon assimilation and peat carbon decomposition under climate change.

    Science.gov (United States)

    Gavazov, Konstantin; Albrecht, Remy; Buttler, Alexandre; Dorrepaal, Ellen; Garnett, Mark H; Gogo, Sebastien; Hagedorn, Frank; Mills, Robert T E; Robroek, Bjorn J M; Bragazza, Luca

    2018-03-23

    Climate change can alter peatland plant community composition by promoting the growth of vascular plants. How such vegetation change affects peatland carbon dynamics remains, however, unclear. In order to assess the effect of vegetation change on carbon uptake and release, we performed a vascular plant-removal experiment in two Sphagnum-dominated peatlands that represent contrasting stages of natural vegetation succession along a climatic gradient. Periodic measurements of net ecosystem CO 2 exchange revealed that vascular plants play a crucial role in assuring the potential for net carbon uptake, particularly with a warmer climate. The presence of vascular plants, however, also increased ecosystem respiration, and by using the seasonal variation of respired CO 2 radiocarbon (bomb- 14 C) signature we demonstrate an enhanced heterotrophic decomposition of peat carbon due to rhizosphere priming. The observed rhizosphere priming of peat carbon decomposition was matched by more advanced humification of dissolved organic matter, which remained apparent beyond the plant growing season. Our results underline the relevance of rhizosphere priming in peatlands, especially when assessing the future carbon sink function of peatlands undergoing a shift in vegetation community composition in association with climate change. © 2018 John Wiley & Sons Ltd.

  12. Life on a warmer earth: Possible climatic consequences of man-made global warming. Executive report 3

    Energy Technology Data Exchange (ETDEWEB)

    Flohn, H

    1981-01-01

    This Executive Report derives from IIASA Research Report RR-80-30, Possible Climatic Consequences of a Man-Made Global Warming, by H. Flohn and published separately. It is based on research undertaken to explore the interaction between energy and climate, including the impact on the global climate of three main energy sources: solar, nuclear, and fossil fuels. Its findings describe the global warming effects caused by carbon dioxide released by burning fossil fuels and by other trace gases released into the atmosphere. The approach is paleoclimatic; it provides insight into what global warming will produce by considering what is known about past periods of the earth's history when the global average surface temperature was higher than it is now. The purpose of this report is to put the research findings into layman's language and add related information to provide a general introduction to the global warming problem. Information is presented under the following chapter titles: the scenario in brief; the climatic system; changes in ice cover; changes in atmosphere and oceans; man's effect on climate; taking the earth's temperature; what a hotter earth might mean; beyond immediate prospects; and, today's mixed signals. (JGB)

  13. Millennium-scale crossdating and inter-annual climate sensitivities of standing California redwoods.

    Science.gov (United States)

    Carroll, Allyson L; Sillett, Stephen C; Kramer, Russell D

    2014-01-01

    Extremely decay-resistant wood and fire-resistant bark allow California's redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI) helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE) have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood species have

  14. Millennium-scale crossdating and inter-annual climate sensitivities of standing California redwoods.

    Directory of Open Access Journals (Sweden)

    Allyson L Carroll

    Full Text Available Extremely decay-resistant wood and fire-resistant bark allow California's redwoods to accumulate millennia of annual growth rings that can be useful in biological research. Whereas tree rings of Sequoiadendron giganteum (SEGI helped formalize the study of dendrochronology and the principle of crossdating, those of Sequoia sempervirens (SESE have proven much more difficult to decipher, greatly limiting dendroclimatic and other investigations of this species. We overcame these problems by climbing standing trees and coring trunks at multiple heights in 14 old-growth forest locations across California. Overall, we sampled 1,466 series with 483,712 annual rings from 120 trees and were able to crossdate 83% of SESE compared to 99% of SEGI rings. Standard and residual tree-ring chronologies spanning up to 1,685 years for SESE and 1,538 years for SEGI were created for each location to evaluate crossdating and to examine correlations between annual growth and climate. We used monthly values of temperature, precipitation, and drought severity as well as summer cloudiness to quantify potential drivers of inter-annual growth variation over century-long time series at each location. SESE chronologies exhibited a latitudinal gradient of climate sensitivities, contrasting cooler northern rainforests and warmer, drier southern forests. Radial growth increased with decreasing summer cloudiness in northern rainforests and a central SESE location. The strongest dendroclimatic relationship occurred in our southernmost SESE location, where radial growth correlated negatively with dry summer conditions and exhibited responses to historic fires. SEGI chronologies showed negative correlations with June temperature and positive correlations with previous October precipitation. More work is needed to understand quantitative relationships between SEGI radial growth and moisture availability, particularly snowmelt. Tree-ring chronologies developed here for both redwood

  15. Solar variability and climate change: An historical perspective

    Science.gov (United States)

    Feldman, Theodore S.

    There is nothing new about the debate over the Sun's influence on terrestrial climate.As early as the late 18th century, widespread concern for the deterioration of the Earth's climate led to speculation about the Sun's role in climate change [Feldman, 1993; Fleming, 1990]. Drawing analogies with variations in the brightness of stars, the British astronomer William Herschel suggested that greater sunspot activity would result in warmer terrestrial climates. Herschel supported his hypothesis by referring to price series for wheat published in Adam Smiths Wealth of Nations [Hufbauer, 1991]. Later, the eminent American physicist Joseph Henry demonstrated by thermopile measurements that, contrary to Herschel's assumption, sunspots were cooler than the unblemished portions of the solar disk.

  16. Interactions of predominant insects and diseases with climate change in Douglas-fir forests of western Oregon and Washington, U.S.A.

    Science.gov (United States)

    Agne, Michelle C; Beedlow, Peter A; Shaw, David C; Woodruff, David R; Lee, E Henry; Cline, Steven P; Comeleo, Randy L

    2018-02-01

    Forest disturbance regimes are beginning to show evidence of climate-mediated changes, such as increasing severity of droughts and insect outbreaks. We review the major insects and pathogens affecting the disturbance regime for coastal Douglas-fir forests in western Oregon and Washington State, USA, and ask how future climate changes may influence their role in disturbance ecology. Although the physiological constraints of light, temperature, and moisture largely control tree growth, episodic and chronic disturbances interacting with biological factors have substantial impacts on the structure and functioning of forest ecosystems in this region. Understanding insect and disease interactions is critical to predicting forest response to climate change and the consequences for ecosystem services, such as timber, clean water, fish and wildlife. We focused on future predictions for warmer wetter winters, hotter drier summers, and elevated atmospheric CO 2 to hypothesize the response of Douglas-fir forests to the major insects and diseases influencing this forest type: Douglas-fir beetle, Swiss needle cast, black stain root disease, and laminated root rot. We hypothesize that 1) Douglas-fir beetle and black stain root disease could become more prevalent with increasing, fire, temperature stress, and moisture stress, 2) future impacts of Swiss needle cast are difficult to predict due to uncertainties in May-July leaf wetness, but warmer winters could contribute to intensification at higher elevations, and 3) laminated root rot will be influenced primarily by forest management, rather than climatic change. Furthermore, these biotic disturbance agents interact in complex ways that are poorly understood. Consequently, to inform management decisions, insect and disease influences on disturbance regimes must be characterized specifically by forest type and region in order to accurately capture these interactions in light of future climate-mediated changes.

  17. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Science.gov (United States)

    Jiang, Yuan; Zhang, Wentao; Wang, Mingchang; Kang, Muyi; Dong, Manyu

    2014-01-01

    North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1) The two species grew in different rhythms at low and high elevation respectively; (2) Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3) The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4) The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  18. Radial growth of two dominant montane conifer tree species in response to climate change in North-Central China.

    Directory of Open Access Journals (Sweden)

    Yuan Jiang

    Full Text Available North-Central China is a region in which the air temperature has clearly increased for several decades. Picea meyeri and Larix principis-rupprechtii are the most dominant co-occurring tree species within the cold coniferous forest belt ranging vertically from 1800 m to 2800 m a.s.l. in this region. Based on a tree-ring analysis of 292 increment cores sampled from 146 trees at different elevations, this study aimed to examine if the radial growth of the two species in response to climate is similar, whether the responses are consistent along altitudinal gradients and which species might be favored in the future driven by the changing climate. The results indicated the following: (1 The two species grew in different rhythms at low and high elevation respectively; (2 Both species displayed inconsistent relationships between radial growth and climate data along altitudinal gradients. The correlation between radial growth and the monthly mean temperature in the spring or summer changed from negative at low elevation into positive at high elevation, whereas those between the radial growth and the total monthly precipitation displayed a change from positive into negative along the elevation gradient. These indicate the different influences of the horizontal climate and vertical mountainous climate on the radial growth of the two species; (3 The species-dependent different response to climate in radial growth appeared mainly in autumn of the previous year. The radial growth of L. principis-rupprechtii displayed negative responses both to temperature and to precipitation in the previous September, October or November, which was not observed in the radial growth of P. meyeri. (4 The radial growth of both species will tend to be increased at high elevation and limited at low elevation, and L. principis-rupprechtii might be more favored in the future, if the temperature keeps rising.

  19. The Effect of No Agricultural Productivity Growth on Future Land Use and Climate through Biogeophysical Mechanisms

    Science.gov (United States)

    Davies-Barnard, T.; Valdes, P. J.; Singarayer, J. S.; Jones, C.

    2012-12-01

    Future land use and the consequent land cover change will have a significant impact on future climate through biogeophysical (albedo, surface roughness and latent heat transfer, etc.) as well as biogeochemical (greenhouse gas emissions etc.) mechanisms. One of the major determinants of the extent of land use induced land cover change is the agricultural productivity growth within the socio-economic models used for developing the RCP scenarios. There are considerable uncertainties in the size of agricultural productivity under climate change, as yields are projected to vary spatially in signal and strength. Previous climate modeling work has considered the impacts to the carbon cycle of different levels of agricultural productivity growth, but has failed to consider the biogeophysical effects of the land use induced land cover change on climate. Here we examine the climate impacts of the assumption of agricultural productivity growth and business as usual land use. The effects are considered through the biogeophysical land use induced land cover change, using the Hadley Centre climate model HadGEM2. The model simulations use the set biogeochemical climate forcing of the RCP 4.5 scenario, but the biogeophysical land use change specification is altered over a 100 year simulation. Simulations are run with combinations of no land use change; standard RCP 4.5 land use change; business as usual land use change; and zero agricultural productivity growth. The key effect of no agricultural productivity growth is that more cropland is required to feed the same population, necessitating cropland expansion. The expansion of cropland and consequent deforestation increases the albedo and gives an extensive cooling effect in the northern hemisphere (up to 2°C). Differences in global mean temperature between the zero agricultural productivity growth with business as usual land use change specified run and the standard RCP 4.5 run are -0.2°C by 2040 and -0.7°C by 2100. There is

  20. Six Degrees. Our Future on a Hotter Planet; Zes graden. Onze toekomst op een warmere planeet

    Energy Technology Data Exchange (ETDEWEB)

    Lynas, M.

    2008-07-01

    This grade-by-grade guide describes the effects of global warming at 1, 2, 3, 4, 5 and 6C. The author presents scientific scenarios in a row. How can we imagine a warmer climate? Already 1C warming will be a plague for granaries in the USA and tropical cyclones will happen in the Mediterranean Sea. Beyond 2C global warming is irreversible. 3C will burn the Amazon area. Then methane will burst out of the Siberian permafrost and later from the deep sea. At 6C we will be in hell. So we must prevent global warming above 2C. Now we are already at 0.75 C and the thermal inertia of the planet will double that anyway. Serious action is absolutely required. Action that goes far beyond any current policy. [Dutch] Deze graad-voor-graad-gids beschrijft de gevolgen van de opwarming bij 1, 2, 3, 4, 5 en 6C. De auteur zet als eerste alle wetenschappelijke scenario's op een rij. Wat moeten we ons voorstellen bij een warmer klimaat? Al bij 1C teisteren extreme droogtes graanschuur Amerika en verschijnen tropische orkanen in de Middellandse Zee. Voorbij de 2C wordt de opwarming onomkeerbaar. Bij 3C verbrandt het Amazonegebied. Daarna barst methaan uit de Siberische permafrost en later uit de diepzee. Bij 6C betreden we de hel. We moeten dus voorkomen dat de opwarming boven de 2C uitkomt. Nu zitten we al op 0,75C en de thermische traagheid van de planeet gaat dat sowieso nog verdubbelen. Drastische actie is absoluut vereist. Actie die veel verder gaat dan alle huidige beleid.

  1. Climate-associated population declines reverse recovery and threaten future of an iconic high-elevation plant

    Science.gov (United States)

    Krushelnycky, Paul D.; Loope, Lloyd L.; Giambelluca, Thomas W.; Starr, Forest; Starr, Kim; Drake, Donald R.; Taylor, Andrew D.; Robichaux, Robert H.

    2013-01-01

    Although climate change is predicted to place mountain-top and other narrowly endemic species at severe risk of extinction, the ecological processes involved in such extinctions are still poorly resolved. In addition, much of this biodiversity loss will likely go unobserved, and therefore largely unappreciated. The Haleakalā silversword is restricted to a single volcano summit in Hawai‘i, but is a highly charismatic giant rosette plant that is viewed by 1–2 million visitors annually. We link detailed local climate data to a lengthy demographic record, and combine both with a population-wide assessment of recent plant mortality and recruitment, to show that after decades of strong recovery following successful management, this iconic species has entered a period of substantial climate-associated decline. Mortality has been highest at the lower end of the distributional range, where most silverswords occur, and the strong association of annual population growth rates with patterns of precipitation suggests an increasing frequency of lethal water stress. Local climate data confirm trends toward warmer and drier conditions on the mountain, and signify a bleak outlook for silverswords if these trends continue. The silversword example foreshadows trouble for diversity in other biological hotspots, and illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses.

  2. Improving predictions of tropical forest response to climate change through integration of field studies and ecosystem modeling

    Science.gov (United States)

    Xiaohui Feng; María Uriarte; Grizelle González; Sasha Reed; Jill Thompson; Jess K. Zimmerman; Lora Murphy

    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...

  3. Climate-growth relationships for largemouth bass (Micropterus salmoides) across three southeastern USA states

    Science.gov (United States)

    Andrew L. Rypel

    2009-01-01

    The role of climate variability in the ecology of freshwater fishes is of increasing interest. However, there are relatively few tools available for examining how freshwater fish populations respond to climate variations. Here, I apply tree-ring techniques to incremental growth patterns in largemouth bass (Micropterus salmoides Lacepe`de) otoliths to explore...

  4. Effect of warming and flow rate conditions of blood warmers on red blood cell integrity.

    Science.gov (United States)

    Poder, T G; Pruneau, D; Dorval, J; Thibault, L; Fisette, J-F; Bédard, S K; Jacques, A; Beauregard, P

    2016-11-01

    Fluid warmers are routinely used to reduce the risk of hypothermia and cardiac complications associated with the infusion of cold blood products. However, warming blood products could generate haemolysis. This study was undertaken to compare the impact of temperature of blood warmers on the per cent haemolysis of packed red blood cells (RBCs) heated at different flow rates as well as non-flow conditions. Infusion warmers used were calibrated at 41·5°C ± 0·5°C and 37·5°C ± 0·5°C. Cold RBC units stored at 4°C in AS-3 (n = 30), aged 30-39 days old, were divided into half units before being allocated under two different scenarios (i.e. infusion pump or syringe). Blood warmers were effective to warm cold RBCs to 37·5°C or 41·5°C when used in conjunction with an infusion pump at flow rate up to 600 ml/h. However, when the warmed blood was held in a syringe for various periods of time, such as may occur in neonatal transfusions, the final temperature was below the expected requirements with measurement as low as 33·1°C. Increasing the flow with an infusion pump increased haemolysis in RBCs from 0·2% to up to 2·1% at a flow rate of 600 ml/h regardless of the warming device used (P < 0·05). No relevant increase of haemolysis was observed using a syringe. The use of a blood warmer adjusted to 41·5°C is probably the best choice for reducing the risk of hypothermia for the patient without generating haemolysis. However, we should be cautious with the use of an infusion pump for RBC transfusion, particularly at high flow rates. © 2016 International Society of Blood Transfusion.

  5. Genetic variation in Pinus strobiformis growth and drought tolerance from southwestern US populations.

    Science.gov (United States)

    Goodrich, Betsy A; Waring, Kristen M; Kolb, Thomas E

    2016-10-01

    The persistence of some tree species is threatened by combinations of novel abiotic and biotic stressors. To examine the hypothesis that Pinus strobiformis Engelm., a tree threatened by an invasive forest pathogen and a changing climate, exhibits intraspecific genetic variation in adaptive traits, we conducted a common garden study of seedlings at one location with two watering regimes using 24 populations. Four key findings emerged: (i) growth and physiological traits were low to moderately differentiated among populations but differentiation was high for some traits in water-stressed populations; (ii) seedlings from warmer climates grew larger, had higher stomatal density and were more water-use efficient (as measured by the carbon isotope ratio) than populations from colder climates; (iii) seedlings from the northern edge of the species' distribution had lower water-use efficiency, higher stomatal conductance, slower growth and longer survival in a lethal drought experiment compared with seedlings from more southern populations; and (iv) based on non-metric multidimensional scaling analyses, populations clustered into southern and northern groups, which did not correspond to current seed transfer zones. Our discovery of a clinal geographic pattern of genetic variation in adaptive traits of P. strobiformis seedlings will be useful in developing strategies to maintain the species during ongoing climate change and in the face of an invasive pathogen. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Impact of choice of future climate change projection on growth chamber experimental outcomes: a preliminary study in potato

    Science.gov (United States)

    Leisner, Courtney P.; Wood, Joshua C.; Vaillancourt, Brieanne; Tang, Ying; Douches, Dave S.; Robin Buell, C.; Winkler, Julie A.

    2017-11-01

    Understanding the impacts of climate change on agriculture is essential to ensure adequate future food production. Controlled growth experiments provide an effective tool for assessing the complex effects of climate change. However, a review of the use of climate projections in 57 previously published controlled growth studies found that none considered within-season variations in projected future temperature change, and few considered regional differences in future warming. A fixed, often arbitrary, temperature perturbation typically was applied for the entire growing season. This study investigates the utility of employing more complex climate change scenarios in growth chamber experiments. A case study in potato was performed using three dynamically downscaled climate change projections for the mid-twenty-first century that differ in terms of the timing during the growing season of the largest projected temperature changes. The climate projections were used in growth chamber experiments for four elite potato cultivars commonly planted in Michigan's major potato growing region. The choice of climate projection had a significant influence on the sign and magnitude of the projected changes in aboveground biomass and total tuber count, whereas all projections suggested an increase in total tuber weight and a decrease in specific gravity, a key market quality trait for potato, by mid-century. These results demonstrate that the use of more complex climate projections that extend beyond a simple incremental change can provide additional insights into the future impacts of climate change on crop production and the accompanying uncertainty.

  7. Effects of projected climate change on vegetation in the Blue Mountains ecoregion, USA

    Directory of Open Access Journals (Sweden)

    Becky K. Kerns

    2018-04-01

    Full Text Available We used autecological, paleoecological, and modeling information to explore the potential effects of climate change on vegetation in the Blue Mountains ecoregion, Oregon (USA. Although uncertainty exists about the exact nature of future vegetation change, we infer that the following are likely to occur by the end of the century: (1 dominance of ponderosa pine and sagebrush will increase in many locations, (2 the forest-steppe ecotone will move upward in latitude and elevation, (3 ponderosa pine will be distributed at higher elevations, (4 subalpine and alpine systems will be replaced by grass species, pine, and Douglas-fir, (5 moist forest types may increase under wetter scenarios, (6 the distribution and abundance of juniper woodlands may decrease if the frequency and extent of wildfire increase, and (7 grasslands and shrublands will increase at lower elevations. Tree growth in energy-limited landscapes (high elevations, north aspects will increase as the climate warms and snowpack decreases, whereas tree growth in water-limited landscapes (low elevations, south aspects will decrease. Ecological disturbances, including wildfire, insect outbreaks, and non-native species, which are expected to increase in a warmer climate, will affect species distribution, tree age, and vegetation structure, facilitating transitions to new combinations of species and vegetation patterns. In dry forests where fire has not occurred for several decades, crown fires may result in high tree mortality, and the interaction of multiple disturbances and stressors will probably exacerbate stress complexes. Increased disturbance will favor species with physiological and phenological traits that allow them to tolerate frequent disturbance. Keywords: Climate change, Disturbance, Vegetation, Wildfire

  8. Younger Dryas cooling and the Greenland climate response to CO2.

    Science.gov (United States)

    Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

    2012-07-10

    Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

  9. Review of scientific linkages and interactions between climate change and air quality, with implications for air quality management in South Africa

    CSIR Research Space (South Africa)

    Thambiran, Tirusha

    2010-04-01

    Full Text Available In recent years there has been considerable advancement in our scientific understanding of the linkages and interactions between climate change and air quality. A warmer, evolving climate is likely to have severe consequences for air quality due...

  10. Projected Impact of Urban Growth on Climate Change

    Science.gov (United States)

    Amato, Federico; Murgante, Beniamino; Martellozzo, Federico

    2017-04-01

    Human activities on land use such as intensive agricultural techniques and urbanization are generating a number of social and economic benefit for contemporary society. Besides, these phenomena are one of the most significant causes of Land Degradation. Firstly, intensive agriculture is on the one hand creating an advantage in the short-period in terms of food production, while on the other is producing serious long-period problems in terms of loss of ecosystem services, including some important for agriculture itself. Secondly, the rapid growth of urban areas in recent decades is generating deep environmental issues. The World Urbanization Prospect by the United Nations (UN) shows that more than half of the world's population today (54%) lives in urban areas. This figure was only 30% in 1950, and estimates are that it will rise to 66% by 2050. Urban growth is responsible for the increase of air pollution, waste production, energy consumption, and land take. Moreover, the expansion of urban areas is making the problem of urban heat islands more relevant, and studies are proving how land cover changes are among the main factors that affect local microclimates. Consequently, territorial planning will play an important role in the fight to mitigate the effects of climate change, as land cover has a significant impact on the energy exchanges between the earth and the atmosphere. This study couples urban growth simulation models based on cellular automata to multiple linear regression techniques that are used to formulate equations for predicting the effects of simulated urban development on soil surface temperature. The proposed methodology is applied to the case study of the Italian national territory, considering various alternative scenarios of land use changes and of their impact on local surface temperatures. The results show that the areas with the greatest urban pressure might be subject to significant climatic changes due to the increased impact of urban heat

  11. Early kit mortality and growth in farmed mink are affected by litter size rather than nest climate.

    Science.gov (United States)

    Schou, T M; Malmkvist, J

    2017-09-01

    We investigated the effects of nest box climate on early mink kit mortality and growth. We hypothesised that litters in warm nest boxes experience less hypothermia-induced mortality and higher growth rates during the 1st week of life. This study included data from 749, 1-year-old breeding dams with access to nesting materials. Kits were weighed on days 1 and 7, dead kits were collected daily from birth until day 7 after birth, and nest climate was measured continuously from days 1 to 6. We tested the influences of the following daily temperature (T) and humidity (H) parameters on the number of live-born kit deaths and kit growth: T mean, T min, T max, T var (fluctuation) and H mean. The nest microclimate experienced by the kits was buffered against the ambient climate, with higher temperatures and reduced climate fluctuation. Most (77.0%) live-born kit deaths in the 1st week occurred on days 0 and 1. Seven of 15 climate parameters on days 1 to 3 had significant effects on live-born kit mortality. However, conflicting effects among days, marginal effects and late effects indicated that climate was not the primary cause of kit mortality. Five of 30 climate parameters had significant effects on kit growth. Few and conflicting effects indicated that the climate effect on growth was negligible. One exception was that large nest temperature fluctuations on day 1 were associated with reduced deaths of live-born kit (P<0.001) and increased kit growth (P=0.003). Litter size affected kit vitality; larger total litter size at birth was associated with greater risks of kit death (P<0.001) and reduced growth (P<0.001). The number of living kits in litters had the opposite effect, as kits in large liveborn litters had a reduced risk of death (P<0.001) and those with large mean litter size on days 1 to 7 had increased growth (P=0.026). Nest box temperature had little effect on early kit survival and growth, which could be due to dams' additional maternal behaviour. Therefore, we

  12. Lagging adaptation to warming climate in Arabidopsis thaliana.

    Science.gov (United States)

    Wilczek, Amity M; Cooper, Martha D; Korves, Tonia M; Schmitt, Johanna

    2014-06-03

    If climate change outpaces the rate of adaptive evolution within a site, populations previously well adapted to local conditions may decline or disappear, and banked seeds from those populations will be unsuitable for restoring them. However, if such adaptational lag has occurred, immigrants from historically warmer climates will outperform natives and may provide genetic potential for evolutionary rescue. We tested for lagging adaptation to warming climate using banked seeds of the annual weed Arabidopsis thaliana in common garden experiments in four sites across the species' native European range: Valencia, Spain; Norwich, United Kingdom; Halle, Germany; and Oulu, Finland. Genotypes originating from geographic regions near the planting site had high relative fitness in each site, direct evidence for broad-scale geographic adaptation in this model species. However, genotypes originating in sites historically warmer than the planting site had higher average relative fitness than local genotypes in every site, especially at the northern range limit in Finland. This result suggests that local adaptive optima have shifted rapidly with recent warming across the species' native range. Climatic optima also differed among seasonal germination cohorts within the Norwich site, suggesting that populations occurring where summer germination is common may have greater evolutionary potential to persist under future warming. If adaptational lag has occurred over just a few decades in banked seeds of an annual species, it may be an important consideration for managing longer-lived species, as well as for attempts to conserve threatened populations through ex situ preservation.

  13. Post-1980 shifts in the sensitivity of boreal tree growth to North Atlantic Ocean dynamics and seasonal climate. Tree growth responses to North Atlantic Ocean dynamics

    Science.gov (United States)

    Ols, Clémentine; Trouet, Valerie; Girardin, Martin P.; Hofgaard, Annika; Bergeron, Yves; Drobyshev, Igor

    2018-06-01

    The mid-20th century changes in North Atlantic Ocean dynamics, e.g. slow-down of the Atlantic meridional overturning thermohaline circulation (AMOC), have been considered as early signs of tipping points in the Earth climate system. We hypothesized that these changes have significantly altered boreal forest growth dynamics in northeastern North America (NA) and northern Europe (NE), two areas geographically adjacent to the North Atlantic Ocean. To test our hypothesis, we investigated tree growth responses to seasonal large-scale oceanic and atmospheric indices (the AMOC, North Atlantic Oscillation (NAO), and Arctic Oscillation (AO)) and climate (temperature and precipitation) from 1950 onwards, both at the regional and local levels. We developed a network of 6876 black spruce (NA) and 14437 Norway spruce (NE) tree-ring width series, extracted from forest inventory databases. Analyses revealed post-1980 shifts from insignificant to significant tree growth responses to summer oceanic and atmospheric dynamics both in NA (negative responses to NAO and AO indices) and NE (positive response to NAO and AMOC indices). The strength and sign of these responses varied, however, through space with stronger responses in western and central boreal Quebec and in central and northern boreal Sweden, and across scales with stronger responses at the regional level than at the local level. Emerging post-1980 associations with North Atlantic Ocean dynamics synchronized with stronger tree growth responses to local seasonal climate, particularly to winter temperatures. Our results suggest that ongoing and future anomalies in oceanic and atmospheric dynamics may impact forest growth and carbon sequestration to a greater extent than previously thought. Cross-scale differences in responses to North Atlantic Ocean dynamics highlight complex interplays in the effects of local climate and ocean-atmosphere dynamics on tree growth processes and advocate for the use of different spatial scales in

  14. Climatic and anthropogenic changes in Western Switzerland: Impacts on water stress.

    Science.gov (United States)

    Milano, Marianne; Reynard, Emmanuel; Köplin, Nina; Weingartner, Rolf

    2015-12-01

    Recent observed hydro-climatic changes in mountainous areas are of concern as they may directly affect capacity to fulfill water needs. The canton of Vaud in Western Switzerland is an example of such a region as it has experienced water shortage episodes during the past decade. Based on an integrated modeling framework, this study explores how hydro-climatic conditions and water needs could evolve in mountain environments and assesses their potential impacts on water stress by the 2060 horizon. Flows were simulated based on a daily semi-distributed hydrological model. Future changes were derived from Swiss climate scenarios based on two regional climate models. Regarding water needs, the authorities of the canton of Vaud provided a population growth scenario while irrigation and livestock trends followed a business-as-usual scenario. Currently, the canton of Vaud experiences moderate water stress from June to August, except in its Alpine area where no stress is noted. In the 2060 horizon, water needs could exceed 80% of the rivers' available resources in low- to mid-altitude environments in mid-summer. This arises from the combination of drier and warmer climate that leads to longer and more severe low flows, and increasing urban (+40%) and irrigation (+25%) water needs. Highlighting regional differences supports the development of sustainable development pathways to reduce water tensions. Based on a quantitative assessment, this study also calls for broader impact studies including water quality issues. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Seasonal Differences in Climatic Controls of Vegetation Growth in the Beijing-Tianjin Sand Source Region of China.

    Science.gov (United States)

    Wang, H.

    2017-12-01

    Seasonal differences in climatic controls of vegetation growth in the Beijing-Tianjin Sand Source Region of China Bin He1 , Haiyan Wan11 State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China Corresponding author: Bin He, email addresses: hebin@bnu.edu.cnPhone:+861058806506, Address: Beijing Normal University, College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China. Email addresses of co-authors: wanghaiyan@mail.bnu.edu.cnABSTRACTLaunched in 2000, the Beiing-Tainjin Sand Source Controlling Project (BTSSCP) is an ecological restoration project intended to prevent desertification in China. Evidence from multiple sources has confirmed increases in vegetation growth in the BTSSCP region since the initiation of the project. Precipitation and related soil moisture conditions typically are considered to be the main drivers of vegetation growth in this arid region. However, by investigating the relationships between vegetation growth and corresponding climatic factors, we identified seasonal variation in the climatic constraints of vegetation growth. In spring, vegetation growth is stimulated mainly by elevated temperature, whereas precipitation is the lead driver of summer greening. In autumn, positive effects of both temperature and precipitation on vegetation growth were observed. Furthermore, strong biosphere-atmosphere interactions were observed in this region. Spring warming promotes vegetation growth, but also reduces soil moisture. Summer greening has a strong cooling effect on land surface temperature. These results indicate that 1) precipitation-based projections of vegetation growth may be misleading; and 2) the ecological and environment consequences of ecological projects should be comprehensively evaluated. KEYWORDS: vegetation growth, climatic drivers, seasonal variation, BTSSCP

  16. Climate warming and interannual variability of phytoplankton phenology in the Northern Red Sea

    KAUST Repository

    Gittings, John

    2016-12-01

    In agreement with global patterns of climate change and increasing temperatures in the tropical oceans, the Northern Red Sea (NRS) has been warming over the last few decades. Using 18 years of remotely-sensed chlorophyll-a data (Chl-a, an index of phytoplankton biomass), we investigate the potential impacts of climate warming on phytoplankton abundance and phenology in the Northern Red Sea by exploring the mechanistic links with the regional physical environment. The results of the analysis reveal that, in accordance with other tropical ecosystems, phytoplankton biomass in the NRS will decrease in response to warmer climate scenarios. This is attributed to lower heat fluxes (heat loss to the atmosphere) during the bloom period, and enhanced vertical stratification, which prevents vertical mixing of nutrients into the euphotic layer. In addition, we show that during warmer conditions (when heat fluxes are weakened), the winter bloom initiates significantly later (by up to 10 weeks) and its duration is considerably reduced. The biological implications of alterations to phytoplankton phenology may include increased larval mortality of pelagic species, reduced recruitment, fisheries impacts and changes to community structure.

  17. Tree growth response to climate change at the deciduous-boreal forest ecotone, Ontario, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Goldblum, D. [Wisconsin-Whitewater Univ., Whitewater, WI (United States). Dept. of Geography and Geology; Rigg, L.S. [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Geography

    2005-11-01

    Recent interest in the impact that future climate change may have on forest communities can be attributed to the fact that migration of tree species has been slow with respect to past climate changes and also because of the high degree of habitat fragmentation that has occurred in the recent past. For that reason, this study examined the implications of climate change on the future of sugar maple, white spruce and balsam fir. These trees represent the 3 dominant forest species at the deciduous-boreal forest ecotone in Ontario, Canada. The analysis was based on the responses of individual species to past monthly temperature and precipitation conditions as well as simulated monthly temperature and precipitation conditions in the study area for the 2080s. The sensitivity of the tree species to past climate with predicted conditions for the 2080 period was also considered. In particular, tree-ring analysis was used to compare local species-specific growth responses with instrumental climate records since 1900 to determine which climate variables control growth rates of these 3 species. Present temperature and precipitation averages were compared with general circulation model (GCM) predictions of monthly temperature and monthly precipitation to evaluate the potential benefit or harm to the dominant tree species over the next 80 years. It was concluded that sugar maple may persist in the medium term up to several centuries, as existing trees pass through their natural life-span without reproductive replacement. However, with extreme climate change, over many centuries, even the sugar maple at this northern range limit might be in jeopardy. White spruce is likely to benefit less, and the dominant balsam fir is likely to experience a decrease in growth potential. These projected changes would enhance the future status of sugar maple at its northern limit and facilitate range expansion northward in response to global warming. Although the study concerns only a small area

  18. Towards a More Biologically-meaningful Climate Characterization: Variability in Space and Time at Multiple Scales

    Science.gov (United States)

    Christianson, D. S.; Kaufman, C. G.; Kueppers, L. M.; Harte, J.

    2013-12-01

    Sampling limitations and current modeling capacity justify the common use of mean temperature values in summaries of historical climate and future projections. However, a monthly mean temperature representing a 1-km2 area on the landscape is often unable to capture the climate complexity driving organismal and ecological processes. Estimates of variability in addition to mean values are more biologically meaningful and have been shown to improve projections of range shifts for certain species. Historical analyses of variance and extreme events at coarse spatial scales, as well as coarse-scale projections, show increasing temporal variability in temperature with warmer means. Few studies have considered how spatial variance changes with warming, and analysis for both temporal and spatial variability across scales is lacking. It is unclear how the spatial variability of fine-scale conditions relevant to plant and animal individuals may change given warmer coarse-scale mean values. A change in spatial variability will affect the availability of suitable habitat on the landscape and thus, will influence future species ranges. By characterizing variability across both temporal and spatial scales, we can account for potential bias in species range projections that use coarse climate data and enable improvements to current models. In this study, we use temperature data at multiple spatial and temporal scales to characterize spatial and temporal variability under a warmer climate, i.e., increased mean temperatures. Observational data from the Sierra Nevada (California, USA), experimental climate manipulation data from the eastern and western slopes of the Rocky Mountains (Colorado, USA), projected CMIP5 data for California (USA) and observed PRISM data (USA) allow us to compare characteristics of a mean-variance relationship across spatial scales ranging from sub-meter2 to 10,000 km2 and across temporal scales ranging from hours to decades. Preliminary spatial analysis at

  19. Predicting Summer Dryness Under a Warmer Climate: Modeling Land Surface Processes in the Midwestern United States

    Science.gov (United States)

    Winter, J. M.; Eltahir, E. A.

    2009-12-01

    One of the most significant impacts of climate change is the potential alteration of local hydrologic cycles over agriculturally productive areas. As the world’s food supply continues to be taxed by its burgeoning population, a greater percentage of arable land will need to be utilized and land currently producing food must become more efficient. This study seeks to quantify the effects of climate change on soil moisture in the American Midwest. A series of 24-year numerical experiments were conducted to assess the ability of Regional Climate Model Version 3 coupled to Integrated Biosphere Simulator (RegCM3-IBIS) and Biosphere-Atmosphere Transfer Scheme 1e (RegCM3-BATS1e) to simulate the observed hydroclimatology of the midwestern United States. Model results were evaluated using NASA Surface Radiation Budget, NASA Earth Radiation Budget Experiment, Illinois State Water Survey, Climate Research Unit Time Series 2.1, Global Soil Moisture Data Bank, and regional-scale estimations of evapotranspiration. The response of RegCM3-IBIS and RegCM3-BATS1e to a surrogate climate change scenario, a warming of 3oC at the boundaries and doubling of CO2, was explored. Precipitation increased significantly during the spring and summer in both RegCM3-IBIS and RegCM3-BATS1e, leading to additional runoff. In contrast, enhancement of evapotranspiration and shortwave radiation were modest. Soil moisture remained relatively unchanged in RegCM3-IBIS, while RegCM3-BATS1e exhibited some fall and winter wetting.

  20. Tracking climate impacts on the migratory monarch butterfly

    Science.gov (United States)

    Zipkin, Elise F.; Ries, Leslie; Reeves, Rick; Regetz, James; Oberhauser, Karen S.

    2012-01-01

    Understanding the impacts of climate on migratory species is complicated by the fact that these species travel through several climates that may be changing in diverse ways throughout their complete migratory cycle. Most studies are not designed to tease out the direct and indirect effects of climate at various stages along the migration route. We assess the impacts of spring and summer climate conditions on breeding monarch butterflies, a species that completes its annual migration cycle over several generations. No single, broad-scale climate metric can explain summer breeding phenology or the substantial year-to-year fluctuations observed in population abundances. As such, we built a Poisson regression model to help explain annual arrival times and abundances in the Midwestern United States. We incorporated the climate conditions experienced both during a spring migration/breeding phase in Texas as well as during subsequent arrival and breeding during the main recruitment period in Ohio. Using data from a state-wide butterfly monitoring network in Ohio, our results suggest that climate acts in conflicting ways during the spring and summer seasons. High spring precipitation in Texas is associated with the largest annual population growth in Ohio and the earliest arrival to the summer breeding ground, as are intermediate spring temperatures in Texas. On the other hand, the timing of monarch arrivals to the summer breeding grounds is not affected by climate conditions within Ohio. Once in Ohio for summer breeding, precipitation has minimal impacts on overall abundances, whereas warmer summer temperatures are generally associated with the highest expected abundances, yet this effect is mitigated by the average seasonal temperature of each location in that the warmest sites receive no benefit of above average summer temperatures. Our results highlight the complex relationship between climate and performance for a migrating species and suggest that attempts to

  1. Comparative seed germination traits in alpine and subalpine grasslands: higher elevations are associated with warmer germination temperatures.

    Science.gov (United States)

    Fernández-Pascual, E; Jiménez-Alfaro, B; Bueno, Á

    2017-01-01

    Seed germination traits in alpine grasslands are poorly understood, despite the sensitivity of these communities to climate change. We hypothesise that germination traits predict species occurrence along the alpine-subalpine elevation gradient. Phylogenetic comparative analyses were performed using fresh seeds of 22 species from alpine and subalpine grasslands (1600-2400 m) of the Cantabrian Mountains, Spain (43° N, 5° W). Laboratory experiments were conducted to characterise germinability, optimum germination temperature and effect of cold and warm stratification on dormancy breaking. Variability in these traits was reduced by phylogenetic principal component analysis (phyl.PCA). Phylogenetic generalised least squares regression (PGLS) was used to fit a model in which species average elevation was predicted from their position on the PCA axes. Most subalpine species germinated in snow-like conditions, whereas most alpine species needed accumulation of warm temperatures. Phylogenetic signal was low. PCA1 ordered species according to overall germinability, whilst PCA2 ordered them according to preference for warm or cold germination. PCA2 significantly predicted species occurrence in the alpine-subalpine gradient, as higher elevation species tended to have warmer germination preferences. Our results show that germination traits in high-mountain grasslands are closely linked to the alpine-subalpine gradient. Alpine species, especially those from stripped and wind-edge communities, prefer warmer germination niches, suggesting that summer emergence prevents frost damage during seedling establishment. In contrast, alpine snowfield and subalpine grassland plants have cold germination niches, indicating that winter emergence may occur under snow to avoid drought stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Climate-Induced Larch Growth Response Within the Central Siberian Permafrost Zone

    Science.gov (United States)

    Kharuk, Viacheslav I.; Ranson, Kenneth J.; Im, Sergei T.; Petrov, Il'ya A.

    2015-01-01

    Aim: estimation of larch (Larix gmelinii) growth response to current climate changes. Location: permafrost area within the northern part of Central Siberia (approximately 65.8 deg N, 98.5 deg E). Method: analysis of dendrochronological data, climate variables, drought index SPEI, GPP (gross primary production) and EVI vegetation index (both Aqua/MODIS satellite derived), and soil water content anomalies (GRACE satellite measurements of equivalent water thickness anomalies, EWTA). Results: larch tree ring width (TRW) correlated with previous year August precipitation (r = 0.63), snow accumulation (r = 0.61), soil water anomalies (r = 0.79), early summer temperatures and water vapor pressure (r = 0.73 and r = 0.69, respectively), May and June drought index (r = 0.68-0.82). There are significant positive trends of TRW since late 1980s and GPP since the year 2000. Mean TRW increased by about 50%, which is similar to post-Little Ice Age warming. TRW correlated with GPP and EVI of larch stands (r = 0.68-0.69). Main conclusions: within the permafrost zone of central Siberia larch TRW growth is limited by early summer temperatures, available water from snowmelt, water accumulated within soil in the previous year, and permafrost thaw water. Water stress is one of the limiting factors of larch growth. Larch TRW growth and GPP increased during recent decades.

  3. Water and growth: An econometric analysis of climate and policy impacts

    Science.gov (United States)

    Khan, Hassaan Furqan; Morzuch, Bernard J.; Brown, Casey M.

    2017-06-01

    Water-related hazards such as floods, droughts, and disease cause damage to an economy through the destruction of physical capital including property and infrastructure, the loss of human capital, and the interruption of economic activities, like trade and education. The question for policy makers is whether the impacts of water-related risk accrue to manifest as a drag on economic growth at a scale suggesting policy intervention. In this study, the average drag on economic growth from water-related hazards faced by society at a global level is estimated. We use panel regressions with various specifications to investigate the relationship between economic growth and hydroclimatic variables at the country-river basin level. In doing so, we make use of surface water runoff variables never used before. The analysis of the climate variables shows that water availability and water hazards have significant effects on economic growth, providing further evidence beyond earlier studies finding that precipitation extremes were at least as important or likely more important than temperature effects. We then incorporate a broad set of variables representing the areas of infrastructure, institutions, and information to identify the characteristics of a region that determine its vulnerability to water-related risks. The results identify water scarcity, governance, and agricultural intensity as the most relevant measures affecting vulnerabilities to climate variability effects.

  4. Assessing climate-change risks to cultural and natural resources in the Yakima River Basin, Washington, USA

    Science.gov (United States)

    Hatten, James R.; Waste, Stephen M.; Maule, Alec G.

    2014-01-01

    We provide an overview of an interdisciplinary special issue that examines the influence of climate change on people and fish in the Yakima River Basin, USA. Jenni et al. (2013) addresses stakeholder-relevant climate change issues, such as water availability and uncertainty, with decision analysis tools. Montag et al. (2014) explores Yakama Tribal cultural values and well-being and their incorporation into the decision-making process. Graves and Maule (2012) simulates effects of climate change on stream temperatures under baseline conditions (1981–2005) and two future climate scenarios (increased air temperature of 1 °C and 2 °C). Hardiman and Mesa (2013) looks at the effects of increased stream temperatures on juvenile steelhead growth with a bioenergetics model. Finally, Hatten et al. (2013) examines how changes in stream flow will affect salmonids with a rule-based fish habitat model. Our simulations indicate that future summer will be a very challenging season for salmonids when low flows and high water temperatures can restrict movement, inhibit or alter growth, and decrease habitat. While some of our simulations indicate salmonids may benefit from warmer water temperatures and increased winter flows, the majority of simulations produced less habitat. The floodplain and tributary habitats we sampled are representative of the larger landscape, so it is likely that climate change will reduce salmonid habitat potential throughout particular areas of the basin. Management strategies are needed to minimize potential salmonid habitat bottlenecks that may result from climate change, such as keeping streams cool through riparian protection, stream restoration, and the reduction of water diversions. An investment in decision analysis and support technologies can help managers understand tradeoffs under different climate scenarios and possibly improve water and fish conservation over the next century.

  5. Limited evidence for CO2 -related growth enhancement in northern Rocky Mountain lodgepole pine populations across climate gradients.

    Science.gov (United States)

    Reed, Charlotte C; Ballantyne, Ashley P; Cooper, Leila Annie; Sala, Anna

    2018-04-15

    Forests sequester large amounts of carbon annually and are integral in buffering against effects of global change. Increasing atmospheric CO 2 may enhance photosynthesis and/or decrease stomatal conductance (g s ) thereby enhancing intrinsic water-use efficiency (iWUE), having potential indirect and direct benefits to tree growth. While increasing iWUE has been observed in most trees globally, enhanced growth is not ubiquitous, possibly due to concurrent climatic constraints on growth. To investigate our incomplete understanding of interactions between climate and CO 2 and their impacts on tree physiology and growth, we used an environmental gradient approach. We combined dendrochronology with carbon isotope analysis (δ 13 C) to assess the covariation of basal area increment (BAI) and iWUE over time in lodgepole pine. Trees were sampled at 18 sites spanning two climatically distinct elevation transects on the lee and windward sides of the Continental Divide, encompassing the majority of lodgepole pine's northern Rocky Mountain elevational range. We analyzed BAI and iWUE from 1950 to 2015, and explored correlations with monthly climate variables. As expected, iWUE increased at all sites. However, concurrent growth trends depended on site climatic water deficit (CWD). Significant growth increases occurred only at the driest sites, where increases in iWUE were strongest, while growth decreases were greatest at sites where CWD has been historically lowest. Late summer drought of the previous year negatively affected growth across sites. These results suggest that increasing iWUE, if strong enough, may indirectly benefit growth at drier sites by effectively extending the growing season via reductions in g s . Strong growth decreases at high elevation windward sites may reflect increasing water stress as a result of decreasing snowpack, which was not offset by greater iWUE. Our results imply that increasing iWUE driven by decreasing g s may benefit tree growth in

  6. Developing global climate anomalies suggest potential disease risks for 2006 – 2007

    OpenAIRE

    Tucker Compton J; Small Jennifer; Chretien Jean-Paul; Anyamba Assaf; Linthicum Kenneth J

    2006-01-01

    Abstract Background El Niño/Southern Oscillation (ENSO) related climate anomalies have been shown to have an impact on infectious disease outbreaks. The Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA/CPC) has recently issued an unscheduled El Niño advisory, indicating that warmer than normal sea surface temperatures across the equatorial eastern Pacific may have pronounced impacts on global tropical precipitation patterns extending into the northern hem...

  7. Growth of and partitioning between shoot and storage root of carrot in a northern climate

    Directory of Open Access Journals (Sweden)

    T. SUOJALA

    2008-12-01

    Full Text Available Matching the growth pattern of a vegetable cultivar with the seasonal changes in climate is a prerequisite for successful yield production in a northern climate. This paper describes the growth characteristics of two carrot cultivars in relation to climatic conditions in two years, with special reference to the factors associated with high yield. Cv. Fontana produced twice as large a leaf area and shoot weight as cv. Panther. Increased partitioning to shoot in the former cultivar also resulted in a higher root yield. Uniformity in relative growth rates during the period of analysis suggests that intervarietal differences in the shoot to root ratio and in the yield potential appear very early. Nearly half of the root weight at final harvest was gained after mid-August, when temperature and daily irradiance began to decrease. A large leaf area may ensure better utilisation of diminishing growth resources at the end of the growing season. In the more favourable growing season, 1997, plants invested more in leaf production than they did in 1996: shoot fresh and dry weights were considerably higher but leaf area was not much higher.;

  8. Shifts in climate suitability for wine production as a result of climate change in a temperate climate wine region of Romania

    Science.gov (United States)

    Irimia, Liviu Mihai; Patriche, Cristian Valeriu; Quenol, Hervé; Sfîcă, Lucian; Foss, Chris

    2018-02-01

    Climate change is causing important shifts in the suitability of regions for wine production. Fine scale mapping of these shifts helps us to understand the evolution of vineyard climates, and to find solutions through viticultural adaptation. The aim of this study is to identify and map the structural and spatial shifts that occurred in the climatic suitability for wine production of the Cotnari wine growing region (Romania) between 1961 and 2013. Discontinuities in trends of temperature were identified, and the averages and trends of 13 climatic parameters for the 1961 to 1980 and 1981 to 2013 time periods were analysed. Using the averages of these climatic parameters, climate suitability for wine production was calculated at a resolution of 30 m and mapped for each time period, and the changes analysed. The results indicate shifts in the area's historic climatic profile, due to an increase of heliothermal resources and precipitation constancy. The area's climate suitability for wine production was modified by the loss of climate suitability for white table wines, sparkling wines and wine for distillates; shifts in suitability to higher altitudes by about 67 m, and a 48.6% decrease in the area suitable for quality white wines; and the occurrence of suitable climates for red wines at lower altitudes. The study showed that climate suitability for wine production has a multi-level spatial structure, with classes requiring a cooler climate being located at a higher altitude than those requiring a warmer climate. Climate change has therefore resulted in the shift of climate suitability classes for wine production to higher altitudes.

  9. Topography and age mediate the growth responses of Smith fir to climate warming in the southeastern Tibetan Plateau.

    Science.gov (United States)

    Liu, B; Wang, Y; Zhu, H; Liang, E; Camarero, J J

    2016-10-01

    The Tibetan Plateau holds some of the world's highest undisturbed natural treelines and timberlines. Such extreme environments constitute potentially valuable monitoring sites of the effects of climate warming on high-elevation forests. Here, we analyze a network of 21 Smith fir forests situated in the Sygera Mountains, southeastern Tibetan Plateau, using tree-ring width (TRW) and basal area increment (BAI) chronologies. Sampled sites encompassed a wide elevation gradient, from 3600 to 4400 m, including some treeline sites and diverse aspects and tree ages. In comparison with TRW series, BAI series better capture the long-term warming signal. Previous November and current April and summer temperatures are the dominant climatic factors controlling Smith fir radial growth. The mean inter-series correlations of TRW increased upwards, but the forest limit presented the highest potential to reconstruct past temperature variability. Moreover, the growth responses of young trees were less stable than those of trees older than 100 years. Climate warming is accelerating radial growth of Smith fir forest subjected to mesic conditions. Collectively, these findings confirm that the effects of site elevation and tree age should be considered when quantifying climate-growth relationships. The type of tree-ring data (BAI vs. TRW) is also relevant since BAI indices seem to be a better climatic proxy of low-frequency temperature signals than TRW indices. Therefore, site (e.g., elevation) and tree (e.g., age) features should be considered to properly evaluate the effects of climate warming on growth of high-elevation forests.

  10. Topography and age mediate the growth responses of Smith fir to climate warming in the southeastern Tibetan Plateau

    Science.gov (United States)

    Liu, B.; Wang, Y.; Zhu, H.; Liang, E.; Camarero, J. J.

    2016-10-01

    The Tibetan Plateau holds some of the world's highest undisturbed natural treelines and timberlines. Such extreme environments constitute potentially valuable monitoring sites of the effects of climate warming on high-elevation forests. Here, we analyze a network of 21 Smith fir forests situated in the Sygera Mountains, southeastern Tibetan Plateau, using tree-ring width (TRW) and basal area increment (BAI) chronologies. Sampled sites encompassed a wide elevation gradient, from 3600 to 4400 m, including some treeline sites and diverse aspects and tree ages. In comparison with TRW series, BAI series better capture the long-term warming signal. Previous November and current April and summer temperatures are the dominant climatic factors controlling Smith fir radial growth. The mean inter-series correlations of TRW increased upwards, but the forest limit presented the highest potential to reconstruct past temperature variability. Moreover, the growth responses of young trees were less stable than those of trees older than 100 years. Climate warming is accelerating radial growth of Smith fir forest subjected to mesic conditions. Collectively, these findings confirm that the effects of site elevation and tree age should be considered when quantifying climate-growth relationships. The type of tree-ring data (BAI vs. TRW) is also relevant since BAI indices seem to be a better climatic proxy of low-frequency temperature signals than TRW indices. Therefore, site (e.g., elevation) and tree (e.g., age) features should be considered to properly evaluate the effects of climate warming on growth of high-elevation forests.

  11. Preparing for a warmer world: Towards a global governance system to protect climate refugees

    NARCIS (Netherlands)

    Biermann, F.; Boas, I.J.C.

    2010-01-01

    Climate change threatens to cause the largest refugee crisis in human history. Millions of people, largely in Africa and Asia, might be forced to leave their homes to seek refuge in other places or countries over the course of the century. Yet the current institutions, organizations, and funding

  12. Projected drought risk in 1.5°C and 2°C warmer climates

    Science.gov (United States)

    Lehner, F.; Coats, S.; Stocker, T. F.; Pendergrass, A. G.; Sanderson, B. M.; Raible, C.; Smerdon, J. E.

    2017-12-01

    The large socioeconomic costs of droughts make them a crucial target for impact assessments of climate change scenarios. Using multiple drought metrics and a set of simulations with the Community Earth System Model (CESM) targeting 1.5°C and 2°C above preindustrial global mean temperatures, we investigate changes in aridity and the risk of consecutive drought years. The latter metric is motivated by recent droughts in California and the US Southwest in general, where consecutive years of moderate precipitation deficit can quickly lead to significant drought and elevated pressure on water resources. If warming is limited to 2°C, these simulations suggest little change in drought risk for the U.S. Southwest and Central Plains compared to present day, an interesting result that arises from a delicate balance between increases in evaporative demand and precipitation in CESM in that region. In the Mediterranean, central Europe, and a number of other regions across the globe, however, drought risk increases significantly for both 1.5°C and 2°C warming targets, and the additional 0.5°C of the 2°C climate leads to significantly higher drought risk. Our study suggests that limiting anthropogenic warming to 1.5°C rather than 2°C, as aspired to by the Paris Climate Agreement, may have benefits for future drought risk but that such benefits may be regional and in some cases highly uncertain. We will therefore also discuss the robustness of results across different drought metrics as well as the model uncertainties associated with drought projections for low warming targets.

  13. Climate tolerances and trait choices shape continental patterns of urban tree biodiversity

    Science.gov (United States)

    G. Darrel Jenerette; Lorraine W. Clarke; Meghan L. Avolio; Diane E. Pataki; Thomas W. Gillespie; Stephanie Pincetl; Dave J. Nowak; Lucy R. Hutyra; Melissa McHale; Joseph P. McFadden; Michael Alonzo

    2016-01-01

    Aim. We propose and test a climate tolerance and trait choice hypothesis of urban macroecological variation in which strong filtering associated with low winter temperatures restricts urban biodiversity while weak filtering associated with warmer temperatures and irrigation allows dispersal of species from a global source pool, thereby...

  14. Vulnerability of white spruce tree growth in interior Alaska in response to climate variability: dendrochronological, demographic, and experimental perspectives

    Science.gov (United States)

    A.D. McGuire; R.W. Ruess; A. Lloyd; J. Yarie; J.S. Clein; G.P. Juday

    2010-01-01

    This paper integrates dendrochronological, demographic, and experimental perspectives to improve understanding of the response of white spruce (Picea glauca (Moench) Voss) tree growth to climatic variability in interior Alaska. The dendrochronological analyses indicate that climate warming has led to widespread declines in white spruce growth...

  15. Assessing climate change effects on long-term forest development: adjusting growth, phenology, and seed production in a gap model

    NARCIS (Netherlands)

    Meer, van der P.J.; Jorritsma, I.T.M.; Kramer, K.

    2002-01-01

    The sensitivity of forest development to climate change is assessed using a gap model. Process descriptions in the gap model of growth, phenology, and seed production were adjusted for climate change effects using a detailed process-based growth modeland a regression analysis. Simulation runs over

  16. Climate change moisture stresses on northern coniferous forests

    International Nuclear Information System (INIS)

    Wein, R.W.; Hogg, E.H.

    1990-01-01

    The predictions of general circulation models suggest major climatic changes for high latitude tundra ecosystems and lower latitude forested ecosystems. Of particular interest to Canadians is the predicted shift in the boreal forest climate northward, with a considerable northern expansion of the grasslands of western Canada. Reductions in soil moisture would have both direct and indirect effects on forest composition and productivity. The most important likely physical factors subject to alteration are permafrost, hydrological regimes and fire. Under warmer and drier conditions, potential fire burn frequency will increase, and might lead to greater proportions of jack pine than previously present. It is anticipated that permafrost will disappear from the extensive discontinuous permafrost zone where soil permafrost temperatures are presently -3 degree C or higher. In wet sites, melting of the permafrost could lead to drowning of forests as soils subside and become temporarily waterlogged. In more northerly areas, forest growth may increase in drier areas as the depth of the active layer increases. Fire may be a significant feed-back mechanism that could enhance the greenhouse effect. The estimated proportion of carbon in Canadian peatlands is in the order of 170 gigatonnes, whereas one-tenth of a gigatonne of carbon is released annually by fossil fuel combustion in Canada. 11 refs

  17. Climate finance, climate investors and assets for low emission development

    Directory of Open Access Journals (Sweden)

    Collins C Ngwakwe

    2015-05-01

    Full Text Available This research examines the relationship between climate finance, growth in climate investors and growth in climate assets for low emission development. It also evaluates the effect of climate policy evolution on the growth of climate investors and climate assets. Adopting a positivist paradigm, the paper makes use of a quantitative research approach and applies the causal and correlational research design. The paper made use of secondary data from the World Bank Carbon Finance Unit and from the Carbon Disclosure Project (ADP. The major objective was to examine the combined effect of climate finance and climate policy on the growth of carbon investors and carbon assets for the companies in the Carbon Disclosure Project which includes the 100 JSE companies. Findings from the test reveal that the combined effect of growth in climate finance and climate policy evolution has a significant relationship with growth in climate investors and climate assets. Given this result the paper proceeded to examine if the growth in climate finance has any correlation with South Africa’s emission reduction trend. Results however indicate that South Africa’s GHG emission trend does not correlate with climate finance availability; GHG emissions in South Africa have continued to soar despite a seeming growth in climate finance. The paper reasoned that the global climate finance might not be effectively available to corporates in South Africa at the expected level of financing to initiate the expected level of climate investment to effect a significant reduction in greenhouse gas emissions. This confirms literature assertions that global climate finance might not easily be accessible, at least to entities in developing countries. In conclusion, the paper suggests the establishment of a Southern African Climate Finance pool where the public and private sector can contribute and that such pool should be made easily available to carbon investors at a cheap rate with

  18. Photosynthetic oxygen production in a warmer ocean: the Sargasso Sea as a case study.

    Science.gov (United States)

    Richardson, Katherine; Bendtsen, Jørgen

    2017-09-13

    Photosynthetic O 2 production can be an important source of oxygen in sub-surface ocean waters especially in permanently stratified oligotrophic regions of the ocean where O 2 produced in deep chlorophyll maxima (DCM) is not likely to be outgassed. Today, permanently stratified regions extend across approximately 40% of the global ocean and their extent is expected to increase in a warmer ocean. Thus, predicting future ocean oxygen conditions requires a better understanding of the potential response of photosynthetic oxygen production to a warmer ocean. Based on our own and published observations of water column processes in oligotrophic regions, we develop a one-dimensional water column model describing photosynthetic oxygen production in the Sargasso Sea to quantify the importance of photosynthesis for the downward flux of O 2 and examine how it may be influenced in a warmer ocean. Photosynthesis is driven in the model by vertical mixing of nutrients (including eddy-induced mixing) and diazotrophy and is found to substantially increase the downward O 2 flux relative to physical-chemical processes alone. Warming (2°C) surface waters does not significantly change oxygen production at the DCM. Nor does a 15% increase in re-mineralization rate (assuming Q 10  = 2; 2°C warming) have significant effect on net sub-surface oxygen accumulation. However, changes in the relative production of particulate (POM) and dissolved organic material (DOM) generate relatively large changes in net sub-surface oxygen production. As POM/DOM production is a function of plankton community composition, this implies plankton biodiversity and food web structure may be important factors influencing O 2 production in a warmer ocean.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'. © 2017 The Author(s).

  19. Climate during the Roman and early-medieval periods in North-western Europe: a review of climate reconstructions from terrestrial archives

    Science.gov (United States)

    Reichelmann, Dana F. C.; Gouw-Bouman, Marjolein T. I. J.; Hoek, Wim Z.; van Lanen, Rowin J.; Stouthamer, Esther; Jansma, Esther

    2016-04-01

    High-resolution palaeoclimate reconstructions are essential to identify possible influences of climate variability on landscape evolution and landscape-related cultural changes (e.g., shifting settlement patterns and long-distance trade relations). North-western Europe is an ideal research area for comparison between climate variability and cultural transitions given its geomorphological diversity and the significant cultural changes that took place in this region during the last two millennia (e.g., the decline of the Roman Empire and the transition to medieval kingdoms). Compared to more global climate records, such as ice cores and marine sediments, terrestrial climate proxies have the advantage of representing a relatively short response time to regional climatic change. Furthermore for this region large quantity of climate reconstructions is available covering the last millennium, whereas for the first millennium AD only few high resolution climate reconstructions are available. We compiled climate reconstructions for sites in North-western Europe from the literature and its underlying data. All these reconstructions cover the time period of AD 1 to 1000. We only selected data with an annual to decadal resolution and a minimum resolution of 50 years. This resulted in 18 climate reconstructions from different archives such as chironomids (1), pollen (4), Sphagnum cellulose (1), stalagmites (6), testate amoebae (4), and tree-rings (2). The compilation of the different temperature reconstructions shows similar trends in most of the records. Colder conditions since AD 300 for a period of approximately 400 years and warmer conditions after AD 700 become apparent. A contradicting signal is found before AD 300 with warmer conditions indicated by most of the records but not all. This is likely the result of the use of different proxies, reflecting temperatures linked to different seasons. The compilation of the different precipitation reconstructions also show similar

  20. Climate-associated population declines reverse recovery and threaten future of an iconic high-elevation plant.

    Science.gov (United States)

    Krushelnycky, Paul D; Loope, Lloyd L; Giambelluca, Thomas W; Starr, Forest; Starr, Kim; Drake, Donald R; Taylor, Andrew D; Robichaux, Robert H

    2013-03-01

    Although climate change is predicted to place mountain-top and other narrowly endemic species at severe risk of extinction, the ecological processes involved in such extinctions are still poorly resolved. In addition, much of this biodiversity loss will likely go unobserved, and therefore largely unappreciated. The Haleakalā silversword is restricted to a single volcano summit in Hawai'i, but is a highly charismatic giant rosette plant that is viewed by 1-2 million visitors annually. We link detailed local climate data to a lengthy demographic record, and combine both with a population-wide assessment of recent plant mortality and recruitment, to show that after decades of strong recovery following successful management, this iconic species has entered a period of substantial climate-associated decline. Mortality has been highest at the lower end of the distributional range, where most silverswords occur, and the strong association of annual population growth rates with patterns of precipitation suggests an increasing frequency of lethal water stress. Local climate data confirm trends toward warmer and drier conditions on the mountain, and signify a bleak outlook for silverswords if these trends continue. The silversword example foreshadows trouble for diversity in other biological hotspots, and illustrates how even well-protected and relatively abundant species may succumb to climate-induced stresses. © 2012 Blackwell Publishing Ltd.

  1. Explaining the dependence of climatic response of tree radial growth on permafrost

    Science.gov (United States)

    Bryukhanova, Marina; Benkova, Anna; von Arx, Georg; Fonti, Patrick; Simanko, Valentina; Kirdyanov, Alexander; Shashkin, Alexander

    2015-04-01

    In northern regions of Siberia it is infrequent to have long-term observations of the variability of soil features, phenological data, duration of the growing season, which can be used to infer the influence of the environment on tree growth and productivity. The best way to understand tree-growth and tree responses to environmental changes is to make use of mechanistic models, allowing to combine already available experiment/field data with other parameters based on biological principles of tree growth. The goal of our study is to estimate which tree species (deciduous, conifer deciduous or conifer evergreen) is more plastic under possible climate changes in permafrost zone. The studied object is located in the northern part of central Siberia, Russia (64°N, 100°E). The study plot was selected within a post-fire succession and representatives for 100 years old even aged mixed forest of Larix gmelinii (Rupr.) Rupr. and Betula pubescens Ehrh. with few exemplars of Spruce (Picea obovata Ledeb.). To understand physiological response of larch, birch and spruce trees to climatic changes the ecological-physiological process-based model of tree photosynthesis (Benkova and Shashkin 2003) was applied. Multiparametric tree-ring chronologies were analyzed and correlated with climatic parameters over the last 77 years. This work is supported by the Ministry of Education and Science of the Russian Federation (Grant from the President of RF for Young Scientists MK-1589.2014.4).

  2. Exploring climatic controls on blanket bog litter decomposition across an altitudinal gradient

    Science.gov (United States)

    Bell, Michael; Ritson, Jonathan P.; Clark, Joanna M.; Verhoef, Anne; Brazier, Richard E.

    2016-04-01

    The hydrological and ecological functioning of blanket bogs is strongly coupled, involving multiple ecohydrological feedbacks which can affect carbon cycling. Cool and wet conditions inhibit decomposition, and favour the growth of Sphagnum mosses which produce highly recalcitrant litter. A small but persistent imbalance between production and decomposition has led to blanket bogs in the UK accumulating large amounts of carbon. Additionally, healthy bogs provide a suite of other ecosystems services including water regulation and drinking water provision. However, there is concern that climate change could increase rates of litter decomposition and disrupt this carbon sink. Furthermore, it has been argued that the response of these ecosystems in the warmer south west and west of the UK may provide an early analogue for later changes in the more extensive northern peatlands. In order to investigate the effects of climate change on blanket bog litter decomposition, we set-up a litter bag experiment across an altitudinal gradient spanning 200 m of elevation (including a transition from moorland to healthy blanket bog) on Dartmoor, an area of hitherto unstudied, climatically marginal blanket bog in the south west of the UK. At seven sites, water table depth and soil and surface temperature were recorded continuously. Litter bags filled with the litter of three vegetation species dominant on Dartmoor were incubated just below the bog surface and retrieved over a period of 12 months. We found significant differences in the rate of decomposition between species. At all sites, decomposition progressed in the order Calluna vulgaris (dwarf shrub) > Molinia caerulea (graminoid) > Sphagnum (bryophyte). However, while soil temperature did decrease along the altitudinal gradient, being warmer in the lower altitudes, a hypothesised accompanying decrease in decomposition rates did not occur. This could be explained by greater N deposition at the higher elevation sites (estimated

  3. The Last Interglacial recorded in a Remouchamps cave speleothem (Belgium) -Information on seasonal changes and on the chronology of first climate deteriorations.

    Science.gov (United States)

    Verheyden, Sophie; Genty, Dominique; Blamart, Dominique; Cheng, Hai; Hodel, Florent; Vansteenberghe, Stef; McGavick, Matthew L.; Gillikin, David P.; Quinif, Yves

    2015-04-01

    A ~3m long stalagmite from the Remouchamps and ~15cm long stalagmite from the Han-sur-Lesse caves (Belgium) grew from ~124 to 100ka with growth rates going from 0.8mm/century to 30mm/century. Stable isotope (d18O and d13C) and growth-rate analyses suggest a rather stable climate from 122.0 to 115.8 ka. A clear climate deterioration is observed at ~115.8 ka and lasts until 111.2ka (±0.5ka, 2s), which corresponds well with Greenland Stadial 26. Several short-term but clear changes are observed in the stable isotopic composition at ~121.5, 119.5, 118.4, 117.6 (±0.5ka, 2s)) and are interpreted as climatic events of ~several hundred years long. They correspond with changes in stalagmite diameter and growth rate. Depending on the combination of changes in the d18O, d13C, growth rate and stalagmite diameter, the events are interpreted as corresponding to changes in rainfall amount or temperature. The RSM17 stalagmite exhibits visible seasonal layering during the entire 120-115ka period on which changes in Mg, Sr, Ba en P have been observed. This well pronounced lamination, likely annual as suggested by the U-Th data, demonstrates a strong seasonal character of the climate and/or vegetation activity during this period. We compare these MIS5 seasonality to the present day calcite layering observed in the cave. Both stalagmites, with a growth-rate increase after 125ka globally corresponding to the so-called Eemian optimum, seem to start later than other southern stalagmites from France, Italy or Spain. This observation raises the question of a possible late onset of interglacial conditions in north-west Europe and a progressive S-N advance of warmer conditions between 130 and 125ka through Western Europe.

  4. Spatial variability in growth-increment chronologies of long-lived freshwater mussels: Implications for climate impacts and reconstructions

    Science.gov (United States)

    Black, Bryan A.; Dunham, Jason B.; Blundon, Brett W.; Raggon, Mark F.; Zima, Daniela

    2010-01-01

    Estimates of historical variability in river ecosystems are often lacking, but long-lived freshwater mussels could provide unique opportunities to understand past conditions in these environments. We applied dendrochronology techniques to quantify historical variability in growth-increment widths in valves (shells) of western pearlshell freshwater mussels (Margaritifera falcata). A total of 3 growth-increment chronologies, spanning 19 to 26 y in length, were developed. Growth was highly synchronous among individuals within each site, and to a lesser extent, chronologies were synchronous among sites. All 3 chronologies negatively related to instrumental records of stream discharge, while correlations with measures of water temperature were consistently positive but weaker. A reconstruction of stream discharge was performed using linear regressions based on a mussel growth chronology and the regional Palmer Drought Severity Index (PDSI). Models based on mussel growth and PDSI yielded similar coefficients of prediction (R2Pred) of 0.73 and 0.77, respectively, for predicting out-ofsample observations. From an ecological perspective, we found that mussel chronologies provided a rich source of information for understanding climate impacts. Responses of mussels to changes in climate and stream ecosystems can be very site- and process-specific, underscoring the complex nature of biotic responses to climate change and the need to understand both regional and local processes in projecting climate impacts on freshwater species.

  5. Potential ecological and economic consequences of climate-driven agricultural and silvicultural transformations in central Siberia

    Science.gov (United States)

    Tchebakova, Nadezhda M.; Zander, Evgeniya V.; Pyzhev, Anton I.; Parfenova, Elena I.; Soja, Amber J.

    2014-05-01

    Increased warming predicted from general circulation models (GCMs) by the end of the century is expected to dramatically impact Siberian forests. Both natural climate-change-caused disturbance (weather, wildfire, infestation) and anthropogenic disturbance (legal/illegal logging) has increased, and their impact on Siberian boreal forest has been mounting over the last three decades. The Siberian BioClimatic Model (SiBCliM) was used to simulate Siberian forests, and the resultant maps show a severely decreased forest that has shifted northwards and a changed composition. Predicted dryer climates would enhance the risks of high fire danger and thawing permafrost, both of which challenge contemporary ecosystems. Our current goal is to evaluate the ecological and economic consequences of climate warming, to optimise economic loss/gain effects in forestry versus agriculture, to question the relative economic value of supporting forestry, agriculture or a mixed agro-forestry at the southern forest border in central Siberia predicted to undergo the most noticeable landcover and landuse changes. We developed and used forest and agricultural bioclimatic models to predict forest shifts; novel tree species and their climatypes are introduced in a warmer climate and/or potential novel agriculture are introduced with a potential variety of crops by the end of the century. We applied two strategies to estimate climate change effects, motivated by forest disturbance. One is a genetic means of assisting trees and forests to be harmonized with a changing climate by developing management strategies for seed transfer to locations that are best ecologically suited to the genotypes in future climates. The second strategy is the establishment of agricultural lands in new forest-steppe and steppe habitats, because the forests would retreat northwards. Currently, food, forage, and biofuel crops primarily reside in the steppe and forest-steppe zones which are known to have favorable

  6. Anthropogenic nitrogen deposition alters growth responses of European beech (Fagus sylvativa L.) to climate change.

    Science.gov (United States)

    Hess, Carsten; Niemeyer, Thomas; Fichtner, Andreas; Jansen, Kirstin; Kunz, Matthias; Maneke, Moritz; von Wehrden, Henrik; Quante, Markus; Walmsley, David; von Oheimb, Goddert; Härdtle, Werner

    2018-02-01

    Global change affects the functioning of forest ecosystems and the services they provide, but little is known about the interactive effects of co-occurring global change drivers on important functions such as tree growth and vitality. In the present study we quantified the interactive (i.e. synergistic or antagonistic) effects of atmospheric nitrogen (N) deposition and climatic variables (temperature, precipitation) on tree growth (in terms of tree-ring width, TRW), taking forest ecosystems with European beech (Fagus sylvatica L.) as an example. We hypothesised that (i) N deposition and climatic variables can evoke non-additive responses of the radial increment of beech trees, and (ii) N loads have the potential to strengthen the trees' sensitivity to climate change. In young stands, we found a synergistic positive effect of N deposition and annual mean temperature on TRW, possibly linked to the alleviation of an N shortage in young stands. In mature stands, however, high N deposition significantly increased the trees' sensitivity to increasing annual mean temperatures (antagonistic effect on TRW), possibly due to increased fine root dieback, decreasing mycorrhizal colonization or shifts in biomass allocation patterns (aboveground vs. belowground). Accordingly, N deposition and climatic variables caused both synergistic and antagonistic effects on the radial increment of beech trees, depending on tree age and stand characteristics. Hence, the nature of interactions could mediate the long-term effects of global change drivers (including N deposition) on forest carbon sequestration. In conclusion, our findings illustrate that interaction processes between climatic variables and N deposition are complex and have the potential to impair growth and performance of European beech. This in turn emphasises the importance of multiple-factor studies to foster an integrated understanding and models aiming at improved projections of tree growth responses to co-occurring drivers

  7. Suitable Days for Plant Growth Disappear under Projected Climate Change: Potential Human and Biotic Vulnerability.

    Directory of Open Access Journals (Sweden)

    Camilo Mora

    2015-06-01

    Full Text Available Ongoing climate change can alter conditions for plant growth, in turn affecting ecological and social systems. While there have been considerable advances in understanding the physical aspects of climate change, comprehensive analyses integrating climate, biological, and social sciences are less common. Here we use climate projections under alternative mitigation scenarios to show how changes in environmental variables that limit plant growth could impact ecosystems and people. We show that although the global mean number of days above freezing will increase by up to 7% by 2100 under "business as usual" (representative concentration pathway [RCP] 8.5, suitable growing days will actually decrease globally by up to 11% when other climatic variables that limit plant growth are considered (i.e., temperature, water availability, and solar radiation. Areas in Russia, China, and Canada are projected to gain suitable plant growing days, but the rest of the world will experience losses. Notably, tropical areas could lose up to 200 suitable plant growing days per year. These changes will impact most of the world's terrestrial ecosystems, potentially triggering climate feedbacks. Human populations will also be affected, with up to ~2,100 million of the poorest people in the world (~30% of the world's population highly vulnerable to changes in the supply of plant-related goods and services. These impacts will be spatially variable, indicating regions where adaptations will be necessary. Changes in suitable plant growing days are projected to be less severe under strong and moderate mitigation scenarios (i.e., RCP 2.6 and RCP 4.5, underscoring the importance of reducing emissions to avoid such disproportionate impacts on ecosystems and people.

  8. A Framework Predicting Water Availability in a Rapidly Growing, Semi-Arid Region under Future Climate Change

    Science.gov (United States)

    Han, B.; Benner, S. G.; Glenn, N. F.; Lindquist, E.; Dahal, K. R.; Bolte, J.; Vache, K. B.; Flores, A. N.

    2014-12-01

    Climate change can lead to dramatic variations in hydrologic regime, affecting both surface water and groundwater supply. This effect is most significant in populated semi-arid regions where water availability are highly sensitive to climate-induced outcomes. However, predicting water availability at regional scales, while resolving some of the key internal variability and structure in semi-arid regions is difficult due to the highly non-linearity relationship between rainfall and runoff. In this study, we describe the development of a modeling framework to evaluate future water availability that captures elements of the coupled response of the biophysical system to climate change and human systems. The framework is built under the Envision multi-agent simulation tool, characterizing the spatial patterns of water demand in the semi-arid Treasure Valley area of Southwest Idaho - a rapidly developing socio-ecological system where urban growth is displacing agricultural production. The semi-conceptual HBV model, a population growth and allocation model (Target), a vegetation state and transition model (SSTM), and a statistically based fire disturbance model (SpatialAllocator) are integrated to simulate hydrology, population and land use. Six alternative scenarios are composed by combining two climate change scenarios (RCP4.5 and RCP8.5) with three population growth and allocation scenarios (Status Quo, Managed Growth, and Unconstrained Growth). Five-year calibration and validation performances are assessed with Nash-Sutcliffe efficiency. Irrigation activities are simulated using local water rights. Results show that in all scenarios, annual mean stream flow decreases as the projected rainfall increases because the projected warmer climate also enhances water losses to evapotranspiration. Seasonal maximum stream flow tends to occur earlier than in current conditions due to the earlier peak of snow melting. The aridity index and water deficit generally increase in the

  9. Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient.

    Science.gov (United States)

    Gentilesca, Tiziana; Rita, Angelo; Brunetti, Michele; Giammarchi, Francesco; Leonardi, Stefano; Magnani, Federico; van Noije, Twan; Tonon, Giustino; Borghetti, Marco

    2018-07-01

    In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m -2  y -1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites. © 2018 John Wiley & Sons Ltd.

  10. The ecology of climate change and infectious diseases

    Science.gov (United States)

    Lafferty, Kevin D.

    2009-01-01

    The projected global increase in the distribution and prevalence of infectious diseases with climate change suggests a pending societal crisis. The subject is increasingly attracting the attention of health professionals and climate-change scientists, particularly with respect to malaria and other vector-transmitted human diseases. The result has been the emergence of a crisis discipline, reminiscent of the early phases of conservation biology. Latitudinal, altitudinal, seasonal, and interannual associations between climate and disease along with historical and experimental evidence suggest that climate, along with many other factors, can affect infectious diseases in a nonlinear fashion. However, although the globe is significantly warmer than it was a century ago, there is little evidence that climate change has already favored infectious diseases. While initial projections suggested dramatic future increases in the geographic range of infectious diseases, recent models predict range shifts in disease distributions, with little net increase in area. Many factors can affect infectious disease, and some may overshadow the effects of climate.

  11. Climate change and economic growth: a heterogeneous panel data approach.

    Science.gov (United States)

    Sequeira, Tiago Neves; Santos, Marcelo Serra; Magalhães, Manuela

    2018-05-31

    Climate change is a global phenomenon. Its impact on economic growth must therefore be analyzed in accordance with its (time-varying) common effects. We present an econometric analysis that evaluates this effect taking into account its global nature. Contrary to previous evidence that ignores the global effects, we obtain that the rising temperature has not decreased growth in real GDP per capita in the second half of the twentieth century for the world countries. However, we obtain a negative effect of rising temperatures and a positive effect of rising precipitation in poor countries. This positive effect of rising precipitation is also confirmed for hot and temperate countries.

  12. Quantifying the Influence of Climate on Human Conflict

    Science.gov (United States)

    Hsiang, S. M.; Burke, M.; Miguel, E.

    2014-12-01

    A rapidly growing body of research examines whether human conflict can be affected by climatic changes. Drawing from archaeology, criminology, economics, geography, history, political science, and psychology, we assemble and analyze the most rigorous quantitative studies and document, for the first time, a striking convergence of results. We find strong causal evidence linking climatic events to human conflict across a range of spatial and temporal scales and across all major regions of the world. The magnitude of climate's influence is substantial: for each one standard deviation (1sd) change in climate toward warmer temperatures or more extreme rainfall, median estimates indicate that the frequency of interpersonal violence rises 4% and the frequency of intergroup conflict rises 14%. Because locations throughout the inhabited world are expected to warm 2sd to 4sd by 2050, amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change.

  13. Climate change and timing of avian breeding and migration: evolutionary versus plastic changes

    NARCIS (Netherlands)

    Charmantier, A.; Gienapp, P.

    2014-01-01

    There are multiple observations around the globe showing that in many avian species, both the timing of migration and breeding have advanced, due to warmer springs. Here, we review the literature to disentangle the actions of evolutionary changes in response to selection induced by climate change

  14. Different parts, different stories: climate sensitivity of growth is stronger in root collars vs. stems in tundra shrubs.

    Science.gov (United States)

    Ropars, Pascale; Angers-Blondin, Sandra; Gagnon, Marianne; Myers-Smith, Isla H; Lévesque, Esther; Boudreau, Stéphane

    2017-08-01

    Shrub densification has been widely reported across the circumpolar arctic and subarctic biomes in recent years. Long-term analyses based on dendrochronological techniques applied to shrubs have linked this phenomenon to climate change. However, the multi-stemmed structure of shrubs makes them difficult to sample and therefore leads to non-uniform sampling protocols among shrub ecologists, who will favor either root collars or stems to conduct dendrochronological analyses. Through a comparative study of the use of root collars and stems of Betula glandulosa, a common North American shrub species, we evaluated the relative sensitivity of each plant part to climate variables and assessed whether this sensitivity is consistent across three different types of environments in northwestern Québec, Canada (terrace, hilltop and snowbed). We found that root collars had greater sensitivity to climate than stems and that these differences were maintained across the three types of environments. Growth at the root collar was best explained by spring precipitation and summer temperature, whereas stem growth showed weak and inconsistent responses to climate variables. Moreover, sensitivity to climate was not consistent among plant parts, as individuals having climate-sensitive root collars did not tend to have climate-sensitive stems. These differences in sensitivity of shrub parts to climate highlight the complexity of resource allocation in multi-stemmed plants. Whereas stem initiation and growth are driven by microenvironmental variables such as light availability and competition, root collars integrate the growth of all plant parts instead, rendering them less affected by mechanisms such as competition and more responsive to signals of global change. Although further investigations are required to determine the degree to which these findings are generalizable across the tundra biome, our results indicate that consistency and caution in the choice of plant parts are a key

  15. Thermodynamics of climate change: generalized sensitivities

    Directory of Open Access Journals (Sweden)

    V. Lucarini

    2010-10-01

    Full Text Available Using a recent theoretical approach, we study how global warming impacts the thermodynamics of the climate system by performing experiments with a simplified yet Earth-like climate model. The intensity of the Lorenz energy cycle, the Carnot efficiency, the material entropy production, and the degree of irreversibility of the system change monotonically with the CO2 concentration. Moreover, these quantities feature an approximately linear behaviour with respect to the logarithm of the CO2 concentration in a relatively wide range. These generalized sensitivities suggest that the climate becomes less efficient, more irreversible, and features higher entropy production as it becomes warmer, with changes in the latent heat fluxes playing a predominant role. These results may be of help for explaining recent findings obtained with state of the art climate models regarding how increases in CO2 concentration impact the vertical stratification of the tropical and extratropical atmosphere and the position of the storm tracks.

  16. 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

  17. An introduction to climate change : a Canadian perspective

    International Nuclear Information System (INIS)

    Hengeveld, H.; Whitewood, B.; Fergusson, A.

    2005-10-01

    Chapters 1 to 4 of the report summarize our current scientific understanding of climate change and its global impact. The data in these chapters have been derived primarily from the reports of the Intergovernmental Panel on Climate Change (particularly the third assessment report released in 2001) and key scientific papers published in the international peer reviewed literature in recent years. The Panel's reports represent the most recent and comprehensive assessments of the issue by the international scientific community. Chapter 5 examines the many possible impacts of a warmer climate on Canada. Much of the information in this chapter is derived from related national assessments. In conclusion, Chapter 6 examines what must be and is being done to respond to this important issue

  18. 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

  19. Sensitivity of tree ring growth to local and large-scale climate variability in a region of Southeastern Brazil

    Science.gov (United States)

    Venegas-González, Alejandro; Chagas, Matheus Peres; Anholetto Júnior, Claudio Roberto; Alvares, Clayton Alcarde; Roig, Fidel Alejandro; Tomazello Filho, Mario

    2016-01-01

    We explored the relationship between tree growth in two tropical species and local and large-scale climate variability in Southeastern Brazil. Tree ring width chronologies of Tectona grandis (teak) and Pinus caribaea (Caribbean pine) trees were compared with local (Water Requirement Satisfaction Index—WRSI, Standardized Precipitation Index—SPI, and Palmer Drought Severity Index—PDSI) and large-scale climate indices that analyze the equatorial pacific sea surface temperature (Trans-Niño Index-TNI and Niño-3.4-N3.4) and atmospheric circulation variations in the Southern Hemisphere (Antarctic Oscillation-AAO). Teak trees showed positive correlation with three indices in the current summer and fall. A significant correlation between WRSI index and Caribbean pine was observed in the dry season preceding tree ring formation. The influence of large-scale climate patterns was observed only for TNI and AAO, where there was a radial growth reduction in months preceding the growing season with positive values of the TNI in teak trees and radial growth increase (decrease) during December (March) to February (May) of the previous (current) growing season with positive phase of the AAO in teak (Caribbean pine) trees. The development of a new dendroclimatological study in Southeastern Brazil sheds light to local and large-scale climate influence on tree growth in recent decades, contributing in future climate change studies.

  20. Climate Change Will Make Recovery from Eutrophication More Difficult in Shallow Danish Lake Søbygaard

    DEFF Research Database (Denmark)

    Rolighed, Jonas; Jeppesen, Erik; Søndergaard, Martin

    2016-01-01

    . The nutrient loading reduction scenarios predicted increased diatom dominance, accompanied by an increase in the zooplankton:phytoplankton biomass ratio. Simulations generally showed phytoplankton to benefit from a warmer climate and the fraction of cyanobacteria to increase. In the 6 ◦C warming scenario...

  1. Climate change, fire management, and ecological services in the southwestern US

    Science.gov (United States)

    Hurteau, Matthew D.; Bradford, John B.; Fulé, Peter Z.; Taylor, Alan H.; Martin, Katherine L.

    2014-01-01

    The diverse forest types of the southwestern US are inseparable from fire. Across climate zones in California, Nevada, Arizona, and New Mexico, fire suppression has left many forest types out of sync with their historic fire regimes. As a result, high fuel loads place them at risk of severe fire, particularly as fire activity increases due to climate change. A legacy of fire exclusion coupled with a warming climate has led to increasingly large and severe wildfires in many southwest forest types. Climate change projections include an extended fire season length due to earlier snowmelt and a general drying trend due to rising temperatures. This suggests the future will be warmer and drier regardless of changes in precipitation. Hotter, drier conditions are likely to increase forest flammability, at least initially. Changes in climate alone have the potential to alter the distribution of vegetation types within the region, and climate-driven shifts in vegetation distribution are likely to be accelerated when coupled with stand-replacing fire. Regardless of the rate of change, the interaction of climate and fire and their effects on Southwest ecosystems will alter the provisioning of ecosystem services, including carbon storage and biodiversity. Interactions between climate, fire, and vegetation growth provide a source of great uncertainty in projecting future fire activity in the region, as post-fire forest recovery is strongly influenced by climate and subsequent fire frequency. Severe fire can be mitigated with fuels management including prescribed fire, thinning, and wildfire management, but new strategies are needed to ensure the effectiveness of treatments across landscapes. We review the current understanding of the relationship between fire and climate in the Southwest, both historical and projected. We then discuss the potential implications of climate change for fire management and examine the potential effects of climate change and fire on ecosystem

  2. Proposal for new climate agreements: Economic growth determines the emission quota

    International Nuclear Information System (INIS)

    Kallbekken, Steffen; Tjernshaugen, Andreas

    2002-01-01

    Long-term obligations to curb the emission of climate gases involve economic uncertainty because it is difficult to determine the cost of future reductions. This may be the principle reason why the USA and the developing countries are reluctant to accept binding demands on their emissions of climate gases. For example, the commitments of the Kyoto Protocol were agreed upon more than ten years before they shall be put to force. Over such a long time span it is impossible to predict the development of the economy as well as the gas emissions. Usually economical development leads to increased gas emission. If a country commits itself to a quantified limit on its emission, and the economical development turns out to be much faster than predicted, then living up to the commitments may be very expensive. The same is true if the economic growth occurs in the polluting sectors to a larger degree than expected. Many heads of state thus fear that binding emission targets may restrain economic growth

  3. Thermal controls of Yellowstone cutthroat trout and invasive fishes under climate change

    Science.gov (United States)

    Al-Chokhachy, Robert K.; Alder, Jay R.; Hostetler, Steven W.; Gresswell, Robert E.; Shepard, Bradley

    2013-01-01

    We combine large observed data sets and dynamically downscaled climate data to explore historic and future (2050–2069) stream temperature changes over the topographically diverse Greater Yellowstone Ecosystem (elevation range = 824–4017 m). We link future stream temperatures with fish growth models to investigate how changing thermal regimes could influence the future distribution and persistence of native Yellowstone cutthroat trout (YCT) and competing invasive species. We find that stream temperatures during the recent decade (2000–2009) surpass the anomalously warm period of the 1930s. Climate simulations indicate air temperatures will warm by 1 °C to >3 °C over the Greater Yellowstone by mid-21st century, resulting in concomitant increases in 2050–2069 peak stream temperatures and protracted periods of warming from May to September (MJJAS). Projected changes in thermal regimes during the MJJAS growing season modify the trajectories of daily growth rates at all elevations with pronounced growth during early and late summer. For high-elevation populations, we find considerable increases in fish body mass attributable both to warming of cold-water temperatures and to extended growing seasons. During peak July to August warming, mid-21st century temperatures will cause periods of increased thermal stress, rendering some low-elevation streams less suitable for YCT. The majority (80%) of sites currently inhabited by YCT, however, display minimal loss (changes in total body mass by midcentury; we attribute this response to the fact that many low-elevation populations of YCT have already been extirpated by historical changes in land use and invasions of non-native species. Our results further suggest that benefits to YCT populations due to warmer stream temperatures at currently cold sites could be offset by the interspecific effects of corresponding growth of sympatric, non-native species, underscoring the importance of developing climate adaptation

  4. Anthropogenic nitrogen deposition ameliorates the decline in tree growth caused by a drier climate.

    Science.gov (United States)

    Ibáñez, Inés; Zak, Donald R; Burton, Andrew J; Pregitzer, Kurt S

    2018-02-01

    Most forest ecosystems are simultaneously affected by concurrent global change drivers. However, when assessing these effects, studies have mainly focused on the responses to single factors and have rarely evaluated the joined effects of the multiple aspects of environmental change. Here, we analyzed the combined effects of anthropogenic nitrogen (N) deposition and climatic conditions on the radial growth of Acer saccharum, a dominant tree species in eastern North American forests. We capitalized on a long-term N deposition study, replicated along a latitudinal gradient, that has been taking place for more than 20 yr. We analyzed tree radial growth as a function of anthropogenic N deposition (ambient and experimental addition) and of summer temperature and soil water conditions. Our results reveal that experimental N deposition enhances radial growth of this species, an effect that was accentuated as temperature increased and soil water became more limiting. The spatial and temporal extent of our data also allowed us to assert that the positive effects of growing under the experimental N deposition are likely due to changes in the physiological performance of this species, and not due to the positive correlation between soil N and soil water holding capacity, as has been previously speculated in other studies. Our simulations of tree growth under forecasted climate scenarios specific for this region also revealed that although anthropogenic N deposition may enhance tree growth under a large array of environmental conditions, it will not mitigate the expected effects of growing under the considerably drier conditions characteristic of our most extreme climatic scenario. © 2018 by the Ecological Society of America.

  5. The Growth of Bosnian Pine (Pinus hedreichii Christ. at Tree-Line Locations from Kosovo and its Response to Climate

    Directory of Open Access Journals (Sweden)

    Faruk Bojaxhi

    2016-12-01

    Full Text Available Background and Purpose: Pinus heldreichii Christ. is a sub-endemic species occurring at tree-line locations in Kosovo and covering an area of 2500 ha. In high elevation sites radial growth is mainly controlled by low temperatures. The main purpose of this study was the analysis of radial growth of P. heldreichii and its response to local climate conditions. Materials and Methods: Research sites comprise of three high elevation stands of P. heldreichii with specific site conditions. Core samples were collected from 98 healthy dominant and co-dominant trees at breast height using increment borer. They were prepared and cross-dated using standard dendrochronological methods, while tree-ring widths were measured to the nearest 0.001 mm using the TSAP software. The ARSTAN program was used to standardize the tree-ring widths and to calculate dendrochronological statistical parameters. The growth-climate relationship was investigated using bootstrapped correlation function analysing the residual chronologies of each sampled site as a dependent variable and the climatic data from May of the (n-1 year up to the October of the n year for the common period 1951-2013 as an independent variable. Results: The length of Bosnian pine chronologies ranged from 175 to 541 years. All chronologies had high values of first-order autocorrelation indicating that radial growth of P. heldreichii is affected by the climate conditions of the previous growing year. Koritnik chronology had the highest values of the mean sensitivity due to the influence of drought stress. This conclusion is also supported by the result of growth-climate relationship where radial growth is negatively correlated with June temperatures and positively associated with July and August precipitation. We found that radial growth of young trees from Koritnik site is limited by the combined effect of temperatures and summer drought stress. In high elevation sites, temperature is expected to control the

  6. Assessing the impacts of climate change and nitrogen deposition on Norway spruce growth in Austria with BIOME-BGC

    Energy Technology Data Exchange (ETDEWEB)

    Eastaugh, Chris S.; Potzelsberger, Elisabeth; Hasenaueur, Hubert

    2011-03-15

    The purpose of this study is to determine if the climate change has had an apparent impact in Austrian forests. This research has been conducted on Norway spruce forests as this is the predominant species in Austria. Growth data between regions which have different temperature and precipitation trendsw was then compared, with results showing increased productivity in all regions thus implying that growth of the forest is driven by other factors than climate. This conclusion is consistent with previous studies supporting that forest growth is mainly driven by increasing nitrogen deposition.

  7. Climate Reconstruction on the Growth of Teak in Umphang Wildlife Sanctuary, Thailand

    Directory of Open Access Journals (Sweden)

    Pichit Lumyai

    2017-11-01

    Full Text Available Teak is an example of proxy data that can be used to indirectly deduce past climatic conditions. The objective of this study was to investigate the relationship between teak growth and climate data in western Thailand. Dendrochronological techniques were used to analyze 52 sample cores from Umphang Wildlife Sanctuary. The crossdated ring width data could be extended back 127 years (1886-2012. The relationship between ring-width index and climatic data indicated a positive correlation (p<0.01 with the current year total rainfall in March and June. Thus, only March and June data were used to reconstruct the annual ring width index which indicated a downward trend in the reconstructed rainfall. Considering the March and June average total rainfall, a wet period occurred in 1887-1895 and this gradually decreased to a stable pattern in 1927-1945 with a further decline to another stable level in 1957-1964. Similarly, the dry periods occurring in 1896-1926, 1946-1955, 1965-1981 and 1982-2012 could explain the high fluctuations in rainfall. Periods of 2.2-2.7 and 25.2 years were found to be common with the variations in the El Niño-Southern Oscillation. In conclusion, teak growth information can be used to monitor global warming events.

  8. Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

    Science.gov (United States)

    Siddon, Elizabeth Calvert; Kristiansen, Trond; Mueter, Franz J; Holsman, Kirstin K; Heintz, Ron A; Farley, Edward V

    2013-01-01

    Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included local predator and prey energy densities, and (2) an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting recruitment variability.

  9. The Effect of Climate Change on Optimal Wetlands and Waterfowl Management in Western Canada

    NARCIS (Netherlands)

    Whitey, P.; Kooten, van G.C.

    2011-01-01

    Warmer temperatures and a decrease in precipitation in the 21st century could severely deplete wetlands in the prairie pothole region of western Canada. In this study, we employ linear regression analysis to determine the casual effect of climate change on wetlands in this region, with temperature,

  10. Recent climatic drying leads to age-independent growth reductions of white spruce stands in western Canada.

    Science.gov (United States)

    Hogg, Edward H; Michaelian, Michael; Hook, Trisha I; Undershultz, Michael E

    2017-12-01

    Since 2001, climatic conditions have been notably drier than normal across large areas of the western Canadian interior, leading to widespread impacts on the forests of this region. This poses a major concern for the future, given climate change projections for continued warming and drying. We conducted tree-ring analysis in 75 pure stands of white spruce (Picea glauca) across Alberta and west-central Saskatchewan to examine the effects of recent climatic drying on the growth of this important boreal tree species. Allometric equations were used to calculate annual growth in aboveground tree biomass (G BM ) from ring width measurements. Results showed an increasing trend in G BM from the 1960s to the 1990s, followed by a sharp decline during the severe drought of 2001-2002. Of the 75 stands, only 18 recovered sufficiently to cause an increase in mean G BM from the predrought decade of 1991-2000 to the subsequent decade of 2001-2010. The remaining 57 stands exhibited a decline in mean G BM between these decades. Climatic drying was a major cause of the growth decline, as shown by the significant stand-level relationship between percentage change in decadal mean G BM and the change in decadal mean values of a climate moisture index from 1991-2000 to 2001-2010. Subsequent analyses of boreal stands sampled across Alberta during 2015 revealed that white spruce growth had declined even further as drought conditions intensified during 2014-2015. Overall, there was a 38% decrease in mean G BM between 1997 and 2015, but surprisingly, the percentage decrease was not significantly different for young, productive stands compared with older, less productive stands. Thus, stand ageing cannot explain the observed decline in white spruce growth during the past quarter century, suggesting that these forests are at risk if the trend towards more frequent, severe drought continues in the region. © 2017 Her Majesty the Queen in Right of Canada Global Change Biology ©2017 John Wiley

  11. Predicting tree biomass growth in the temperate-boreal ecotone: is tree size, age, competition or climate response most important?

    Science.gov (United States)

    Foster, Jane R.; Finley, Andrew O.; D'Amato, Anthony W.; Bradford, John B.; Banerjee, Sudipto

    2016-01-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2and thereby slow rising CO2 concentrations. Forests’ ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals’ size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species likeAcer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92–95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth

  12. Predicting tree biomass growth in the temperate-boreal ecotone: Is tree size, age, competition, or climate response most important?

    Science.gov (United States)

    Foster, Jane R; Finley, Andrew O; D'Amato, Anthony W; Bradford, John B; Banerjee, Sudipto

    2016-06-01

    As global temperatures rise, variation in annual climate is also changing, with unknown consequences for forest biomes. Growing forests have the ability to capture atmospheric CO2 and thereby slow rising CO2 concentrations. Forests' ongoing ability to sequester C depends on how tree communities respond to changes in climate variation. Much of what we know about tree and forest response to climate variation comes from tree-ring records. Yet typical tree-ring datasets and models do not capture the diversity of climate responses that exist within and among trees and species. We address this issue using a model that estimates individual tree response to climate variables while accounting for variation in individuals' size, age, competitive status, and spatially structured latent covariates. Our model allows for inference about variance within and among species. We quantify how variables influence aboveground biomass growth of individual trees from a representative sample of 15 northern or southern tree species growing in a transition zone between boreal and temperate biomes. Individual trees varied in their growth response to fluctuating mean annual temperature and summer moisture stress. The variation among individuals within a species was wider than mean differences among species. The effects of mean temperature and summer moisture stress interacted, such that warm years produced positive responses to summer moisture availability and cool years produced negative responses. As climate models project significant increases in annual temperatures, growth of species like Acer saccharum, Quercus rubra, and Picea glauca will vary more in response to summer moisture stress than in the past. The magnitude of biomass growth variation in response to annual climate was 92-95% smaller than responses to tree size and age. This means that measuring or predicting the physical structure of current and future forests could tell us more about future C dynamics than growth responses

  13. Integrating geological archives and climate models for the mid-Pliocene warm period.

    Science.gov (United States)

    Haywood, Alan M; Dowsett, Harry J; Dolan, Aisling M

    2016-02-16

    The mid-Pliocene Warm Period (mPWP) offers an opportunity to understand a warmer-than-present world and assess the predictive ability of numerical climate models. Environmental reconstruction and climate modelling are crucial for understanding the mPWP, and the synergy of these two, often disparate, fields has proven essential in confirming features of the past and in turn building confidence in projections of the future. The continual development of methodologies to better facilitate environmental synthesis and data/model comparison is essential, with recent work demonstrating that time-specific (time-slice) syntheses represent the next logical step in exploring climate change during the mPWP and realizing its potential as a test bed for understanding future climate change.

  14. Climate Change Adaptation. Challenges and Opportunities for a Smart Urban Growth

    Directory of Open Access Journals (Sweden)

    Adriana Galderisi

    2014-04-01

    Full Text Available Climate change is one of the main environmental issues challenging cities in the 21th century. At present, more than half of the world population lives in cities and the latter are responsible for 60% to 80% of global energy consumption and greenhouse gas (GHG emissions, which are the main causes of the change in climate conditions. In the meantime, they are seriously threatened by the heterogeneous climate-related phenomena, very often exacerbated by the features of the cities themselves. In the last decade, international and European efforts have been mainly focused on mitigation rather than on adaptation strategies. Europe is one of the world leaders in global mitigation policies, while the issue of adaptation has gained growing importance in the last years. As underlined by the EU Strategy on adaptation to climate change, even though climate change mitigation still remains a priority for the global community, large room has to be devoted to adaptation measures, in order to effectively face the unavoidable impacts and related economic, environmental and social costs of climate change (EC, 2013. Thus, measures for adaptation to climate change are receiving an increasing financial support and a growing number of European countries are implementing national and urban adaptation strategies to deal with the actual and potential climate change impacts. According to the above considerations, this paper explores strengths and weaknesses of current adaptation strategies in European cities. First the main suggestions of the European Community to improve urban adaptation to climate change are examined; then, some recent Adaptation Plans are analyzed, in order to highlight challenges and opportunities arising from the adaptation processes at urban level and to explore the potential of Adaptation Plans to promote a smart growth in the European cities.

  15. Spatial variability of night temperatures at a fine scale over the Stellenbosch wine district, South Africa

    Directory of Open Access Journals (Sweden)

    Valérie Bonnardot

    2012-03-01

    Significance and impact of the study: In the context of climate change, it is crucial to improve knowledge of current climatic conditions at fine scale during periods of grapevine growth and berry ripening in order to have a baseline from which to work when discussing and considering future local adaptations to accommodate to a warmer environnement.

  16. A Projection of the Effects of the Climate Change Induced by Increased CO2 on Extreme Hydrologic Events in the Western U.S

    International Nuclear Information System (INIS)

    Kim, Jinwon

    2005-01-01

    The effects of increased atmospheric CO2 on the frequency of extreme hydrologic events in the Western United States (WUS) for the 10-yr period of 2040-2049 are examined using dynamically downscaled regional climate change signals. For assessing the changes in the occurrence of hydrologic extremes, downscaled climate change signals in daily precipitation and runoff that are likely to indicate the occurrence of extreme events are examined. Downscaled climate change signals in the selected indicators suggest that the global warming induced by increased CO2 is likely to increase extreme hydrologic events in the WUS. The indicators for heavy precipitation events show largest increases in the mountainous regions of the northern California Coastal Range and the Sierra Nevada. Increased cold season precipitation and increased rainfall-portion of precipitation at the expense of snowfall in the projected warmer climate result in large increases in high runoff events in the Sierra Nevada river basins that are already prone to cold season flooding in todays climate. The projected changes in the hydrologic characteristics in the WUS are mainly associated with higher freezing levels in the warmer climate and increases in the cold season water vapor influx from the Pacific Ocean

  17. Climate perceptions of local communities validated through scientific signals in Sikkim Himalaya, India.

    Science.gov (United States)

    Sharma, R K; Shrestha, D G

    2016-10-01

    Sikkim, a tiny Himalayan state situated in the north-eastern region of India, records limited research on the climate change. Understanding the changes in climate based on the perceptions of local communities can provide important insights for the preparedness against the unprecedented consequences of climate change. A total of 228 households in 12 different villages of Sikkim, India, were interviewed using eight climate change indicators. The results from the public opinions showed a significant increase in temperature compared to a decade earlier, winters are getting warmer, water springs are drying up, change in concept of spring-water recharge (locally known as Mul Phutnu), changes in spring season, low crop yields, incidences of mosquitoes during winter, and decrease in rainfall in last 10 years. In addition, study also showed significant positive correlations of increase in temperature with other climate change indicators viz. spring-water recharge concept (R (2) = 0.893), warmer winter (R (2) = 0.839), drying up of water springs (R (2) = 0.76), changes in spring season (R (2) = 0.68), low crop yields (R (2) = 0.68), decrease in rainfall (R (2) = 0.63), and incidences of mosquitoes in winter (R (2) = 0.50). The air temperature for two meteorological stations of Sikkim indicated statistically significant increasing trend in mean minimum temperature and mean minimum winter temperature (DJF). The observed climate change is consistent with the people perceptions. This information can help in planning specific adaptation strategies to cope with the impacts of climate change by framing village-level action plan.

  18. Workshop on Pliocene Climate

    Directory of Open Access Journals (Sweden)

    Nabil Khélifi

    2010-04-01

    Full Text Available The warm Pliocene epoch (5–3 million years ago is often cited as a good analog for the near future climate because of its striking resemblance to the predictions of the “Intergovernmental Panel on Climate Change” for the next decades. Indeed, relative to today, during the Pliocene epoch, surface temperatures were 3–4°C warmer, sea level was about 5–40 meters higher, atmospheric CO2 concentrationswere relatively similar or slightly higher (~400 ± 50 ppmv, and ice sheets were restrained to Antarctica. However, since 3.0 Ma ago, the Earth’s climate has undergone a major transition from a warm and relatively stable state towards cold conditions marked by amplified glacial/interglacial cycles and widespread ice sheets in the Northern Hemisphere (NHG, and to a lesser extent over Antarctica. The causes and consequences of this global climate transition—driving warm periods to “icehouse” conditions marked by “Quaternary-style” glacial/interglacial cycles—are still uncertain. Yet, they may include the interaction of several mechanisms tied to oceanic and atmospheric circulations, tectonic-, greenhouse gases-, and biological activity, biogeochemical processes, and changes in Earth’s orbit.

  19. Climate is a stronger driver of tree and forest growth rates than soil and disturbance

    NARCIS (Netherlands)

    Toledo, M.; Poorter, L.; Peña-Claros, M.; Alarcón, A.; Balcázar, J.; Leaño, C.; Licona, J.C.; Llanque, O.; Vroomans, V.; Zuidema, P.; Bongers, F.

    2011-01-01

    1. Essential resources such as water, nutrients and light vary over space and time and plant growth rates are expected to vary accordingly. We examined the effects of climate, soil and logging disturbances on diameter growth rates at the tree and stand level, using 165 1-ha permanent sample plots

  20. Potential benefits of early vigor and changes in phenology in wheat to adapt to warmer and drier climates

    NARCIS (Netherlands)

    Ludwig, F.; Asseng, S.

    2010-01-01

    Developing crop cultivars with novel traits could help agriculture adapt to climate change. As introducing new traits into crops is expensive and time consuming, it is helpful to develop methods which can test whether a potential new plant trait increases or maintains production in future climates.

  1. Public Perception of Climate Change and the New Climate Dice

    Science.gov (United States)

    Hansen, James; Sato, Makiko; Ruedy, Reto

    2012-01-01

    "Climate dice", describing the chance of unusually warm or cool seasons, have become more and more "loaded" in the past 30 years, coincident with rapid global warming. The distribution of seasonal mean temperature anomalies has shifted toward higher temperatures and the range of anomalies has increased. An important change is the emergence of a category of summertime extremely hot outliers, more than three standard deviations (3 sigma) warmer than the climatology of the 1951-1980 base period. This hot extreme, which covered much less than 1% of Earth's surface during the base period, now typically covers about 10% of the land area. It follows that we can state, with a high degree of confidence, that extreme anomalies such as those in Texas and Oklahoma in 2011 and Moscow in 2010 were a consequence of global warming, because their likelihood in the absence of global warming was exceedingly small. We discuss practical implications of this substantial, growing, climate change.

  2. Assessing future suitability of tree species under climate change by multiple methods: a case study in southern Germany

    Directory of Open Access Journals (Sweden)

    Helge Walentowski

    2017-07-01

    Full Text Available We compared results derived using three different approaches to assess the suitability of common tree species on the Franconian Plateau in southern Germany under projected warmer and drier climate conditions in the period 2061-2080. The study area is currently a relatively warm and dry region of Germany. We calculated species distribution models (SDMs using information on species’ climate envelopes to predict regional species spectra under 63 different climate change scenarios. We complemented this with fine-scale ecological niche analysis using data from 51 vegetation surveys in seven forest reserves in the study area, and tree-ring analysis (TRA from local populations of five tree species to quantify their sensitivity to climatic extreme years. The SDMs showed that predicted future climate change in the region remains within the climate envelope of certain species (e.g. Quercus petraea, whilst for e.g. Fagus sylvatica, future climate conditions in one third of the scenarios are too warm and dry. This was confirmed by the TRA: sensitivity to drought periods is lower for Q. petraea than for F. sylvatica. The niche analysis shows that the local ecological niches of Quercus robur and Fraxinus excelsior are mainly characterized by soils providing favorable water supply than by climate, and Pinus sylvestris (planted is strongly influenced by light availability. The best adapted species for a warmer and potentially drier climate in the study region are Acer campestre, Sorbus torminalis, S. aria, Ulmus minor, and Tilia platyphyllos, which should therefore play a more prominent role in future climate-resilient mixed forest ecosystems.

  3. Effect of passive cooling strategies on overheating in low energy residential buildings for Danish climate

    DEFF Research Database (Denmark)

    Simone, Angela; Avantaggiato, Marta; de Carli, Michele

    2014-01-01

    creating not negligible thermal discomfort. In the present work the effect of passive strategies, such as solar shading and natural night-time ventilation, are evaluated through computer simulations. The analyses are performed for 1½-storey single-family house in Copenhagen’s climate. The main result......Climate changes have progressively produced an increase of outdoors temperature resulting in tangible warmer summers even in cold climate regions. An increased interest for passive cooling strategies is rising in order to overcome the newly low energy buildings’ overheating issue. The growing level...

  4. 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....

  5. Species-specific growth responses to climate variations in understory trees of a Central African rain forest

    NARCIS (Netherlands)

    Couralet, C.; Sterck, F.J.; Sass-Klaassen, U.; Acker, Van J.; Beekman, H.

    2010-01-01

    Basic knowledge of the relationships between tree growth and environmental variables is crucial for understanding forest dynamics and predicting vegetation responses to climate variations. Trees growing in tropical areas with a clear seasonality in rainfall often form annual growth rings. In the

  6. Recent Studies on Attributions of Climate Change in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zongci; DING Yihui; LUO Yong; Wang Shaowu

    2005-01-01

    Attributions of floods/cooler along the Yangtze River Valley and droughts/warmer in North China for the last 25 years have been reviewed in this paper. Both natural climate variability and human activities are considered. Some stronger evidences contributed to the natural climate variability, such as decadal and interdecadal variabilities of East Asian summer monsoon, the periodicities and transitions of rainfall and temperature changes in China, abrupt climate change, NAO, AO, AAO, ENSO, and snow cover. The signals produced by the human activities such as greenhouse gases and "brown clouds" likely play the role for the patterns. But the physical feedbacks and mechanisms still keep ambiguous and vague. More researches should be carried out in future to solve this issue.

  7. Climate change projections for Greek viticulture as simulated by a regional climate model

    Science.gov (United States)

    Lazoglou, Georgia; Anagnostopoulou, Christina; Koundouras, Stefanos

    2017-07-01

    Viticulture represents an important economic activity for Greek agriculture. Winegrapes are cultivated in many areas covering the whole Greek territory, due to the favorable soil and climatic conditions. Given the dependence of viticulture on climate, the vitivinicultural sector is expected to be affected by possible climatic changes. The present study is set out to investigate the impacts of climatic change in Greek viticulture, using nine bioclimatic indices for the period 1981-2100. For this purpose, reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and data from the regional climatic model Regional Climate Model Version 3 (RegCM3) are used. It was found that the examined regional climate model estimates satisfactorily these bioclimatic indices. The results of the study show that the increasing trend of temperature and drought will affect all wine-producing regions in Greece. In vineyards in mountainous regions, the impact is positive, while in islands and coastal regions, it is negative. Overall, it should be highlighted that for the first time that Greece is classified into common climatic characteristic categories, according to the international Geoviticulture Multicriteria Climatic Classification System (MCC system). According to the proposed classification, Greek viticulture regions are estimated to have similar climatic characteristics with the warmer wine-producing regions of the world up to the end of twenty-first century. Wine growers and winemakers should take the findings of the study under consideration in order to take measures for Greek wine sector adaptation and the continuation of high-quality wine production.

  8. Indian Ocean warming modulates Pacific climate change

    Science.gov (United States)

    Luo, Jing-Jia; Sasaki, Wataru; Masumoto, Yukio

    2012-01-01

    It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east–west Walker circulation) through the Pacific ocean–atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific’s could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries. PMID:23112174

  9. Indian Ocean warming modulates Pacific climate change.

    Science.gov (United States)

    Luo, Jing-Jia; Sasaki, Wataru; Masumoto, Yukio

    2012-11-13

    It has been widely believed that the tropical Pacific trade winds weakened in the last century and would further decrease under a warmer climate in the 21st century. Recent high-quality observations, however, suggest that the tropical Pacific winds have actually strengthened in the past two decades. Precise causes of the recent Pacific climate shift are uncertain. Here we explore how the enhanced tropical Indian Ocean warming in recent decades favors stronger trade winds in the western Pacific via the atmosphere and hence is likely to have contributed to the La Niña-like state (with enhanced east-west Walker circulation) through the Pacific ocean-atmosphere interactions. Further analysis, based on 163 climate model simulations with centennial historical and projected external radiative forcing, suggests that the Indian Ocean warming relative to the Pacific's could play an important role in modulating the Pacific climate changes in the 20th and 21st centuries.

  10. Maize growth and yield in Peshawar under changing climate

    International Nuclear Information System (INIS)

    Shah, A.; Akmal, M.; Asim, M.

    2012-01-01

    Global climate change is consequence of accumulating greenhouse gases (Carbon) at lower atmosphere which might affects crops growth and yield. Maize is an important summer cereals, grown on considerable area in Pakistan every year. We, therefore, study the delay sowing response with changing climate on maize. Field experiment was conducted at Agronomy Research Farm, Agricultural University Peshawar, Pakistan in a randomized complete block design. Sowing was done from June 8 to July 24, 2010 with ten days intervals. Mazie (cv. Azam) was planted in rows at 0.75 m distance in NS orientations. Crop was raised under the uniform recommended cultural practices. Data regarding days to emergence, tasseling and maturity showed a consecutive decrease when so wing was delayed form June 08 onwards. However, the crop life cycle (i.e. vegetative and reproductive durations) initially remained uniform but expanded for late sowing dates (July). Delay sowing showed an increase in the leaf area index with an abrupt decline for the late sown crop. Nonetheless, plant stand at harvest remained static during the growth for all sowing dates. A stable to moderate reduction was noticed in ear length (cm) when sowings was delayed from Jun 08 onwards. Grain rows cob/-1 did not influence by the delay sowing in the season. Moreover, delay sowing did not show any significant (P<0.05) change for the grain number. However, thousand grains weight was initially remained stable but declined (P<0.05) by delay in sowing. Biological yield, dry matter and grains yield (g m/sup -2/) revealed almost a similar decreasing trend when sowing was delayed. Dry matter to grain yield relationship was linear (r/sup 2/ = 0.95) and revealed a mean loss of 1.65 g m/sup 2/ when sowing delayed from June 08 to July 24 in the season. Radiation use efficiency (RUE), the growth function, was also declined by the delay in sowing. We inferred that losses in leaf area indices, ear length and grain weights were basis of the

  11. In-line Microwave Warmer for Blood and Intravenous Fluids. Phase 2.

    Science.gov (United States)

    1988-02-15

    occuring in the battlefield often requires restoring normothermia and infusion of fluids, such as saline or blood, into the patient. These two...elevation is required to restore normal body temperature in response to hypothermic cardioplegic arrest induced prior to the operation. 6 1.2 System... Microfiltration Devices," Acta Annaesth Scand, 23:40- 45, 1979. [20] K Linko, K Hynynen, "Erythrocyte Damage Caused by the Haemotherm Microwave Blood Warmer

  12. Relating annual increments of the endangered Blanding's turtle plastron growth to climate.

    Science.gov (United States)

    Richard, Monik G; Laroque, Colin P; Herman, Thomas B

    2014-05-01

    This research is the first published study to report a relationship between climate variables and plastron growth increments of turtles, in this case the endangered Nova Scotia Blanding's turtle (Emydoidea blandingii). We used techniques and software common to the discipline of dendrochronology to successfully cross-date our growth increment data series, to detrend and average our series of 80 immature Blanding's turtles into one common chronology, and to seek correlations between the chronology and environmental temperature and precipitation variables. Our cross-dated chronology had a series intercorrelation of 0.441 (above 99% confidence interval), an average mean sensitivity of 0.293, and an average unfiltered autocorrelation of 0.377. Our master chronology represented increments from 1975 to 2007 (33 years), with index values ranging from a low of 0.688 in 2006 to a high of 1.303 in 1977. Univariate climate response function analysis on mean monthly air temperature and precipitation values revealed a positive correlation with the previous year's May temperature and current year's August temperature; a negative correlation with the previous year's October temperature; and no significant correlation with precipitation. These techniques for determining growth increment response to environmental variables should be applicable to other turtle species and merit further exploration.

  13. School climate and bullying victimization: a latent class growth model analysis.

    Science.gov (United States)

    Gage, Nicholas A; Prykanowski, Debra A; Larson, Alvin

    2014-09-01

    Researchers investigating school-level approaches for bullying prevention are beginning to discuss and target school climate as a construct that (a) may predict prevalence and (b) be an avenue for school-wide intervention efforts (i.e., increasing positive school climate). Although promising, research has not fully examined and established the social-ecological link between school climate factors and bullying/peer aggression. To address this gap, we examined the association between school climate factors and bullying victimization for 4,742 students in Grades 3-12 across 3 school years in a large, very diverse urban school district using latent class growth modeling. Across 3 different models (elementary, secondary, and transition to middle school), a 3-class model was identified, which included students at high-risk for bullying victimization. Results indicated that, for all students, respect for diversity and student differences (e.g., racial diversity) predicted within-class decreases in reports of bullying. High-risk elementary students reported that adult support in school was a significant predictor of within-class reduction of bullying, and high-risk secondary students report peer support as a significant predictor of within-class reduction of bullying. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  14. Non-stationary influence of El Niño-Southern Oscillation and winter temperature on oak latewood growth in NW Iberian Peninsula.

    Science.gov (United States)

    Rozas, Vicente; García-González, Ignacio

    2012-09-01

    The properties of El Niño-Southern Oscillation (ENSO), such as period, amplitude, and teleconnection strength to extratropical regions, have changed since the mid-1970s. ENSO affects the regional climatic regime in SW Europe, thus tree performance in the Iberian Peninsula could be affected by recent ENSO dynamics. We established four Quercus robur chronologies of earlywood and latewood widths in the NW Iberian Peninsula. The relationship between tree growth and the Southern Oscillation Index (SOI), the atmospheric expression of ENSO, showed that only latewood growth was correlated negatively with the SOI of the previous summer-autumn-winter. This relationship was non-stationary, with significant correlations only during the period 1952-1980; and also non-linear, with enhanced latewood growth only in La Niña years, i.e. years with a negative SOI index for the previous autumn. Non-linear relationship between latewood and SOI indicates an asymmetric influence of ENSO on tree performance, biassed towards negative SOI phases. During La Niña years, climate in the study area was warmer and wetter than during positive years, but only for 1952-1980. Winter temperatures became the most limiting factor for latewood growth since 1980, when mean regional temperatures increased by 1°C in comparison to previous periods. As a result, higher winter respiration rates, and the extension of the growing season, would probably cause an additional consumption of stored carbohydrates. The influence of ENSO and winter temperatures proved to be of great importance for tree growth, even at lower altitudes and under mild Atlantic climate in the NW Iberian Peninsula.

  15. Forest ecotone response to climate change: sensitivity to temperature response functional forms

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C. [National Council for Air and Stream Improvement, Naperville, IL (United States)

    2000-10-01

    Past simulation studies have been in general agreement that climatic change could have adverse effects on forests, including geographic range shrinkages, conversion to grassland, and catastrophic forest decline or dieback. Some other recent studies, however, concluded that this agreement is generally based on parabolic temperature response rather than functional responses or data, and may therefore exaggerate dieback effects. This paper proposes a new model of temperature response that is based on a trade-off between cold tolerance and growth rate. In this model, the growth rate increases at first, and then levels off with increasing growing degree-days. Species from more southern regions have a higher minimum temperature and a faster maximum height growth rate. It is argued that faster growth rates of southern types lead to their competitive superiority in warmer environments and that such temperature response should produce less dieback and slower rates of change than the more common parabolic response model. Theoretical justification of this model is provided, followed by application of the model to a simulated ecotone under a warming scenario. Results of the study based on the proposed asymptotic model showed no dieback and only a gradual ecotone movement north, suggesting that ecotone shifts will, in fact, take many hundreds to thousands of years, with the result that species will not face the risk of extinction. 56 refs., 1 tab., 8 figs.

  16. Changes in Vegetation Growth Dynamics and Relations with Climate over China’s Landmass from 1982 to 2011

    Directory of Open Access Journals (Sweden)

    Guang Xu

    2014-04-01

    Full Text Available Understanding how the dynamics of vegetation growth respond to climate change at different temporal and spatial scales is critical to projecting future ecosystem dynamics and the adaptation of ecosystems to global change. In this study, we investigated vegetated growth dynamics (annual productivity, seasonality and the minimum amount of vegetated cover in China and their relations with climatic factors during 1982–2011, using the updated Global Inventory Modeling and Mapping Studies (GIMMS third generation global satellite Advanced Very High Resolution Radiometer (AVHRR Normalized Difference Vegetation Index (NDVI dataset and climate data acquired from the National Centers for Environmental Prediction (NCEP. Major findings are as follows: (1 annual mean NDVI over China significantly increased by about 0.0006 per year from 1982 to 2011; (2 of the vegetated area in China, over 33% experienced a significant positive trend in vegetation growth, mostly located in central and southern China; about 21% experienced a significant positive trend in growth seasonality, most of which occurred in northern China (>35°N; (3 changes in vegetation growth dynamics were significantly correlated with air temperature and precipitation (p < 0.001 at a region scale; (4 at the country scale, changes in NDVI was significantly and positively correlated with annual air temperature (r = 0.52, p < 0.01 and not associated with annual precipitation (p > 0.1; (5 of the vegetated area, about 24% showed significant correlations between annual mean NDVI and air temperature (93% positive and remainder negative, and 12% showed significant correlations of annual mean NDVI with annual precipitation (65% positive and 35% negative. The spatiotemporal variations in vegetation growth dynamics were controlled primarily by temperature and secondly by precipitation. Vegetation growth was also affected by human activities; and (6 monthly NDVI was significantly correlated with the

  17. Forest responses to climate change in the northwestern United States: ecophysiological foundations for adaptive management

    Science.gov (United States)

    Daniel J. Chmura; Paul D. Anderson; Glenn T. Howe; Constance A. Harrington; Jessica E. Halofsky; David L. Peterson; David C. Shaw; Brad J. St Clair

    2011-01-01

    Climate change resulting from increased concentrations of atmospheric carbon dioxide ([C02]) is expected to result in warmer temperatures and changed precipitation regimes during this century. In the northwestern U.S., these changes will likely decrease snowpack, cause earlier snowmelt, increase summer evapotranspiration, and increase the...

  18. Spatiotemporal variability of stone pine (Pinus pinea L.) growth response to climate across the Iberian Peninsula

    Czech Academy of Sciences Publication Activity Database

    Natalini, F.; Alejano, R.; Vazquez-Pique, J.; Pardos, M.; Calama, R.; Büntgen, Ulf

    2016-01-01

    Roč. 40, dec (2016), s. 72-84 ISSN 1125-7865 Institutional support: RVO:67179843 Keywords : tree-rings * genetically depauperate * mediterranean climate * phenotypic plasticity * cambial activity * fagus-sylvatica * spain * drought * widespread * halepensis * Climate change * Dendroecology * Growth plasticity * Mediterranean * Tree rings * Drought Subject RIV: EH - Ecology, Behaviour Impact factor: 2.259, year: 2016

  19. Sensitivity of climate models: Comparison of simulated and observed patterns for past climates

    International Nuclear Information System (INIS)

    Prell, W.L.; Webb, T. III.

    1992-08-01

    Predicting the potential climatic effects of increased concentrations of atmospheric carbon dioxide requires the continuing development of climate models. Confidence in the predictions will be much enhanced once the models are thoroughly tested in terms of their ability to simulate climates that differ significantly from today's climate. As one index of the magnitude of past climate change, the global mean temperature increase during the past 18,000 years is similar to that predicted for carbon dioxide--doubling. Simulating the climatic changes of the past 18,000 years, as well as the warmer-than-present climate of 6000 years ago and the climate of the last interglacial, around 126,000 years ago, provides an excellent opportunity to test the models that are being used in global climate change research. During the past several years, we have used paleoclimatic data to test the accuracy of the National Center for Atmospheric Research, Community Climate Model, Version 0, after changing its boundary conditions to those appropriate for past climates. We have assembled regional and near-global paleoclimatic data sets of pollen, lake level, and marine plankton data and calibrated many of the data in terms of climatic variables. We have also developed methods that permit direct quantitative comparisons between the data and model results. Our research has shown that comparing the model results with the data is an evolutionary process, because the models, the data, and the methods for comparison are continually being improved. During 1992, we have completed new modeling experiments, further analyzed previous model experiments, compiled new paleodata, made new comparisons between data and model results, and participated in workshops on paleoclimatic modeling

  20. Study on the Future Climate Change and Its Influence on the Growth Stage and Yield of Wheat in Weifang City

    Institute of Scientific and Technical Information of China (English)

    Jing; YUAN; Jianping; XU; Lijuan; SUN; Xiuzhen; ZHANG; Xiaoli; WANG

    2015-01-01

    In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were simulated by using the regional climate model PRECIS.And then put the meteorological data into the crop model to simulate the growth of wheat under climate change conditions in the future.The results showed that there would be a trend of rising temperature and increasing precipitation in Weifang in the future.Climate warming would result in growth period of wheat to be ahead of schedule and yield reduction.If taking into account the effect of CO2,the yield of wheat would increase.

  1. Growth trends and climate responses of Norway spruce along elevational gradients in East-Central Europe

    Czech Academy of Sciences Publication Activity Database

    Ponočná, T.; Spyt, B.; Kaczka, R. J.; Büntgen, Ulf; Treml, V.

    2016-01-01

    Roč. 30, č. 5 (2016), s. 1633-1646 ISSN 0931-1890 R&D Projects: GA MŠk(CZ) EE2.3.20.0248 Institutional support: RVO:67179843 Keywords : abies l. karst. * tree-ring chronologies * basal area increment * radial growth * forest growth * altitudinal gradient * sudetes mountains * northern europe * tatra mountains * alps * climate change * mountain forests * picea abies * radial growth * rree rings * trend preservation Subject RIV: GK - Forestry Impact factor: 1.842, year: 2016

  2. Poleward shift and weakening of summer season synoptic activity over India in a warming climate

    Science.gov (United States)

    Ravindran, A. M.; Sandeep, S.; Boos, W. R.; TP, S.; Praveen, V.

    2017-12-01

    One of the main components of the Indian summer monsoon is the presence of low intensity cyclonic systems popularly known as Low Pressure Systems (LPS), which contribute more than half of the precipitation received over the fertile Central Indian region. An average of 13 (±2.5) storms develop each boreal summer, with most originating over the Bay of Bengal (BoB) and adjoining land. These systems typically follow a north-west track along the monsoon trough. Despite its significance, the future variability of these storms is not studied, due to the inadequate representation of these systems in current generation climate models. A series of numerical experiments are performed here using the High Resolution Atmospheric Model (HiRAM) with a horizontal grid spacing of 50 km globally to simulate these rain-bearing systems. One set of simulations represents the historical (HIST) period and the other a late 21st century climate scenario based on the strongest Representative Concentration Pathway (RCP8.5). Four ensemble members of these simulations are run, with sea surface temperatures (SSTs) taken from different CMIP5 GCMs selected for their skill in simulating the Indian monsoon. In addition, ten ensemble members of `decadal' experiments are run for both HIST and RCP8.5 to assess model uncertainty, in which the model is forced with annual cycles of decadal mean SSTs. We show that the strength of monsoon LPS activity would decline as much as 50% by the end of the 21st century, under business as usual emission scenario. The overall reduction in the LPS activity is contributed by a 60% decrease in the frequency of storms over the Bay of Bengal, while the weaker systems that form over the land has increased 10% in a warmer climate. Further analysis suggests that a relatively slower rate of warming over the Bay of Bengal compared to the surrounding regions has resulted in an enhanced moist stability over the main genesis region of LPS, which in turn suppressed the growth of

  3. Climate vulnerability of native cold-water salmonids in the Northern Rockies Region [Chapter 5

    Science.gov (United States)

    Michael K. Young; Daniel J. Isaak; Scott Spaulding; Cameron A. Thomas; Scott A. Barndt; Matthew C. Groce; Dona Horan; David E. Nagel

    2018-01-01

    During the 21st century, climate change is expected to alter aquatic habitats throughout the Northern Rocky Mountains, intermountain basins, and western Great Plains. Particularly in montane watersheds, direct changes are likely to include warmer water temperatures, earlier snowmelt-driven runoff, earlier declines to summer baseflow, downhill movement of perennial...

  4. Climate Change and Health Risks from Extreme Heat and Air Pollution in the Eastern United States

    Science.gov (United States)

    Limaye, V.; Vargo, J.; Harkey, M.; Holloway, T.; Meier, P.; Patz, J.

    2013-12-01

    Climate change is expected to exacerbate health risks from exposure to extreme heat and air pollution through both direct and indirect mechanisms. Directly, warmer ambient temperatures promote biogenic emissions of ozone precursors and favor the formation of ground-level ozone, while an anticipated increase in the frequency of stagnant air masses will allow fine particulates to accumulate. Indirectly, warmer summertime temperatures stimulate energy demand and exacerbate polluting emissions from the electricity sector. Thus, while technological adaptations such as air conditioning can reduce risks from exposures to extreme heat, they can trigger downstream damage to air quality and public health. Through an interdisciplinary modeling effort, we quantify the impacts of climate change on ambient temperatures, summer energy demand, air quality, and public health. The first phase of this work explores how climate change will directly impact the burden of heat-related mortality. Climatic patterns, demographic trends, and epidemiologic risk models suggest that populations in the eastern United States are likely to experience an increasing heat stress mortality burden in response to rising summertime air temperatures. We use North American Regional Climate Change Assessment Program modeling data to estimate mid-century 2-meter air temperatures and humidity across the eastern US from June-August, and quantify how long-term changes in actual and apparent temperatures from present-day will affect the annual burden of heat-related mortality across this region. With the US Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program, we estimate health risks using concentration-response functions, which relate temperature increases to changes in annual mortality rates. We compare mid-century summertime temperature data, downscaled using the Weather Research and Forecasting model, to 2007 baseline temperatures at a 12 km resolution in order to estimate

  5. Adapting to the reality of climate change at Glacier National Park, Montana, USA

    Science.gov (United States)

    Fagre, Daniel B.

    2007-01-01

    The glaciers of Glacier National Park (GNP) are disappearing rapidly and likely will be gone by 2030. These alpine glaciers have been continuously present for approximately 7,000 years so their loss from GNP in another 25 years underscores the significance of current climate change. There are presently only 27 glaciers remaining of the 150 estimated to have existed when GNP was created in 1910. Mean annual temperature in GNP has increased 1.6 0 C during the past cen- tury, three times the global mean increase. The temperature increase has affected other parts of the mountain ecosystem, too. Snowpacks hold less water equivalent and melt 2+ weeks earlier in the spring. Forest growth rates have increased, alpine treelines have expanded upward and be- come denser, and subalpine meadows have been invaded by high elevation tree species. These latter responses can be mostly attributed to longer growing seasons and warmer temperatures.

  6. Integrating geological archives and climate models for the mid-Pliocene warm period

    Science.gov (United States)

    Haywood, Alan M.; Dowsett, Harry J.; Dolan, Aisling M.

    2016-01-01

    The mid-Pliocene Warm Period (mPWP) offers an opportunity to understand a warmer-than-present world and assess the predictive ability of numerical climate models. Environmental reconstruction and climate modelling are crucial for understanding the mPWP, and the synergy of these two, often disparate, fields has proven essential in confirming features of the past and in turn building confidence in projections of the future. The continual development of methodologies to better facilitate environmental synthesis and data/model comparison is essential, with recent work demonstrating that time-specific (time-slice) syntheses represent the next logical step in exploring climate change during the mPWP and realizing its potential as a test bed for understanding future climate change. PMID:26879640

  7. CO{sub 2} and climate protection. Facts, mistakes, policy; CO{sub 2} und Klimaschutz. Fakten, Irrtuemer, Politk

    Energy Technology Data Exchange (ETDEWEB)

    Luedecke, H.J.

    2008-07-01

    The author outlines the technical fundamental coherences of the CO{sub 2} problem generally clear and without unnecessary technical details. ''Which measuring methods founds on climate warning, are extrem weather disasters increasing, is the sea level raising, is a warmer climate harmful or useful, are wind turbines solar cells or biofuels meaningful, who is profitting from climate fear, which role play policy and ideology?'' are questions this book dealt with. Expert fundamentals, not political opinions are derived from reports of Intergovernmental Panel on Climate Change (IPCC), the climatic department of the UN, reference items from internet contributions and specialist books. (GL)

  8. Influence of ecohydrologic feedbacks from simulated crop growth on integrated regional hydrologic simulations under climate scenarios

    Science.gov (United States)

    van Walsum, P. E. V.; Supit, I.

    2012-06-01

    Hydrologic climate change modelling is hampered by climate-dependent model parameterizations. To reduce this dependency, we extended the regional hydrologic modelling framework SIMGRO to host a two-way coupling between the soil moisture model MetaSWAP and the crop growth simulation model WOFOST, accounting for ecohydrologic feedbacks in terms of radiation fraction that reaches the soil, crop coefficient, interception fraction of rainfall, interception storage capacity, and root zone depth. Except for the last, these feedbacks are dependent on the leaf area index (LAI). The influence of regional groundwater on crop growth is included via a coupling to MODFLOW. Two versions of the MetaSWAP-WOFOST coupling were set up: one with exogenous vegetation parameters, the "static" model, and one with endogenous crop growth simulation, the "dynamic" model. Parameterization of the static and dynamic models ensured that for the current climate the simulated long-term averages of actual evapotranspiration are the same for both models. Simulations were made for two climate scenarios and two crops: grass and potato. In the dynamic model, higher temperatures in a warm year under the current climate resulted in accelerated crop development, and in the case of potato a shorter growing season, thus partly avoiding the late summer heat. The static model has a higher potential transpiration; depending on the available soil moisture, this translates to a higher actual transpiration. This difference between static and dynamic models is enlarged by climate change in combination with higher CO2 concentrations. Including the dynamic crop simulation gives for potato (and other annual arable land crops) systematically higher effects on the predicted recharge change due to climate change. Crop yields from soils with poor water retention capacities strongly depend on capillary rise if moisture supply from other sources is limited. Thus, including a crop simulation model in an integrated

  9. [Impacts of climate warming on growth period and yield of rice in Northeast China during recent two decades].

    Science.gov (United States)

    Hou, Wen-jia; Geng, Ting; Chen, Qun; Chen, Chang-qing

    2015-01-01

    By using rice growth period, yield and climate observation data during the recent two decades, the impact of climate warming on rice in Northeast China was investigated by mathematical statistics methods. The results indicated that in the three provinces of Northeast China, the average, maximum and minimum temperatures in rice growing season were on the. rise, and the rainfall presented a downward trend during 1989-2009. Compared to 1990s, the rice whole growth periods of Heilongjiang, Jilin and Liaoning provinces in 2000s were prolonged 14 d, 4.5 d and 5.1 d, respectively. The increase of temperature in May, June and September could extend the rice growth period, while that in July would shorten the growth duration. The rice growth duration of registered varieties and experiment sites had a similar increasing trend in Northeast China except for the Heilongjiang Province, and the extension of registered varieties growth period was the main factor causing the prolonged growth period of rice at experiment sites. The change in daily average, minimum and maximum temperatures all could affect the rice yield in Northeast China. The increasing temperature significantly increased the rice yield in Heilongjiang Province, especially in the west region of Sanjiang Plain. Except for the south of Liaoning Province, rice yields in other regions of Northeast China were promoted by increasing temperature. Proper measures for breeding, cultivation and farming, could be adopted to fully improve the adaptation of rice to climate warming in Northeast China.

  10. Putting the rise of the Inca Empire within a climatic and land management context

    Science.gov (United States)

    Chepstow-Lusty, A. J.; Frogley, M. R.; Bauer, B. S.; Leng, M. J.; Boessenkool, K. P.; Carcaillet, C.; Ali, A. A.; Gioda, A.

    2009-07-01

    The rapid expansion of the Inca from the Cuzco area of highland Peru (ca. AD 1400-1532) produced the largest empire in the New World. Although this meteoric growth may in part be due to the adoption of innovative societal strategies, supported by a large labour force and a standing army, we argue that it would not have been possible without increased crop productivity, which was linked to more favourable climatic conditions. Here we present a multi-proxy, high-resolution 1200-year lake sediment record from Marcacocha, located 12 km north of Ollantaytambo, in the heartland of the Inca Empire. This record reveals a period of sustained aridity that began from AD 880, followed by increased warming from AD 1100 that lasted beyond the arrival of the Spanish in AD 1532. These increasingly warmer conditions would have allowed the Inca and their immediate predecessors the opportunity to exploit higher altitudes (post-AD 1150) by constructing agricultural terraces that employed glacial-fed irrigation, in combination with deliberate agroforestry techniques. There may be some important lessons to be learnt today from these strategies for sustainable rural development in the Andes in the light of future climate uncertainty.

  11. Putting the rise of the Inca Empire within a climatic and land management context

    Directory of Open Access Journals (Sweden)

    A. J. Chepstow-Lusty

    2009-07-01

    Full Text Available The rapid expansion of the Inca from the Cuzco area of highland Peru (ca. AD 1400–1532 produced the largest empire in the New World. Although this meteoric growth may in part be due to the adoption of innovative societal strategies, supported by a large labour force and a standing army, we argue that it would not have been possible without increased crop productivity, which was linked to more favourable climatic conditions. Here we present a multi-proxy, high-resolution 1200-year lake sediment record from Marcacocha, located 12 km north of Ollantaytambo, in the heartland of the Inca Empire. This record reveals a period of sustained aridity that began from AD 880, followed by increased warming from AD 1100 that lasted beyond the arrival of the Spanish in AD 1532. These increasingly warmer conditions would have allowed the Inca and their immediate predecessors the opportunity to exploit higher altitudes (post-AD 1150 by constructing agricultural terraces that employed glacial-fed irrigation, in combination with deliberate agroforestry techniques. There may be some important lessons to be learnt today from these strategies for sustainable rural development in the Andes in the light of future climate uncertainty.

  12. Empirically Derived and Simulated Sensitivity of Vegetation to Climate Across Global Gradients of Temperature and Precipitation

    Science.gov (United States)

    Quetin, G. R.; Swann, A. L. S.

    2017-12-01

    Successfully predicting the state of vegetation in a novel environment is dependent on our process level understanding of the ecosystem and its interactions with the environment. We derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness and leaf area to interannual variations in temperature and precipitation. Our analysis provides observations of ecosystem functioning; the vegetation interactions with the physical environment, across a wide range of climates and provide a functional constraint for hypotheses engendered in process-based models. We infer mechanisms constraining ecosystem functioning by contrasting how the observed and simulated sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate as a systematic change across climate space. Our comparison of remote sensing-based vegetation sensitivity with modeled estimates provides evidence for which physiological mechanisms - photosynthetic efficiency, respiration, water supply, atmospheric water demand, and sunlight availability - dominate the ecosystem functioning in places with different climates. Earth system models are generally successful in reproducing the broad sign and shape of ecosystem functioning across climate space. However, this general agreement breaks down in hot wet climates where models simulate less leaf area during a warmer year, while observations show a mixed response but overall more leaf area during warmer years. 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

  13. The potential impacts of climate variability and change on air pollution-related health effects in the United States.

    OpenAIRE

    Bernard, S M; Samet, J M; Grambsch, A; Ebi, K L; Romieu, I

    2001-01-01

    Climate change may affect exposures to air pollutants by affecting weather, anthropogenic emissions, and biogenic emissions and by changing the distribution and types of airborne allergens. Local temperature, precipitation, clouds, atmospheric water vapor, wind speed, and wind direction influence atmospheric chemical processes, and interactions occur between local and global-scale environments. If the climate becomes warmer and more variable, air quality is likely to be affected. However, the...

  14. Climate Change and Global Wine Quality

    Energy Technology Data Exchange (ETDEWEB)

    Jones, G.V. [Department of Geography, Southern Oregon University, 1250 Siskiyou Blvd, Ashland, Oregon, 97520 (United States); White, M.A. [Department of Aquatic, Watershed, and Earth Resources, Utah State University, Logan, Utah, 84322 (United States); Cooper, O.R. [Cooperative Institute for Research in Environmental Sciences CIRES, University of Colorado/NOAA Aeronomy Laboratory, Boulder, Colorado, 80305 (United States); Storchmann, K. [Department of Economics, Yale University, New Haven, Connecticut, 06520 (United States)

    2005-12-01

    From 1950 to 1999 the majority of the world's highest quality wine-producing regions experienced growing season warming trends. Vintage quality ratings during this same time period increased significantly while year-to-year variation declined. While improved winemaking knowledge and husbandry practices contributed to the better vintages it was shown that climate had, and will likely always have, a significant role in quality variations. This study revealed that the impacts of climate change are not likely to be uniform across all varieties and regions. Currently, many European regions appear to be at or near their optimum growing season temperatures, while the relationships are less defined in the New World viticulture regions. For future climates, model output for global wine producing regions predicts an average warming of 2C in the next 50 yr. For regions producing high-quality grapes at the margins of their climatic limits, these results suggest that future climate change will exceed a climatic threshold such that the ripening of balanced fruit required for existing varieties and wine styles will become progressively more difficult. In other regions, historical and predicted climate changes could push some regions into more optimal climatic regimes for the production of current varietals. In addition, the warmer conditions could lead to more poleward locations potentially becoming more conducive to grape growing and wine production.

  15. The Impact of Climate Change on the Balanced-Growth-Equivalent: An Application of FUND

    OpenAIRE

    David Anthoff; Richard S. J. Tol

    2008-01-01

    The Stern Review added balanced growth equivalents (BGE) to the economic climate change research agenda. We first propose rigorous definitions of the BGE for multiple regions and under uncertainty. We show that the change in the BGE is independent of the assumed scenario of per capita income. For comparable welfare economic assumptions as the Stern Review, we calculate lower changes in BGE between a business as usual scenario and one without climate impacts with the model FUND than the Stern ...

  16. Macrophyte growth module for the SWAT model – impact of climate change and management on stream ecology

    DEFF Research Database (Denmark)

    Lu, Shenglan; Trolle, Dennis; Erfurt, Jytte

    To access how multiple stressors affect the water quantity and quality and stream ecology at catchment scale under various management and climate change scenarios, we implemented macrophyte growth modules for the Soil and Water Assessment Tool version 2012 (SWAT). The macrophyte growth module...

  17. Winter forest soil respiration controlled by climate and microbial community composition.

    Science.gov (United States)

    Monson, Russell K; Lipson, David L; Burns, Sean P; Turnipseed, Andrew A; Delany, Anthony C; Williams, Mark W; Schmidt, Steven K

    2006-02-09

    Most terrestrial carbon sequestration at mid-latitudes in the Northern Hemisphere occurs in seasonal, montane forest ecosystems. Winter respiratory carbon dioxide losses from these ecosystems are high, and over half of the carbon assimilated by photosynthesis in the summer can be lost the following winter. The amount of winter carbon dioxide loss is potentially susceptible to changes in the depth of the snowpack; a shallower snowpack has less insulation potential, causing colder soil temperatures and potentially lower soil respiration rates. Recent climate analyses have shown widespread declines in the winter snowpack of mountain ecosystems in the western USA and Europe that are coupled to positive temperature anomalies. Here we study the effect of changes in snow cover on soil carbon cycling within the context of natural climate variation. We use a six-year record of net ecosystem carbon dioxide exchange in a subalpine forest to show that years with a reduced winter snowpack are accompanied by significantly lower rates of soil respiration. Furthermore, we show that the cause of the high sensitivity of soil respiration rate to changes in snow depth is a unique soil microbial community that exhibits exponential growth and high rates of substrate utilization at the cold temperatures that exist beneath the snow. Our observations suggest that a warmer climate may change soil carbon sequestration rates in forest ecosystems owing to changes in the depth of the insulating snow cover.

  18. Evaluation of growth and flowering potential of rosa hybrida cultivars under Faisalabad climatic conditions

    International Nuclear Information System (INIS)

    Nadeem, M.; Khan, M.A.; Riaz, A.

    2011-01-01

    Exotic cultivars of hybrid roses respond uncertainly to new habitat. It is necessary to explore the potential of the introduced cultivars to judge the suitability in a new habitat. In the present study, nine Rosa hybrida cultivars including Autumn Sunset, Ice Berg, Paradise, Angel Face, Louise Odier, Casino, Grand Margina, Handel and Gruss-an-Teplitz were evaluated for growth and yield attributed under the climatic conditions of Faisalabad. Results indicated that there was decreasing trend in the growth and flowering of the bushes as the temperature increased above 32 degree C and humidity decreased to 29 %. Number of flowers per bush and diameter of flower decreased as the temperature increased and humidity decreased in contrast to increment in height of the plant and num ber of primary branches per plant in succeeding months. Interaction between yield traits and months was also significant. Overall, significant variations were observed in each cultivar for length and number of petals per flower, number of prickles, fragrance, flower persistence life and color, bush shape and overall performance with respect to climatic conditions of Faisalabad. It is concluded that the cultivars 'Autumn Sunset' and Gruss-an-Teplitz performed better in climatic conditions of Faisalabad. (author)

  19. Soil Dissolved Organic Carbon Fluxes are Controlled by both Precipitation and Longer-Term Climate Effects on Boreal Forest Ecosystems

    Science.gov (United States)

    Hotchkiss, E. R.; Ziegler, S. E.; Edwards, K. A.; Bowering, K.

    2017-12-01

    Water acts as a control on the cycling of organic carbon (OC). Forest productivity responses to climate change are linked to water availability while water residence time is a major control on OC loss in aquatic ecosystems. However, controls on the export of terrestrial OC to the aquatic environment remains poorly understood. Transport of dissolved OC (DOC) through soils both vertically to deeper soil horizons and into aquatic systems is a key flux of terrestrial OC, but the climate drivers controlling OC mobilized from soils is poorly understood. We installed zero-tension lysimeters across similar balsam fir forest sites within three regions that span a MAT gradient of 5.2˚C and MAP of 1050-1500 mm. Using soil water collected over all seasons for four years we tested whether a warmer and wetter climate promotes greater DOC fluxes in ecosystems experiencing relatively high precipitation. Variability within and between years was compared to that observed across climates to test the sensitivity of this flux to shorter relative to longer-term climate effects on this flux. The warmest and wettest southern site exhibited the greatest annual DOC flux (25 to 28 g C m-2 y-1) in contrast to the most northern site (8 to 10 g C m -2 y-1). This flux represented 10% of litterfall C inputs across sites and surpassed the DOC export from associated forested headwater streams (1 to 16 g C m-2 y-1) suggesting terrestrial to aquatic interface processing. Historical climate and increased soil C inputs explain the greater DOC flux in the southern region. Even in years with comparable annual precipitation among regions the DOC flux differed by climate region. Furthermore, neither quantity nor form of precipitation could explain inter-annual differences in DOC flux within each region. Region specific relationships between precipitation and soil water flux instead suggest historical climate effects may impact soil water transport efficiency thereby controlling the regional variation in

  20. Transgenerational acclimation of fishes to climate change and ocean acidification

    OpenAIRE

    Munday, Philip L.

    2014-01-01

    There is growing concern about the impacts of climate change and ocean acidification on marine organisms and ecosystems, yet the potential for acclimation and adaptation to these threats is poorly understood. Whereas many short-term experiments report negative biological effects of ocean warming and acidification, new studies show that some marine species have the capacity to acclimate to warmer and more acidic environments across generations. Consequently, transgenerational plasticity may be...

  1. Braking effect of climate and topography on global change-induced upslope forest expansion.

    Science.gov (United States)

    Alatalo, Juha M; Ferrarini, Alessandro

    2017-03-01

    Forests are expected to expand into alpine areas due to global climate change. It has recently been shown that temperature alone cannot realistically explain this process and that upslope tree advance in a warmer scenario may depend on the availability of sites with adequate geomorphic/topographic characteristics. Here, we show that, besides topography (slope and aspect), climate itself can produce a braking effect on the upslope advance of subalpine forests and that tree limit is influenced by non-linear and non-monotonic contributions of the climate variables which act upon treeline upslope advance with varying relative strengths. Our results suggest that global climate change impact on the upslope advance of subalpine forests should be interpreted in a more complex way where climate can both speed up and slow down the process depending on complex patterns of contribution from each climate and non-climate variable.

  2. Risks of Climate Change with Respect to the Singapore-Malaysia High Speed Rail System

    OpenAIRE

    Sazrul Leena Binti Sa’adin; Sakdirat Kaewunruen; David Jaroszweski

    2016-01-01

    Warming of the climate system is unequivocal, and many of the observed changes are unprecedented over the past five decades. Globally, the atmosphere and the ocean are becoming increasingly warmer, the amount of ice on the earth is decreasing over the oceans, and the sea level has risen. According to the Intergovernmental Panel on Climate Change, the average increase in global temperature (combined land and surface) between the 1850–1900 period and the 2003–2012 period was 0.78 °C (0.72 to 0....

  3. Separating Trends in Whitebark Pine Radial Growth Related to Climate and Mountain Pine Beetle Outbreaks in the Northern Rocky Mountains, USA

    Directory of Open Access Journals (Sweden)

    Saskia L. van de Gevel

    2017-06-01

    Full Text Available Drought and mountain pine beetle (Dendroctonus ponderosae Hopkins outbreaks have affected millions of hectares of high-elevation conifer forests in the Northern Rocky Mountains during the past century. Little research has examined the distinction between mountain pine beetle outbreaks and climatic influence on radial growth in endangered whitebark pine (Pinus albicaulis Engelm. ecosystems. We used a new method to explore divergent periods in whitebark pine radial growth after mountain pine beetle outbreaks across six sites in western Montana. We examined a 100-year history of mountain pine beetle outbreaks and climate relationships in whitebark pine radial growth to distinguish whether monthly climate variables or mountain pine outbreaks were the dominant influence on whitebark pine growth during the 20th century. High mortality of whitebark pines was caused by the overlapping effects of previous and current mountain pine beetle outbreaks and white pine blister rust infection. Wet conditions from precipitation and snowpack melt in the previous summer, current spring, and current summer benefit whitebark pine radial growth during the following growing season. Whitebark pine radial growth and climate relationships were strongest in sites less affected by the mountain pine beetle outbreaks or anthropogenic disturbances. Whitebark pine population resiliency should continue to be monitored as more common periods of drought will make whitebark pines more susceptible to mountain pine beetle attack and to white pine blister rust infection.

  4. Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California's Central Valley.

    Directory of Open Access Journals (Sweden)

    Elliott L Matchett

    Full Text Available The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006-2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the "existing" landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration

  5. Projected Impacts of Climate, Urbanization, Water Management, and Wetland Restoration on Waterbird Habitat in California's Central Valley.

    Science.gov (United States)

    Matchett, Elliott L; Fleskes, Joseph P

    2017-01-01

    The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006-2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the "existing" landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

  6. Assessing the Impact of Laurentide Ice-sheet Topography on Glacial Climate

    Science.gov (United States)

    Ullman, D. J.; LeGrande, A. N.; Carlson, A. E.; Anslow, F. S.; Licciardi, J. M.

    2014-01-01

    Simulations of past climates require altered boundary conditions to account for known shifts in the Earth system. For the Last Glacial Maximum (LGM) and subsequent deglaciation, the existence of large Northern Hemisphere ice sheets caused profound changes in surface topography and albedo. While ice-sheet extent is fairly well known, numerous conflicting reconstructions of ice-sheet topography suggest that precision in this boundary condition is lacking. Here we use a high-resolution and oxygen-isotopeenabled fully coupled global circulation model (GCM) (GISS ModelE2-R), along with two different reconstructions of the Laurentide Ice Sheet (LIS) that provide maximum and minimum estimates of LIS elevation, to assess the range of climate variability in response to uncertainty in this boundary condition.We present this comparison at two equilibrium time slices: the LGM, when differences in ice-sheet topography are maximized, and 14 ka, when differences in maximum ice-sheet height are smaller but still exist. Overall, we find significant differences in the climate response to LIS topography, with the larger LIS resulting in enhanced Atlantic Meridional Overturning Circulation and warmer surface air temperatures, particularly over northeastern Asia and the North Pacific. These up- and downstream effects are associated with differences in the development of planetary waves in the upper atmosphere, with the larger LIS resulting in a weaker trough over northeastern Asia that leads to the warmer temperatures and decreased albedo from snow and sea-ice cover. Differences between the 14 ka simulations are similar in spatial extent but smaller in magnitude, suggesting that climate is responding primarily to the larger difference in maximum LIS elevation in the LGM simulations. These results suggest that such uncertainty in ice-sheet boundary conditions alone may significantly impact the results of paleoclimate simulations and their ability to successfully simulate past climates

  7. Physiological and ecological effects of increasing temperature on fish production in lakes of Arctic Alaska

    Science.gov (United States)

    Carey, Michael P.; Zimmerman, Christian E.

    2014-01-01

    Lake ecosystems in the Arctic are changing rapidly due to climate warming. Lakes are sensitive integrators of climate-induced changes and prominent features across the Arctic landscape, especially in lowland permafrost regions such as the Arctic Coastal Plain of Alaska. Despite many studies on the implications of climate warming, how fish populations will respond to lake changes is uncertain for Arctic ecosystems. Least Cisco (Coregonus sardinella) is a bellwether for Arctic lakes as an important consumer and prey resource. To explore the consequences of climate warming, we used a bioenergetics model to simulate changes in Least Cisco production under future climate scenarios for lakes on the Arctic Coastal Plain. First, we used current temperatures to fit Least Cisco consumption to observed annual growth. We then estimated growth, holding food availability, and then feeding rate constant, for future projections of temperature. Projected warmer water temperatures resulted in reduced Least Cisco production, especially for larger size classes, when food availability was held constant. While holding feeding rate constant, production of Least Cisco increased under all future scenarios with progressively more growth in warmer temperatures. Higher variability occurred with longer projections of time mirroring the expanding uncertainty in climate predictions further into the future. In addition to direct temperature effects on Least Cisco growth, we also considered changes in lake ice phenology and prey resources for Least Cisco. A shorter period of ice cover resulted in increased production, similar to warming temperatures. Altering prey quality had a larger effect on fish production in summer than winter and increased relative growth of younger rather than older age classes of Least Cisco. Overall, we predicted increased production of Least Cisco due to climate warming in lakes of Arctic Alaska. Understanding the implications of increased production of Least Cisco to

  8. Holocene Tree Line and Climate Change on the Queen Charlotte Islands, Canada

    Science.gov (United States)

    Pellatt, Marlow G.; Mathewes, Rolf W.

    1997-07-01

    Palynological study of two subalpine ponds on the Queen Charlotte Islands reveals changes in tree line and climate during the Holocene. The findings agree with previous reconstructions, from nearby Louise Pond on the Queen Charlotte Islands, that suggest a warmer-than-present climate and higher-than-present tree lines in the early Holocene (ca. 9600-6600 14C yr B.P.). Basal ages at SC1 Pond and Shangri-La Bog indicate that the basins did not hold permanent water before 7200 14C yr B.P., consistent with a warmer and drier early Holocene previously inferred from Louise Pond. Pollen and plant macrofossils indicate the initial establishment of subalpine conditions by 6090 ± 90 14C yr B.P., similar to the 5790 ± 130 14C yr B.P. age for cooling inferred from Louise Pond. Conditions similar to present were established at SC1 Pond by 3460 ± 100 14C yr B.P., confirming the previous estimate of 3400 14C yr B.P. at Louise Pond. This 3400 14C yr B.P. vegetation shift on the Queen Charlotte Islands corresponds with the beginning of the Tiedemann glacial advance in the south-coastal mountains of British Columbia (ca. 3300 14C yr B.P.), the Peyto and Robson glacial advances between 3300 and 2800 14C yr B.P. in the Rocky Mountains, and climatic cooling inferred from palynological studies throughout southern British Columbia, northern Washington, and southeast Alaska. These findings confirm that changes in regional climate influenced changes in vegetation in coastal British Columbia.

  9. Temperature extremes: Effect on plant growth and development

    Directory of Open Access Journals (Sweden)

    Jerry L. Hatfield

    2015-12-01

    Full Text Available Temperature is a primary factor affecting the rate of plant development. Warmer temperatures expected with climate change and the potential for more extreme temperature events will impact plant productivity. Pollination is one of the most sensitive phenological stages to temperature extremes across all species and during this developmental stage temperature extremes would greatly affect production. Few adaptation strategies are available to cope with temperature extremes at this developmental stage other than to select for plants which shed pollen during the cooler periods of the day or are indeterminate so flowering occurs over a longer period of the growing season. In controlled environment studies, warm temperatures increased the rate of phenological development; however, there was no effect on leaf area or vegetative biomass compared to normal temperatures. The major impact of warmer temperatures was during the reproductive stage of development and in all cases grain yield in maize was significantly reduced by as much as 80−90% from a normal temperature regime. Temperature effects are increased by water deficits and excess soil water demonstrating that understanding the interaction of temperature and water will be needed to develop more effective adaptation strategies to offset the impacts of greater temperature extreme events associated with a changing climate.

  10. Long-term forest resilience to climate change indicated by mortality, regeneration, and growth in semiarid southern Siberia.

    Science.gov (United States)

    Xu, Chongyang; Liu, Hongyan; Anenkhonov, Oleg A; Korolyuk, Andrey Yu; Sandanov, Denis V; Balsanova, Larisa D; Naidanov, Bulat B; Wu, Xiuchen

    2017-06-01

    Several studies have documented that regional climate warming and the resulting increase in drought stress have triggered increased tree mortality in semiarid forests with unavoidable impacts on regional and global carbon sequestration. Although climate warming is projected to continue into the future, studies examining long-term resilience of semiarid forests against climate change are limited. In this study, long-term forest resilience was defined as the capacity of forest recruitment to compensate for losses from mortality. We observed an obvious change in long-term forest resilience along a local aridity gradient by reconstructing tree growth trend and disturbance history and investigating postdisturbance regeneration in semiarid forests in southern Siberia. In our study, with increased severity of local aridity, forests became vulnerable to drought stress, and regeneration first accelerated and then ceased. Radial growth of trees during 1900-2012 was also relatively stable on the moderately arid site. Furthermore, we found that smaller forest patches always have relatively weaker resilience under the same climatic conditions. Our results imply a relatively higher resilience in arid timberline forest patches than in continuous forests; however, further climate warming and increased drought could possibly cause the disappearance of small forest patches around the arid tree line. This study sheds light on climate change adaptation and provides insight into managing vulnerable semiarid forests. © 2016 John Wiley & Sons Ltd.

  11. Icebreakers, Fillers y Warmers: actividades breves para la clase de inglés

    Directory of Open Access Journals (Sweden)

    Ramiro DURÁN MARTÍNEZ

    2009-11-01

    Full Text Available RESUMEN: En el siguiente artículo vamos a presentar diversos tipos de ejercicios de carácter breve que hemos utilizado en la clase de inglés con el objetivo de facilitar a los alumnos la práctica de la destreza oral. Estas actividades tienen distintos nombres dependiendo de la función que desempeñen: icebreakers, fillers y warmers. Se denominan icebreakers los ejercicios diseñados para romper la tensión que normalmente rodea las primeras sesiones de cualquier nueva actividad, como, por ejemplo, la primera clase de un curso de inglés. Cuando se habla de fillers se enfatiza su función comodín: tareas independientes que normalmente sirven para completar los últimos minutos del horario establecido para la clase de idiomas. El término warmer se aplica a las actividades que se llevan a cabo después de un período vacacional con el propósito de favorecer el reencuentro del alumno con el idioma que está estudiando. El principal objetivo de estos ejercicios es el desarrollo de la capacidad de los alumnos para expresarse de forma oral utilizando la lengua inglesa, concentrándose más en la práctica de la fluidez (fluency que en la precisión (accuracy. Por otra parte, sirven para favorecer la creación de vínculos de unión entre un grupo de estudiantes.ABSTRACT: In this paper, we are going to present a number of short activities that have been used in the English class in order to give students extra speaking practice. These activities were given different names depending on the role they play in the class: icebreakers, fillers and warmers. Icebreakers are fluency practice exercises produced to defuse the tension that the first sessions of every new activity imply: i.e. the first lesson of English. When talking about fillers, we refer to short independent activities that are used when the projected exercises have taken less time than expected. Warmers are also fluency practice activities devised to put students back in touch with the

  12. Climate change, renewable energy and population impact on future energy demand for Burkina Faso build environment

    Science.gov (United States)

    Ouedraogo, B. I.

    This research addresses the dual challenge faced by Burkina Faso engineers to design sustainable low-energy cost public buildings and domestic dwellings while still providing the required thermal comfort under warmer temperature conditions caused by climate change. It was found base don climate change SRES scenario A2 that predicted mean temperature in Burkina Faso will increase by 2oC between 2010 and 2050. Therefore, in order to maintain a thermally comfortable 25oC inside public buildings, the projected annual energy consumption for cooling load will increase by 15%, 36% and 100% respectively for the period between 2020 to 2039, 2040 to 2059 and 2070 to 2089 when compared to the control case. It has also been found that a 1% increase in population growth will result in a 1.38% and 2.03% increase in carbon emission from primary energy consumption and future electricity consumption respectively. Furthermore, this research has investigated possible solutions for adaptation to the severe climate change and population growth impact on energy demand in Burkina Faso. Shading devices could potentially reduce the cooling load by up to 40%. Computer simulation programming of building energy consumption and a field study has shown that adobe houses have the potential of significantly reducing energy demand for cooling and offer a formidable method for climate change adaptation. Based on the Net Present Cost, hybrid photovoltaic (PV) and Diesel generator energy production configuration is the most cost effective local electricity supply system, for areas without electricity at present, with a payback time of 8 years when compared to diesel generator stand-alone configuration. It is therefore a viable solution to increase electricity access to the majority of the population.

  13. Effects of Population Growth and Climate Variability on Sustainable Groundwater in Mali, West Africa

    Directory of Open Access Journals (Sweden)

    Alexandra Lutz

    2010-12-01

    Full Text Available Groundwater is increasingly relied on as a source of potable water in developing countries, but factors such as population growth, development, and climate variability, pose potential challenges for ongoing sustainable supply. The effect of these factors on the groundwater system was considered in four scenarios using a numerical model to represent the Bani area of Mali, West Africa. By 2040, population growth, climate variability, and development as urbanization, agriculture, and industry creates scenarios in which groundwater extraction is an increasingly larger percentage of the groundwater system. Consumption from agriculture and industry increases extraction rates from less than 1 to 3.8% of mean annual precipitation, which will likely affect the groundwater system. For instance, concentrated pumping in local areas may result in water level declines. The results of this study contribute to an ongoing evaluation of sustainable groundwater resources in West Africa.

  14. Climate-growth analysis for a Mexican dry forest tree shows strong impact of sea surface temperatures and predicts future growth declines

    NARCIS (Netherlands)

    Brienen, R.J.W.; Lebrija Trejos, E.E.; Zuidema, P.A.; Martínez- Ramos, M.

    2010-01-01

    Tropical forests will experience relatively large changes in temperature and rainfall towards the end of this century. Little is known about how tropical trees will respond to these changes. We used tree rings to establish climate-growth relations of a pioneer tree, Mimosa acantholoba, occurring in

  15. Tree growth and its climate signal along latitudinal and altitudinal gradients: comparison of tree rings between Finland and the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    L. Lyu

    2017-06-01

    Full Text Available Latitudinal and altitudinal gradients can be utilized to forecast the impact of climate change on forests. To improve the understanding of how these gradients impact forest dynamics, we tested two hypotheses: (1 the change of the tree growth–climate relationship is similar along both latitudinal and altitudinal gradients, and (2 the time periods during which climate affects growth the most occur later towards higher latitudes and altitudes. To address this, we utilized tree-ring data from a latitudinal gradient in Finland and from two altitudinal gradients on the Tibetan Plateau. We analysed the latitudinal and altitudinal growth patterns in tree rings and investigated the growth–climate relationship of trees by correlating ring-width index chronologies with climate variables, calculating with flexible time windows, and using daily-resolution climate data. High latitude and altitude plots showed higher correlations between tree-ring chronologies and growing season temperature. However, the effects of winter temperature showed contrasting patterns for the gradients. The timing of the highest correlation with temperatures during the growing season at southern sites was approximately 1 month ahead of that at northern sites in the latitudinal gradient. In one out of two altitudinal gradients, the timing for the strongest negative correlation with temperature at low-altitude sites was ahead of treeline sites during the growing season, possibly due to differences in moisture limitation. Mean values and the standard deviation of tree-ring width increased with increasing mean July temperatures on both types of gradients. Our results showed similarities of tree growth responses to increasing seasonal temperature between latitudinal and altitudinal gradients. However, differences in climate–growth relationships were also found between gradients due to differences in other factors such as moisture conditions. Changes in the timing of the most

  16. Disturbance legacies and climate jointly drive tree growth and mortality in an intensively studied boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Bond-Lamberty, Benjamin; Rocha, Adrian; Calvin, Katherine V.; Holmes, Bruce; Wang, Chuankuan; Goulden, Michael L.

    2014-01-01

    How will regional growth and mortality change with even relatively small climate shifts, even independent of catastrophic disturbances? This question is particularly acute for the North American boreal forest, which is carbon-dense and subject The goals of this study were to combine dendrochronological sampling, inventory records, and machine-learning algorithms to understand how tree growth and death have changed at one highly studied site (Northern Old Black Spruce, NOBS) in the central Canadian boreal forest. Over the 1999-2012 inventory period, mean DBH increased even as stand density and basal area declined significantly from 41.3 to 37.5 m2 ha-1. Tree mortality averaged 1.4±0.6% yr-1, with most mortality occurring in medium-sized trees. A combined tree ring chronology constructed from 2001, 2004, and 2012 sampling showed several periods of extreme growth depression, with increased mortality lagging depressed growth by ~5 years. Minimum and maximum air temperatures exerted a negative influence on tree growth, while precipitation and climate moisture index had a positive effect; both current- and previous-year data exerted significant effects. Models based on these variables explained 23-44% of the ring-width variability. There have been at least one, and probably two, significant recruitment episodes since stand initiation, and we infer that past climate extremes led to significant NOBS mortality still visible in the current forest structure. These results imply that a combination of successional and demographic processes, along with mortality driven by abiotic factors, continue to affect the stand, with significant implications for our understanding of previous work at NOBS and the sustainable management of regional forests.

  17. Land-use change interacts with climate to determine elevational species redistribution.

    Science.gov (United States)

    Guo, Fengyi; Lenoir, Jonathan; Bonebrake, Timothy C

    2018-04-03

    Climate change is driving global species redistribution with profound social and economic impacts. However, species movement is largely constrained by habitat availability and connectivity, of which the interaction effects with climate change remain largely unknown. Here we examine published data on 2798 elevational range shifts from 43 study sites to assess the confounding effect of land-use change on climate-driven species redistribution. We show that baseline forest cover and recent forest cover change are critical predictors in determining the magnitude of elevational range shifts. Forest loss positively interacts with baseline temperature conditions, such that forest loss in warmer regions tends to accelerate species' upslope movement. Consequently, not only climate but also habitat loss stressors and, importantly, their synergistic effects matter in forecasting species elevational redistribution, especially in the tropics where both stressors will increase the risk of net lowland biotic attrition.

  18. Climate-Induced Boreal Forest Change: Predictions versus Current Observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

    2007-01-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  19. Winter Precipitation Efficiency of Mountain Ranges in the Colorado Rockies Under Climate Change

    Science.gov (United States)

    Eidhammer, Trude; Grubišić, Vanda; Rasmussen, Roy; Ikdea, Kyoko

    2018-03-01

    Orographic precipitation depends on the environmental conditions and the barrier shape. In this study we examine the sensitivity of the precipitation efficiency (i.e., drying ratio (DR)), defined as the ratio of precipitation to incoming water flux, to mountain shape, temperature, stability, and horizontal velocity of the incoming air mass. Furthermore, we explore how the DR of Colorado mountain ranges might change under warmer and moister conditions in the future. For given environmental conditions, we find the DR to be primarily dependent on the upwind slope for mountain ranges wider than about 70 km and on both the slope and width for narrower ranges. Temperature is found to exert an influence on the DR for all Colorado mountain ranges, with DR decreasing with increasing temperature, under both the current and future climate conditions. The decrease of DR with temperature under warmer climate was found to be stronger for wider mountains than the narrower ones. We attribute this asymmetry to the sensitivity of DR to reduced horizontal velocity under warmer conditions. Specifically, while DR for wider mountains shows no sensitivity to changes in horizontal velocity, the DR for narrow ranges increases as the horizontal velocity decreases and more time is provided for precipitation to form. Thus, for narrower ranges, the horizontal velocity appears to offset the temperature effect slightly. The percentagewise decrease of DR for all examined mountain ranges is about 4%K-1. In comparison, the increase in precipitation is about 6%K-1 while the vapor flux increase is about 9%K-1.

  20. Climate change and its potential impact on mechanical, hydraulic and chemical conditions

    International Nuclear Information System (INIS)

    Naslund, J.O.

    2009-01-01

    The strategy for managing climate related conditions in SKB ' s safety assessments are based on the notion that it is not possible to predict climate in a 100 000-year time perspective. Instead, the approach in the SR-Can safety assessment was to identify and analyse both moderate climate evolutions as well as extremes within which the climate in Scandinavia may vary. To this end, knowledge on general climate variations in Scandinavia was used to identify characteristic climate domains which in turn were used to build a number of selected climate scenarios. The relevant climate domains for the Forsmark and Laxemar sites in the 100 000-year time perspective are; 1) a temperate climate domain, 2) a peri-glacial climate domain, and 3) a glacial climate domain. Also submerged/non-submerged conditions at the sites are of importance. In the SR-Can safety assessment several climate scenarios were investigated, including a reference evolution based on a repetition of reconstructed conditions for last glacial cycle (the Weichselian glaciation and the Holocene interglacial). For this reconstruction, extensive numerical simulations of ice sheets, isostatic changes, and permafrost were conducted. The resulting scenario showed site-specific timing and duration of the three climate domains and submerged periods for the full glacial cycle. This scenario is not a prediction of a future climate evolution. Instead it is one example of a future evolution that in a realistic and consistent way covers all relevant climate related changes that can be expected in a 100 000-year time perspective. Subsequently, this scenario formed the basis for the construction of additional climate scenarios that were used to analyse the effects of more extreme climate evolutions than during the last glacial cycle. Examples of complementary scenarios are a warmer and wetter climate scenario caused by an increased greenhouse effect, and colder scenarios with deeper permafrost or thicker ice sheets than in

  1. Projected impacts of climate, urbanization, water management, and wetland restoration on waterbird habitat in California’s Central Valley

    Science.gov (United States)

    Matchett, Elliott L.; Fleskes, Joseph

    2017-01-01

    The Central Valley of California is one of the most important regions for wintering waterbirds in North America despite extensive anthropogenic landscape modification and decline of historical wetlands there. Like many other mediterranean-climate ecosystems across the globe, the Central Valley has been subject to a burgeoning human population and expansion and intensification of agricultural and urban development that have impacted wildlife habitats. Future effects of urban development, changes in water supply management, and precipitation and air temperature related to global climate change on area of waterbird habitat in the Central Valley are uncertain, yet potentially substantial. Therefore, we modeled area of waterbird habitats for 17 climate, urbanization, water supply management, and wetland restoration scenarios for years 2006–2099 using a water resources and scenario modeling framework. Planned wetland restoration largely compensated for adverse effects of climate, urbanization, and water supply management changes on habitat areas through 2065, but fell short thereafter for all except one scenario. Projected habitat reductions due to climate models were more frequent and greater than under the recent historical climate and their magnitude increased through time. After 2065, area of waterbird habitat in all scenarios that included severe warmer, drier climate was projected to be >15% less than in the “existing” landscape most years. The greatest reduction in waterbird habitat occurred in scenarios that combined warmer, drier climate and plausible water supply management options affecting priority and delivery of water available for waterbird habitats. This scenario modeling addresses the complexity and uncertainties in the Central Valley landscape, use and management of related water supplies, and climate to inform waterbird habitat conservation and other resource management planning. Results indicate that increased wetland restoration and additional

  2. Plant establishment on unirrigated green roof modules in a subtropical climate

    Science.gov (United States)

    Dvorak, Bruce D.; Volder, Astrid

    2012-01-01

    Background and aims The application of green roof technology has become more common in the central, northwestern and eastern USA, and is now being employed across the southern USA as well. However, there is little research in the literature that evaluated plant survival on unirrigated green roofs in subtropical climates that experience frequent drought and heat stress. Here, we summarize the results of a study of plant establishment on a modular green roof in south-central Texas. Methodology Fifteen plant species were field tested in 11.4-cm-deep green roof modules on a four-storey building in College Station, Texas, with irrigation limited to the first several weeks of establishment. Climate data, plant growth and species survival were measured over three growing seasons. Principal results Four species survived growing seasons without any losses: Graptopetalum paraguayense, Malephora lutea, Manfreda maculosa and Phemeranthus calycinus. Six species experienced varying levels of mortality: Bulbine frutescens, Delosperma cooperi, Lampranthus spectabilis, Sedum kamtschaticum, Sedum mexicanum and Nassella tenuissima. Five species had no survivors: Dichondra argentea, Stemodia lanata, Myoporum parvifolium, Sedum moranense and Sedum tetractinum. Conclusions The establishment and survival of several plant species without any mortality suggests that irrigation limited to the first few weeks after planting may be an effective approach on green roofs in spite of the more challenging climatic conditions in the southern USA. Since the climate in south-central Texas had been consistently drier and warmer than normal during the study period, longer-term research on these species is recommended to expand knowledge of establishment requirements for these species under a wider range of conditions, including wetter than normal years.

  3. Height-growth response to climatic changes differs among populations of Douglas-fir: A novel analysis of historic data

    Science.gov (United States)

    Laura P. Leites; Andrew P. Robinson; Gerald E. Rehfeldt; John D. Marshall; Nicholas L. Crookston

    2012-01-01

    Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach,...

  4. Political economy of climate change, ecological destruction and uneven development

    International Nuclear Information System (INIS)

    O'Hara, Phillip Anthony

    2009-01-01

    The purpose of this paper is to analyze climate change and ecological destruction through the prism of the core general principles of political economy. The paper starts with the principle of historical specificity, and the various waves of climate change through successive cooler and warmer periods on planet Earth, including the most recent climate change escalation through the open circuit associated with the treadmill of production. Then we scrutinize the principle of contradiction associated with the disembedded economy, social costs, entropy and destructive creation. The principle of uneven development is then explored through core-periphery dynamics, ecologically unequal exchange, metabolic rift and asymmetric global (in)justice. The principles of circular and cumulative causation (CCC) and uncertainty are then related to climate change dynamics through non-linear transformations, complex interaction of dominant variables, and threshold effects. Climate change and ecological destruction are impacting on most areas, especially the periphery, earlier and more intensely than previously thought likely. A political economy approach to climate change is able to enrich the analysis of ecological economics and put many critical themes in a broad context. (author)

  5. Effects of Climatic Conditions and Soil Properties on Cabernet Sauvignon Berry Growth and Anthocyanin Profiles

    Directory of Open Access Journals (Sweden)

    Guo Cheng

    2014-09-01

    Full Text Available Climatic conditions and soil type have significant influence on grape ripening and wine quality. The reported study was conducted in two “Cabernet Sauvignon (Vitis vinifera L.V” vineyards located in Xinjiang, a semiarid wine-producing region of China during two vintages (2011 and 2012. The results indicate that soil and climate affected berry growth and anthocyanin profiles. These two localities were within a distance of 5 km from each other and had soils of different physical and chemical composition. For each vineyard, the differences of anthocyanin concentrations, and parameters concerning berry growth and composition between the two years could be explained by different climatic conditions. Soil effect was studied by investigation of differences in berry composition and anthocyanin profiles between the two vineyards in the same year, which could be explained mainly by the different soil properties, vine water and nitrogen status. Specifically, the soils with less water and organic matter produced looser clusters, heavier berry skins and higher TSS, which contributed to the excellent performance of grapes. Compared with 2011, the increases in anthocyanin concentrations for each vineyard in 2012 could be attributed to smaller number of extreme temperature (>35 °C days and rainfall, lower vine water status and N level. The explanation for higher anthocyanin concentrations in grape skins from the soils with less water and organic matter could be the vine status differences, lighter berry weight and heavier skin weight at harvest. In particular, grapes from the soils with less water and organic matter had higher levels of 3′5′-substituded, O-methylated and acylated anthocyanins, which represented a positive characteristic conferring more stable pigmentation to the corresponding wine in the future. The present work clarifies the effects of climate and soil on berry growth and anthocyanin profiles, thus providing guidance for production of

  6. Impact of Population Growth and Climate Change on the Freshwater Resources of Lamu Island, Kenya

    Directory of Open Access Journals (Sweden)

    Cornelius Okello

    2015-03-01

    Full Text Available Demand for freshwater is rising with factors, such as population growth, land use change and climate variations, rendering water availability in the future uncertain. Groundwater resources are being increasingly exploited to meet this growing demand. The aim of this study is to identify the influence of population growth induced by land use change and climate change on the future state of freshwater resources of Lamu Island in Kenya where a major port facility is under construction. The results of this study show that the “no industrial development” population scenario (assuming the port was not constructed would be expected to reach ~50,000 people by 2050, while the projected population upon completion is expected to reach 1.25 million in the same year when the Lamu Port-South Sudan-Ethiopia Transport Corridor Program (LAPSSET port reaches its full cargo-handling capacity. The groundwater abstraction in 2009 was 0.06 m3 daily per capita, while the demand is expected to raise to 0.1 m3 by 2050 according to the “LAPSSET development” projection. The modelling results show that the Shela aquifer in Lamu, which is the main source of water on the island, will not experience stress by 2065 for the “no industrial development” population scenario, whereas for the “LAPSSET development projection” population scenario, it will occur sooner (between 2020 and 2028. The modelling results show that the Representative Concentration Pathways (RCP climate change scenarios will have a smaller impact on the effective water volume reserves than Special Report on Emissions Scenarios (SRES for the “no industrial development”, while the impact is expected to be similar for the “LAPSSET development”, suggesting that population growth exacerbated by land use change will be a more significant driving force than climate change in affecting freshwater availability.

  7. Effects of climatic conditions and soil properties on Cabernet Sauvignon berry growth and anthocyanin profiles.

    Science.gov (United States)

    Cheng, Guo; He, Yan-Nan; Yue, Tai-Xin; Wang, Jun; Zhang, Zhen-Wen

    2014-09-02

    Climatic conditions and soil type have significant influence on grape ripening and wine quality. The reported study was conducted in two "Cabernet Sauvignon (Vitis vinifera L.V)" vineyards located in Xinjiang, a semiarid wine-producing region of China during two vintages (2011 and 2012). The results indicate that soil and climate affected berry growth and anthocyanin profiles. These two localities were within a distance of 5 km from each other and had soils of different physical and chemical composition. For each vineyard, the differences of anthocyanin concentrations, and parameters concerning berry growth and composition between the two years could be explained by different climatic conditions. Soil effect was studied by investigation of differences in berry composition and anthocyanin profiles between the two vineyards in the same year, which could be explained mainly by the different soil properties, vine water and nitrogen status. Specifically, the soils with less water and organic matter produced looser clusters, heavier berry skins and higher TSS, which contributed to the excellent performance of grapes. Compared with 2011, the increases in anthocyanin concentrations for each vineyard in 2012 could be attributed to smaller number of extreme temperature (>35 °C) days and rainfall, lower vine water status and N level. The explanation for higher anthocyanin concentrations in grape skins from the soils with less water and organic matter could be the vine status differences, lighter berry weight and heavier skin weight at harvest. In particular, grapes from the soils with less water and organic matter had higher levels of 3'5'-substituded, O-methylated and acylated anthocyanins, which represented a positive characteristic conferring more stable pigmentation to the corresponding wine in the future. The present work clarifies the effects of climate and soil on berry growth and anthocyanin profiles, thus providing guidance for production of high-quality wine grapes

  8. Among-tree variability and feedback effects result in different growth responses to climate change at the upper treeline in the Swiss Alps.

    Science.gov (United States)

    Jochner, Matthias; Bugmann, Harald; Nötzli, Magdalena; Bigler, Christof

    2017-10-01

    Upper treeline ecotones are important life form boundaries and particularly sensitive to a warming climate. Changes in growth conditions at these ecotones have wide-ranging implications for the provision of ecosystem services in densely populated mountain regions like the European Alps. We quantify climate effects on short- and long-term tree growth responses, focusing on among-tree variability and potential feedback effects. Although among-tree variability is thought to be substantial, it has not been considered systematically yet in studies on growth-climate relationships. We compiled tree-ring data including almost 600 trees of major treeline species ( Larix decidua , Picea abies , Pinus cembra , and Pinus mugo ) from three climate regions of the Swiss Alps. We further acquired tree size distribution data using unmanned aerial vehicles. To account for among-tree variability, we employed information-theoretic model selections based on linear mixed-effects models (LMMs) with flexible choice of monthly temperature effects on growth. We isolated long-term trends in ring-width indices (RWI) in interaction with elevation. The LMMs revealed substantial amounts of previously unquantified among-tree variability, indicating different strategies of single trees regarding when and to what extent to invest assimilates into growth. Furthermore, the LMMs indicated strongly positive temperature effects on growth during short summer periods across all species, and significant contributions of fall ( L. decidua ) and current year's spring ( L. decidua , P. abies ). In the longer term, all species showed consistently positive RWI trends at highest elevations, but different patterns with decreasing elevation. L. decidua exhibited even negative RWI trends compared to the highest treeline sites, whereas P. abies , P. cembra , and P. mugo showed steeper or flatter trends with decreasing elevation. This does not only reflect effects of ameliorated climate conditions on tree

  9. Simulating Hydrologic Changes with Climate Change Scenarios in the Haihe River Basin

    Institute of Scientific and Technical Information of China (English)

    YUAN Fei; XIE Zheng-Hui; LIU Qian; XIA Jun

    2005-01-01

    Climate change scenarios, predicted using the regional climate modeling system of PRECIS (providing regional climates for impacts studies), were used to derive three-layer variable infiltration capacity (VIC-3L) land surface model for the simulation of hydrologic processes at a spatial resolution of 0.25°× 0.25° in the Haihe River Basin. Three climate scenaxios were considered in this study: recent climate (1961-1990), future climate A2 (1991-2100) and future climate B2 (1991-2100) with A2 and B2 being two storylines of future emissions developed with the Intergovernmental Panel on Climate Change (IPCC) special report on emissions scenarios. Overall, under future climate scenarios A2 and B2, the Haihe River Basin would experience warmer climate with increased precipitation, evaporation and runoff production as compared with recent climate, but would be still likely prone to water shortages in the period of 2031-2070. In addition,under future climate A2 and B2, an increase in runoff during the wet season was noticed, indicating a future rise in the flood occurrence possibility in the Haihe River Basin.

  10. Will changes in phenology track climate change? A study of growth initiation timing in coast Douglas-fir

    Science.gov (United States)

    Kevin Ford; Connie Harrington; Sheel Bansal; Peter J. Gould; Brad St. Clair

    2016-01-01

    Under climate change, the reduction of frost risk, onset of warm temperatures and depletion of soil moisture are all likely to occur earlier in the year in many temperate regions. The resilience of tree species will depend on their ability to track these changes in climate with shifts in phenology that lead to earlier growth initiation in the spring. Exposure to warm...

  11. Assessing the impacts of climate change and nitrogen deposition on Norway spruce (Picea abies L. Karst) growth in Austria with BIOME-BGC.

    Science.gov (United States)

    Eastaugh, Chris S; Pötzelsberger, Elisabeth; Hasenauer, Hubert

    2011-03-01

    The aim of this paper is to determine whether a detectable impact of climate change is apparent in Austrian forests. In regions of complex terrain such as most of Austria, climatic trends over the past 50 years show marked geographic variability. As climate is one of the key drivers of forest growth, a comparison of growth characteristics between regions with different trends in temperature and precipitation can give insights into the impact of climatic change on forests. This study uses data from several hundred climate recording stations, interpolated to measurement sites of the Austrian National Forest Inventory (NFI). Austria as a whole shows a warming trend over the past 50 years and little overall change in precipitation. The warming trends, however, vary considerably across certain regions and regional precipitation trends vary widely in both directions, which cancel out on the national scale These differences allow the delineation of 'climatic change zones' with internally consistent climatic trends that differ from other zones. This study applies the species-specific adaptation of the biogeochemical model BIOME-BGC to Norway spruce (Picea abies (L.) Karst) across a range of Austrian climatic change zones, using input data from a number of national databases. The relative influence of extant climate change on forest growth is quantified, and compared with the far greater impact of non-climatic factors. At the national scale, climate change is found to have negligible effect on Norway spruce productivity, due in part to opposing effects at the regional level. The magnitudes of the modeled non-climatic influences on aboveground woody biomass increment increases are consistent with previously reported values of 20-40 kg of added stem carbon sequestration per kilogram of additional nitrogen deposition, while climate responses are of a magnitude difficult to detect in NFI data.

  12. Using CAM3 and the Alkenone Method to Understand how Pliocene SST's Affect California and Other Climates Adjacent to Upwelling Regions

    Science.gov (United States)

    Searles, Z. A.; Otto-Bliesner, B. L.; Rosenbloom, N. A.; Dekens, P. S.

    2008-12-01

    The Intergovernmental Panel on Climate Change fourth assessment report established with 90% confidence that anthropogenic climate change will result in a warmer world. In order to more fully understand possible future climate, past analogues of warm periods should be analyzed. The early Pliocene is an appropriate analogue because the continental configuration was similar to today and CO2 levels were comparable to present (~100ppm higher than pre-anthropogenic levels). This project has two objectives: 1.To test the atmospheric sensitivity to USGS PRISM2 dataset revised to better approximate proxy data indicating warmer SST's in upwelling regions and 2. To provide early-Pliocene (2.7- 3.5 Ma) SST estimates for ODP site 1018 on the California Margin (36°59.4'N, 123°16.5'W) using the UK'37 SST proxy. Recent UK'37 proxy data reveals that PRISM2 underestimates SST's in Pacific and Atlantic coastal upwelling regions. The sensitivity of the atmosphere to significantly warmer SST's in upwelling regions was tested using the National Center for Atmospheric Research (NCAR) Community Atmospheric Model, version 3 (CAM3). Initial conditions were supplied by the USGS PRISM2 project and include Pliocene SST's, vegetation cover, sea level height, topography, marine and continental ice extent. Pliocene SST's along the Californian, Peruvian, North African and South African margin were modified to reflect proxy observations from 4 sites. The lack of observational coverage (1 data point per region) required interpolation of the areal extent of the SST warming anomaly indicated by the proxies. Experiment results show increased cumulative precipitation and humidity in regions where the original PRISM2 predicted drying. The predicted North American increase in precipitation is in better agreement with geologic proxies indicating wetter conditions. Warmer SST's also causes weaker wind velocities along the North American, Peruvian, and North African margins, and stronger winds along the

  13. Climate Change and Fish Availability

    Science.gov (United States)

    Teng, Paul P. S.; Lassa, Jonatan; Caballero-Anthony, Mely

    Human consumption of fish has been trending upwards in the past decades and this is projected to continue. The main sources of fish are from wild fisheries (marine and freshwater) and aquaculture. Climate change is anticipated to affect the availability of fish through its effect on these two sources as well as on supply chain processes such as storage, transport, processing and retail. Climate change is known to result in warmer and more acid oceans. Ocean acidification due to higher CO2 concentration levels at sea modifies the distribution of phytoplankton and zooplankton to affect wild, capture fisheries. Higher temperature causes warm-water coral reefs to respond with species replacement and bleaching, leading to coral cover loss and habitat loss. Global changes in climatic systems may also cause fish invasion, extinction and turnover. While this may be catastrophic for small scale fish farming in poor tropical communities, there are also potential effects on animal protein supply shifts at local and global scales with food security consequences. This paper discusses the potential impacts of climate change on fisheries and aquaculture in the Asian Pacific region, with special emphasis on Southeast Asia. The key question to be addressed is “What are the impacts of global climate change on global fish harvests and what does it mean to the availability of fish?”

  14. Green Growth - an Illusion? Energy and Climate Risk: Rethinking our Developmental Models

    International Nuclear Information System (INIS)

    Dessus, B.

    2011-01-01

    The years go by and international conferences come and go, with their quota of cries of alarm and calls to action to counter climate change. But in reality few large-scale programmes have been launched anywhere in the world involving concrete action to bring down greenhouse gas emissions. As one who has campaigned for many years for policies of energy consumption control, Benjamin Dessus shows here that the energy challenge is as great as it has ever been in a world of expanding populations in which most peoples aspire to reach the developmental level of the northern countries, despite the fact that our climate probably cannot support such a state of affairs. He argues here against a certain number of common suppositions, such as the idea of focussing exclusively on CO 2 in the fight against global warming, the need for a continuous economic growth on the order of 2% per annum or excessive faith in market mechanisms to bring down greenhouse gas emissions. He also stresses the ambiguities of so-called 'green' growth and compares different energy conservation scenarios. In this way, he shows that, against a relatively dominant line of reasoning based largely on (at times near-utopian) technological solutions and the continuation of sustained economic growth, there are more effective paths based on individual/collective energy sobriety and a serious slowdown of economic growth in the most developed countries, if not indeed a total halt to that growth (though these are more ambitious in that they require a revolution in the behaviour of the most affluent peoples). He concludes by proposing some courses of action for implementing such a programme in a country like France, showing the extent to which modern modes of life are going to have to change and how urgent it now is to debate these matters, if such change is to be achieved without - excessive - pain. (author)

  15. Bioaccumulation and elimination of mercury in juvenile seabass (Dicentrarchus labrax) in a warmer environment

    Energy Technology Data Exchange (ETDEWEB)

    Maulvault, Ana Luísa, E-mail: aluisa@ipma.pt [Division of Aquaculture and Seafood Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA), Avenida de Brasília, 1449-006 Lisboa (Portugal); Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais (Portugal); Custódio, Ana [Division of Aquaculture and Seafood Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA), Avenida de Brasília, 1449-006 Lisboa (Portugal); Instituto Superior de Agronomia (ISA), School of Agriculture, University of Lisbon, Tapada da Ajuda, 1349-017 Lisboa (Portugal); Anacleto, Patrícia [Division of Aquaculture and Seafood Upgrading, Portuguese Institute for the Sea and Atmosphere, I.P. (IPMA), Avenida de Brasília, 1449-006 Lisboa (Portugal); Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Universidade do Porto, Rua dos Bragas, 289, 4050-123 Porto (Portugal); MARE – Marine and Environmental Sciences Centre, Laboratório Marítimo da Guia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais (Portugal); and others

    2016-08-15

    , followed by the muscle and liver. • A warmer environment enhances MeHg bioaccumulation and hampers MeHg elimination. • Ocean warming may compromise seafood safety. • Research combining climate change and pollution effects should be strengthened.

  16. Topography- and Species-Dependent Climatic Responses in Radial Growth of Picea meyeri and Larix principis-rupprechtii in the Luyashan Mountains of North-Central China

    Directory of Open Access Journals (Sweden)

    Wentao Zhang

    2015-01-01

    Full Text Available Dendroecological techniques were used to examine the relationships between topographic aspects, climate factors and radial growth of Picea meyeri and Larix principis-rupprechtii in Luyashan Mountains, North-Central China. Four sites were selected at timberline and totally 67 trees and 134 cores were collected. Pearson correlation and regression surface analysis were conducted to reveal the growth-climate relationships. The results indicated that the two species both showed significant negative correlations with temperature during preceding November on the two topographic aspects. On both slope aspects, growth of P. meyeri exhibited significant negative correlations with precipitation in current June, whereas growth of L. principis-rupprechtii showed significant negative correlations with precipitation in preceding September. On north-facing slope, tree growth was limited by low temperature in early growing season, which not shown on south-facing slope. If climate warming continues, L. principis-rupprechtii may be more favored and a reverse between relationships with temperature and precipitation maybe occur in growth of trees. Treeline position on the north-facing slope may possess a greater potential for elevation shifting than the south-facing slope. Our results supply useful information for discussing the potential effect of future climate on the forest growth in North-Central China.

  17. The impact of climate change on the balanced growth equivalent: An application of FUND

    NARCIS (Netherlands)

    Anthoff, D.; Tol, R.S.J.

    2009-01-01

    The Stern Review added balanced growth equivalents (BGE) to the economic climate change research agenda. We first propose rigorous definitions of the BGE for multiple regions and under uncertainty. We show that the change in the BGE is independent of the assumed scenario of per capita income. For

  18. Climate warming could increase recruitment success in glacier foreland plants.

    Science.gov (United States)

    Mondoni, Andrea; Pedrini, Simone; Bernareggi, Giulietta; Rossi, Graziano; Abeli, Thomas; Probert, Robin J; Ghitti, Michele; Bonomi, Costantino; Orsenigo, Simone

    2015-11-01

    Glacier foreland plants are highly threatened by global warming. Regeneration from seeds on deglaciated terrain will be crucial for successful migration and survival of these species, and hence a better understanding of the impacts of climate change on seedling recruitment is urgently needed to predict future plant persistence in these environments. This study presents the first field evidence of the impact of climate change on recruitment success of glacier foreland plants. Seeds of eight foreland species were sown on a foreland site at 2500 m a.s.l., and at a site 400 m lower in altitude to simulate a 2·7 °C increase in mean annual temperature. Soil from the site of origin was used to reproduce the natural germination substrate. Recruitment success, temperature and water potential were monitored for 2 years. The response of seed germination to warming was further investigated in the laboratory. At the glacier foreland site, seedling emergence was low (0 to approx. 40 %) and occurred in summer in all species after seeds had experienced autumn and winter seasons. However, at the warmer site there was a shift from summer to autumn emergence in two species and a significant increase of summer emergence (13-35 % higher) in all species except two. Survival and establishment was possible for 60-75 % of autumn-emerged seedlings and was generally greater under warmer conditions. Early snowmelt in spring caused the main ecological factors enhancing the recruitment success. The results suggest that warming will influence the recruitment of glacier foreland species primarily via the extension of the snow-free period in spring, which increases seedling establishment and results in a greater resistance to summer drought and winter extremes. The changes in recruitment success observed here imply that range shifts or changes in abundance are possible in a future warmer climate, but overall success may be dependent on interactions with shifts in other components of the

  19. Dynamic Response of Satellite-Derived Vegetation Growth to Climate Change in the Three North Shelter Forest Region in China

    Directory of Open Access Journals (Sweden)

    Bin He

    2015-08-01

    Full Text Available Since the late 1970s, the Chinese government has initiated ecological restoration programs in the Three North Shelter Forest System Project (TNSFSP area. Whether accelerated climate change will help or hinder these efforts is still poorly understood. Using the updated and extended AVHRR NDVI3g dataset from 1982 to 2011 and corresponding climatic data, we investigated vegetation variations in response to climate change. The results showed that the overall state of vegetation in the study region has improved over the past three decades. Vegetation cover significantly decreased in 23.1% and significantly increased in 21.8% of the study area. An increase in all three main vegetation types (forest, grassland, and cropland was observed, but the trend was only statistically significant in cropland. In addition, bare and sparsely vegetated areas, mainly located in the western part of the study area, have significantly expanded since the early 2000s. A moisture condition analysis indicated that the study area experienced significant climate variations, with warm-wet conditions in the western region and warm-dry conditions in the eastern region. Correlation analysis showed that variations in the Normalized Difference Vegetation Index (NDVI were positively correlated with precipitation and negatively correlated with temperature. Ultimately, climate change influenced vegetation growth by controlling the availability of soil moisture. Further investigation suggested that the positive impacts of precipitation on NDVI have weakened in the study region, whereas the negative impacts from temperature have been enhanced in the eastern study area. However, over recent years, the negative temperature impacts have been converted to positive impacts in the western region. Considering the variations in the relationship between NDVI and climatic variables, the warm–dry climate in the eastern region is likely harmful to vegetation growth, whereas the warm

  20. Increasing Dengue Incidence in Singapore over the Past 40 Years: Population Growth, Climate and Mobility.

    Directory of Open Access Journals (Sweden)

    Claudio Jose Struchiner

    Full Text Available In Singapore, the frequency and magnitude of dengue epidemics have increased significantly over the past 40 years. It is important to understand the main drivers for the rapid increase in dengue incidence. We studied the relative contributions of putative drivers for the rise of dengue in Singapore: population growth, climate parameters and international air passenger arrivals from dengue endemic countries, for the time period of 1974 until 2011. We used multivariable Poisson regression models with the following predictors: Annual Population Size; Aedes Premises Index; Mean Annual Temperature; Minimum and Maximum Temperature Recorded in each year; Annual Precipitation and Annual Number of Air Passengers arriving from dengue-endemic South-East Asia to Singapore. The relative risk (RR of the increase in dengue incidence due to population growth over the study period was 42.7, while the climate variables (mean and minimum temperature together explained an RR of 7.1 (RR defined as risk at the end of the time period relative to the beginning and goodness of fit associated with the model leading to these estimates assessed by pseudo-R2 equal to 0.83. Estimating the extent of the contribution of these individual factors on the increasing dengue incidence, we found that population growth contributed to 86% while the residual 14% was explained by increase in temperature. We found no correlation with incoming air passenger arrivals into Singapore from dengue endemic countries. Our findings have significant implications for predicting future trends of the dengue epidemics given the rapid urbanization with population growth in many dengue endemic countries. It is time for policy-makers and the scientific community alike to pay more attention to the negative impact of urbanization and urban climate on diseases such as dengue.

  1. Modeling the effects of local climate change on crop acreage

    Directory of Open Access Journals (Sweden)

    Hyunok Lee

    2016-01-01

    Full Text Available The impacts of climate change on agriculture depend on local conditions and crops grown. For instance, warmer winter temperatures in a given area would reduce chill hours, potentially cutting yields for some crops but extending the growing season for others. Using a century of climate data and six decades of acreage data, we established quantitative economic relationships between the evolution of local climate and acreage of 12 important crops in Yolo County. We then used the historical trend in climate change to project future crop acreages in the county. Only marginal changes in acreage in 2050 were projected for tree and vine crops there, in part because chill hours, although lower, remained above critical values. Walnuts were the most vulnerable tree crop, and the projections indicated some cultivars might be marginal in years with particularly warm winters. Processing tomato acreage might increase, due to a longer growing season, and also alfalfa acreage, if water availability and other factors remain constant.

  2. Climate-induced seasonal changes in smallmouth bass growth rate potential at the southern range extent

    Science.gov (United States)

    Middaugh, Christopher R.; Kessinger, Brin; Magoulick, Daniel D.

    2018-01-01

    Temperature increases due to climate change over the coming century will likely affect smallmouth bass (Micropterus dolomieu) growth in lotic systems at the southern extent of their native range. However, the thermal response of a stream to warming climate conditions could be affected by the flow regime of each stream, mitigating the effects on smallmouth bass populations. We developed bioenergetics models to compare change in smallmouth bass growth rate potential (GRP) from present to future projected monthly stream temperatures across two flow regimes: runoff and groundwater-dominated. Seasonal differences in GRP between stream types were then compared. The models were developed for fourteen streams within the Ozark–Ouachita Interior Highlands in Arkansas, Oklahoma and Missouri, USA, which contain smallmouth bass. In our simulations, smallmouth bass mean GRP during summer months decreased by 0.005 g g−1 day−1 in runoff streams and 0.002 g g−1 day−1 in groundwater streams by the end of century. Mean GRP during winter, fall and early spring increased under future climate conditions within both stream types (e.g., 0.00019 g g−1 day−1 in runoff and 0.0014 g g−1 day−1 in groundwater streams in spring months). We found significant differences in change in GRP between runoff and groundwater streams in three seasons in end-of-century simulations (spring, summer and fall). Potential differences in stream temperature across flow regimes could be an important habitat component to consider when investigating effects of climate change as fishes from various flow regimes that are relatively close geographically could be affected differently by warming climate conditions.

  3. Global vs climate change

    International Nuclear Information System (INIS)

    Watson, H.L.; Bach, M.C.; Goklany, I.M.

    1991-01-01

    The various agents of global change that will affect the state of natural resources 50-100 years from now are discussed. These include economic and population growth, technological progress, and climatic change. The importance of climatic change lies in its effects on natural resources and on human activities that depend on those resources. Other factors affecting those resources include the demand on those resources from an increasing population and from a growing economy, and a more efficient use of those resources that comes from technological changes and from the consequences of economic growth itself. It is shown that there is a considerable ability to adapt to climatic change, since humans already have an intrinsic ability to adapt to the wide variations in climates that already exist and since technological developments can make it easier to cope with climatic variability. It appears that agents other than climatic change are more significant to the future state of natural resources than climatic change. Criteria for selecting options for addressing climatic change are outlined. Technological change and economic growth are seen to be key response options, since the vulnerability to climatic change depends on economic resources and technological progress. Specific options to stimulate sustainable economic growth and technological progress are listed. 16 refs., 1 fig., 2 tabs

  4. Growth-climate relationships vary with height along the stem in lodgepole pine.

    Science.gov (United States)

    Chhin, Sophan; Hogg, E H Ted; Lieffers, Victor J; Huang, Shongming

    2010-03-01

    This study tests the hypothesis that ring growth in the upper stem portion of trees is affected by climatic conditions differently than rings formed at breast height (1.3 m). A total of 389 trees from a network of 65 lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) sites in Alberta were examined using detailed stem analysis in order to examine interannual patterns of basal area increment and volume increment at different positions along the stem. Growth at lower sections of the bole was mainly driven by temperature and moisture conditions in the seasons prior to the growing season in the year of ring formation, while upper stem growth was more related to conditions during the year of growth, i.e., temperature in the early summer, or moisture in late winter to early spring. This translates into increased allocation of wood to the lower stem when prior late summer conditions are cool and wet, prior winters are mild (warm with little snow) and early summer conditions in the year of ring formation are hot and dry.

  5. Volcanic Eruptions and Climate: Outstanding Research Issues

    Science.gov (United States)

    Robock, Alan

    2016-04-01

    Large volcanic eruptions inject sulfur gases into the stratosphere, which convert to sulfate aerosols with an e-folding residence time of about one year. The radiative and chemical effects of this aerosol cloud produce responses in the climate system. Based on observations after major eruptions of the past and experiments with numerical models of the climate system, we understand much about their climatic impact, but there are also a number of unanswered questions. Volcanic eruptions produce global cooling, and are an important natural cause of interannual, interdecadal, and even centennial-scale climate change. One of the most interesting volcanic effects is the "winter warming" of Northern Hemisphere continents following major tropical eruptions. During the winter in the Northern Hemisphere following every large tropical eruption of the past century, surface air temperatures over North America, Europe, and East Asia were warmer than normal, while they were colder over Greenland and the Middle East. This pattern and the coincident atmospheric circulation correspond to the positive phase of the Arctic Oscillation. While this response is observed after recent major eruptions, most state-of-the-art climate models have trouble simulating winter warming. Why? High latitude eruptions in the Northern Hemisphere, while also producing global cooling, do not have the same impact on atmospheric dynamics. Both tropical and high latitude eruptions can weaken the Indian and African summer monsoon, and the effects can be seen in past records of flow in the Nile and Niger Rivers. Since the Mt. Pinatubo eruption in the Philippines in 1991, there have been no large eruptions that affected climate, but the cumulative effects of small eruptions over the past decade have had a small effect on global temperature trends. Some important outstanding research questions include: How much seasonal, annual, and decadal predictability is possible following a large volcanic eruption? Do

  6. As Bad as it Gets: How Climate Damage Functions Affect Growth and the Social Cost of Carbon

    OpenAIRE

    Bretschger, Lukas; Pattakou, Aimilia

    2017-01-01

    The paper analyzes the effects of varying climate impacts on the social cost of carbon and economic growth. We use polynomial damage functions in a model of an endogenously growing two-sector economy. The framework includes nonrenewable natural resources which cause greenhouse gas emissions; pollution stock harms capital and reduces economic growth. We find a big effect of the selected damage function on the social cost of carbon and a significant impact on the growth rate. In our calibration...

  7. Climate Change Mitigation A Balanced Approach to Climate Change

    CERN Document Server

    2012-01-01

    This book provides a fresh and innovative perspective on climate change policy. By emphasizing the multiple facets of climate policy, from mitigation to adaptation, from technological innovation and diffusion to governance issues, it contains a comprehensive overview of the economic and policy dimensions of the climate problem. The keyword of the book is balance. The book clarifies that climate change cannot be controlled by sacrificing economic growth and many other urgent global issues. At the same time, action to control climate change cannot be delayed, even though gradually implemented. Therefore, on the one hand climate policy becomes pervasive and affects all dimensions of international policy. On the other hand, climate policy cannot be too ambitious: a balanced approach between mitigation and adaptation, between economic growth and resource management, between short term development efforts and long term innovation investments, should be adopted. I recommend its reading. Carlo Carraro, President, Ca�...

  8. Health and vitality assessment of two common pine species in the context of climate change in southern Europe.

    Science.gov (United States)

    Sicard, Pierre; Dalstein-Richier, Laurence

    2015-02-01

    The Mediterranean Basin is expected to be more strongly affected by ongoing climate change than most other regions of the earth. The South-eastern France can be considered as case study for assessing global change impacts on forests. Based on non-parametric statistical tests, the climatic parameters (temperature, relative humidity, rainfall, global radiation) and forest-response indicators (crown defoliation, discoloration and visible foliar ozone injury) of two pine species (Pinus halepensis and Pinus cembra) were analyzed. In the last 20 years, the trend analyses reveal a clear hotter and drier climate along the coastline and slightly rainier inland. In the current climate change context, a reduction in ground-level ozone (O3) was found at remote sites and the visible foliar O3 injury decreased while deterioration of the crown conditions was observed likely due to a drier and warmer climate. Clearly, if such climatic and ecological changes are now being detected when the climate, in South-eastern France, has warmed in the last 20 years (+0.46-1.08°C), it can be expected that many more impacts on tree species will occur in response to predicted temperature changes by 2100 (+1.95-4.59°C). Climate change is projected to reduce the benefits of O3 precursor emissions controls leading to a higher O3 uptake. However, the drier and warmer climate should induce a soil drought leading to a lower O3 uptake. These two effects, acting together in an opposite way, could mitigate the harmful impacts of O3 on forests. The development of coordinated emission abatement strategies is useful to reduce both climate change and O3 pollution. Climate change will create additional challenges for forest management with substantial socio-economic and biological diversity impacts. However, the development of future sustainable and adaptive forest management strategies has the potential to reduce the vulnerability of forest species to climate change. Copyright © 2014 Elsevier Inc. All

  9. Cutaneous larva migrans in northern climates. A souvenir of your dream vacation.

    Science.gov (United States)

    Edelglass, J W; Douglass, M C; Stiefler, R; Tessler, M

    1982-09-01

    Three young women recently returned to the metropolitan Detroit area with cutaneous larva migrans. All three had vacationed at a popular club resort on the Caribbean island of Martinique. Cutaneous larva migrans is frequently seen in the southern United States, Central and South America, and other subtropical areas but rarely in northern climates. Several organisms can cause cutaneous larva migrans, or creeping eruption. The larvae of the nematode Ancylostoma braziliense are most often the causative organisms. Travel habits of Americans make it necessary for practitioners in northern climates to be familiar with diseases contracted primarily in warmer locations. The life cycle of causative organisms and current therapy are reviewed.

  10. Dynamics at the treeline: differential responses of Picea mariana and Larix laricina to climate change in eastern subarctic Québec

    International Nuclear Information System (INIS)

    Dufour-Tremblay, Geneviève; Boudreau, Stéphane; Lévesque, Esther

    2012-01-01

    Treelines are known to be temperature-sensitive ecotones, and therefore could rapidly expand their range limits in response to climate warming. Observations of lack of range expansion, however, indicate that ecological constraints partly control the treeline ecotones. The main objectives of this study were to evaluate Picea mariana and Larix laricina recruitment and growth at and above the altitudinal treeline of Kangiqsualujjuaq (Nunavik), where warmer temperatures since the 1990s have already triggered shrub expansion. We mapped, harvested, dated and measured tree individuals along two altitudinal gradients from the forested stands below the treeline to hilltops. Since the 1990s, a pulse of L. laricina seedling establishment has occurred at and above the treeline. Dendrochronological analysis revealed that L. laricina underwent a rapid vertical growth and radial growth that accelerated from the 1990s. No recruitment was observed for P. mariana in response to the regional warming, suggesting a regeneration failure of this species. Our results indicated that the L. laricina colonization below and above the treeline in recent decades in response to the regional warming should modify the landscape physiognomy of the study area in the near future. (letter)

  11. The contrasting effects of short-term climate change on the early recruitment of tree species.

    Science.gov (United States)

    Ibáñez, Inés; Katz, Daniel S W; Lee, Benjamin R

    2017-07-01

    Predictions of plant responses to climate change are frequently based on organisms' presence in warmer locations, which are then assumed to reflect future performance in cooler areas. However, as plant life stages may be affected differently by environmental changes, there is little empirical evidence that this approach provides reliable estimates of short-term responses to global warming. Under this premise, we analyzed 8 years of early recruitment data, seed production and seedling establishment and survival, collected for two tree species at two latitudes. We quantified recruitment to a wide range of environmental conditions, temperature, soil moisture and light, and simulated recruitment under two forecasted climatic scenarios. Annual demographic transitions were affected by the particular conditions taking place during their onset, but the effects of similar environmental shifts differed among the recruitment stages; seed production was higher in warmer years, while seedling establishment and survival peaked during cold years. Within a species, these effects also varied between latitudes; increasing temperatures at the southern location will have stronger detrimental effects on recruitment than similar changes at the northern locations. Our simulations illustrate that warmer temperatures may increase seed production, but they will have a negative effect on establishment and survival. When the three early recruitment processes were simultaneously considered, simulations showed little change in recruitment dynamics at the northern site and a slight decrease at the southern site. It is only when we considered these three stages that we were able to assess likely changes in early recruitment under the predicted conditions.

  12. Possible climate warming effects on vegetation, forests, biotic (insect, pathogene) disturbances and agriculture in Central Siberia for 1960- 2050

    Science.gov (United States)

    Tchebakova, N. M.; Parfenova, E. I.; Soja, A. J.; Lysanova, G. I.; Baranchikov, Y. N.; Kuzmina, N. A.

    2012-04-01

    Regional Siberian studies have already registered climate warming over the last half a century (1960-2010). Our analysis showed that winters are already 2-3°C warmer in the north and 1-2°C warmer in the south by 2010. Summer temperatures increased by 1°C in the north and by 1-2°C in the south. Change in precipitation is more complicated, increasing on average 10% in middle latitudes and decreasing 10-20% in the south, promoting local drying in already dry landscapes. Our goal was to summarize results of research we have done for the last decade in the context of climate warming and its consequences for biosystems in Central Siberia. We modeled climate change effects on vegetation shifts, on forest composition and agriculture change, on the insect Siberian moth (Dendrolimus suprans sibiricus Tschetv) and pathogene (Lophodermium pinastri Chev) ranges in Central Siberia for a century (1960-2050) based on historical climate data and GCM-predicted data. Principal results are: In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over 50% of central Siberia due to the dryer climate by 2080. Permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats; At least half of central Siberia is predicted to be climatically suitable for agriculture at the end of the century although potential croplands would be limited by the availability of suitable soils agriculture in central Siberia would likely benefit from climate warming Crop production may twofold increase as climate warms during the century; traditional crops (grain, potato

  13. Climate variations and the enhanced greenhouse effect

    Energy Technology Data Exchange (ETDEWEB)

    Karlen, W. [Stockholm Univ. (Sweden). Dept. of Physical Geography

    1998-06-01

    Changes in the size of glaciers, in the altitude of the alpine tree-limit, and variation in the width of tree-rings during the Holocene clearly indicate that the average Scandinavian summer temperature has fluctuated. During warm periods it has been about 2 deg C warmer than at present; during cold periods it has been almost as cold as it was during the coldest decades of the previous centuries. Superimposed on these long-term variations, which have lasted from 100 to 200 years, are short fluctuations in temperature. The Scandinavian chronology, which is based on glacier and alpine tree-limit fluctuations as well as on dendrochronology, is well correlated with the changes in climate, which studies of ice cores from central Greenland have revealed. It is therefore believed that the Scandinavian climate chronology depicts conditions typical of a large area. The Scandinavian record is compared with data concerning solar irradiation variations estimated as {sup 14}C anomalies obtained from tree-rings. A correlation between major changes in climate and variations in solar irradiation points to a solar forcing of the climate. This means that there is no evidence of a human influence on climate so far Special issue. Research for mountain area development: Europe. 64 refs, 3 figs

  14. The effects of climate, permafrost and fire on vegetation change in Siberia in a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Tchebakova, N M; Parfenova, E [V N Sukachev Institute of Forest, Siberian Branch of the Russian Academy of Sciences, Academgorodok, Krasnoyarsk, 660036 (Russian Federation); Soja, A J, E-mail: ncheby@forest.akadem.r, E-mail: Amber.J.Soja@nasa.go [National Institute of Aerospace (NIA), NASA Langley Research Center, Climate Sciences, 21 Langley Boulevard, Mail Stop 420, Hampton, VA 23681-2199 (United States)

    2009-10-15

    Observations and general circulation model projections suggest significant temperature increases in Siberia this century that are expected to have profound effects on Siberian vegetation. Potential vegetation change across Siberia was modeled, coupling our Siberian BioClimatic Model with several Hadley Centre climate change scenarios for 2020, 2050 and 2080, with explicit consideration of permafrost and fire activity. In the warmer and drier climate projected by these scenarios, Siberian forests are predicted to decrease and shift northwards and forest-steppe and steppe ecosystems are predicted to dominate over half of Siberia due to the dryer climate by 2080. Despite the large predicted increases in warming, permafrost is not predicted to thaw deep enough to sustain dark (Pinus sibirica, Abies sibirica, and Picea obovata) taiga. Over eastern Siberia, larch (Larix dahurica) taiga is predicted to continue to be the dominant zonobiome because of its ability to withstand continuous permafrost. The model also predicts new temperate broadleaf forest and forest-steppe habitats by 2080. Potential fire danger evaluated with the annual number of high fire danger days (Nesterov index is 4000-10 000) is predicted to increase by 2080, especially in southern Siberia and central Yakutia. In a warming climate, fuel load accumulated due to replacement of forest by steppe together with frequent fire weather promotes high risks of large fires in southern Siberia and central Yakutia, where wild fires would create habitats for grasslands because the drier climate would no longer be suitable for forests.

  15. Testing models of speciation from genome sequences: divergence and asymmetric admixture in Island Southeast Asian Sus species during the Plio-Pleistocene climatic fluctuations

    NARCIS (Netherlands)

    Frantz, L.A.F.; Madsen, O.; Megens, H.J.W.C.; Groenen, M.; Lohse, H.

    2014-01-01

    In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here,

  16. Regional climatic and North Atlantic Oscillation signatures in West Virginia red cedar over the past millennium

    Science.gov (United States)

    D'Arrigo, Rosanne; Anchukaitis, Kevin J.; Buckley, Brendan; Cook, Ed; Wilson, Rob

    2012-03-01

    We describe a millennial length (~ 1500-yr) tree-ring chronology developed from West Virginia (WVA), USA red cedar (Juniperus virginiana) ring widths that is significantly correlated with local to regional temperature and precipitation for the region. Using ensemble methods of tree-ring standardization, above average ring widths are indicated for the period between ~ 1000 and 1300 CE, the approximate time of the Medieval Climate Anomaly (MCA), the most recent major warm episode prior to the modern era. The chronology then transitions to more negative overall growth persisting through much of the subsequent period known as the Little Ice Age (LIA). While WVA cedar growth levels during the MCA are broadly similar to the 20th century mean, the most positive values during the MCA are associated with RCS-standardized chronologies, which pseudoproxy tests reveal are likely biased artificially positive, warranting further investigation. This cedar record is significantly correlated with the NAO, due to the tendency for warmer, wetter conditions to occur in the eastern-central USA during the NAO's positive phase. These types of conditions are inferred for this cedar chronology during the MCA period, during which NAO reconstructions suggest a persistently-positive NAO state.

  17. How did Marine Isotope Stage 3 and Last Glacial Maximum climates differ? – Perspectives from equilibrium simulations

    Directory of Open Access Journals (Sweden)

    C. J. Van Meerbeeck

    2009-03-01

    Full Text Available Dansgaard-Oeschger events occurred frequently during Marine Isotope Stage 3 (MIS3, as opposed to the following MIS2 period, which included the Last Glacial Maximum (LGM. Transient climate model simulations suggest that these abrupt warming events in Greenland and the North Atlantic region are associated with a resumption of the Thermohaline Circulation (THC from a weak state during stadials to a relatively strong state during interstadials. However, those models were run with LGM, rather than MIS3 boundary conditions. To quantify the influence of different boundary conditions on the climates of MIS3 and LGM, we perform two equilibrium climate simulations with the three-dimensional earth system model LOVECLIM, one for stadial, the other for interstadial conditions. We compare them to the LGM state simulated with the same model. Both climate states are globally 2°C warmer than LGM. A striking feature of our MIS3 simulations is the enhanced Northern Hemisphere seasonality, July surface air temperatures being 4°C warmer than in LGM. Also, despite some modification in the location of North Atlantic deep water formation, deep water export to the South Atlantic remains unaffected. To study specifically the effect of orbital forcing, we perform two additional sensitivity experiments spun up from our stadial simulation. The insolation difference between MIS3 and LGM causes half of the 30–60° N July temperature anomaly (+6°C. In a third simulation additional freshwater forcing halts the Atlantic THC, yielding a much colder North Atlantic region (−7°C. Comparing our simulation with proxy data, we find that the MIS3 climate with collapsed THC mimics stadials over the North Atlantic better than both control experiments, which might crudely estimate interstadial climate. These results suggest that freshwater forcing is necessary to return climate from warm interstadials to cold stadials during MIS3. This changes our perspective, making the stadial

  18. Regional tree growth and inferred summer climate in the Winnipeg River basin, Canada, since AD 1783

    Science.gov (United States)

    St. George, Scott; Meko, David M.; Evans, Michael N.

    2008-09-01

    A network of 54 ring-width chronologies is used to estimate changes in summer climate within the Winnipeg River basin, Canada, since AD 1783. The basin drains parts of northwestern Ontario, northern Minnesota and southeastern Manitoba, and is a key area for hydroelectric power production. Most chronologies were developed from Pinus resinosa and P. strobus, with a limited number of Thuja occidentalis, Picea glauca and Pinus banksiana. The dominant pattern of regional tree growth can be recovered using only the nine longest chronologies, and is not affected by the method used to remove variability related to age or stand dynamics from individual trees. Tree growth is significantly, but weakly, correlated with both temperature (negatively) and precipitation (positively) during summer. Simulated ring-width chronologies produced by a process model of tree-ring growth exhibit similar relationships with summer climate. High and low growth across the region is associated with cool/wet and warm/dry summers, respectively; this relationship is supported by comparisons with archival records from early 19th century fur-trading posts. The tree-ring record indicates that summer droughts were more persistent in the 19th and late 18th century, but there is no evidence that drought was more extreme prior to the onset of direct monitoring.

  19. Climate control on tree growth at the upper and lower treelines: a case study in the qilian mountains, tibetan plateau.

    Directory of Open Access Journals (Sweden)

    Bao Yang

    Full Text Available It is generally hypothesized that tree growth at the upper treeline is normally controlled by temperature while that at the lower treeline is precipitation limited. However, uniform patterns of inter-annual ring-width variations along altitudinal gradients are also observed in some situations. How changing elevation influences tree growth in the cold and arid Qilian Mountains, on the northeastern Tibetan Plateau, is of considerable interest because of the sensitivity of the region's local climate to different atmospheric circulation patterns. Here, a network of four Qilian juniper (Sabina przewalskii Kom. ring-width chronologies was developed from trees distributed on a typical mountain slope at elevations ranging from 3000 to 3520 m above sea level (a.s.l.. The statistical characteristics of the four tree-ring chronologies show no significant correlation with increasing elevation. All the sampled tree growth was controlled by a common climatic signal (local precipitation across the investigated altitudinal gradient (520 m. During the common reliable period, covering the past 450 years, the four chronologies have exhibited coherent growth patterns in both the high- and low-frequency domains. These results contradict the notion of contrasting climate growth controls at higher and lower elevations, and specifically the assumption that inter-annual tree-growth variability is controlled by temperature at the upper treeline. It should be stressed that these results relate to the relatively arid conditions at the sampling sites in the Qilian Mountains.

  20. Using dendrometer and dendroclimatology data to predict the growth response of Douglas-fir to climate change in the Pacific Northwest, USA

    Science.gov (United States)

    Altered seasonal climate patterns towards hotter, drier summers through the 21st century resulting from global climate change could affect the growth of coniferous forests in the Pacific Northwest (PNW) region of North America. The seasonal effects of temperature, precipitation,...

  1. [Climate-growth relationships of Picea koraiensis and causes of its recent decline in Xiaoxing' an Mountains, China].

    Science.gov (United States)

    Yao, Qi-chao; Wang, Xiao-chun; Xiao, Xing-wei

    2015-07-01

    Two tree-ring width chronologies of Picea koraiensis at two altitudes in Fenglin National Nature Reserve of Xiaoxing'an Mountains, China were developed by using dendrochronological methods. To identify main limiting factors of P. koraiensis radial growth at the two altitudes, the relationships between the chronologies and local temperature, precipitation, Palmer drought severity index (PDSI), and large-scale climatic factors were investigated. Meanwhile, the reasons of P. koraiensis growth decline in recent years were also explored. Results showed that radial growth of P. koraiensis in Xiaoxing'an Mountains was mainly limited by temperatures, especially by the minimum temperature in growing season, while the limiting effect of precipitation was relatively weak. Climate responses of P. koraiensis growth at the different altitudes showed significant differences. Radial growths of P. koraiensis at the low altitude were positively correlated with precipitation in the current growth season (June-September) and whole year, and negatively correlated with soil temperatures at different depths, especially at 80 cm depth in growing season. Meanwhile, it was signi-ficantly positively correlated with PDSI in growing season. However, the relationships between radial growth of P. koraiensis at the high altitude and precipitation, air and soil temperatures, and PDSI were not significant as that at the low altitude. Growth decline of P. koraiensis in Xiaoxing'an Mountains could be related to the phase changes in Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) and the significant global warming since 1980. The coupling effects of the above changes might result in increased soil evaporation and exacerbated warming and drying phenomena, consequently causing the growth decline of P. koraiensis at the low altitude.

  2. Implications of climatic change for tourism and recreation in Ontario

    International Nuclear Information System (INIS)

    Wall, G.; Harrison, R.; Kinnaird, V.; McBoyle, G.; Quinland, C.

    1988-01-01

    Scenarios for climatic change associated with a doubling of atmospheric carbon dioxide were employed in an assessment of the impacts of climate change on tourism and recreation in Ontario. A warmer climate resulting from such change may mean declining lake levels with associated changes in the ecological interest and recreational potential of wetlands, as shown by case studies on two parks near Great Lakes shorelines. In the skiing industry, the length of ski seasons will be reduced in the northern part of the province, but the key holiday periods (when a large portion of total business is conducted) should still fall within the reliable ski season. Further south, the ski season in the South Georgian Bay region could be eliminated. Summer recreational activities are likely to have extended seasons, and the viability of summer recreational enterprises may increase, with associated positive benefits to neighboring communities. 2 refs., 6 figs., 3 tabs

  3. Association of Climatic Variability, Vector Population and Malarial Disease in District of Visakhapatnam, India: A Modeling and Prediction Analysis.

    Science.gov (United States)

    Srimath-Tirumula-Peddinti, Ravi Chandra Pavan Kumar; Neelapu, Nageswara Rao Reddy; Sidagam, Naresh

    2015-01-01

    Malarial incidence, severity, dynamics and distribution of malaria are strongly determined by climatic factors, i.e., temperature, precipitation, and relative humidity. The objectives of the current study were to analyse and model the relationships among climate, vector and malaria disease in district of Visakhapatnam, India to understand malaria transmission mechanism (MTM). Epidemiological, vector and climate data were analysed for the years 2005 to 2011 in Visakhapatnam to understand the magnitude, trends and seasonal patterns of the malarial disease. Statistical software MINITAB ver. 14 was used for performing correlation, linear and multiple regression analysis. Perennial malaria disease incidence and mosquito population was observed in the district of Visakhapatnam with peaks in seasons. All the climatic variables have a significant influence on disease incidence as well as on mosquito populations. Correlation coefficient analysis, seasonal index and seasonal analysis demonstrated significant relationships among climatic factors, mosquito population and malaria disease incidence in the district of Visakhapatnam, India. Multiple regression and ARIMA (I) models are best suited models for modeling and prediction of disease incidences and mosquito population. Predicted values of average temperature, mosquito population and malarial cases increased along with the year. Developed MTM algorithm observed a major MTM cycle following the June to August rains and occurring between June to September and minor MTM cycles following March to April rains and occurring between March to April in the district of Visakhapatnam. Fluctuations in climatic factors favored an increase in mosquito populations and thereby increasing the number of malarial cases. Rainfall, temperatures (20°C to 33°C) and humidity (66% to 81%) maintained a warmer, wetter climate for mosquito growth, parasite development and malaria transmission. Changes in climatic factors influence malaria directly by

  4. Hydrological risks of a 2.0 oC warmer world: Assessing infrastructure exposure to the Paris Agreement.

    Science.gov (United States)

    Paltan, H.; Allen, M. R.; Haustein, K.; Dadson, S. J.

    2017-12-01

    The Conference of the Parties of the United Nations Framework Convention on Climate Change (UNFCC) in its Paris Agreement in December 2015 agreed to hold the increase in the global average temperature to well below 2.0 °C above pre- industrial levels. Nonetheless it is not yet clear how hydrological risks would change when this threshold is reached. In consequence, this may have important repercussions to existent or planned infrastructure as their functioning and the service they provide may be undermined if they do not adapt to shifts in water variability and, thus compromising global water security. In this study, we estimate the way in which hydrological risks will differ in a world 2 °C warmer. We used multi-ensembles outputs from 4 general circulation models (AOGCMs) participating in the HAPPI experimental protocol to generate global future river flows. From here we calculate extreme value probabilistics to calculate the increase in the frequency of the 100-year return period flow. Globally, we find that areas such as China and South Asia will be severly affecteed. Additional important changes are detected in Eastern Europe and in the area sorrounding the Gulf of California. Lastly, as a case study we show the implications of this climate target in the hydropower and transport infrastructure of Myanmar. We find that about 40% of mapped hydropower sites are in areas where the historical 100-year return period flow will significantly increase their frequency. We also find that about 30% of the roads and about 35% of the rail network of Myanmar are importantly exposed to such increases. We expect that this study is an initial step to analyse the propagation of hydrological risk associated with the Paris outcome; and thus, offer a tool to detect vulnerable population groups and economic sectors.

  5. Extreme Temperatures over India in the 1.5°C and 2°C warmer worlds

    Science.gov (United States)

    Thanigachalam, A.; Achutarao, K. M.

    2017-12-01

    n the summer of 2015 a heat wave claimed more than 2500 lives of southeastern India. Wehner et al., (2016) showed that the risk of this heat wave has increased due to anthropogenic forcings. Under the RCP 8.5 scenario, surface temperature over India shows a rate of increase of about 0.2°C/decade during the 21st Century (Basha et al., 2017). The extreme temperatures that have occurred in the recent past and further increases projected for the future have implications for human health and productivity. In light of the Paris accords, future stabilization of global mean temperature at the 1.5°C above pre-industrial aspirational target and the "not to be exceeded" 2°C target (still higher than current temperatures), the possibility of increases in extreme temperatures under these scenarios is very real. In this study we seek to understand the nature of extreme temperatures over India in the 1.5°C and 2°C worlds in comparison to the current climate. We make use of model output contributed under the Half a degree Additional warming, Prognosis and Projected Impacts project (HAPPI; Mitchell et al., 2017). The HAPPI database contains output from many atmospheric GCMs with multiple simulations ( 100 each) of historical (2005-2015), 1.5°C warmer decade, and 2°C warmer decade. The large number of ensembles provides an opportunity to study the extremes in temperature that occur over India and how they may change. In order to provide insights into the future comparable against current operational practices, we make use of definitions of "hot days", "heat waves", and "severe heat waves" used by the India Meteorological Department (IMD). We compare modelled data (and bias corrected model output where available) against observed daily temperatures from the IMD gridded (1°x1°) dataset available for 1951-2015 as also circulation features that lead to such events by comparing against reanalysis products. We also investigate the timing of such events in the future scenarios

  6. Harvesting Atlantic Cod under Climate Variability

    Science.gov (United States)

    Oremus, K. L.

    2016-12-01

    Previous literature links the growth of a fishery to climate variability. This study uses an age-structured bioeconomic model to compare optimal harvest in the Gulf of Maine Atlantic cod fishery under a variable climate versus a static climate. The optimal harvest path depends on the relationship between fishery growth and the interest rate, with higher interest rates dictating greater harvests now at the cost of long-term stock sustainability. Given the time horizon of a single generation of fishermen under assumptions of a static climate, the model finds that the economically optimal management strategy is to harvest the entire stock in the short term and allow the fishery to collapse. However, if the biological growth of the fishery is assumed to vary with climate conditions, such as the North Atlantic Oscillation, there will always be pulses of high growth in the stock. During some of these high-growth years, the growth of the stock and its economic yield can exceed the growth rate of the economy even under high interest rates. This implies that it is not economically optimal to exhaust the New England cod fishery if NAO is included in the biological growth function. This finding may have theoretical implications for the management of other renewable yet exhaustible resources whose growth rates are subject to climate variability.

  7. Data from: Testing models of speciation from genome sequences: divergence and asymmetric admixture in Island Southeast Asian Sus species during the Plio-Pleistocene climatic fluctuations

    NARCIS (Netherlands)

    Frantz, L.A.F.; Madsen, O.; Megens, H.J.W.C.; Groenen, M.; Lohse, H.

    2014-01-01

    In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here,

  8. Characterizing the growth responses of three co-occurring northern conifer tree species to climate variation across a range of conditions

    Energy Technology Data Exchange (ETDEWEB)

    Green, S.; Miyamoto, Y. [Northern British Columbia Univ., Prince George, BC (Canada). Ecosystem Science and Management Program

    2006-07-01

    Climate is the key factor affecting tree growth. Trees regularly adapt to changing environmental conditions. Adjusting forest policies and practices under changing environments necessitates an understanding of species-specific tree responses to climate change. This paper discussed a study that examined the responses of 3 northern conifer tree species, notably the lodgepole pine, subalpine fir, and interior spruce. The purpose of the study was to characterize the climate sensitivities of each species growing under various environmental conditions, represented by mean annual temperatures and mean annual precipitations. The paper provided background information on climate change and tree species and discussed the objectives and implications of the study. Study methods were presented in detail and a geographical map showing the eight sampling sites located in central British Columbia and Yukon was also provided. Last, the paper provided the preliminary results and conclusions. It was found that the impacts of changing seasonal climates on tree growth will be species and site-specific. However, the magnitude of these differences were not completely analysed so that the impacts may be similar or significantly different among species or sites. 15 refs., 4 figs.

  9. Rainbow trout adaptation to a warmer Patagonia and its potential to increase temperature tolerance in cultured stocks

    Directory of Open Access Journals (Sweden)

    Sonia Alejandra Crichigno

    2018-02-01

    Full Text Available The viability of rainbow trout Oncorhynchus mykiss (Walbaum, 1792 culture is being challenged progressively by global warming. Previous trials with Australian and Japanese rainbow trout lines suggested that improvements in thermal performance may be possible. Here, we hypothesized that strain-related differences in physiological response to temperature exist between a north Patagonian hatchery stock (CENSALBA, a Neotropical one (Criadero Boca de Río, and a thermal stream (Valcheta population of wild introduced rainbow trout. This was tested by comparing, at 20 °C, the thermal preference, specific metabolic rate, thermal tolerance, growth, and condition on juveniles of the three strains, and on a Valcheta stream male x CENSALBA female F1 cross. Preferred temperature (PT and loss of equilibrium temperature (LET, a measure of thermal tolerance of Valcheta stream and F1 were significantly higher than those of CENSALBA, and the average PTs of Valcheta stream and F1 were higher than the 95% confidence interval of available reference data for rainbow trout. These results suggest that the F1, reared under standard hatchery conditions and selected by growth and thermal preference, presents higher thermal preference and higher thermal tolerance than the current CENSALBA hatchery stock. Introduction of this naturally adapted strain to hatchery stocks would likely result in the improvement of their temperature resistance to warmer waters. Current studies on adults of this F1 generation are underway.

  10. Changes in continental Europe water cycle in a changing climate

    Science.gov (United States)

    Rouholahnejad, Elham; Schirmer, Mario; Abbaspour, Karim

    2015-04-01

    Changes in atmospheric water vapor content provide strong evidence that the water cycle is already responding to a warming climate. According to IPCC's last report on Climate Change (AR5), the water cycle is expected to intensify in a warmer climate as the atmosphere can hold more water vapor. This changes the frequency of precipitation extremes, increases evaporation and dry periods, and effects the water redistribution in land. This process is represented by most global climate models (GCMs) by increased summer dryness and winter wetness over large areas of continental mid to high latitudes in the Northern Hemisphere, associated with a reduction in water availability at continental scale. Observing changes in precipitation and evaporation directly and at continental scale is difficult, because most of the exchange of fresh water between the atmosphere and the surface happens the oceans. Long term precipitation records are available only from over the land and there are no measurement of evaporation or redistribution of precipitation over the land area. On the other hand, understanding the extent of climate change effects on various components of the water cycle is of strategic importance for public, private sectors, and policy makers when it comes to fresh water management. In order to better understand the extent of climate change impacts on water resources of continental Europe, we developed a distributed hydrological model of Europe at high spatial and temporal resolution using the Soil and Water Assessment Tool (SWAT). The hydrological model was calibrated for 1970 to 2006 using daily observation of streamflow and nitrate loads from 360 gauging stations across Europe. A vegetation growth routine was added to the model to better simulate evapotranspiration. The model results were calibrated with available agricultural crop yield data from other sources. As of future climate scenarios, we used the ISI-MIP project results which provides bias-corrected climate

  11. Impact of wind-driven rain on historic brick wall buildings in a moderately cold and humid climate: Numerical analyses of mould growth risk, indoor climate and energy consumption

    DEFF Research Database (Denmark)

    Masaru, Abuku; Janssen, Hans; Roels, Staf

    2009-01-01

    This paper gives an onset to whole building hygrothermal modelling in which the interaction between interior and exterior climates via building enclosures is simulated under a moderately cold and humid climate. The focus is particularly on the impact of wind-driven rain (WDR) oil the hygrothermal...... response, mould growth at interior wall surfaces, indoor climate and energy consumption. First the WDR load oil the facades of a 4 m x 4 m x 10 m tower is determined. Then the hygrothermal behaviour of the brick walls is analysed oil a horizontal slice through the tower. The simulations demonstrate...

  12. 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.

  13. Sugar beet growth in a changing climate: past, present and future trends in southwest Germany

    Science.gov (United States)

    Kremer, Pascal; Fuchs, Hans-Joachim; Lang, Christian

    2017-04-01

    In the study, single factors and their impact on sugar beet cultivation against the background of past and projected climate change are being analyzed. The database consists of climate data by the German Weather Service and 1x1 km interpolated INTERMET raster data. Impact models were run to assess possible future trends using climate projection data of the REgional MOdel (REMO), emission scenario A1B, Run 1, data stream 2 for Germany, daily resolution, without bias correction, 10x10 km raster (n=150) (MPI on behalf of UBA 2006). Compared periods were: B:1971 2000; K:2021-2050; L:2071-2100. Agronomic data were collected from the field books of regional trials from 1974 2014 (n=448). Moreover, a business survey of regional farmers was carried out and evaluated. Impact models to predict timing for sowing, the date of field emergence and row closure, were derived from these data. The ontogenesis was simulated using a linear, temperature-based leaf-growth model. Sowing shifted forward by 7,3 days in regional field trials from 1974 2014. Progress-oriented, risk-tolerant farmers start sowing 10-14 days earlier compared to 1980. Recently, sowing is being conducted on average on 21 March in southwest Germany. For period K, 17 March, and for period L, 2 March is being projected as the average future sowing date while the same late frost risk applies compared to present climatic conditions. Shifting forward the sowing date with spring warming and, thus, exploiting the associated yield potential is the most promising agronomic adaptation strategy to the projected climate change on the farm level. In connection to earlier sowing, the field emergence tendentially shifted forward by 14 days in the field trials. Assuming sowing on 15 March, projection results show an advance of field emergence form 7 April in period B to 3 April in period L. Row closure in field trials in average shifted forward by 19,6 days. For period L, 29 May and thus, an earlier row closure of 9 days compared

  14. Future climate effects on suitability for growth of oil palms in Malaysia and Indonesia.

    Science.gov (United States)

    Paterson, R Russell M; Kumar, Lalit; Taylor, Subhashni; Lima, Nelson

    2015-09-24

    The production of palm oil (PO) is highly profitable. The economies of the principal producers, Malaysia and Indonesia, and others, benefit considerably. Climate change (CC) will most likely have an impact on the distribution of oil palms (OP) (Elaeis guineensis). Here we present modelled CC projections with respect to the suitability of growing OP, in Malaysia and Indonesia. A process-oriented niche model of OP was developed using CLIMEX to estimate its potential distribution under current and future climate scenarios. Two Global Climate Models (GCMs), CSIRO-Mk3.0 and MIROC-H, were used to explore the impacts of CC under the A1B and A2 scenarios for 2030, 2070 and 2100. Decreases in climatic suitability for OP in the region were gradual by 2030 but became more pronounced by 2100. These projections imply that OP growth will be affected severely by CC, with obvious implications to the economies of (a) Indonesia and Malaysia and (b) the PO industry, but with potential benefits towards reducing CC. A possible remedial action is to concentrate research on development of new varieties of OP that are less vulnerable to CC.

  15. Climate Sensitivity, Sea Level, and Atmospheric Carbon Dioxide

    Science.gov (United States)

    Hansen, James; Sato, Makiko; Russell, Gary; Kharecha, Pushker

    2013-01-01

    Cenozoic temperature, sea level and CO2 covariations provide insights into climate sensitivity to external forcings and sea-level sensitivity to climate change. Climate sensitivity depends on the initial climate state, but potentially can be accurately inferred from precise palaeoclimate data. Pleistocene climate oscillations yield a fast-feedback climate sensitivity of 3+/-1deg C for a 4 W/sq m CO2 forcing if Holocene warming relative to the Last Glacial Maximum (LGM) is used as calibration, but the error (uncertainty) is substantial and partly subjective because of poorly defined LGM global temperature and possible human influences in the Holocene. Glacial-to-interglacial climate change leading to the prior (Eemian) interglacial is less ambiguous and implies a sensitivity in the upper part of the above range, i.e. 3-4deg C for a 4 W/sq m CO2 forcing. Slow feedbacks, especially change of ice sheet size and atmospheric CO2, amplify the total Earth system sensitivity by an amount that depends on the time scale considered. Ice sheet response time is poorly defined, but we show that the slow response and hysteresis in prevailing ice sheet models are exaggerated. We use a global model, simplified to essential processes, to investigate state dependence of climate sensitivity, finding an increased sensitivity towards warmer climates, as low cloud cover is diminished and increased water vapour elevates the tropopause. Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change.

  16. Single rice growth period was prolonged by cultivars shifts, but yield was damaged by climate change during 1981-2009 in China, and late rice was just opposite.

    Science.gov (United States)

    Tao, Fulu; Zhang, Zhao; Shi, Wenjiao; Liu, Yujie; Xiao, Dengpan; Zhang, Shuai; Zhu, Zhu; Wang, Meng; Liu, Fengshan

    2013-10-01

    Based on the crop trial data during 1981-2009 at 57 agricultural experimental stations across the North Eastern China Plain (NECP) and the middle and lower reaches of Yangtze River (MLRYR), we investigated how major climate variables had changed and how the climate change had affected crop growth and yield in a setting in which agronomic management practices were taken based on actual weather. We found a significant warming trend during rice growing season, and a general decreasing trend in solar radiation (SRD) in the MLRYR during 1981-2009. Rice transplanting, heading, and maturity dates were generally advanced, but the heading and maturity dates of single rice in the MLRYR (YZ_SR) and NECP (NE_SR) were delayed. Climate warming had a negative impact on growth period lengths at about 80% of the investigated stations. Nevertheless, the actual growth period lengths of YZ_SR and NE_SR, as well as the actual length of reproductive growth period (RGP) of early rice in the MLRYR (YZ_ER), were generally prolonged due to adoption of cultivars with longer growth period to obtain higher yield. In contrast, the actual growth period length of late rice in the MLRYR (YZ_LR) was shortened by both climate warming and adoption of early mature cultivars to prevent cold damage and obtain higher yield. During 1981-2009, climate warming and decrease in SRD changed the yield of YZ_ER by -0.59 to 2.4%; climate warming during RGP increased the yield of YZ_LR by 8.38-9.56%; climate warming and decrease in SRD jointly reduced yield of YZ_SR by 7.14-9.68%; climate warming and increase in SRD jointly increased the yield of NE_SR by 1.01-3.29%. Our study suggests that rice production in China has been affected by climate change, yet at the same time changes in varieties continue to be the major factor driving yield and growing period trends. © 2013 John Wiley & Sons Ltd.

  17. Climate effects on cork growth in Cork oak plantations in Sicily (Italy

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available Cork oak (Quercus suber L. is usually dominant in silvopastoral systems in many areas of Sicily, where the trees are debarked periodically for cork production. In spite of the importance of cork and cork oak stands in Sicilian forests and the potential economic scenarios, few research works have been carried out on these systems. Given the importance of cork thickness in cork quality evaluation, the main objective of this work is to study cork growth in cork oak productive stands spread on the north (Nebrodi Mountains and south-east (Iblei Mountains of Sicily. Image analysis techniques were used on cork surfaces of transverse sections of planks to measure cork rings. Dendrochronological analysis was applied to study annual fluctuation on rings growth in relation to various climate parameters in a cork cycle production. Results showed that rainfall, summer drought and temperature are determining factors in controlling cork growth. In siliceous areas of Nebrodi Mountains correlation between cork growth index and rainfall indicates that the rain period from May to September strongly influences phellogen activity. Temperature and water stress indices, on the other hand, show a negative correlation with cork growth. In clay and evolved soils of volcanic plateau of Iblei Mountains January precipitation shows a positive correlation with cork growth index. Also absolute minimum temperature in June and absolute maximum temperature in September show a positive correlation when temperature possibly has influence on phellogen activity during growing season.

  18. Adapting crop rotations to climate change in regional impact modelling assessments.

    Science.gov (United States)

    Teixeira, Edmar I; de Ruiter, John; Ausseil, Anne-Gaelle; Daigneault, Adam; Johnstone, Paul; Holmes, Allister; Tait, Andrew; Ewert, Frank

    2018-03-01

    The environmental and economic sustainability of future cropping systems depends on adaptation to climate change. Adaptation studies commonly rely on agricultural systems models to integrate multiple components of production systems such as crops, weather, soil and farmers' management decisions. Previous adaptation studies have mostly focused on isolated monocultures. However, in many agricultural regions worldwide, multi-crop rotations better represent local production systems. It is unclear how adaptation interventions influence crops grown in sequences. We develop a catchment-scale assessment to investigate the effects of tactical adaptations (choice of genotype and sowing date) on yield and underlying crop-soil factors of rotations. Based on locally surveyed data, a silage-maize followed by catch-crop-wheat rotation was simulated with the APSIM model for the RCP 8.5 emission scenario, two time periods (1985-2004 and 2080-2100) and six climate models across the Kaituna catchment in New Zealand. Results showed that direction and magnitude of climate change impacts, and the response to adaptation, varied spatially and were affected by rotation carryover effects due to agronomical (e.g. timing of sowing and harvesting) and soil (e.g. residual nitrogen, N) aspects. For example, by adapting maize to early-sowing dates under a warmer climate, there was an advance in catch crop establishment which enhanced residual soil N uptake. This dynamics, however, differed with local environment and choice of short- or long-cycle maize genotypes. Adaptation was insufficient to neutralize rotation yield losses in lowlands but consistently enhanced yield gains in highlands, where other constraints limited arable cropping. The positive responses to adaptation were mainly due to increases in solar radiation interception across the entire growth season. These results provide deeper insights on the dynamics of climate change impacts for crop rotation systems. Such knowledge can be used

  19. [Responses of Picea likiangensis radial growth to climate change in the Small Zhongdian area of Yunnan Province, Southwest China].

    Science.gov (United States)

    Zhao, Zhi-Jiang; Tan, Liu-Yi; Kang, Dong-Wei; Liu, Qi-Jing; Li, Jun-Qing

    2012-03-01

    Picea likiangensis (Franch. ) Pritz. primary forest is one of the dominant forest types in the Small Zhongdian area in Shangri-La County of Yunnan Province. In this paper, the responses of P. likiangensis tree-ring width to climate change were analyzed by dendrochronological methods, and the dendrochronology was built by using relatively conservative detrending negative exponential curves or linear regression. Correlation analysis and response function analysis were applied to explore the relationships between the residual chronology series (RES) and climatic factors at different time scales, and pointer year analysis was used to explain the reasons of producing narrow and wide rings. In the study area, the radial growth of P. likiangensis and the increasing air temperature from 1990 to 2008 had definite 'abruption'. The temperature and precipitation in previous year growth season were the main factors limiting the present year radial growth, and especially, the temperature in previous July played a negative feedback role in the radial growth, while the sufficient precipitation in previous July promoted the radial growth. The differences in the temperature variation and precipitation variation in previous year were the main reasons for the formation of narrow and wide rings. P. likiangensis radial growth was not sensitive to the variation of PDSI.

  20. To support growth, to limit emissions: is China a model in terms of climate policy?

    International Nuclear Information System (INIS)

    Voita, Thibault

    2012-05-01

    The objective of this paper is to discuss how China has been able to adapt its economic policy to the challenges of climate change without forgetting its final objective of economic growth for the country. The author first describes some characteristics of the Chinese decision political system in the field of industrial and energy policy towards a low carbon economy: articulation between central power and local authorities, and complexity of decision processes at the central level. The author then shows how this system has changed to integrate policies of struggle against climate change, used them as an opportunity towards a low carbon economy, and put them at the service of the national industrial policy. Then, based on several case studies of actual projects (electric vehicles, gas liquefaction, local energy policies), the author proposes an assessment of the system efficiency, and tries to see whether one can talk of a Chinese political model regarding the policy of struggle against climate change. He notably discusses the efficiency of these policies in terms of relationship between industrial independence and climate policy

  1. Interactions of Vegetation and Climate: Remote Observations, Earth System Models, and the Amazon Forest

    Science.gov (United States)

    Quetin, Gregory R.

    The natural composition of terrestrial ecosystems can be shaped by climate to take advantage of local environmental conditions. Ecosystem functioning, e.g. interaction between photosynthesis and temperature, can also acclimate to different climatological states. The combination of these two factors thus determines ecological-climate interactions. The ecosystem functioning also plays a key role in predicting the carbon cycle, hydrological cycle, terrestrial surface energy balance, and the feedbacks in the climate system. Predicting the response of the Earth's biosphere to global warming requires the ability to mechanistically represent the processes controlling ecosystem functioning through photosynthesis, respiration, and water use. The physical environment in a place shapes the vegetation there, but vegetation also has the potential to shape the environment, e.g. increased photosynthesis and transpiration moisten the atmosphere. These two-way ecoclimate interactions create the potential for feedbacks between vegetation at the physical environment that depend on the vegetation and the climate of a place, and can change throughout the year. In Chapter 1, we derive a global empirical map of the sensitivity of vegetation to climate using the response of satellite-observed greenness to interannual variations in temperature and precipitation. We infer mechanisms constraining ecosystem functioning by analyzing how the sensitivity of vegetation to climate varies across climate space. Our analysis yields empirical evidence for multiple physical and biological mediators of the sensitivity of vegetation to climate at large spatial scales. In hot and wet locations, vegetation is greener in warmer years despite temperatures likely exceeding thermally optimum conditions. However, sunlight generally increases during warmer years, suggesting that the increased stress from higher atmospheric water demand is offset by higher rates of photosynthesis. The sensitivity of vegetation

  2. Climate change and early human land-use in a biodiversity hotspot, the Afromontane region

    Science.gov (United States)

    Ivory, S.; Russell, J. M.; Sax, D. F.; Early, R.

    2015-12-01

    African ecosystems are at great risk due to climate and land-use change. Paleo-records illustrate that changes in precipitation and temperature have led to dramatic alterations of African vegetation distribution over the Quaternary; however, despite the fact that the link between mankind and the environment has a longer history in the African tropics than anywhere else on earth, very little is known about pre-colonial land-use. Disentangling the influence of each is particularly critical in areas of exceptional biodiversity and endemism, such as the Afromontane forest region. This region is generally considered to be highly sensitive to temperature and thus at risk to future climate change. However, new evidence suggests that some high elevation species may have occupied warmer areas in the past and thus are not strongly limited by temperature and may be at greater risk from intensifying land-use. First, we use species distribution models constructed from modern and paleo-distributions of high elevation forests in order to evaluate differences in the climatic space occupied today compared to the past. We find that although modern Afromontane species ranges occupy very narrow climate conditions, and in particular that most species occur only in cold areas, in the past most species have tolerated warmer conditions. This suggests that many montane tree species are not currently limited by warm temperatures, and that the region has already seen significant reduction in the climate space occupied, possibly from Holocene land-use. Second, to evaluate human impacts on montane populations, we examine paleoecological records from lakes throughout sub-Saharan Africa that capture ecological processes at difference time scales to reconstruct Afromontane forest range changes. Over long time scales, we observe phases of forest expansion in the lowlands associated with climate variability alone where composition varies little from phase to phase but include both modern low and

  3. Climate mediates the effects of disturbance on ant assemblage structure

    Science.gov (United States)

    Gibb, Heloise; Sanders, Nathan J.; Dunn, Robert R.; Watson, Simon; Photakis, Manoli; Abril, Silvia; Andersen, Alan N.; Angulo, Elena; Armbrecht, Inge; Arnan, Xavier; Baccaro, Fabricio B.; Bishop, Tom R.; Boulay, Raphael; Castracani, Cristina; Del Toro, Israel; Delsinne, Thibaut; Diaz, Mireia; Donoso, David A.; Enríquez, Martha L.; Fayle, Tom M.; Feener, Donald H.; Fitzpatrick, Matthew C.; Gómez, Crisanto; Grasso, Donato A.; Groc, Sarah; Heterick, Brian; Hoffmann, Benjamin D.; Lach, Lori; Lattke, John; Leponce, Maurice; Lessard, Jean-Philippe; Longino, John; Lucky, Andrea; Majer, Jonathan; Menke, Sean B.; Mezger, Dirk; Mori, Alessandra; Munyai, Thinandavha C.; Paknia, Omid; Pearce-Duvet, Jessica; Pfeiffer, Martin; Philpott, Stacy M.; de Souza, Jorge L. P.; Tista, Melanie; Vasconcelos, Heraldo L.; Vonshak, Merav; Parr, Catherine L.

    2015-01-01

    Many studies have focused on the impacts of climate change on biological assemblages, yet little is known about how climate interacts with other major anthropogenic influences on biodiversity, such as habitat disturbance. Using a unique global database of 1128 local ant assemblages, we examined whether climate mediates the effects of habitat disturbance on assemblage structure at a global scale. Species richness and evenness were associated positively with temperature, and negatively with disturbance. However, the interaction among temperature, precipitation and disturbance shaped species richness and evenness. The effect was manifested through a failure of species richness to increase substantially with temperature in transformed habitats at low precipitation. At low precipitation levels, evenness increased with temperature in undisturbed sites, peaked at medium temperatures in disturbed sites and remained low in transformed sites. In warmer climates with lower rainfall, the effects of increasing disturbance on species richness and evenness were akin to decreases in temperature of up to 9°C. Anthropogenic disturbance and ongoing climate change may interact in complicated ways to shape the structure of assemblages, with hot, arid environments likely to be at greatest risk. PMID:25994675

  4. Enhanced poleward propagation of storms under climate change

    Science.gov (United States)

    Tamarin-Brodsky, Talia; Kaspi, Yohai

    2017-12-01

    Earth's midlatitudes are dominated by regions of large atmospheric weather variability—often referred to as storm tracks— which influence the distribution of temperature, precipitation and wind in the extratropics. Comprehensive climate models forced by increased greenhouse gas emissions suggest that under global warming the storm tracks shift poleward. While the poleward shift is a robust response across most models, there is currently no consensus on what the underlying dynamical mechanism is. Here we present a new perspective on the poleward shift, which is based on a Lagrangian view of the storm tracks. We show that in addition to a poleward shift in the genesis latitude of the storms, associated with the shift in baroclinicity, the latitudinal displacement of cyclonic storms increases under global warming. This is achieved by applying a storm-tracking algorithm to an ensemble of CMIP5 models. The increased latitudinal propagation in a warmer climate is shown to be a result of stronger upper-level winds and increased atmospheric water vapour. These changes in the propagation characteristics of the storms can have a significant impact on midlatitude climate.

  5. Life on a warmer earth

    Energy Technology Data Exchange (ETDEWEB)

    Flohn, H

    1981-01-01

    This nontechnical report explores the interaction between energy and climate, particularly the impacts of fossil fuel use. Nuclear energy and solar energy are also discussed, and the expected global warming effects caused by CO/sub 2/ released by burning fossil fuels and other trace gases are described. (JMT)

  6. Impacts of climate warming on industrial management of nuclear power

    International Nuclear Information System (INIS)

    Dueymes, E.; Guidez, J.

    2008-01-01

    Climatic change is an undeniable fact and it will imply 3 consequences. First, the climate will be warmer on average and particularly in summer. Secondly, there will be less snow, a retreat of glaciers, and less contribution through melting to river flow. Thirdly, there will be a lower rate of flow for rivers with an increase of their temperature. As for storms, no increase of events or intensity can be infer from statistical data. The first impact will be on the cooling capacity of power plants settled on river banks. Another impact will be the construction of adequate embankments for seaside plants to counter the continuous rise of the sea level. The future generation of plants will be set either on seaside sites either with cooling towers. The climate situation extrapolated to 2100 has been taking into account for the design and construction of the EPR on the Flamanville site. (A.C.)

  7. Changes of benthic fauna in the Kattegat - An indication of climate change at mid-latitudes?

    Science.gov (United States)

    Göransson, Peter

    2017-07-01

    Several predictions point to changes in the marine benthic macrofauna associated with climate change, but so far only a few and minor changes have been reported. This study relates observed changes in the species composition to climate change by looking on the past decades in the Kattegat between Denmark and Sweden. A reduction of the total number species and a reduction of species with a northern range parallel to an increase of species with a southern range have been observed. The most likely explanation of the changes is the increase in temperature of the bottom water. Increased temperature could change the species distributions but also decrease primary production which impacts recruitment and growth. Hypoxia and bottom trawling could also act synergistic in this process. A sparse occurrence of previously encountered Arctic-Boreal species and critical foundation species, which gives the area its special character, suggests a change in biodiversity and might therefore be designated as early warning signals of a warmer climate. The northern fauna below the halocline with limited capacity of dispersal and low reproduction potential, can be considered as sensitive with low adaptive capacity to climate change. Therefore, not only tropical and high-latitude species, but also benthos on deep bottoms at mid-latitudes, could be vulnerable to warming. As many species live at the edge of their range in the Kattegat, and also are dependent of distant recruitment, large scale changes will probably be detected here at an early stage. It is important to protect relatively undisturbed reference areas in the Kattegat for future studies, but also for preserving a large number of ecosystem services, biotopes, habitats, and fish species.

  8. Research Advances of Impacts of Climate Changes on Crop Climatic Adaptability

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Agriculture received most direct influences from climate changes. Because of climate changes, agricultural climate resources changed and thus influenced climate adaptability of agricultural products. The growth and output of crops were finally affected. The calculation method and application of agricultural products in recent years were summarized. Several questions about the response of agricultural crops to climate elements were proposed for attention.

  9. Drought tolerance and growth in populations of a wide-ranging tree species indicate climate change risks for the boreal north.

    Science.gov (United States)

    Montwé, David; Isaac-Renton, Miriam; Hamann, Andreas; Spiecker, Heinrich

    2016-02-01

    Choosing drought-tolerant planting stock in reforestation programs may help adapt forests to climate change. To inform such reforestation strategies, we test lodgepole pine (Pinus contorta Doug. ex Loud. var latifolia Englm.) population response to drought and infer potential benefits of a northward transfer of seeds from drier, southern environments. The objective is addressed by combining dendroecological growth analysis with long-term genetic field trials. Over 500 trees originating from 23 populations across western North America were destructively sampled in three experimental sites in southern British Columbia, representing a climate warming scenario. Growth after 32 years from provenances transferred southward or northward over long distances was significantly lower than growth of local populations. All populations were affected by a severe natural drought event in 2002. The provenances from the most southern locations showed the highest drought tolerance but low productivity. Local provenances were productive and drought tolerant. Provenances from the boreal north showed lower productivity and less drought tolerance on southern test sites than all other sources, implying that maladaptation to drought may prevent boreal populations from taking full advantage of more favorable growing conditions under projected climate change. © 2015 John Wiley & Sons Ltd.

  10. How soil water storage moderates climate changes effects on transpiration, across the different climates of the Critical Zone Observatories

    Science.gov (United States)

    Heckman, C.; Tague, C.

    2017-12-01

    While the demand side of transpiration is predicted to increase under a warmer climate, actual evapotranspiration (AET) will be moderated by the supply of water available to vegetation. A key question to ask is how will plant accessible water storage capacity (PAWSC) affect the partitioning of precipitation between AET and runoff. Our results indicate that whether AET increases or decreases, and how much, is significantly based upon interactions between PAWSC and characteristics of precipitation such as the amount, frequency, and skew as well the partitioning between rain and snow. In snow dominated climates, if PAWSC cannot make up for the loss of storage as snowpack then AET could decrease, and in rain dominated climates, PAWSC could significantly limit the increase in AET. These results highlight the importance of critical zone research: constraining PAWSC is critical in predicting not only the magnitude but also the direction of the change in AET with climate warming. Due to the highly heterogeneous nature of PAWSC and the difficulty of measuring it across large scales, we use a well-tested hydrologic model to estimate the impacts from a range of PAWSC on the partitioning of precipitation between runoff and AET. We completed this analysis for the range of precipitation and vegetation characteristics found across 9 of the Critical Zone Observatories.

  11. Changes in European wind energy generation potential within a 1.5 °C warmer world

    Science.gov (United States)

    Hosking, J. Scott; MacLeod, D.; Phillips, T.; Holmes, C. R.; Watson, P.; Shuckburgh, E. F.; Mitchell, D.

    2018-05-01

    Global climate model simulations from the ‘Half a degree Additional warming, Prognosis and Projected Impacts’ (HAPPI) project were used to assess how wind power generation over Europe would change in a future world where global temperatures reach 1.5 °C above pre-industrial levels. Comparing recent historical (2006–2015) and future 1.5 °C forcing experiments highlights that the climate models demonstrate a northward shift in the Atlantic jet, leading to a significant (p < 0.01) increase in surface winds over the UK and Northern Europe and a significant (p < 0.05) reduction over Southern Europe. We use a wind turbine power model to transform daily near-surface (10 m) wind speeds into daily wind power output, accounting for sub-daily variability, the height of the turbine, and power losses due to transmission and distribution of electricity. To reduce regional model biases we use bias-corrected 10 m wind speeds. We see an increase in power generation potential over much of Europe, with the greatest increase in load factor over the UK of around four percentage points. Increases in variability are seen over much of central and northern Europe with the largest seasonal change in summer. Focusing on the UK, we find that wind energy production during spring and autumn under 1.5 °C forcing would become as productive as it is currently during the peak winter season. Similarly, summer winds would increase driving up wind generation to resemble levels currently seen in spring and autumn. We conclude that the potential for wind energy in Northern Europe may be greater than has been previously assumed, with likely increases even in a 1.5 °C warmer world. While there is the potential for Southern Europe to see a reduction in their wind resource, these decreases are likely to be negligible.

  12. The uncertainty of future water supply adequacy in megacities: Effects of population growth and climate change

    Science.gov (United States)

    Alarcon, T.; Garcia, M. E.; Small, D. L.; Portney, K.; Islam, S.

    2013-12-01

    Providing water to the expanding population of megacities, which have over 10 million people, with a stressed and aging water infrastructure creates unprecedented challenges. These challenges are exacerbated by dwindling supply and competing demands, altered precipitation and runoff patterns in a changing climate, fragmented water utility business models, and changing consumer behavior. While there is an extensive literature on the effects of climate change on water resources, the uncertainty of climate change predictions continues to be high. This hinders the value of these predictions for municipal water supply planning. The ability of water utilities to meet future water needs will largely depend on their capacity to make decisions under uncertainty. Water stressors, like changes in demographics, climate, and socioeconomic patterns, have varying degrees of uncertainty. Identifying which stressors will have a greater impact on water resources, may reduce the level of future uncertainty for planning and managing water utilities. Within this context, we analyze historical and projected changes of population and climate to quantify the relative impacts of these two stressors on water resources. We focus on megacities that rely primarily on surface water resources to evaluate (a) population growth pattern from 1950-2010 and projected population for 2010-2060; (b) climate change impact on projected climate change scenarios for 2010-2060; and (c) water access for 1950-2010; projected needs for 2010-2060.

  13. Global climate change increases risk of crop yield losses and food insecurity in the tropical Andes.

    Science.gov (United States)

    Tito, Richard; Vasconcelos, Heraldo L; Feeley, Kenneth J

    2018-02-01

    One of the greatest current challenges to human society is ensuring adequate food production and security for a rapidly growing population under changing climatic conditions. Climate change, and specifically rising temperatures, will alter the suitability of areas for specific crops and cultivation systems. In order to maintain yields, farmers may be forced to change cultivation practices, the timing of cultivation, or even the type of crops grown. Alternatively, farmers can change the location where crops are cultivated (e.g., to higher elevations) to track suitable climates (in which case the plants will have to grow in different soils), as cultivated plants will otherwise have to tolerate warmer temperatures and possibly face novel enemies. We simulated these two last possible scenarios (for temperature increases of 1.3°C and 2.6°C) in the Peruvian Andes through a field experiment in which several traditionally grown varieties of potato and maize were planted at different elevations (and thus temperatures) using either the local soil or soil translocated from higher elevations. Maize production declined by 21%-29% in response to new soil conditions. The production of maize and potatoes declined by >87% when plants were grown under warmer temperatures, mainly as a result of the greater incidence of novel pests. Crop quality and value also declined under simulated migration and warming scenarios. We estimated that local farmers may experience severe economic losses of up to 2,300 US$ ha -1  yr -1 . These findings reveal that climate change is a real and imminent threat to agriculture and that there is a pressing need to develop effective management strategies to reduce yield losses and prevent food insecurity. Importantly, such strategies should take into account the influences of non-climatic and/or biotic factors (e.g., novel pests) on plant development. © 2017 John Wiley & Sons Ltd.

  14. [Growth response of Abies fargesii to climate in Shennongjia Mount of Hubei Province, Southeastern China].

    Science.gov (United States)

    Hou, Xin-yuan; Shi, Jiang-feng; Li, Ling-ling; Lu, Hua-yu

    2015-03-01

    A well-replicated Abies fargesii tree-ring width chronology in the Shennongjia Mount was developed to investigate its radial growth response to climate variables (e.g., monthly mean tempe- rature and total precipitation) and other growing season indicators (e.g., cumulative temperature, continuous days, initial and final dates). Correlation analyses showed that the tree-ring width was positively correlated to the mean temperatures of February, April and September, and negatively correlated to the total precipitation of September, prior September and prior December. The analyses between the chronology and other growing season parameters showed that tree growth responded positively to the cumulative temperature and continuous days of the growing season. The correlation was the highest when the growing season was defined as the days above the temperature threshold of 9.0 °C. Defined this way, the growing season typically started in late-May and ended in mid-September, lasting about 120 days. Correlation analyses were also conducted between the tree-ring growth and the initial and final dates of the growing season. Results showed that correlation was the highest for initial dates defined at 9.0 °C (with the coefficient of -0.25 and p-value close to 0.05), and for final dates defined at 9.3 °C (with the coefficient of 0.33 and p-value less than 0.05). All these results indicated that the sensitive temperature threshold for photosynthesis of A. fargesii was around 9.0 °C. The year 1978 marked an abrupt shift of climate in southeast China. We compared A. fargesii growth between pre-1978 and post-1978 periods. Results showed that as temperature rose, the growing season was lengthened with both earlier initial dates and later final dates. Longer growing season increased the A. fargesii growth in the Shennongjia Mount, southeastern China.

  15. Long-term effects of climate change on carbon storage and tree species composition in a dry deciduous forest.

    Science.gov (United States)

    Fekete, István; Lajtha, Kate; Kotroczó, Zsolt; Várbíró, Gábor; Varga, Csaba; Tóth, János Attila; Demeter, Ibolya; Veperdi, Gábor; Berki, Imre

    2017-08-01

    Forest vegetation and soils have been suggested as potentially important sinks for carbon (C) with appropriate management and thus are implicated as effective tools in stabilizing climate even with increasing anthropogenic release of CO 2 . Drought, however, which is often predicted to increase in models of future climate change, may limit net primary productio (NPP) of dry forest types, with unknown effects on soil C storage. We studied C dynamics of a deciduous temperate forest of Hungary that has been subject to significant decreases in precipitation and increases in temperature in recent decades. We resampled plots that were established in 1972 and repeated the full C inventory by analyzing more than 4 decades of data on the number of living trees, biomass of trees and shrubs, and soil C content. Our analyses show that the decline in number and biomass of oaks started around the end of the 1970s with a 71% reduction in the number of sessile oak stems by 2014. Projected growth in this forest, based on the yield table's data for Hungary, was 4.6 kg C/m 2 . Although new species emerged, this new growth and small increases in oak biomass resulted in only 1.9 kg C/m 2 increase over 41 years. The death of oaks increased inputs of coarse woody debris to the surface of the soil, much of which is still identifiable, and caused an increase of 15.5%, or 2.6 kg C/m 2 , in the top 1 m of soil. Stability of this fresh organic matter input to surface soil is unknown, but is likely to be low based on the results of a colocated woody litter decomposition study. The effects of a warmer and drier climate on the C balance of forests in this region will be felt for decades to come as woody litter inputs decay, and forest growth remains impeded. © 2017 John Wiley & Sons Ltd.

  16. Responses of Hail and Storm Days to Climate Change in the Tibetan Plateau

    Science.gov (United States)

    Zou, Tian; Zhang, Qinghong; Li, Wenhong; Li, Jihong

    2018-05-01

    There is increasing concern that local severe storm occurrence may be changing as a result of climate change. The Tibetan Plateau (TP), one of the world's most sensitive areas to climate change, became significantly warmer during recent decades. Since 1960 (1980), storm (hail) days have been decreasing by 6.2%/decade (18.3%/decade) in the region. However, what caused the frequency changes of storm and hail in the TP is largely unknown. Based on 53-year continuous weather records at 48 TP stations and reanalysis data, we show here for the first time that the consistent decline of storm days is strongly related to a drier midtroposphere since 1960. Further analysis demonstrated that fewer hail days are driven by an elevation of the melting level (thermodynamically) and a weaker wind shear (dynamically) in a warming climate. These results imply that less storm and hail may occur over TP when climate warms.

  17. Hydrogeologic influence on changes in snowmelt runoff with climate warming: Numerical experiments on a mid-elevation catchment in the Sierra Nevada, USA

    Science.gov (United States)

    S.M. Jepsen; T.C. Harmon; M.W. Meadows; C.T. Hunsaker

    2016-01-01

    The role of hydrogeology in mediating long-term changes in mountain streamflow, resulting from reduced snowfall in a potentially warmer climate, is currently not well understood. We explore this by simulating changes in stream discharge and evapotranspiration from a mid-elevation, 1-km2 catchment in the southern Sierra Nevada of California (USA)...

  18. A Global Perspective on Warmer Droughts as a Key Driver of Forest Disturbances and Tree Mortality (Invited)

    Science.gov (United States)

    Allen, C. D.

    2013-12-01

    Recent global warming, in concert with episodic droughts, is causing elevated levels of both chronic and acute forest water stress across large regions. Such increases in water stress affect forest dynamics in multiple ways, including by amplifying the incidence and severity of many significant forest disturbances, particularly drought-induced tree mortality, wildfire, and outbreaks of damaging insects and diseases. Emerging global-scale patterns of drought-related forest die-off are presented, including a newly updated map overview of documented drought- and heat-induced tree mortality events from around the world, demonstrating the vulnerability of all major forest types to forest drought stress, even in typically wet environments. Comparative patterns of drought stress and associated forest disturbances are reviewed for several regions (southwestern Australia, Inner Asia, western North America, Mediterranean Basin), including interactions among climate and various disturbance processes. From the Southwest USA, research is presented that derives a tree-ring-based Forest Drought Stress Index (FDSI) for the most regionally-widespread conifer species (Pinus edulis, Pinus ponderosa, and Pseudotsuga menziesii), demonstrating recent escalation of FDSI to extreme levels relative to the past 1000 years, due to both drought and especially warming. This new work further highlights strong correlations between drought stress and amplified forest disturbances (fire, bark beetle outbreaks), and projects that by CE 2050 anticipated regional warming will cause mean FDSI values to reach historically unprecedented levels that may exceed thresholds for the survival of current tree species in large portions of their current range in the Southwest. Similar patterns of recent climate-amplified forest disturbance risk are apparent from a variety of relatively dry regions across this planet, and given climate projections for substantially warmer temperatures and greater drought stress

  19. Health and vitality assessment of two common pine species in the context of climate change in southern Europe

    International Nuclear Information System (INIS)

    Sicard, Pierre; Dalstein-Richier, Laurence

    2015-01-01

    The Mediterranean Basin is expected to be more strongly affected by ongoing climate change than most other regions of the earth. The South-eastern France can be considered as case study for assessing global change impacts on forests. Based on non-parametric statistical tests, the climatic parameters (temperature, relative humidity, rainfall, global radiation) and forest-response indicators (crown defoliation, discoloration and visible foliar ozone injury) of two pine species (Pinus halepensis and Pinus cembra) were analyzed. In the last 20 years, the trend analyses reveal a clear hotter and drier climate along the coastline and slightly rainier inland. In the current climate change context, a reduction in ground-level ozone (O 3 ) was found at remote sites and the visible foliar O 3 injury decreased while deterioration of the crown conditions was observed likely due to a drier and warmer climate. Clearly, if such climatic and ecological changes are now being detected when the climate, in South-eastern France, has warmed in the last 20 years (+0.46–1.08 °C), it can be expected that many more impacts on tree species will occur in response to predicted temperature changes by 2100 (+1.95–4.59 °C). Climate change is projected to reduce the benefits of O 3 precursor emissions controls leading to a higher O 3 uptake. However, the drier and warmer climate should induce a soil drought leading to a lower O 3 uptake. These two effects, acting together in an opposite way, could mitigate the harmful impacts of O 3 on forests. The development of coordinated emission abatement strategies is useful to reduce both climate change and O 3 pollution. Climate change will create additional challenges for forest management with substantial socio-economic and biological diversity impacts. However, the development of future sustainable and adaptive forest management strategies has the potential to reduce the vulnerability of forest species to climate change. - Highlights: • We

  20. Building when the climate gets warmer; Bauen, wenn das Klima waermer wird - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, C. U. [Energieplaner, CUB Architektur Energie Umwelt, Zuerich (Switzerland); Steinemann, U. [Ingenieurbuero Urs Steinemann, Wollerau (Switzerland); Nipkow, J. [Arena, Arbeitsgemeinschaft Energie-Alternativen, Zuerich (Switzerland)

    2007-07-01

    This final report for the Swiss Federal Office of Energy (SFOE), takes a look at how the building process will have to take account of climate change with higher summer temperatures in Switzerland. The authors consider the situation as being in strong contrast to the past in Switzerland, when attention was devoted to energy demand in buildings during the winter. Today there is a new focus with the anticipation of increasingly frequent, extended hot spells in summer. The goal of this investigation is to analyse and present economic measures to assure a high level of summer comfort with a reduced demand for electricity under these changing conditions. Strategies with respect to construction, technology and operation are addressed. The current spread of technically questionable and inefficient room air conditioning units in residential and commercial buildings is considered as being strongly reminiscent of a dangerous, analogous case in the past, when small electric heaters became widespread. A largely untapped potential exists for increasing the efficiency of air conditioning and chiller technologies for both central systems and room units by the careful use of small temperature differences. Several new and unconventional solution paths are discussed, including high-efficiency room air conditioners, solar cooling equipment, balanced mechanical ventilation, phase-change materials, thermal storage, etc., all aimed at reducing electricity consumption. The expected additional electricity demand of around 1.9 TWh annually for ventilation and air conditioning is commented on.

  1. Interactive effects of ozone and climate on tree growth and water use in a southern Appalachian forest in the USA

    Science.gov (United States)

    S.B. McLaughlin; S.D. Wullschleger; G. Sun

    2007-01-01

    A lack of data on responses of mature tree growth and water use to ambient ozone (O3) concentrations has been a major limitation in efforts to understand and model responses of forests to current and future changes in climate.Here, hourly to seasonal patterns of stem growth and sap flow velocity were...

  2. Climate Warming Can Increase Soil Carbon Fluxes Without Decreasing Soil Carbon Stocks in Boreal Forests

    Science.gov (United States)

    Ziegler, S. E.; Benner, R. H.; Billings, S. A.; Edwards, K. A.; Philben, M. J.; Zhu, X.; Laganiere, J.

    2016-12-01

    Ecosystem C fluxes respond positively to climate warming, however, the net impact of changing C fluxes on soil organic carbon (SOC) stocks over decadal scales remains unclear. Manipulative studies and global-scale observations have informed much of the existing knowledge of SOC responses to climate, providing insights on relatively short (e.g. days to years) and long (centuries to millennia) time scales, respectively. Natural climate gradient studies capture integrated ecosystem responses to climate on decadal time scales. Here we report the soil C reservoirs, fluxes into and out of those reservoirs, and the chemical composition of inputs and soil organic matter pools along a mesic boreal forest climate transect. The sites studied consist of similar forest composition, successional stage, and soil moisture but differ by 5.2°C mean annual temperature. Carbon fluxes through these boreal forest soils were greatest in the lowest latitude regions and indicate that enhanced C inputs can offset soil C losses with warming in these forests. Respiration rates increased by 55% and the flux of dissolved organic carbon from the organic to mineral soil horizons tripled across this climate gradient. The 2-fold increase in litterfall inputs to these soils coincided with a significant increase in the organic horizon C stock with warming, however, no significant difference in the surface mineral soil C stocks was observed. The younger mean age of the mineral soil C ( 70 versus 330 YBP) provided further evidence for the greater turnover of SOC in the warmer climate soils. In spite of these differences in mean radiocarbon age, mineral SOC exhibited chemical characteristics of highly decomposed material across all regions. In contrast with depth trends in soil OM diagenetic indices, diagenetic shifts with latitude were limited to increases in C:N and alkyl to O-alkyl ratios in the overlying organic horizons in the warmer relative to the colder regions. These data indicate that the

  3. Know your limits? Climate extremes impact the range of Scots pine in unexpected places.

    Science.gov (United States)

    Julio Camarero, J; Gazol, Antonio; Sancho-Benages, Santiago; Sangüesa-Barreda, Gabriel

    2015-11-01

    Although extreme climatic events such as drought are known to modify forest dynamics by triggering tree dieback, the impact of extreme cold events, especially at the low-latitude margin ('rear edge') of species distributional ranges, has received little attention. The aim of this study was to examine the impact of one such extreme cold event on a population of Scots pine (Pinus sylvestris) along the species' European southern rear-edge range limit and to determine how such events can be incorporated into species distribution models (SDMs). A combination of dendrochronology and field observation was used to quantify how an extreme cold event in 2001 in eastern Spain affected growth, needle loss and mortality of Scots pine. Long-term European climatic data sets were used to contextualize the severity of the 2001 event, and an SDM for Scots pine in Europe was used to predict climatic range limits. The 2001 winter reached record minimum temperatures (equivalent to the maximum European-wide diurnal ranges) and, for trees already stressed by a preceding dry summer and autumn, this caused dieback and large-scale mortality. Needle loss and mortality were particularly evident in south-facing sites, where post-event recovery was greatly reduced. The SDM predicted European Scots pine distribution mainly on the basis of responses to maximum and minimum monthly temperatures, but in comparison with this the observed effects of the 2001 cold event at the southerly edge of the range limit were unforeseen. The results suggest that in order to better forecast how anthropogenic climate change might affect future forest distributions, distribution modelling techniques such as SDMs must incorporate climatic extremes. For Scots pine, this study shows that the effects of cold extremes should be included across the entire distribution margin, including the southern 'rear edge', in order to avoid biased predictions based solely on warmer climatic scenarios. © The Author 2015. Published by

  4. Water runoff vs modern climatic warming in mountainous cryolithic zone in North-East Russia

    Science.gov (United States)

    Glotov, V. E.; Glotova, L. P.

    2018-01-01

    The article presents the results of studying the effects of current climatic warming for both surface and subsurface water runoffs in North-East Russia, where the Main Watershed of the Earth separates it into the Arctic and Pacific continental slopes. The process of climatic warming is testified by continuous weather records during 80-100 years and longer periods. Over the Arctic slope and in the northern areas of the Pacific slope, climatic warming results in a decline in a total runoff of rivers whereas the ground-water recharge becomes greater in winter low-level conditions. In the southern Pacific slope and in the Sea of Okhotsk basin, the effect of climatic warming is an overall increase in total runoff including its subsurface constituents. We believe these peculiar characters of river runoff there to be related to the cryolithic zone environments. Over the Arctic slope and the northern Pacific slope, where cryolithic zone is continuous, the total runoff has its subsurface constituent as basically resulting from discharge of ground waters hosted in seasonally thawing rocks. Warmer climatic conditions favor growth of vegetation that needs more water for the processes of evapotranspiration and evaporation from rocky surfaces in summer seasons. In the Sea of Okhotsk basin, where the cryolithic zone is discontinuous, not only ground waters in seasonally thawing layers, but also continuous taliks and subpermafrost waters participate in processes of river recharges. As a result, a greater biological productivity of vegetation cover does not have any effect on ground-water supply and river recharge processes. If a steady climate warming is provided, a continuous cryolithic zone can presumably degrade into a discontinuous and then into an island-type permafrost layer. Under such a scenario, there will be a general increase in the total runoff and its subsurface constituent. From geoecological viewpoints, a greater runoff will have quite positive effects, whereas some

  5. Climate at the edge of human dispersal in the European Middle Pleistocene

    Science.gov (United States)

    Horne, David

    2014-05-01

    Pleistocene palaeoclimatic reconstructions based on fossils from sites containing archaeological evidence of human occupation can answer key questions about the climatic context of early human dispersal in Europe. Biological proxies including foraminifera, ostracods, diatoms, chironomid larvae, molluscs and pollen are widely used to estimate palaeoclimatic parameters, typically palaeotemperatures, using indicator species, Mutual Climatic Range (MCR), Modern Analogue Technique (MAT) and transfer function approaches. Any single proxy method will yield plausible results, but there is a need for multi-proxy testing; matching or overlapping results inspire confidence, whereas if independent proxies yield results that do not match or even overlap, one or more must be wrong. The Multi-Proxy Consensus (MPC) approach not only compares two or more proxy results in order to check for agreement, but also offers potential for more refined results to be obtained from the range of mutual agreement between two or more overlapping palaeotemperature ranges. Studies of MIS9 (late Middle Pleistocene) deposits in the Thames-Medway river system in SE England (some of which contain stone implements representing human occupation) have yielded palaeotemperature estimates based on ostracods, beetles, fish, herpetiles, pollen and plant macrofossils. The MPC approach demonstrates the consistency of the results and defines a more continental climate than today (mean July air temperatures similar or 1 degree warmer, mean January air temperatures at least 2 degrees colder). Two River Thames MIS11 sites (Ebbsfleet and Swanscombe) have yielded MPC results indicating summers up to 1.5 degrees warmer and winters at least 5 degrees colder than today. British early Middle Pleistocene sites record the earliest human presence in Europe North of the Alps. At Boxgrove (MIS13), well-known for its rich record of human activity (stone tools and butchered bones), combined ostracod and herpetile MCR results

  6. [On academic thought and clinical application of LI Yan-Fang's middle-warmer energy method].

    Science.gov (United States)

    Li, Li-Jun

    2010-10-01

    The present paper introduces LI Yan-Fang's middle-warmer energy method from acupoint selection, needling methods, treatment principle and his clinical experiences in treatment of stroke and insomnia etc. The acupuncture prescription of this method consist of Shangwan (CV 13), Zhongwan (CV 12), Jianli (CV 11), Xiawan (CV 10), Shuifen (CV 9), Huangshu (KI 16) and Qihai (CV 6) etc as the main acupoints combined with strict manipulation and depth of needling to treat clinical diseases.

  7. Extreme Weather and Climate: Workshop Report

    Science.gov (United States)

    Sobel, Adam; Camargo, Suzana; Debucquoy, Wim; Deodatis, George; Gerrard, Michael; Hall, Timothy; Hallman, Robert; Keenan, Jesse; Lall, Upmanu; Levy, Marc; hide

    2016-01-01

    Extreme events are the aspects of climate to which human society is most sensitive. Due to both their severity and their rarity, extreme events can challenge the capacity of physical, social, economic and political infrastructures, turning natural events into human disasters. Yet, because they are low frequency events, the science of extreme events is very challenging. Among the challenges is the difficulty of connecting extreme events to longer-term, large-scale variability and trends in the climate system, including anthropogenic climate change. How can we best quantify the risks posed by extreme weather events, both in the current climate and in the warmer and different climates to come? How can we better predict them? What can we do to reduce the harm done by such events? In response to these questions, the Initiative on Extreme Weather and Climate has been created at Columbia University in New York City (extreme weather.columbia.edu). This Initiative is a University-wide activity focused on understanding the risks to human life, property, infrastructure, communities, institutions, ecosystems, and landscapes from extreme weather events, both in the present and future climates, and on developing solutions to mitigate those risks. In May 2015,the Initiative held its first science workshop, entitled Extreme Weather and Climate: Hazards, Impacts, Actions. The purpose of the workshop was to define the scope of the Initiative and tremendously broad intellectual footprint of the topic indicated by the titles of the presentations (see Table 1). The intent of the workshop was to stimulate thought across disciplinary lines by juxtaposing talks whose subjects differed dramatically. Each session concluded with question and answer panel sessions. Approximately, 150 people were in attendance throughout the day. Below is a brief synopsis of each presentation. The synopses collectively reflect the variety and richness of the emerging extreme event research agenda.

  8. Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watershed using SWAT model

    Science.gov (United States)

    Lee, Sangchul; Sadeghi, Ali M.; Yeo, In-Young; McCarty, Gregory W.; Hively, W. Dean

    2017-01-01

    Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrate loads from agriculture. Accordingly, the question remains whether WCCs are sufficient to mitigate increased nutrient loads caused by FCCs. In this study, we assessed the impacts of FCCs on WCC nitrate reduction efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. Three FCC scenarios (2085 – 2098) were prepared using General Circulation Models (GCMs), considering three Intergovernmnental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) greenhouse gas emission scenarios. We also developed six representative WCC implementation scenarios based on the most commonly used planting dates and species of WCCs in this region. Simulation results showed that WCC biomass increased by ~ 58 % under FCC scenarios, due to climate conditions conducive to the WCC growth. Prior to implementing WCCs, annual nitrate loads increased by ~ 43 % under FCC scenarios compared to the baseline scenario (2001 – 2014). When WCCs were planted, annual nitrate loads were substantially reduced by ~ 48 % and WCC nitrate reduction efficiency water ~ 5 % higher under FCC scenarios relative to the baseline. The increase rate of WCC nitrate reduction efficiency varied by FCC scenarios and WCC planting methods. As CO2 concentration was higher and winters were warmer under FCC scenarios, WCCs had greater biomass and therefore showed higher nitrate reduction efficiency. In response to FCC scenarios, the performance of less effective WCC practices (e.g., barley, wheat, and late planting) under the baseline indicated ~ 14 % higher increase rate of nitrate reduction efficiency compared to ones with better effectiveness under the baseline (e

  9. Beyond Climate Scenarios: Advancing from Changes in the Mean to a Better Understanding of Physical Processes to Enhance Stakeholder Engagement

    Science.gov (United States)

    Yates, D. N.; Kaatz, L.; Ammann, C. M.

    2017-12-01

    Great strides have been made within the climate sciences community to make Global Climate Model (GCM) output and their results as meaningful as possible to the broad community of stakeholders that might benefit from this information. Regardless of these good intentions, the fact remains that most data from GCMs are viewed as being highly uncertain and thus not actionable for water resources planning. The most common use of GCM data is informing projected future climate by use of a mean change, primarily for temperature, given the generally greater confidence in this variable. In contrast, precipitation is viewed as highly uncertain, primarily because it has not validated well against observed precipitation climatologies at local and regional levels. Simple perturbations to historical mean temperature and precipitation sequences are not as complex as using direct GCM outputs and have fewer analytical requirements. Mean climate change information can still give valuable information to water managers, providing meaningful insights and sign posts into future vulnerabilities and is an approach that is arguably deemed more actionable. These temperature and precipitation sign posts can be monitored and used as indicators when certain actions become necessary and/or until there are improvements in actionable climate science information. Recent advances in regional climate modeling (RCM), particularly those run at very high resolution and are cloud resolving, show promise in advancing our understanding of the interaction among climate variables at the regional level. Thus, in addition to exploring how changes in the mean climate (e.g. 2oC warming) might impact a water system, this bottom-up approach makes use of carefully constructed regional climate experiments that are conducted, for example, under conditions of a warmer atmosphere that can hold more moisture. One can then explore what happens to, for example, rain-snow partitioning at various elevations across a snow

  10. Differential responses of production and respiration to temperature and moisture drive the carbon balance across a climatic gradient in New Mexico

    Science.gov (United States)

    Kristina J. Anderson-Teixeira; John P. Delong; Andrew M. Fox; Daniel A. Brese; Marcy E. Litvak

    2011-01-01

    Southwestern North America faces an imminent transition to a warmer, more arid climate, and it is critical to understand how these changes will affect the carbon balance of southwest ecosystems. In order to test our hypothesis that differential responses of production and respiration to temperature and moisture shape the carbon balance across a range of spatio-temporal...

  11. Climate Change Decouples Drought from Early Wine Grape Harvests in France

    Science.gov (United States)

    Cook, Benjamin I.; Wolkovich, Elizabeth M.

    2016-01-01

    Across the world, wine grape phenology has advanced in recent decades, in step with climate-change-induced trends in temperature - the main driver of fruit maturation - and drought. Fully understanding how climate change contributes to changes in harvest dates, however, requires analysing wine grape phenology and its relationship to climate over a longer-term context, including data predating anthropogenic interference in the climate system. Here, we investigate the climatic controls of wine grape harvest dates from 1600-2007 in France and Switzerland using historical harvest and climate data. Early harvests occur with warmer temperatures (minus 6 days per degree Centigrade) and are delayed by wet conditions (plus 0.07 days per millimeter; plus 1.68 days per PDSI (Palmer drought severity index)) during spring and summer. In recent decades (1981-2007), however, the relationship between harvest timing and drought has broken down. Historically, high summer temperatures in Western Europe, which would hasten fruit maturation, required drought conditions to generate extreme heat. The relationship between drought and temperature in this region, however, has weakened in recent decades and enhanced warming from anthropogenic greenhouse gases can generate the high temperatures needed for early harvests without drought. Our results suggest that climate change has fundamentally altered the climatic drivers of early wine grape harvests in France, with possible ramifications for viticulture management and wine quality.

  12. Implications of climate change on wind erosion of agricultural lands in the Columbia plateau

    Directory of Open Access Journals (Sweden)

    B.S. Sharratt

    2015-12-01

    Full Text Available Climate change may impact soil health and productivity as a result of accelerated or decelerated rates of erosion. Previous studies suggest a greater risk of wind erosion on arid and semi-arid lands due to loss of biomass under a future warmer climate. There have been no studies conducted to assess the impact of climate change on wind erosion in the Columbia Plateau of the Pacific Northwest United States where wind erosion of agricultural lands can cause exceedance of national air quality standards. The Wind Erosion Prediction System (WEPS was used to assess wind erosion and PM10 (particulate matter ≤10 µm in aerodynamic diameter emissions under a future climate projected by downscaling 18 Global Climate Models (GCM for a conservative emissions pathway. Wind erosion simulations were conducted at Lacrosse and Lind, WA and Moro, OR on a winter wheat-summer fallow (WW-SF rotation and at Lind on an additional winter wheat-camelina-summer fallow (WW-Cam-SF rotation. Each rotation was subject to conservation or conventional tillage practices for a baseline (1970–1999 and mid-21st century climate (2035–2064. A significant increase in temperature and nominal increases in precipitation were projected by an ensemble of climate models for the Columbia Plateau by the mid-21st century. Soil and PM10 losses were 25–84% lower for a mid-21st century climate, due in part to greater biomass production associated with CO2 fertilization and warmer temperatures. The reduction in soil and PM10 loss is projected to be more apparent for conservation tillage practices in the future. Soil and PM10 losses were greater from a WW-Cam-SF rotation than WW-SF rotation when conservation tillage practices were employed during the fallow phase of the rotations. Despite accounting for differences in the length of each rotation, annual soil and PM10 losses remained higher for the WW-Cam-SF rotation than the WW-SF rotation. Soil and PM10 losses were more variable across

  13. Effects of climate change on long-term population growth of pronghorn in an arid environment

    Science.gov (United States)

    Gedir, Jay V.; Cain, James W.; Harris, Grant; Turnbull, Trey T.

    2015-01-01

    Climate often drives ungulate population dynamics, and as climates change, some areas may become unsuitable for species persistence. Unraveling the relationships between climate and population dynamics, and projecting them across time, advances ecological understanding that informs and steers sustainable conservation for species. Using pronghorn (Antilocapra americana) as an ecological model, we used a Bayesian approach to analyze long-term population, precipitation, and temperature data from 18 populations in the southwestern United States. We determined which long-term (12 and 24 months) or short-term (gestation trimester and lactation period) climatic conditions best predicted annual rate of population growth (λ). We used these predictions to project population trends through 2090. Projections incorporated downscaled climatic data matched to pronghorn range for each population, given a high and a lower atmospheric CO2 concentration scenario. Since the 1990s, 15 of the pronghorn populations declined in abundance. Sixteen populations demonstrated a significant relationship between precipitation and λ, and in 13 of these, temperature was also significant. Precipitation predictors of λ were highly seasonal, with lactation being the most important period, followed by early and late gestation. The influence of temperature on λ was less seasonal than precipitation, and lacked a clear temporal pattern. The climatic projections indicated that all of these pronghorn populations would experience increased temperatures, while the direction and magnitude of precipitation had high population-specific variation. Models predicted that nine populations would be extirpated or approaching extirpation by 2090. Results were consistent across both atmospheric CO2 concentration scenarios, indicating robustness of trends irrespective of climatic severity. In the southwestern United States, the climate underpinning pronghorn populations is shifting, making conditions increasingly

  14. Climate-society feedbacks and the avoidance of dangerous climate change

    Science.gov (United States)

    Jarvis, A. J.; Leedal, D. T.; Hewitt, C. N.

    2012-09-01

    The growth in anthropogenic CO2 emissions experienced since the onset of the Industrial Revolution is the most important disturbance operating on the Earth's climate system. To avoid dangerous climate change, future greenhouse-gas emissions will have to deviate from business-as-usual trajectories. This implies that feedback links need to exist between climate change and societal actions. Here, we show that, consciously or otherwise, these feedbacks can be represented by linking global mean temperature change to the growth dynamics of CO2 emissions. We show that the global growth of new renewable sources of energy post-1990 represents a climate-society feedback of ~0.25%yr-1 per degree increase in global mean temperature. We also show that to fulfil the outcomes negotiated in Durban in 2011, society will have to become ~ 50 times more responsive to global mean temperature change than it has been since 1990. If global energy use continues to grow as it has done historically then this would result in amplification of the long-term endogenous rate of decarbonization from -0.6%yr-1 to ~-13%yr-1. It is apparent that modest levels of feedback sensitivity pay large dividends in avoiding climate change but that the marginal return on this effort diminishes rapidly as the required feedback strength increases.

  15. 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.

  16. Impact of climate change on radial growth of Siberian spruce and Scots pine in North-western Russia

    Directory of Open Access Journals (Sweden)

    Lopatin E

    2007-01-01

    Full Text Available When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

  17. Climate variability and sedimentation of a hydropower reservoir

    International Nuclear Information System (INIS)

    Riedel, M.

    2008-01-01

    As part of the relicensing of a large Hydroelectric Project in the central Appalachians, large scale watershed and reservoir sedimentation models were developed to forecast potential sedimentation scenarios. The GIS based watershed model was spatially explicit and calibrated to long term observed data. Potential socio/economic development scenarios were used to construct future watershed land cover scenarios. Climatic variability and potential change analysis were used to identify future climate regimes and shifts in precipitation and temperature patterns. Permutations of these development and climate changes were forecasted over 50 years and used to develop sediment yield regimes to the project reservoir. Extensive field work and reservoir survey, including current and wave instrumentation, were used to characterize the project watershed, rivers and reservoir hydrodynamics. A fully 3 dimensional hydrodynamic reservoir sedimentation model was developed for the project and calibrated to observed data. Hydrologic and sedimentation results from watershed forecasting provided boundary conditions for reservoir inputs. The calibrated reservoir model was then used to forecast changes in reservoir sedimentation and storage capacity under different future climate scenarios. Results indicated unique zones of advancing sediment deltas and temporary storage areas. Forecasted changes in reservoir bathymetry and sedimentation patterns were also developed for the various climate change scenarios. The warmer and wetter scenario produced sedimentation impacts similar to extensive development under no climate change. The results of these analyses are being used to develop collaborative watershed and soil conservation partnerships to reduce future soil losses and reservoir sedimentation from projected development. (author)

  18. Socio-economic assessment of the physical and ecological impacts of climate change on the marine environment of the Atlantic region of Canada. Evaluation socio-economic des consequences physiques et ecologiques du changement climatique sur le milieu marin dans la region de l'Atlantique; Phase 1

    Energy Technology Data Exchange (ETDEWEB)

    Stokoe, P

    1988-01-01

    A study on the implications of long term climatic change for Atlantic Canada is summarized. The impacts on the marine environment, fisheries, marine transportation, energy development, coastal infrastructure, and tourism or outdoor recreation under a climate warming caused by a doubling of atmospheric carbon dioxide are assessed. The major physical changes projected include a rise in mean sea level, an increase in the average sea surface temperature, and an absence of sea ice south of Labrador for most years. A warmer climate would favor continuing growth of the aquaculture industry, longer fishing seasons, and an extension of summer recreational and tourism activities. Absence of sea ice could reduce costs for ferry services and marine transport in the region and permit extended seasons on some routes. Costs of ice-related downtime in offshore oil and gas operations could be practically eliminated. Changes in precipitation patterns would affect hydroelectric power output in various regions, with corresponding gains or losses in revenue. Heating oil demand in the region would decrease by about 25%.

  19. Socio-climatic Exposure of an Afghan Poppy Farmer

    Science.gov (United States)

    Mankin, J. S.; Diffenbaugh, N. S.

    2011-12-01

    Many posit that climate impacts from anthropogenic greenhouse gas emissions will have consequences for the natural and agricultural systems on which humans rely for food, energy, and livelihoods, and therefore, on stability and human security. However, many of the potential mechanisms of action in climate impacts and human systems response, as well as the differential vulnerabilities of such systems, remain underexplored and unquantified. Here I present two initial steps necessary to characterize and quantify the consequences of climate change for farmer livelihood in Afghanistan, given both climate impacts and farmer vulnerabilities. The first is a conceptual model mapping the potential relationships between Afghanistan's climate, the winter agricultural season, and the country's political economy of violence and instability. The second is a utility-based decision model for assessing farmer response sensitivity to various climate impacts based on crop sensitivities. A farmer's winter planting decision can be modeled roughly as a tradeoff between cultivating the two crops that dominate the winter growing season-opium poppy (a climate tolerant cash crop) and wheat (a climatically vulnerable crop grown for household consumption). Early sensitivity analysis results suggest that wheat yield dominates farmer decision making variability; however, such initial results may dependent on the relative parameter ranges of wheat and poppy yields. Importantly though, the variance in Afghanistan's winter harvest yields of poppy and wheat is tightly linked to household livelihood and thus, is indirectly connected to the wider instability and insecurity within the country. This initial analysis motivates my focused research on the sensitivity of these crops to climate variability in order to project farmer well-being and decision sensitivity in a warmer world.

  20. Possible mechanisms of pollination failure in hybrid carrot seed and implications for industry in a changing climate.

    Science.gov (United States)

    Broussard, Melissa Ann; Mas, Flore; Howlett, Brad; Pattemore, David; Tylianakis, Jason M

    2017-01-01

    Approximately one-third of our food globally comes from insect-pollinated crops. The dependence on pollinators has been linked to yield instability, which could potentially become worse in a changing climate. Insect-pollinated crops produced via hybrid breeding (20% of fruit and vegetable production globally) are especially at risk as they are even more reliant on pollinators than open-pollinated plants. We already observe a wide range of fruit and seed yields between different cultivars of the same crop species, and it is unknown how existing variation will be affected in a changing climate. In this study, we examined how three hybrid carrot varieties with differential performance in the field responded to three temperature regimes (cooler than the historical average, average, and warmer that the historical average). We tested how temperature affected the plants' ability to set seed (seed set, pollen viability) as well as attract pollinators (nectar composition, floral volatiles). We found that there were significant intrinsic differences in nectar phenolics, pollen viability, and seed set between the carrot varieties, and that higher temperatures did not exaggerate those differences. However, elevated temperature did negatively affect several characteristics relating to the attraction and reward of pollinators (lower volatile production and higher nectar sugar concentration) across all varieties, which may decrease the attractiveness of this already pollinator-limited crop. Given existing predictions of lower pollinator populations in a warmer climate, reduced attractiveness would add yet another challenge to future food production.

  1. Long-term growth-increment chronologies reveal diverse influences of climate forcing on freshwater and forest biota in the Pacific Northwest.

    Science.gov (United States)

    Black, Bryan A; Dunham, Jason B; Blundon, Brett W; Brim-Box, Jayne; Tepley, Alan J

    2015-02-01

    Analyses of how organisms are likely to respond to a changing climate have focused largely on the direct effects of warming temperatures, though changes in other variables may also be important, particularly the amount and timing of precipitation. Here, we develop a network of eight growth-increment width chronologies for freshwater mussel species in the Pacific Northwest, United States and integrate them with tree-ring data to evaluate how terrestrial and aquatic indicators respond to hydroclimatic variability, including river discharge and precipitation. Annual discharge averaged across water years (October 1-September 30) was highly synchronous among river systems and imparted a coherent pattern among mussel chronologies. The leading principal component of the five longest mussel chronologies (1982-2003; PC1(mussel)) accounted for 47% of the dataset variability and negatively correlated with the leading principal component of river discharge (PC1(discharge); r = -0.88; P < 0.0001). PC1(mussel) and PC1(discharge) were closely linked to regional wintertime precipitation patterns across the Pacific Northwest, the season in which the vast majority of annual precipitation arrives. Mussel growth was also indirectly related to tree radial growth, though the nature of the relationships varied across the landscape. Negative correlations occurred in forests where tree growth tends to be limited by drought while positive correlations occurred in forests where tree growth tends to be limited by deep or lingering snowpack. Overall, this diverse assemblage of chronologies illustrates the importance of winter precipitation to terrestrial and freshwater ecosystems and suggests that a complexity of climate responses must be considered when estimating the biological impacts of climate variability and change. © 2014 John Wiley & Sons Ltd.

  2. Climate change

    NARCIS (Netherlands)

    Marchal, V.; Dellink, R.; Vuuren, D.P. van; Clapp, C.; Chateau, J.; Magné, B.; Lanzi, E.; Vliet, J. van

    2012-01-01

    This chapter analyses the policy implications of the climate change challenge. Are current emission reduction pledges made in Copenhagen/Cancun enough to stabilise the climate and limit global average temperature increase to 2 oC? If not, what will the consequences be? What alternative growth

  3. Only one simple conclusion about the climate

    Energy Technology Data Exchange (ETDEWEB)

    Jaremko, G.

    2000-07-24

    Findings concerning climate change, by a three-man team of scientists from the North Dakota Geological Survey, which were presented in a paper read at the Eight International Williston Basin Horizontal Well Workshop, are discussed. The survey by the three scientists covered more than 6,000 scholarly publications. It reported that while the rise in the Earth's temperature is beyond argument, there is anything but agreement as to the causes, or whether the trend is unusual enough to justify concerted and costly actions to change lifestyles. It is shown by direct instrumental measurements that the average temperature at the Earth's surface increased about 0.8 degree Celsius between 1866 and 1998. During that time the concentration of carbon dioxide in the atmosphere increased from 280 to 353 parts per million. While it is generally assumed that the global warming was caused by human activities, new techniques of measurement such as glacier ice coring, dendrochronology (tree-growth rings), lichenometry (measuring the diameter of lichens) and counting concentrations of oxygen 18 and 16 (isotopes whose presence in marine fossils varies depending on temperature) suggest that most of the global warming took place before the increase in carbon dioxide concentration occurred, raising the possibility that the increase in average temperature had causes other than the increase in greenhouse gases. Some of the studies reviewed by the group show that in Europe between ice ages during the Eemian period, some 135,000 to 110,000 years ago, temperature variations of seven degrees Celsius took place; they dropped from two degree Celsius warmer than today to five degree Celsius colder than today. Based on these findings the group's only firm conclusion was that climate is in a continual flux.

  4. Northern peatlands in global climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Laiho, R.; Laine, J.; Vasander, H. [eds.] [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    Northern peatlands are important in regulating the global climate. While sequestering carbon dioxide, these peatlands release ca. 24-39 Tg methane annually to the atmosphere. This is 5-20 % of the annual anthropogenic methane emissions to the atmosphere. The greenhouse gas balance of peatlands may change as a consequence of water level draw-down after land-use change, or if summers become warmer and drier, as has been predicted for high latitudes after climatic warming. Subsequent emissions of methane would decrease, whereas emissions of carbon dioxide and nitrous oxide would increase. Within the Finnish Research Programme on Climate Change (SILMU), the research project `Carbon Balance of Peatlands and Climate Change` (SUOSILMU) has been under progress since 1990. It is a co-operative research project, with research groups from the Universities of Helsinki and Joensuu, the Finnish Forest Research Institute, the National Public Health Institute and the Finnish Environment Agency. The research consortium of this project organised a workshop entitled `Northern Peatlands in Global Climatic Change - Hyytiaelae Revisited` October 8-12, 1995. The main objective of the workshop was to review the state of the art of the carbon cycling research in natural and managed peatlands. The role of peatlands in the greenhouse effect, their response and feedback to the predicted climate change, and the consequences of land-use changes were assessed, and the future research needs were evaluated. The latest information on the role of peatlands in the atmospheric change was given in 50 posters and 4 key lectures. Results of SUOSILMU projects were demonstrated during a 1-day field excursion to one of the intensive study sites, Lakkasuo near Hyytiaelae

  5. Impact of climate change on waterborne diseases

    Directory of Open Access Journals (Sweden)

    Enzo Funari

    2012-12-01

    Full Text Available Change in climate and water cycle will challenge water availability but it will also increase the exposure to unsafe water. Floods, droughts, heavy storms, changes in rain pattern, increase of temperature and sea level, they all show an increasing trend worldwide and will affect biological, physical and chemical components of water through different paths thus enhancing the risk of waterborne diseases. This paper is intended, through reviewing the available literature, to highlight environmental changes and critical situations caused by floods, drought and warmer temperature that will lead to an increase of exposure to water related pathogens, chemical hazards and cyanotoxins. The final aim is provide knowledge-based elements for more focused adaptation measures.

  6. Sensitivity of North American agriculture to ENSO-based climate scenarios and their socio-economic consequences: Modeling in an integrated assessment framework

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, N.J.; Izaurralde, R.C.; Brown, R.A.; Sands, R.D. [Pacific Northwest National Lab., Richland, WA (United States); Legler, D. [Florida State Univ., Tallahassee, FL (United States). Center for Ocean Atmosphere Prediction Studies; Srinivasan, R. [Texas A and M Univ., College Station, TX (United States). Blacklands Research Center; Tiscareno-Lopez, M.

    1997-09-01

    A group of Canadian, US and Mexican natural resource specialists, organized by the Pacific Northwest National Laboratory (PNNL) under its North American Energy, Environment and Economy (NA3E) Program, has applied a simulation modeling approach to estimating the impact of ENSO-driven climatic variations on the productivity of major crops grown in the three countries. Methodological development is described and results of the simulations presented in this report. EPIC (the Erosion Productivity Impact Calculator) was the agro-ecosystem model selected-for this study. EPIC uses a daily time step to simulate crop growth and yield, water use, runoff and soil erosion among other variables. The model was applied to a set of so-called representative farms parameterized through a specially-assembled Geographic Information System (GIS) to reflect the soils, topography, crop management and weather typical of the regions represented. Fifty one representative farms were developed for Canada, 66 for the US and 23 for Mexico. El Nino-Southern Oscillation (ENSO) scenarios for the EPIC simulations were created using the historic record of sea-surface temperature (SST) prevailing in the eastern tropical Pacific for the period October 1--September 30. Each year between 1960 and 1989 was thus assigned to an ENSO category or state. The ENSO states were defined as El Nino (EN, SST warmer than the long-term mean), Strong El Nino (SEN, much warmer), El Viejo (EV, cooler) and Neutral (within {+-}0.5 C of the long-term mean). Monthly means of temperature and precipitation were then calculated at each farm for the period 1960--1989 and the differences (or anomalies) between the means in Neutral years and EN, SEN and EV years determined. The average monthly anomalies for each ENSO state were then used to create new monthly statistics for each farm and ENSO-state combination. The adjusted monthly statistics characteristic of each ENSO state were then used to drive a stochastic-weather simulator

  7. Co-occurrence of viruses and mosquitoes at the vectors' optimal climate range: An underestimated risk to temperate regions?

    Science.gov (United States)

    Blagrove, Marcus S C; Caminade, Cyril; Waldmann, Elisabeth; Sutton, Elizabeth R; Wardeh, Maya; Baylis, Matthew

    2017-06-01

    Mosquito-borne viruses have been estimated to cause over 100 million cases of human disease annually. Many methodologies have been developed to help identify areas most at risk from transmission of these viruses. However, generally, these methodologies focus predominantly on the effects of climate on either the vectors or the pathogens they spread, and do not consider the dynamic interaction between the optimal conditions for both vector and virus. Here, we use a new approach that considers the complex interplay between the optimal temperature for virus transmission, and the optimal climate for the mosquito vectors. Using published geolocated data we identified temperature and rainfall ranges in which a number of mosquito vectors have been observed to co-occur with West Nile virus, dengue virus or chikungunya virus. We then investigated whether the optimal climate for co-occurrence of vector and virus varies between "warmer" and "cooler" adapted vectors for the same virus. We found that different mosquito vectors co-occur with the same virus at different temperatures, despite significant overlap in vector temperature ranges. Specifically, we found that co-occurrence correlates with the optimal climatic conditions for the respective vector; cooler-adapted mosquitoes tend to co-occur with the same virus in cooler conditions than their warmer-adapted counterparts. We conclude that mosquitoes appear to be most able to transmit virus in the mosquitoes' optimal climate range, and hypothesise that this may be due to proportionally over-extended vector longevity, and other increased fitness attributes, within this optimal range. These results suggest that the threat posed by vector-competent mosquito species indigenous to temperate regions may have been underestimated, whilst the threat arising from invasive tropical vectors moving to cooler temperate regions may be overestimated.

  8. Fossil palm beetles refine upland winter temperatures in the Early Eocene Climatic Optimum.

    Science.gov (United States)

    Archibald, S Bruce; Morse, Geoffrey E; Greenwood, David R; Mathewes, Rolf W

    2014-06-03

    Eocene climate and associated biotic patterns provide an analog system to understand their modern interactions. The relationship between mean annual temperatures and winter temperatures-temperature seasonality-may be an important factor in this dynamic. Fossils of frost-intolerant palms imply low Eocene temperature seasonality into high latitudes, constraining average winter temperatures there to >8 °C. However, their presence in a paleocommunity may be obscured by taphonomic and identification factors for macrofossils and pollen. We circumvented these problems by establishing the presence of obligate palm-feeding beetles (Chrysomelidae: Pachymerina) at three localities (a fourth, tentatively) in microthermal to lower mesothermal Early Eocene upland communities in Washington and British Columbia. This provides support for warmer winter Eocene climates extending northward into cooler Canadian uplands.

  9. Shifts in frog size and phenology: Testing predictions of climate change on a widespread anuran using data from prior to rapid climate warming.

    Science.gov (United States)

    Sheridan, Jennifer A; Caruso, Nicholas M; Apodaca, Joseph J; Rissler, Leslie J

    2018-01-01

    Changes in body size and breeding phenology have been identified as two major ecological consequences of climate change, yet it remains unclear whether climate acts directly or indirectly on these variables. To better understand the relationship between climate and ecological changes, it is necessary to determine environmental predictors of both size and phenology using data from prior to the onset of rapid climate warming, and then to examine spatially explicit changes in climate, size, and phenology, not just general spatial and temporal trends. We used 100 years of natural history collection data for the wood frog, Lithobates sylvaticus with a range >9 million km 2 , and spatially explicit environmental data to determine the best predictors of size and phenology prior to rapid climate warming (1901-1960). We then tested how closely size and phenology changes predicted by those environmental variables reflected actual changes from 1961 to 2000. Size, phenology, and climate all changed as expected (smaller, earlier, and warmer, respectively) at broad spatial scales across the entire study range. However, while spatially explicit changes in climate variables accurately predicted changes in phenology, they did not accurately predict size changes during recent climate change (1961-2000), contrary to expectations from numerous recent studies. Our results suggest that changes in climate are directly linked to observed phenological shifts. However, the mechanisms driving observed body size changes are yet to be determined, given the less straightforward relationship between size and climate factors examined in this study. We recommend that caution be used in "space-for-time" studies where measures of a species' traits at lower latitudes or elevations are considered representative of those under future projected climate conditions. Future studies should aim to determine mechanisms driving trends in phenology and body size, as well as the impact of climate on population

  10. The impact of climatic variability and climate change on arabic coffee crop in Brazil

    OpenAIRE

    Camargo,Marcelo Bento Paes de

    2010-01-01

    The climatic variability is the main factor responsible for the oscillations and frustrations of the coffee grain yield in Brazil. The relationships between the climatic parameters and the agricultural production are quite complex, because environmental factors affect the growth and the development of the plants under different forms during the growth stages of the coffee crop. Agrometeorological models related to the growth, development and productivity can supply information for the soil wa...

  11. Intra-operative warming with a forced-air warmer in preventing hypothermia after tourniquet deflation in elderly patients.

    Science.gov (United States)

    Kim, Y-S; Jeon, Y-S; Lee, J-A; Park, W-K; Koh, H-S; Joo, J-D; In, J-H; Seo, K-W

    2009-01-01

    This randomized, single-blind study aimed to explore the effects of intra-operative warming with a forced-air warmer in the prevention of hypothermia after tourniquet deflation in elderly patients undergoing unilateral total knee replacement arthroplasty under general anaesthesia. Patients were randomized to receive either intra-operative warming using a forced-air warmer with an upper body blanket (warming group; n = 12) or no intra-operative warming (nonwarming group; n = 12). Oesophageal temperature was measured as core body temperature. At 30 min following tourniquet inflation, the core body temperature started to increase in the warming group whereas it continued to drop in the non-warming group. This difference was statistically significant. The final core body temperature after tourniquet deflation was significantly higher in the warming group (mean +/- SD 36.1 +/- 0.2 degrees C) than in the non-warming group (35.4 +/- 0.3 degrees C). Intra-operative forced-air warming increased the core body temperature before tourniquet deflation and prevented subsequent hypothermia in elderly patients under general anaesthesia.

  12. Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D

    Directory of Open Access Journals (Sweden)

    B. Leterme

    2012-08-01

    Full Text Available The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain, considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.

  13. Long-Term Arctic Peatland Dynamics, Vegetation and Climate History of the Pur-Taz Region, Western Siberia

    Science.gov (United States)

    Peteet, Dorothy; Andreev, Andrei; Bardeen, William; Mistretta, Francesca

    1998-01-01

    Stratigraphic analyses of peat composition, LOI, pollen, spores, macrofossils, charcoal, and AMS ages are used to reconstruct the peatland, vegetation and climatic dynamics in the Pur-Taz region of western Siberia over 5000 years (9300 - 4500 BP). Section stratigraphy shows many changes from shallow lake sediment to different combinations of forested or open sedge, moss, and Equisetum fen and peatland environments. Macrofossil and pollen data indicate that Larix sibirica and Betula pubescens trees were first to arrive, followed by Picea obovata. The dominance of Picea macrofossils 6000-5000 BP in the Pur-Taz peatland along with regional Picea pollen maxima indicate warmer conditions and movement of the spruce treeline northward at this time. The decline of pollen and macrofossils from all of these tree species in uppermost peats suggests a change in the environment less favorable for their growth, perhaps cooler temperatures and/or less moisture. Of major significance is the evidence for old ages of the uppermost peats in this area of Siberia, suggesting a real lack of peat accumulation in recent millennia or recent oxidation of uppermost peat.

  14. Integrating ecophysiology and forest landscape models to improve projections of drought effects under climate change.

    Science.gov (United States)

    Gustafson, Eric J; De Bruijn, Arjan M G; Pangle, Robert E; Limousin, Jean-Marc; McDowell, Nate G; Pockman, William T; Sturtevant, Brian R; Muss, Jordan D; Kubiske, Mark E

    2015-02-01

    Fundamental drivers of ecosystem processes such as temperature and precipitation are rapidly changing and creating novel environmental conditions. Forest landscape models (FLM) are used by managers and policy-makers to make projections of future ecosystem dynamics under alternative management or policy options, but the links between the fundamental drivers and projected responses are weak and indirect, limiting their reliability for projecting the impacts of climate change. We developed and tested a relatively mechanistic method to simulate the effects of changing precipitation on species competition within the LANDIS-II FLM. Using data from a field precipitation manipulation experiment in a piñon pine (Pinus edulis) and juniper (Juniperus monosperma) ecosystem in New Mexico (USA), we calibrated our model to measurements from ambient control plots and tested predictions under the drought and irrigation treatments against empirical measurements. The model successfully predicted behavior of physiological variables under the treatments. Discrepancies between model output and empirical data occurred when the monthly time step of the model failed to capture the short-term dynamics of the ecosystem as recorded by instantaneous field measurements. We applied the model to heuristically assess the effect of alternative climate scenarios on the piñon-juniper ecosystem and found that warmer and drier climate reduced productivity and increased the risk of drought-induced mortality, especially for piñon. We concluded that the direct links between fundamental drivers and growth rates in our model hold great promise to improve our understanding of ecosystem processes under climate change and improve management decisions because of its greater reliance on first principles. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  15. Climate variability in West Greenland during the past 1500 years

    DEFF Research Database (Denmark)

    dos Santos Ribeiro, Sofia Isabel; Moros, Matthias; Ellegaard, Marianne

    2012-01-01

    -surface temperatures in Disko Bay are out-of-phase with Greenland ice-core reconstructed temperatures and marine proxy data from South and East Greenland. This is probably governed by an NAO-type pattern, which results in warmer sea-surface conditions with less extensive sea ice in the area for the later part....... Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea...

  16. Functional traits drive plant community and ecosystem response to global change across arctic and alpine environments

    DEFF Research Database (Denmark)

    Chisholm, Chelsea Lee

    hierarchical Bayesian modelling. Here I found that competition is generally stronger in warmer climates, and that functional traits do not consistently predict growth across climate space. I also demonstrated that the inclusion of functional trait information as stabilizing niche differences in competition...... delayed in ice-rich areas. Finally, colleagues and I used an observational approach to assess changes in nutrient dynamics across replicated treeline transects in temperate regions around the globe, where we found consistent temperature-mediated changes in both ground-layer plant and soil nutrients across...

  17. A Hydrological Response Analysis Considering Climatic Variability: Case Study of Hunza Catchment

    Directory of Open Access Journals (Sweden)

    A. N. Laghari

    2018-06-01

    Full Text Available The hydrological response of mountainous catchments particularly dependent on melting runoff is very vulnerable to climatic variability. This study is an attempt to assess hydrological response towards climatic variability of the Hunza catchment located in the mountainous chain of greater Hindu Kush-Himalaya (HKH region. The hydrological response is analyzed through changes in snowmelt, ice melt and total runoff simulated through the application of the hydrological modeling system PREVAH under hypothetically developed climate change scenarios. The developed scenarios are based on changes in precipitation (Prp and temperature (Tmp and their combination. Under all the warmer scenarios, the increase in temperature systematically decreases the mean annual snow melt and increases significantly glacier melt volume. Temperature changes from 1°C to 4°C produce a large increase in spring and summer runoff, while no major variation was observed in the winter and autumn runoff. The maximum seasonal changes recorded under the Tmp+4°C, Prp+10% scenario.

  18. Seed dormancy and germination changes of snowbed species under climate warming: the role of pre- and post-dispersal temperatures

    Science.gov (United States)

    Bernareggi, Giulietta; Carbognani, Michele; Mondoni, Andrea; Petraglia, Alessandro

    2016-01-01

    Background and Aims Climate warming has major impacts on seed germination of several alpine species, hence on their regeneration capacity. Most studies have investigated the effects of warming after seed dispersal, and little is known about the effects a warmer parental environment may have on germination and dormancy of the seed progeny. Nevertheless, temperatures during seed development and maturation could alter the state of dormancy, affecting the timing of emergence and seedling survival. Here, the interplay between pre- and post-dispersal temperatures driving seed dormancy release and germination requirements of alpine plants were investigated. Methods Three plant species inhabiting alpine snowbeds were exposed to an artificial warming treatment (i.e. +1·5 K) and to natural conditions in the field. Seeds produced were exposed to six different periods of cold stratification (0, 2, 4, 8, 12 and 20 weeks at 0 °C), followed by four incubation temperatures (5, 10, 15 and 20 °C) for germination testing. Key Results A warmer parental environment produced either no or a significant increase in germination, depending on the duration of cold stratification, incubation temperatures and their interaction. In contrast, the speed of germination was less sensitive to changes in the parental environment. Moreover, the effects of warming appeared to be linked to the level of (physiological) seed dormancy, with deeper dormant species showing major changes in response to incubation temperatures and less dormant species in response to cold stratification periods. Conclusions Plants developed under warmer climates will produce seeds with changed germination responses to temperature and/or cold stratification, but the extent of these changes across species could be driven by seed dormancy traits. Transgenerational plastic adjustments of seed germination and dormancy shown here may result from increased seed viability, reduced primary and secondary dormancy state, or both, and

  19. Application of a Hybrid Forest Growth Model to Evaluate Climate Change Impacts on Productivity, Nutrient Cycling and Mortality in a Montane Forest Ecosystem.

    Science.gov (United States)

    Seely, Brad; Welham, Clive; Scoullar, Kim

    2015-01-01

    Climate change introduces considerable uncertainty in forest management planning and outcomes, potentially undermining efforts at achieving sustainable practices. Here, we describe the development and application of the FORECAST Climate model. Constructed using a hybrid simulation approach, the model includes an explicit representation of the effect of temperature and moisture availability on tree growth and survival, litter decomposition, and nutrient cycling. The model also includes a representation of the impact of increasing atmospheric CO2 on water use efficiency, but no direct CO2 fertilization effect. FORECAST Climate was evaluated for its ability to reproduce the effects of historical climate on Douglas-fir and lodgepole pine growth in a montane forest in southern British Columbia, Canada, as measured using tree ring analysis. The model was subsequently used to project the long-term impacts of alternative future climate change scenarios on forest productivity in young and established stands. There was a close association between predicted sapwood production and measured tree ring chronologies, providing confidence that model is able to predict the relative impact of annual climate variability on tree productivity. Simulations of future climate change suggest a modest increase in productivity in young stands of both species related to an increase in growing season length. In contrast, results showed a negative impact on stemwood biomass production (particularly in the case of lodgepole pine) for established stands due to increased moisture stress mortality.

  20. Sapling growth of Eucalyptus tereticornis under various edapho-climatic regions of Tamil Nadu

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswami, S; Rai, R S.V.; Srinivasan, V M

    1982-01-01

    Girth at b.h. (o.b.) was measured in 2-4 yr old plantations at 6 sites on various soil types with annual rainfalls of 70-100 cm. Best average growth at 2x2-m spacing (over 29 cm girth at 4 yr old) was on sandy river banks with 90 cm rainfall and the worst (20-21 cm at 4 yr old) on poor gravelly and lateritic soils with low rainfall. It is suggested that strains should be selected to suit different local soil and climatic conditions. (Refs. 8).

  1. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration.

    Science.gov (United States)

    Otis Prud'homme, Guillaume; Lamhamedi, Mohammed S; Benomar, Lahcen; Rainville, André; DeBlois, Josianne; Bousquet, Jean; Beaulieu, Jean

    2017-01-01

    With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce ( Picea glauca [Moench] Voss) seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1) evaluate the morpho-physiological responses of the different seed sources and (2) determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a significant effect on

  2. Ecophysiology and Growth of White Spruce Seedlings from Various Seed Sources along a Climatic Gradient Support the Need for Assisted Migration

    Directory of Open Access Journals (Sweden)

    Guillaume Otis Prud'homme

    2018-01-01

    Full Text Available With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea glauca [Moench] Voss seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1 evaluate the morpho-physiological responses of the different seed sources and (2 determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a

  3. Increasing carbon discrimination rates and depth of water uptake favor the growth of Mediterranean evergreen trees in the ecotone with temperate deciduous forests.

    Science.gov (United States)

    Barbeta, Adrià; Peñuelas, Josep

    2017-12-01

    Tree populations at the low-altitudinal or -latitudinal limits of species' distributional ranges are predicted to retreat toward higher altitudes and latitudes to track the ongoing changes in climate. Studies have focused on the climatic sensitivity of the retreating species, whereas little is known about the potential replacements. Competition between tree species in forest ecotones will likely be strongly influenced by the ecophysiological responses to heat and drought. We used tree-ring widths and δ 13 C and δ 18 O chronologies to compare the growth rates and long-term ecophysiological responses to climate in the temperate-Mediterranean ecotone formed by the deciduous Fagus sylvatica and the evergreen Quercus ilex at the low altitudinal and southern latitudinal limit of F. sylvatica (NE Iberian Peninsula). F. sylvatica growth rates were similar to those of other southern populations and were surprisingly not higher than those of Q. ilex, which were an order of magnitude higher than those in nearby drier sites. Higher Q. ilex growth rates were associated with high temperatures, which have increased carbon discrimination rates in the last 25 years. In contrast, stomatal regulation in F. sylvatica was proportional to the increase in atmospheric CO 2 . Tree-ring δ 18 O for both species were mostly correlated with δ 18 O in the source water. In contrast to many previous studies, relative humidity was not negatively correlated with tree-ring δ 18 O but had a positive effect on Q. ilex tree-ring δ 18 O. Furthermore, tree-ring δ 18 O decreased in Q. ilex over time. The sensitivity of Q. ilex to climate likely reflects the uptake of deep water that allowed it to benefit from the effect of CO 2 fertilization, in contrast to the water-limited F. sylvatica. Consequently, Q. ilex is a strong competitor at sites currently dominated by F. sylvatica and could be favored by increasingly warmer conditions. © 2017 John Wiley & Sons Ltd.

  4. Possible consequences of climate change on the Swedish energy sector - impacts, vulnerability and adaptation

    International Nuclear Information System (INIS)

    Gode, Jenny; Axelsson, Johan; Eriksson, Sara; Holmgren, Kristina; Hovsenius, Gunnar; Kjellstroem, Erik; Larsson, Per; Lundstroem, Love; Persson, Gunn

    2007-06-01

    hydropower other than the ability for regulation to control water levels. However, hydropower is indirectly affected by flooding since public attention is often focused on the industry when high flows occur. A warmer climate will reduce the country's heating requirement by approximately 15 TWh. While electricity usage for heating is estimated to decrease by around 3 TWh as a result of a warmer climate, a probable rise in demand for air conditioning could lead to increased electricity usage during the summer. However, future energy usage for heating and air conditioning will be strongly dependent on factors other than the climate, such as the implementation of energy efficiency measures, changes in behaviour, the use of heat generating appliances, population growth, etc. The project has included a rough assessment of how both climate-related and non climate-related factors may affect energy usage for heating of homes and businesses (not industrial facilities) in a 20- to 25-year perspective. A lower energy requirement for heating would also reduce the production base for CHP. To maintain production it will be necessary to expand district heating to areas that are currently without, convert from other heating systems to district heating and/or utilise new business opportunities such as absorption cooling or energy combines with CHP utilising renewable fuels like biomass or pellets. Changes in production potential and energy usage patterns and the occurrence of climate-related problems will affect the entire energy system. Increased production potential for the northern hydropower stations, particularly in combination with a growing share of power types that are difficult to regulate, may increase the need for power transmission capacity from north to south. This is especially true if the north-to-south shift continues and in the event of rising demand for electricity in the rest of Europe

  5. Ultrascale Visualization of Climate Data

    Science.gov (United States)

    Williams, Dean N.; Bremer, Timo; Doutriaux, Charles; Patchett, John; Williams, Sean; Shipman, Galen; Miller, Ross; Pugmire, David R.; Smith, Brian; Steed, Chad; hide

    2013-01-01

    Fueled by exponential increases in the computational and storage capabilities of high-performance computing platforms, climate simulations are evolving toward higher numerical fidelity, complexity, volume, and dimensionality. These technological breakthroughs are coming at a time of exponential growth in climate data, with estimates of hundreds of exabytes by 2020. To meet the challenges and exploit the opportunities that such explosive growth affords, a consortium of four national laboratories, two universities, a government agency, and two private companies formed to explore the next wave in climate science. Working in close collaboration with domain experts, the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT) project aims to provide high-level solutions to a variety of climate data analysis and visualization problems.

  6. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, F.; Maguire, D.A.; González-Martínez, S.G.

    2017-11-01

    Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain). Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain) during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson) model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO) index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO), local stand density (here estimated from the six nearest trees), tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results). Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency) influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO) are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  7. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    Directory of Open Access Journals (Sweden)

    Felipe Bravo

    2017-10-01

    Full Text Available Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain. Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO, local stand density (here estimated from the six nearest trees, tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results. Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  8. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    International Nuclear Information System (INIS)

    Bravo, F.; Maguire, D.A.; González-Martínez, S.G.

    2017-01-01

    Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain). Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain) during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson) model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO) index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO), local stand density (here estimated from the six nearest trees), tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results). Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency) influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO) are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  9. Increased wind risk from sting-jet windstorms with climate change

    Science.gov (United States)

    Martínez-Alvarado, Oscar; Gray, Suzanne L.; Hart, Neil C. G.; Clark, Peter A.; Hodges, Kevin; Roberts, Malcolm J.

    2018-04-01

    Extra-tropical cyclones dominate autumn and winter weather over western Europe. The strongest cyclones, often termed windstorms, have a large socio-economic impact on landfall due to strong surface winds and coastal storm surges. Climate model integrations have predicted a future increase in the frequency of, and potential damage from, European windstorms and yet these integrations cannot properly represent localised jets, such as sting jets, that may significantly enhance damage. Here we present the first prediction of how the climatology of sting-jet-containing cyclones will change in a future warmer climate, considering the North Atlantic and Europe. A proven sting-jet precursor diagnostic is applied to 13 year present-day and future (~2100) climate integrations from the Met Office Unified Model in its Global Atmosphere 3.0 configuration. The present-day climate results are consistent with previously-published results from a reanalysis dataset (with around 32% of cyclones exhibiting the sing-jet precursor), lending credibility to the analysis of the future-climate integration. The proportion of cyclones exhibiting the sting-jet precursor in the future-climate integration increases to 45%. Furthermore, while the proportion of explosively-deepening storms increases only slightly in the future climate, the proportion of those storms with the sting-jet precursor increases by 60%. The European resolved-wind risk associated with explosively-deepening storms containing a sting-jet precursor increases substantially in the future climate; in reality this wind risk is likely to be further enhanced by the release of localised moist instability, unresolved by typical climate models.

  10. Cumulus Microphysics and Climate Sensitivity.

    Science.gov (United States)

    del Genio, Anthony D.; Kovari, William; Yao, Mao-Sung; Jonas, Jeffrey

    2005-07-01

    Precipitation processes in convective storms are potentially a major regulator of cloud feedback. An unresolved issue is how the partitioning of convective condensate between precipitation-size particles that fall out of updrafts and smaller particles that are detrained to form anvil clouds will change as the climate warms. Tropical Rainfall Measuring Mission (TRMM) observations of tropical oceanic convective storms indicate higher precipitation efficiency at warmer sea surface temperature (SST) but also suggest that cumulus anvil sizes, albedos, and ice water paths become insensitive to warming at high temperatures. International Satellite Cloud Climatology Project (ISCCP) data show that instantaneous cirrus and deep convective cloud fractions are positively correlated and increase with SST except at the highest temperatures, but are sensitive to variations in large-scale vertical velocity. A simple conceptual model based on a Marshall-Palmer drop size distribution, empirical terminal velocity-particle size relationships, and assumed cumulus updraft speeds reproduces the observed tendency for detrained condensate to approach a limiting value at high SST. These results suggest that the climatic behavior of observed tropical convective clouds is intermediate between the extremes required to support the thermostat and adaptive iris hypotheses.

  11. Predicting species-specific responses of fungi to climatic variation using historical records.

    Science.gov (United States)

    Diez, Jeffrey M; James, Timothy Y; McMunn, Marshall; Ibáñez, Inés

    2013-10-01

    Although striking changes have been documented in plant and animal phenology over the past century, less is known about how the fungal kingdom's phenology has been changing. A few recent studies have documented changes in fungal fruiting in Europe in the last few decades, but the geographic and taxonomic extent of these changes, the mechanisms behind these changes, and their relationships to climate are not well understood. Here, we analyzed herbarium data of 274 species of fungi from Michigan to test the hypotheses that fruiting times of fungi depend on annual climate and that responses depend on taxonomic and functional groups. We show that the fungal community overall fruits later in warmer and drier years, which has led to a shift toward later fruiting dates for autumn-fruiting species, consistent with existing evidence. However, we also show that these effects are highly variable among species and are partly explained by basic life-history characteristics. Resulting differences in climate sensitivities are expected to affect community structure as climate changes. This study provides a unique picture of the climate dependence of fungal phenology in North America and an approach for quantifying how individual species and broader fungal communities will respond to ongoing climate change. © 2013 John Wiley & Sons Ltd.

  12. Disentangling the effects of climate, species, and management on growth and mortality of southeast Asian mangroves

    Science.gov (United States)

    Baker, Patrick; Bunyavejchewin, Sarayudh; Robinson, Andrew

    2013-04-01

    Mangrove forests are one of the most biologically important ecosystems of the littoral tropics. They provide a wide range of ecosystem services including tsunami protection, food production, and waste processing. They are also rapidly disappearing due to increasing rates of clearance for development and aquaculture. It remains unclear how mangroves will respond to changing climatic conditions. Here we discuss the results of a long-term study that explored the interacting effects of climate, species, and management practices on annual variability of growth and mortality of mangroves in peninsular Thailand. The 15-year study period included the extreme 1997-98 ENSO event that led to widespread drought-induced mortality and forest fires across the region, but which appeared to have little impact on the mangroves. Our results provide an important, and much-needed, framework for conservation and forest management planning in these mangrove forests given future concerns and uncertainty about climate change in the tropics.

  13. Possibilities and limitations of using historic provenance tests to infer forest species growth responses to climate change

    Science.gov (United States)

    Laura P. Leites; Gerald E. Rehfeldt; Andrew P. Robinson; Nicholas L. Crookston; Barry Jaquish

    2012-01-01

    Under projected changes in global climate, the growth and survival of existing forests will depend on their ability to adjust physiologically in response to environmental change. Quantifying their capacity to adjust and whether the response is species- or population-specific is important to guide forest management strategies. New analyses of historic provenance tests...

  14. Stronger sexual selection in warmer waters: the case of a sex role reversed pipefish.

    Directory of Open Access Journals (Sweden)

    Nuno M Monteiro

    Full Text Available In order to answer broader questions about sexual selection, one needs to measure selection on a wide array of phenotypic traits, simultaneously through space and time. Nevertheless, studies that simultaneously address temporal and spatial variation in reproduction are scarce. Here, we aimed to investigate the reproductive dynamics of a cold-water pipefish simultaneously through time (encompassing variation within each breeding cycle and as individuals grow and space (by contrasting populations experiencing distinct water temperature regimes in order to test hypothesized differences in sexual selection. Even though the sampled populations inhabited locations with very different water temperature regimes, they exhibited considerable similarities in reproductive parameters. The most striking was the existence of a well-defined substructure in reproductive activity, where larger individuals reproduce for longer periods, which seemed dependent on a high temperature threshold for breeding rather than on the low temperatures that vary heavily according to latitude. Furthermore, the perceived disparities among populations, such as size at first reproduction, female reproductive investment, or degree of sexual size dimorphism, seemed dependent on the interplay between seawater temperature and the operational sex ratio (OSR. Contrary to our expectations of an enhanced opportunity for sexual selection in the north, we found the opposite: higher female reproductive investment coupled with increased sexual size dimorphism in warmer waters, implying that a prolonged breeding season does not necessarily translate into reduced sexual selection pressure. In fact, if the limited sex has the ability to reproduce either continuously or recurrently during the entire breeding season, an increased opportunity for sexual selection might arise from the need to compete for available partners under strongly biased OSRs across protracted breeding seasons. A more general

  15. Growth of juvenile steelhead Oncorhynchus mykiss under size-selective pressure limited by seasonal bioenergetic and environmental constraints

    Science.gov (United States)

    Thompson, Jamie N.; Beauchamp, David A.

    2016-01-01

    Increased freshwater growth of juvenile steelhead Oncorhynchus mykiss improved survival to smolt and adult stages, thus prompting an examination of factors affecting growth during critical periods that influenced survival through subsequent life stages. For three tributaries with contrasting thermal regimes, a bioenergetics model was used to evaluate how feeding rate and energy density of prey influenced seasonal growth and stage-specific survival of juvenile O. mykiss. Sensitivity analysis examined target levels for feeding rate and energy density of prey during the growing season that improved survival to the smolt and adult stages in each tributary. Simulated daily growth was greatest during warmer months (1 July to 30 September), whereas substantial body mass was lost during cooler months (1 December to 31 March). Incremental increases in annual feeding rate or energy density of prey during summer broadened the temperature range at which faster growth occurred and increased the growth of the average juvenile to match those that survived to smolt and adult stages. Survival to later life stages could be improved by increasing feeding rate or energy density of the diet during summer months, when warmer water temperatures accommodated increased growth potential. Higher growth during the summer period in each tributary could improve resiliency during subsequent colder periods that lead to metabolic stress and weight loss. As growth and corresponding survival rates in fresh water are altered by shifting abiotic regimes, it will be increasingly important for fisheries managers to better understand the mechanisms affecting growth limitations in rearing habitats and what measures might maintain or improve growth conditions and survival.

  16. Major Changes in Growth Rate and Growth Variability of Beech (Fagus sylvatica L.) Related to Soil Alteration and Climate Change in Belgium

    OpenAIRE

    Latte, Nicolas; Perin, Jérôme; Kint, Vincent; Lebourgeois, François; Claessens, Hugues

    2016-01-01

    Global change-particularly climate change, forest management, and atmospheric deposition-has significantly altered forest growing conditions in Europe. The influences of these changes on beech growth (Fagus sylvatica L.) were investigated for the past 80 years in Belgium, using non-linear mixed effects models on ring-width chronologies of 149 mature and dominant beech trees (87-186 years old). The effects of the developmental stage (i.e., increasing tree size) were filtered out in order to fo...

  17. Seasonal response of biomass growth and allocation of a boreal bioenergy crop (Phalaris arundinacea L.) to climate change

    Energy Technology Data Exchange (ETDEWEB)

    Chang Zhang

    2013-06-01

    in the growing season. Compared to CON, ET and ETC increased LMF and SMF, and decreased RMF over the whole growing season under NW and HW. Under LW, ET and ETC decreased LMF and increased RMF throughout the growing season, and increased SMF in early periods and then decreased later in the growing season. EC decreased the LMF and SMF and increased the RMF over the growing season but did not significantly affect the seasonal biomass allocation pattern between plant organs. The LMF was higher and the RMF was lower throughout the growing season in response to the higher groundwater level, while the effect of groundwater level on the SMF depended on the developmental phase of the plants. Our results show that climatic treatments affected biomass growth and biomass allocation to each of the three plant organs, while the direction and extent of climate-related changes in biomass growth and allocation depended on the availability of groundwater. The influence of groundwater level appeared to be crucial for the carbon gain regarding the production of RCG biomass for energy purposes and the concurrent sequestration of carbon in soils under changing climates in the mire sites used to cultivate RCG. (orig.)

  18. Health and vitality assessment of two common pine species in the context of climate change in southern Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sicard, Pierre, E-mail: pierre.sicard@acri-st.fr [ACRI-ST, 260 route du Pin Montard, BP 234, 06904 Sophia Antipolis cedex (France); Dalstein-Richier, Laurence [GIEFS (Groupe International d’Etudes des Forêts Sud-européennes) – 60, Avenue des Hespérides, 06300 Nice (France)

    2015-02-15

    The Mediterranean Basin is expected to be more strongly affected by ongoing climate change than most other regions of the earth. The South-eastern France can be considered as case study for assessing global change impacts on forests. Based on non-parametric statistical tests, the climatic parameters (temperature, relative humidity, rainfall, global radiation) and forest-response indicators (crown defoliation, discoloration and visible foliar ozone injury) of two pine species (Pinus halepensis and Pinus cembra) were analyzed. In the last 20 years, the trend analyses reveal a clear hotter and drier climate along the coastline and slightly rainier inland. In the current climate change context, a reduction in ground-level ozone (O{sub 3}) was found at remote sites and the visible foliar O{sub 3} injury decreased while deterioration of the crown conditions was observed likely due to a drier and warmer climate. Clearly, if such climatic and ecological changes are now being detected when the climate, in South-eastern France, has warmed in the last 20 years (+0.46–1.08 °C), it can be expected that many more impacts on tree species will occur in response to predicted temperature changes by 2100 (+1.95–4.59 °C). Climate change is projected to reduce the benefits of O{sub 3} precursor emissions controls leading to a higher O{sub 3} uptake. However, the drier and warmer climate should induce a soil drought leading to a lower O{sub 3} uptake. These two effects, acting together in an opposite way, could mitigate the harmful impacts of O{sub 3} on forests. The development of coordinated emission abatement strategies is useful to reduce both climate change and O{sub 3} pollution. Climate change will create additional challenges for forest management with substantial socio-economic and biological diversity impacts. However, the development of future sustainable and adaptive forest management strategies has the potential to reduce the vulnerability of forest species to climate

  19. Climate classifications and building energy use implications in China

    International Nuclear Information System (INIS)

    Wan, Kevin K.W.; Li, Danny H.W.; Lam, Joseph C.; Yang, Liu

    2010-01-01

    Cluster analysis of summer and winter discomfort in terms of heat and cold stresses based on 102-year (1901-2002) weather data in China was conducted. Five bioclimate zones were identified. These were compared with the corresponding thermal and solar zoning classifications. Bio-I and Bio-II tended to locate largely within severe cold and cold climates in the north with excellent solar availability (annual clearness index K t generally exceeding 0.5). Bio-III and Bio-IV covered mostly the hot summer and cold winter and mild climate zones. Despite the relatively low K t in winter, passive solar heating should be able to meet a significant proportion of the heating requirements. Bio-V covered the hot summer and warmer winter region, where heat stress and hence cooling requirement dominated. Decreasing trends in the zone-average annual cumulative cold stress during the 102-year period were observed for all five zones. There was, however, no distinct pattern for the heat stress and the changes tended to be more subtle. These indicate that climate change during the 20 th century affected winter discomfort (especially in colder climates in the north) more than the summer discomfort. This could have significant implications for energy use in buildings if such trends persist. (author)

  20. Climate Responses in Growth and Wood Anatomy of Imoprtant Forest Tree Species in Denmark

    DEFF Research Database (Denmark)

    Huang, Weiwei

    and high temperatures on the development of Danish tree species are scarcely investigated. Through a dendroecological approach this dissertation assessed the growth responses related to increment, xylem anatomy and wood property of eight different important tree species, namely Picea abies (L.) Karst......., Picea sitchensis (Bong.) Carr., Abies alba Mill., Abies grandis (Dougl.) Lindl., Pseudotsuga mensiesii (Mirb.) Franco, Larix kaempferi (Lamb.) Carr., Quercus robur L. and Fagus sylvatica L., to long-term drought and high temperatures, aiming at identifying a species portfolio matching future climate...... intolerant species, mainly due to their low drought tolerance (both species) and susceptibility to high autumn temperature (only P. abies). Overall, this dissertation improves the understanding of how drought and high temperatures have impacted and will influence the growth of tree species in Danish forest...