WorldWideScience

Sample records for terrestrial ecosystems

  1. Terrestrial ecosystems and their change

    Science.gov (United States)

    Anatoly Z. Shvidenko; Eric Gustafson; A. David McGuire; Vjacheslav I. Kharuk; Dmitry G. Schepaschenko; Herman H. Shugart; Nadezhda M. Tchebakova; Natalia N. Vygodskaya; Alexander A. Onuchin; Daniel J. Hayes; Ian McCallum; Shamil Maksyutov; Ludmila V. Mukhortova; Amber J. Soja; Luca Belelli-Marchesini; Julia A. Kurbatova; Alexander V. Oltchev; Elena I. Parfenova; Jacquelyn K. Shuman

    2012-01-01

    This chapter considers the current state of Siberian terrestrial ecosystems, their spatial distribution, and major biometric characteristics. Ongoing climate change and the dramatic increase of accompanying anthropogenic pressure provide different but mostly negative impacts on Siberian ecosystems. Future climates of the region may lead to substantial drying on large...

  2. Terrestrial ecosystems and climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Emanuel, W.R. (Oak Ridge National Lab., TN (USA)); Schimel, D.S. (Colorado State Univ., Fort Collins, CO (USA). Natural Resources Ecology Lab.)

    1990-01-01

    The structure and function of terrestrial ecosystems depend on climate, and in turn, ecosystems influence atmospheric composition and climate. A comprehensive, global model of terrestrial ecosystem dynamics is needed. A hierarchical approach appears advisable given currently available concepts, data, and formalisms. The organization of models can be based on the temporal scales involved. A rapidly responding model describes the processes associated with photosynthesis, including carbon, moisture, and heat exchange with the atmosphere. An intermediate model handles subannual variations that are closely associated with allocation and seasonal changes in productivity and decomposition. A slow response model describes plant growth and succession with associated element cycling over decades and centuries. These three levels of terrestrial models are linked through common specifications of environmental conditions and constrain each other. 58 refs.

  3. Terrestrial ecosystems under warmer and drier climates

    Science.gov (United States)

    Pan, Y.

    2016-12-01

    Future warmer and drier climates will likely affect many of the world's terrestrial ecosystems. These changes will fundamentally reshape terrestrial systems through their components and across organization levels. However, it is unclear to what extent terrestrial ecosystems would be resilient enough to stay put to increased temperature and water stress by only adjusting carbon fluxes and water balances? And to what extent it would reach the thresholds at which terrestrial ecosystems were forced to alter species compositions and ecosystem structures for adapting to newer climates? The energy balance of terrestrial ecosystems link thermal and water conditions to defines terrestrial carbon processes and feedbacks to climate, which will inevitably change under warmer and drier climates. Recent theoretical studies provide a new framework, suggesting that terrestrial ecosystems were capable of balancing costs of carbon gain and water transport to achieve optimums for functioning and distribution. Such a paradigm is critical for understanding the dynamics of future terrestrial ecosystems under climate changes, and facilitate modeling terrestrial ecosystems which needs generalized principles for formulating ecosystem behaviors. This study aims to review some recent studies that explore responses of terrestrial ecosystems to rather novel climate conditions, such as heat-induced droughts, intending to provide better comprehension of complex carbon-water interactions through plants to an ecosystem, and relevant factors that may alleviate or worsen already deteriorated climates such as elevated CO2 and soil conditions.

  4. Terrestrial Ecosystems of the Conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey (USGS) modeled the distribution of terrestrial ecosystems for the contiguous United States using a standardized, deductive approach to...

  5. Consumer Control of Terrestrial Ecosystems

    Science.gov (United States)

    Frank, D.

    2012-12-01

    More than half of the earth's terrestrial surface is grazed by large herbivores and their effects on plant and soil carbon and nitrogen processes are large and widespread. Yet the large effects of these animals on terrestrial processes have largely been ignored in global change models. This presentation will explore the many pathways that consumers affect short and long time-scale terrestrial nitrogen and carbon processes. Large herbivores influence the quality of soil organic matter and the size of the active (i.e., labile) pool of soil carbon and nitrogen in several ways. Herbivory leads to greater abundance of species producing low quality material in forest and dry grassland, via feeding preferentially on high quality forage, and high quality material in mesic grassland habitat, via the high quality of material that regrows after a plant is grazed. Defoliation stimulates the rate of root exudation that enhances rhizospheric processes and the availability of nitrogen in the plant rhizosphere. Herbivores also change the species composition of mycorrhizae fungal associates that influence plant growth and affect soil structure and the turnover rate of soil carbon. Recent radiocarbon measurements have revealed that herbivores also markedly affect the turnover dynamics of the large pool of old soil carbon. In Yellowstone Park, ungulates slow the mean turnover of the relatively old (i.e., slow and passive) 0 - 20 cm deep soil organic carbon by 350 years in upland, dry grassland and speed up that rate in slope-bottom, mesic grassland by 300 years. This represents a 650 year swing in the turnover period of old soil carbon across the Yellowstone landscape. By comparison, mean turnover time for the old pool of 0 - 10 cm deep soil organic carbon shifts by about 300 years across the steep climatic gradient that includes tropical, temperate, and northern hardwood forest, and tallgrass, shortgrass and desert grassland. This large body of evidence suggests consumers play a

  6. The microbiology of terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Richards, B.N.

    1987-01-01

    Emphasizing the role of soil organisms, especially fungi and bacteria, in maintaining productive and stable ecosystems, this book addresses the imbalance found in most ecological texts, which often neglect microorganisms. It stresses the inter-relationship between soil microbes and plants in functional activities such as the capture and transfer of energy and the circulation of chemical elements in ecological systems. It begins with a review of basic concepts followed by a description of the soil as a living entity, including its physical and chemical characteristics, and the life forms found within it. Organic matter mineralization is treated in the context if energy flow and carbon turnover in the biosphere. Also covered are mineral cycling, the microbiology of the rhizosphere, mycorrhiza, root nodule symbiosis, and the cycling of nutrients in the soil-plant-atmosphere system.

  7. Divergent apparent temperature sensitivity of terrestrial ecosystem respiration

    Science.gov (United States)

    Bing Song; Shuli Niu; Ruise Luo; Yiqi Luo; Jiquan Chen; Guirui Yu; Janusz Olejnik; Georg Wohlfahrt; Gerard Kiely; Ako Noormets; Leonardo Montagnani; Alessandro Cescatti; Vincenzo Magliulo; Beverly Elizabeth Law; Magnus Lund; Andrej Varlagin; Antonio Raschi; Matthias Peichl; Mats B. Nilsson; Lutz Merbold

    2014-01-01

    Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and...

  8. Estimation of evapotranspiration over the terrestrial ecosystems in China

    Science.gov (United States)

    Xianglan Li; Shunlin Liang; Wenping Yuan; Guirui Yu; Xiao Cheng; Yang Chen; Tianbao Zhao; Jinming Feng; Zhuguo Ma; Mingguo Ma; Shaomin Liu; Jiquan Chen; Changliang Shao; Shenggong Li; Xudong Zhang; Zhiqiang Zhang; Ge Sun; Shiping Chen; Takeshi Ohta; Andrej Varlagin; Akira Miyata; Kentaro Takagi; Nobuko Saiqusa; Tomomichi Kato

    2014-01-01

    Quantifying regional evapotranspiration (ET) and environmental constraints are particularly important for understanding water and carbon cycles of terrestrial ecosystems. However, a large uncertainty in the regional estimation of ET still remains for the terrestrial ecosystems in China. This study used ET measurements of 34 eddy covariance sites within China and...

  9. Remote sensing the vulnerability of vegetation in natural terrestrial ecosystems

    Science.gov (United States)

    Alistair M. S. Smith; Crystal A. Kolden; Wade T. Tinkham; Alan F. Talhelm; John D. Marshall; Andrew T. Hudak; Luigi Boschetti; Michael J. Falkowski; Jonathan A. Greenberg; John W. Anderson; Andrew Kliskey; Lilian Alessa; Robert F. Keefe; James R. Gosz

    2014-01-01

    Climate change is altering the species composition, structure, and function of vegetation in natural terrestrial ecosystems. These changes can also impact the essential ecosystem goods and services derived from these ecosystems. Following disturbances, remote-sensing datasets have been used to monitor the disturbance and describe antecedent conditions as a means of...

  10. Global change and terrestrial ecosystems: the operational plan

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, W.L.; Walker, B.H.; Ingram, J.S.I.; Koch, G.W. (eds.)

    1992-04-01

    The International Geosphere-Biosphere Programme (IGBP) has established a core project on Global Change and Terrestrial Ecosystems (GCTE). The objectives of GCTE are: to predict the effects of changes in climate, atmospheric composition, and land use on terrestrial ecosystems, including agricultural and production forest systems; and to determine how these effects lead to feedbacks to the atmosphere and the physical climate system. The research plan has four foci: ecosystem physiology, change in ecosystem structure, global change impact on agriculture and forestry; and global change and ecological complexity. The research strategy is outlined. 17 refs., 6 figs.

  11. Herbivores Enforce Sharp Boundaries Between Terrestrial and Aquatic Ecosystems

    NARCIS (Netherlands)

    Sarneel, Judith M.; Huig, N.; Veen, G. F.; Rip, W.; Bakker, E. S.

    2014-01-01

    The transitions between ecosystems (ecotones) are often biodiversity hotspots, but we know little about the forces that shape them. Today, often sharp boundaries with low diversity are found between terrestrial and aquatic ecosystems. This has been attributed to environmental factors that hamper

  12. Function of Wildfire-Deposited Pyrogenic Carbon in Terrestrial Ecosystems

    OpenAIRE

    Melissa R. A. Pingree; DeLuca, Thomas H

    2017-01-01

    Fire is an important driver of change in most forest, savannah, and prairie ecosystems and fire-altered organic matter, or pyrogenic carbon (PyC), conveys numerous functions in soils of fire-maintained terrestrial ecosystems. Although an exceptional number of recent review articles and books have addressed agricultural soil application of charcoal or biochar, few reviews have addressed the functional role of naturally formed PyC in fire-maintained ecosystems. Recent advances in molecular spec...

  13. NEON Airborne Remote Sensing of Terrestrial Ecosystems

    Science.gov (United States)

    Kampe, T. U.; Leisso, N.; Krause, K.; Karpowicz, B. M.

    2012-12-01

    The National Ecological Observatory Network (NEON) is the continental-scale research platform that will collect information on ecosystems across the United States to advance our understanding and ability to forecast environmental change at the continental scale. One of NEON's observing systems, the Airborne Observation Platform (AOP), will fly an instrument suite consisting of a high-fidelity visible-to-shortwave infrared imaging spectrometer, a full waveform small footprint LiDAR, and a high-resolution digital camera on a low-altitude aircraft platform. NEON AOP is focused on acquiring data on several terrestrial Essential Climate Variables including bioclimate, biodiversity, biogeochemistry, and land use products. These variables are collected throughout a network of 60 sites across the Continental United States, Alaska, Hawaii and Puerto Rico via ground-based and airborne measurements. Airborne remote sensing plays a critical role by providing measurements at the scale of individual shrubs and larger plants over hundreds of square kilometers. The NEON AOP plays the role of bridging the spatial scales from that of individual organisms and stands to the scale of satellite-based remote sensing. NEON is building 3 airborne systems to facilitate the routine coverage of NEON sites and provide the capacity to respond to investigator requests for specific projects. The first NEON imaging spectrometer, a next-generation VSWIR instrument, was recently delivered to NEON by JPL. This instrument has been integrated with a small-footprint waveform LiDAR on the first NEON airborne platform (AOP-1). A series of AOP-1 test flights were conducted during the first year of NEON's construction phase. The goal of these flights was to test out instrument functionality and performance, exercise remote sensing collection protocols, and provide provisional data for algorithm and data product validation. These test flights focused the following questions: What is the optimal remote

  14. Integrating ecosystem services in terrestrial conservation planning.

    Science.gov (United States)

    Yuan, Mei-Hua; Lo, Shang-Lien; Yang, Chih-Kai

    2017-05-01

    The purpose of this study is to estimate the benefits of ecosystem services for prioritization of land use conservation and to highlight the importance of ecosystem services by comparison between ecosystem service value and green GDP accounting. Based on land use pattern and benefit transfer method, this research estimated value of ecosystem services in Taiwan. Scientific information of land use and land cover change is accessed through multi-year satellite imagery moderate resolution imaging spectroradiometer (MODIS), and geographic information system (GIS) technology. Combined with benefit transfer method, this research estimated the ecosystem service valuation of forest, grassland, cropland, wetland, water, and urban for the period of 2000 to 2015 in Taiwan. It is found that forest made the greatest contribution and the significant increasing area of wetland has huge potential benefit for environmental conservation in Taiwan. We recommend placing maintaining wetland ecosystem in Taiwan with higher priority. This research also compared ecosystem service value with natural capital consumption which would essentially facilitate policy makers to understand the relationship between benefits gained from natural capital and the loss from human-made capital.

  15. Observing terrestrial ecosystems and the carbon cycle from space

    Energy Technology Data Exchange (ETDEWEB)

    Schimel, David [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Pavlick, Ryan [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Fisher, Joshua B. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Asner, Gregory P. [Department of Global Ecology, Carnegie Institution for Science, 260 Panama St. Stanford CA 94305 USA; Saatchi, Sassan [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Townsend, Philip [University of Wisconsin-Madison, Madison WI 53706 USA; Miller, Charles [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Frankenberg, Christian [Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA 91101 USA; Hibbard, Kathy [Pacific Northwest National Laboratory, PO Box 999 MSIN: K9-34 Richland WA 99352 USA; Cox, Peter [College of Engineering, Mathematics and Physical Sciences, University of Exeter, North Park Road Streatham Campus Harrison Building Exeter EX4 4QF UK

    2015-02-06

    Modeled terrestrial ecosystem and carbon cycle feedbacks contribute substantial uncertainty to projections of future climate. The limitations of current observing networks contribute to this uncertainty. Here we present a current climatology of global model predictions and observations for photosynthesis, biomass, plant diversity and plant functional diversity. Carbon cycle tipping points occur in terrestrial regions where fluxes or stocks are largest, and where biological variability is highest, the tropics and Arctic/Boreal zones. Global observations are predominately in the mid-latitudes and are sparse in high and low latitude ecosystems. Observing and forecasting ecosystem change requires sustained observations of sufficient density in time and space in critical regions. Using data and theory available now, we can develop a strategy to detect and forecast terrestrial carbon cycle-climate interactions, by combining in situ and remote techniques.

  16. The Functionally-Assembled Terrestrial Ecosystem Simulator Version 1

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-02

    The Functionally-Assembled Terrestrial Ecosystem Simulator (FATES) is a vegetation model for use in Earth system models (ESMs). The model includes a size- and age-structured representation of tree dynamics, competition between functionally diverse plant functional types, and the biophysics underpinning plant growth, competition, mortality, as well as the carbon, water, and energy exchange with the atmosphere. The FATES model is designed as a modular vegetation model that can be integrated within a host land model for inclusion in ESMs. The model is designed for use in global change studies to understand and project the responses and feedbacks between terrestrial ecosystems and the Earth system under changing climate and other forcings.

  17. Soil inoculation steers restoration of terrestrial ecosystems

    NARCIS (Netherlands)

    Wubs, E.R.J.; Putten, van der W.H.; Bosch, M.; Bezemer, T.M.

    2016-01-01

    Many natural ecosystems have been degraded because of
    human activities1,2 and need to be restored so that biodiversity
    is protected. However, restoration can take decades and restoration
    activities are often unsuccessful3 because of abiotic
    constraints (for example, eutrophication,

  18. Soil inoculation steers restoration of terrestrial ecosystems

    NARCIS (Netherlands)

    Wubs, E.R.J.; van der Putten, W.H.; Bosch, M.; Bezemer, T.M. Bezemer

    2016-01-01

    Many natural ecosystems have been degraded because of human activities1,2 and need to be restored so that biodiversity is protected. However, restoration can take decades and restoration activities are often unsuccessful3 because of abiotic constraints (for example, eutrophication, acidification)

  19. Identifying and prioritising services in European terrestrial and freshwater ecosystems

    OpenAIRE

    Harrison, P. A.; Vandewalle, M; Sykes, M.T.; Berry, P. M. (Peter M.); Bugter, R.J.F.; Bello,; Feld, C.K.; Grandin, U.; Harrington, R.; Haslett, J.R.; Jongman, R. H. G.; Luck, G.W.; Martins da Silva, P.; Moora, M.; Settele, J.

    2010-01-01

    Ecosystems are multifunctional and provide humanity with a broad array of vital services. Effective management of services requires an improved evidence base, identifying the role of ecosystems in delivering multiple services, which can assist policy-makers in maintaining them. Here, information from the literature and scientific experts was used to systematically document the importance of services and identify trends in their use and status over time for the main terrestrial and freshwater ...

  20. Terrestrial ecosystem responses to global change: A research strategy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    Uncertainty about the magnitude of global change effects on terrestrial ecosystems and consequent feedbacks to the atmosphere impedes sound policy planning at regional, national, and global scales. A strategy to reduce these uncertainties must include a substantial increase in funding for large-scale ecosystem experiments and a careful prioritization of research efforts. Prioritization criteria should be based on the magnitude of potential changes in environmental properties of concern to society, including productivity; biodiversity; the storage and cycling of carbon, water, and nutrients; and sensitivity of specific ecosystems to environmental change. A research strategy is proposed that builds on existing knowledge of ecosystem responses to global change by (1) expanding the spatial and temporal scale of experimental ecosystem manipulations to include processes known to occur at large scales and over long time periods; (2) quantifying poorly understood linkages among processes through the use of experiments that manipulate multiple interacting environmental factors over a broader range of relevant conditions than did past experiments; and (3) prioritizing ecosystems for major experimental manipulations on the basis of potential positive and negative impacts on ecosystem properties and processes of intrinsic and/or utilitarian value to humans and on feedbacks of terrestrial ecosystems to the atmosphere.

  1. Effects of carbon turnover time on terrestrial ecosystem carbon storage

    Science.gov (United States)

    Yan, Yaner; Zhou, Xuhui; Jiang, Lifeng; Luo, Yiqi

    2017-12-01

    Carbon (C) turnover time is a key factor in determining C storage capacity in various plant and soil pools as well as terrestrial C sink in a changing climate. However, the effects of C turnover time on ecosystem C storage have not been well explored. In this study, we compared mean C turnover times (MTTs) of ecosystem and soil, examined their variability to climate, and then quantified the spatial variation in ecosystem C storage over time from changes in C turnover time and/or net primary production (NPP). Our results showed that mean ecosystem MTT based on gross primary production (GPP; MTTEC_GPP = Cpool/GPP, 25.0 ± 2.7 years) was shorter than soil MTT (MTTsoil = Csoil/NPP, 35.5 ± 1.2 years) and NPP-based ecosystem MTT (MTTEC_NPP = Cpool/NPP, 50.8 ± 3 years; Cpool and Csoil referred to ecosystem or soil C storage, respectively). On the biome scale, temperature is the best predictor for MTTEC (R2 = 0.77, p < 0.001) and MTTsoil (R2 = 0.68, p < 0.001), while the inclusion of precipitation in the model did not improve the performance of MTTEC (R2 = 0.76, p < 0.001). Ecosystem MTT decreased by approximately 4 years from 1901 to 2011 when only temperature was considered, resulting in a large C release from terrestrial ecosystems. The resultant terrestrial C release caused by the decrease in MTT only accounted for about 13.5 % of that due to the change in NPP uptake (159.3 ± 1.45 vs. 1215.4 ± 11.0 Pg C). However, the larger uncertainties in the spatial variation of MTT than temporal changes could lead to a greater impact on ecosystem C storage, which deserves further study in the future.

  2. Experimental nutrient additions accelerate terrestrial carbon loss from stream ecosystems

    Science.gov (United States)

    Amy D. Rosemond; Jonathan P. Benstead; Phillip M. Bumpers; Vladislav Gulis; John S. Kominoski; David W.P. Manning; Keller Suberkropp; J. Bruce. Wallace

    2015-01-01

    Nutrient pollution of freshwater ecosystems results in predictable increases in carbon (C) sequestration by algae. Tests of nutrient enrichment on the fates of terrestrial organic C, which supports riverine food webs and is a source of CO2, are lacking. Using whole-stream nitrogen (N) and phosphorus (P) additions spanning the equivalent of 27 years, we found that...

  3. Enchytraeids as indicator organisms for chemical stress in terrestrial ecosystems

    NARCIS (Netherlands)

    Didden, W.; Römbke, J.

    2001-01-01

    This review article surveys the available data on enchytraeid sensitivity toward chemical stress, and the effects of chemical stress on enchytraeid communities in terrestrial ecosystems. The factors affecting bioavailability of stressors to enchytraeids and the nature of direct and indirect effects

  4. Microplastics as an emerging threat to terrestrial ecosystems.

    Science.gov (United States)

    de Souza Machado, Anderson Abel; Kloas, Werner; Zarfl, Christiane; Hempel, Stefan; Rillig, Matthias C

    2017-12-15

    Microplastics (plastics microplastics might first interact with biota eliciting ecologically relevant impacts. This article introduces the pervasive microplastic contamination as a potential agent of global change in terrestrial systems, highlights the physical and chemical nature of the respective observed effects, and discusses the broad toxicity of nanoplastics derived from plastic breakdown. Making relevant links to the fate of microplastics in aquatic continental systems, we here present new insights into the mechanisms of impacts on terrestrial geochemistry, the biophysical environment, and ecotoxicology. Broad changes in continental environments are possible even in particle-rich habitats such as soils. Furthermore, there is a growing body of evidence indicating that microplastics interact with terrestrial organisms that mediate essential ecosystem services and functions, such as soil dwelling invertebrates, terrestrial fungi, and plant-pollinators. Therefore, research is needed to clarify the terrestrial fate and effects of microplastics. We suggest that due to the widespread presence, environmental persistence, and various interactions with continental biota, microplastic pollution might represent an emerging global change threat to terrestrial ecosystems. © 2017 John Wiley & Sons Ltd.

  5. Global variation of carbon use efficiency in terrestrial ecosystems

    Science.gov (United States)

    Tang, Xiaolu; Carvalhais, Nuno; Moura, Catarina; Reichstein, Markus

    2017-04-01

    Carbon use efficiency (CUE), defined as the ratio between net primary production (NPP) and gross primary production (GPP), is an emergent property of vegetation that describes its effectiveness in storing carbon (C) and is of significance for understanding C biosphere-atmosphere exchange dynamics. A constant CUE value of 0.5 has been widely used in terrestrial C-cycle models, such as the Carnegie-Ames-Stanford-Approach model, or the Marine Biological Laboratory/Soil Plant-Atmosphere Canopy Model, for regional or global modeling purposes. However, increasing evidence argues that CUE is not constant, but varies with ecosystem types, site fertility, climate, site management and forest age. Hence, the assumption of a constant CUE of 0.5 can produce great uncertainty in estimating global carbon dynamics between terrestrial ecosystems and the atmosphere. Here, in order to analyze the global variations in CUE and understand how CUE varies with environmental variables, a global database was constructed based on published data for crops, forests, grasslands, wetlands and tundra ecosystems. In addition to CUE data, were also collected: GPP and NPP; site variables (e.g. climate zone, site management and plant function type); climate variables (e.g. temperature and precipitation); additional carbon fluxes (e.g. soil respiration, autotrophic respiration and heterotrophic respiration); and carbon pools (e.g. stem, leaf and root biomass). Different climate metrics were derived to diagnose seasonal temperature (mean annual temperature, MAT, and maximum temperature, Tmax) and water availability proxies (mean annual precipitation, MAP, and Palmer Drought Severity Index), in order to improve the local representation of environmental variables. Additionally were also included vegetation phenology dynamics as observed by different vegetation indices from the MODIS satellite. The mean CUE of all terrestrial ecosystems was 0.45, 10% lower than the previous assumed constant CUE of 0

  6. Shallow groundwater subsidies to terrestrial ecosystems (Invited)

    Science.gov (United States)

    Jackson, R. B.; Jayawickreme, D.; Nosetto, M.; Jobbagy, E. G.

    2010-12-01

    Throughout the world, shallow groundwater systems subsidize much higher net primary productivity (NPP) than would be expected based solely on local rainfall. Such subsidies are far more prevalent and less recognized in upland systems than in more commonly studied riparian ones. We present a quantitative framework for examining and quantifying groundwater subsidies globally, illustrating subsidies to NPP across rainfall gradients in Argentina and the southern United States, including Texas and California. In the Argentine Pampas, we determined that the presence of relatively shallow ground water increased the transpiration of forest plantations by 300 to 400 mm. Farther west, the presence of well developed Prosopis flexuosa woodlands in the Monte desert region east of the Andes has puzzled scientists for decades. We explored the vulnerability and importance of phreatic ground water for the productivity of the region, comparing the contributions of local rainfall to that of remote mountain recharge that is increasingly being diverted for irrigated agriculture before it reaches the desert. The isotopic composition of phreatic ground waters (δ2H; -137±5 ‰) closely matched the signature of water brought to the region by the Mendoza River (-137±6 ‰), suggesting that mountain river infiltration rather than in-situ rainfall deep drainage (-39±19 ‰) was the dominant mechanism of recharge. Vegetation in woodland ecosystems there relied on regionally derived ground water from Andean snowmelt located from 6.5 to 9.5 m underground. Understanding the ecohydrological coupling of surface and ground waters is vital for estimating net primary productivity and for balancing the demands of managed ecosystems with the conservation of unique natural systems.

  7. Early terrestrial ecosystems: the animal evidence

    Energy Technology Data Exchange (ETDEWEB)

    Gray, J.

    1985-01-01

    Work on fossil spores indicates that plants at a level of vegetative organization comparable to bryophytes and vascular plants existed on land in the Early Silurian. Vascular plants, limnetic fishes, and probable Ascomycetes have Late Silurian records. Charophytes are known in the Late Silurian but may have been marine. The presence of microarthropods in the Ludlovian has been hypothesized from fungal masses in the Burgsvik Sandstone that closely resemble microarthropod frass. A number of microarthropods such as collembolans and mites are microphagous; these animals are among the earliest known from the Early Devonian. These fungal masses as animal traces have been given added credibility by the recovery of animal body fossils from basal Llandovery age fluvial deposits of the Central Appalachians that yield abundant plant spores but that lack marine invertebrates, phytoplankton or chitinozoans. The remains are abundant and sufficiently varied to suggest that they may represent a variety of organisms. Some are eurypterid-like, others grossly arthropod-like, although they may represent an unknown phylum or phyla. Many small invertebrates are associated with extant bryophytes, which have been viewed as stepping stones or halfway houses for them as they emerged from water onto land. The occurrence of these Early Silurian invertebrate remains with abundant spore tetrads, which Gray has hypothesized represent land plants at a bryophyte or hepatic grade of organization, is of great interest in trying to understand the early development of nonmarine ecosystems.

  8. The potential for regime shifts in high latitude terrestrial ecosystems

    Science.gov (United States)

    Beck, P. S.; Goetz, S. J.

    2011-12-01

    Climate constrains the extent of the two major terrestrial biomes at high latitudes: boreal forests and arctic tundra. Model simulations provide considerable evidence that physical and biogeochemical feedbacks from these regions to the climate system act to maintain a status quo of climate and biome distribution. Ongoing anthropogenically driven changes in climate are particularly pronounced in high latitude regions, and empirical evidence for their influence on tundra and boreal ecosystems is mounting. Global vegetation models project changes to accelerate in coming decades, culminating in profound shifts in high latitude biomes by the end of this century. Regime shifts are surprisingly large changes in a system that occur when a it moves between alternative stable states ('attractors'), without the equivalent large shift of an external driver. In association with climate change, regime shifts in ecosystems could theoretically generate significant modifications to ecosystem-climate feedbacks, in the Arctic for example through the respiration or combustion of large amounts of soil carbon. Here we review evidence for historical regime shifts in terrestrial ecosystems at high latitudes, including shifts in species dominance and distribution. We describe ongoing changes in characteristics of these ecosystems, including vegetation productivity, composition, and the fire regime, and discuss whether they can be indicators of impeding regime shifts. Finally, we discuss the potential of exploiting regime shifts in tundra and boreal systems for climate change mitigation or resource management by forcing ecosystems to shift towards a more desirable stable state.

  9. A new map of standardized terrestrial ecosystems of Africa

    Science.gov (United States)

    Sayre, Roger G.; Comer, Patrick; Hak, Jon; Josse, Carmen; Bow, Jacquie; Warner, Harumi; Larwanou, Mahamane; Kelbessa, Ensermu; Bekele, Tamrat; Kehl, Harald; Amena, Ruba; Andriamasimanana, Rado; Ba, Taibou; Benson, Laurence; Boucher, Timothy; Brown, Matthew; Cress, Jill J.; Dassering, Oueddo; Friesen, Beverly A.; Gachathi, Francis; Houcine, Sebei; Keita, Mahamadou; Khamala, Erick; Marangu, Dan; Mokua, Fredrick; Morou, Boube; Mucina, Ladislav; Mugisha, Samuel; Mwavu, Edward; Rutherford, Michael; Sanou, Patrice; Syampungani, Stephen; Tomor, Bojoi; Vall, Abdallahi Ould Mohamed; Vande Weghe, Jean Pierre; Wangui, Eunice; Waruingi, Lucy

    2013-01-01

    Terrestrial ecosystems and vegetation of Africa were classified and mapped as part of a larger effort and global protocol (GEOSS – the Global Earth Observation System of Systems), which includes an activity to map terrestrial ecosystems of the earth in a standardized, robust, and practical manner, and at the finest possible spatial resolution. To model the potential distribution of ecosystems, new continental datasets for several key physical environment datalayers (including coastline, landforms, surficial lithology, and bioclimates) were developed at spatial and classification resolutions finer than existing similar datalayers. A hierarchical vegetation classification was developed by African ecosystem scientists and vegetation geographers, who also provided sample locations of the newly classified vegetation units. The vegetation types and ecosystems were then mapped across the continent using a classification and regression tree (CART) inductive model, which predicted the potential distribution of vegetation types from a suite of biophysical environmental attributes including bioclimate region, biogeographic region, surficial lithology, landform, elevation and land cover. Multi-scale ecosystems were classified and mapped in an increasingly detailed hierarchical framework using vegetation-based concepts of class, subclass, formation, division, and macrogroup levels. The finest vegetation units (macrogroups) classified and mapped in this effort are defined using diagnostic plant species and diagnostic growth forms that reflect biogeographic differences in composition and sub-continental to regional differences in mesoclimate, geology, substrates, hydrology, and disturbance regimes (FGDC, 2008). The macrogroups are regarded as meso-scale (100s to 10,000s of hectares) ecosystems. A total of 126 macrogroup types were mapped, each with multiple, repeating occurrences on the landscape. The modeling effort was implemented at a base spatial resolution of 90 m. In

  10. Resource subsidies between stream and terrestrial ecosystems under global change

    Science.gov (United States)

    Larsen, Stefano; Muehlbauer, Jeffrey D.; Marti Roca, Maria Eugenia

    2016-01-01

    Streams and adjacent terrestrial ecosystems are characterized by permeable boundaries that are crossed by resource subsidies. Although the importance of these subsidies for riverine ecosystems is increasingly recognized, little is known about how they may be influenced by global environmental change. Drawing from available evidence, in this review we propose a conceptual framework to evaluate the effects of global change on the quality and spatiotemporal dynamics of stream–terrestrial subsidies. We illustrate how changes to hydrological and temperature regimes, atmospheric CO2 concentration, land use and the distribution of nonindigenous species can influence subsidy fluxes by affecting the biology and ecology of donor and recipient systems and the physical characteristics of stream–riparian boundaries. Climate-driven changes in the physiology and phenology of organisms with complex life cycles will influence their development time, body size and emergence patterns, with consequences for adjacent terrestrial consumers. Also, novel species interactions can modify subsidy dynamics via complex bottom-up and top-down effects. Given the seasonality and pulsed nature of subsidies, alterations of the temporal and spatial synchrony of resource availability to consumers across ecosystems are likely to result in ecological mismatches that can scale up from individual responses, to communities, to ecosystems. Similarly, altered hydrology, temperature, CO2 concentration and land use will modify the recruitment and quality of riparian vegetation, the timing of leaf abscission and the establishment of invasive riparian species. Along with morphological changes to stream–terrestrial boundaries, these will alter the use and fluxes of allochthonous subsidies associated with stream ecosystems. Future research should aim to understand how subsidy dynamics will be affected by key drivers of global change, including agricultural intensification, increasing water use and biotic

  11. Some effects of pollutants in terrestrial ecosystems

    Science.gov (United States)

    Stickel, W.H.; McIntyre, A.D.; Mills, C.F.

    1975-01-01

    occur when persistent chemicals enter organisms that eliminate them poorly. However, loss of chemicals in the food chain must be more common than accumulation. The great concentration from water to aquatic organism is chiefly a physical phenomenon, not a food chain effect, but it affords high starting levels for these chains. Terrestrial food chains often start at a high level with heavily contaminated, struggling prey. Litter feeders are another important base. Vegetation may be contaminated enough to be dangerous to animals that eat it. Dermal and respiratory routes of intoxication occur in the wild, but the oral route is far more important at most times and places. The organisms that govern soil fertility and texture are affected more by cultivation than by pesticides. Above ground, growing knowledge of resistance, species differences, and biological controls is leading to integrated control, in which use of chemicals is limited and specific. We do not know what is happening to most nontarget invertebrates. Amphibians and reptiles may be killed by applications of insecticides, but are not highly sensitive and can carry large residues. Effects of these residues on reproduction are little known. Heavy kills of birds by pesticides still occur in the field. Fish-eating and bird-eating birds also undergo shell thinning and related reproductive troubles in many areas, sometimes to the point of population decline and local or regional extermination. DDE most often correlates with shell thinning in the wild and in experiments. No other known chemical approaches DDE in causing severe and lasting shell thinning. Herbivorous birds seem to be largely immune to this effect. It is uncertain how much dieldrin and PCBs contribute to embryotoxicity in carnivorous birds. Mammals may be killed by the more toxic pesticides, but some of the commonest small rodents are so resistant, and lose their residues so rapidly, that they are of little

  12. How lichens impact on terrestrial community and ecosystem properties.

    Science.gov (United States)

    Asplund, Johan; Wardle, David A

    2017-08-01

    Lichens occur in most terrestrial ecosystems; they are often present as minor contributors, but in some forests, drylands and tundras they can make up most of the ground layer biomass. As such, lichens dominate approximately 8% of the Earth's land surface. Despite their potential importance in driving ecosystem biogeochemistry, the influence of lichens on community processes and ecosystem functioning have attracted relatively little attention. Here, we review the role of lichens in terrestrial ecosystems and draw attention to the important, but often overlooked role of lichens as determinants of ecological processes. We start by assessing characteristics that vary among lichens and that may be important in determining their ecological role; these include their growth form, the types of photobionts that they contain, their key functional traits, their water-holding capacity, their colour, and the levels of secondary compounds in their thalli. We then assess how these differences among lichens influence their impacts on ecosystem and community processes. As such, we consider the consequences of these differences for determining the impacts of lichens on ecosystem nutrient inputs and fluxes, on the loss of mass and nutrients during lichen thallus decomposition, and on the role of lichenivorous invertebrates in moderating decomposition. We then consider how differences among lichens impact on their interactions with consumer organisms that utilize lichen thalli, and that range in size from microfauna (for which the primary role of lichens is habitat provision) to large mammals (for which lichens are primarily a food source). We then address how differences among lichens impact on plants, through for example increasing nutrient inputs and availability during primary succession, and serving as a filter for plant seedling establishment. Finally we identify areas in need of further work for better understanding the role of lichens in terrestrial ecosystems. These include

  13. The carbon balance of terrestrial ecosystems of China

    Directory of Open Access Journals (Sweden)

    Pilli R

    2009-05-01

    Full Text Available A comment is made on a recent letter published on Nature, in which different methodologies are applied to estimate the carbon balance of terrestrial ecosystems of China. A global carbon sink of 0.19-0.26 Pg per year is estimated during the 1980s and 1990s, and it is estimated that in 2006 terrestrial ecosystems have absorbed 28-37 per cent of global carbon emissions in China. Most of the carbon absorption is attributed to large-scale plantation made since the 1980s and shrub recovery. These results will certainly be valuable in the frame of the so-called “REDD” (Reducing Emissions from Deforestation forest Degradation in developing countries mechanism (UN convention on climate change UNFCCC.

  14. VALUING THE IMPACTS OF CLIMATE CHANGE ON TERRESTRIAL ECOSYSTEM SERVICES

    OpenAIRE

    ALAN KRUPNICK; DAVID McLAUGHLIN

    2012-01-01

    Climate change is already having impacts on terrestrial ecosystem services and such impacts are only expected to broaden and worsen as greenhouse gas emissions (GHGs) continue at their historic levels. To set appropriate policies for reducing GHG emissions, economists recommend the use of cost-benefit analysis. To perform such analyses, the predominant approach has been to use integrated assessment models. There is a need for more targeted valuation studies to serve as further evidence about ...

  15. Terrestrial Ecosystem Responses to Global Change: A Research Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Ecosystems Working Group,

    1998-09-23

    Uncertainty about the magnitude of global change effects on terrestrial ecosystems and consequent feedbacks to the atmosphere impedes sound policy planning at regional, national, and global scales. A strategy to reduce these uncertainties must include a substantial increase in funding for large-scale ecosystem experiments and a careful prioritization of research efforts. Prioritization criteria should be based on the magnitude of potential changes in environmental properties of concern to society, including productivity; biodiversity; the storage and cycling of carbon, water, and nutrients; and sensitivity of specific ecosystems to environmental change. A research strategy is proposed that builds on existing knowledge of ecosystem responses to global change by (1) expanding the spatial and temporal scale of experimental ecosystem manipulations to include processes known to occur at large scales and over long time periods; (2) quantifying poorly understood linkages among processes through the use of experiments that manipulate multiple interacting environmental factors over a broader range of relevant conditions than did past experiments; and (3) prioritizing ecosystems for major experimental manipulations on the basis of potential positive and negative impacts on ecosystem properties and processes of intrinsic and/or utilitarian value to humans and on feedbacks of terrestrial ecosystems to the atmosphere. Models and experiments are equally important for developing process-level understanding into a predictive capability. To support both the development and testing of mechanistic ecosystem models, a two-tiered design of ecosystem experiments should be used. This design should include both (1) large-scale manipulative experiments for comprehensive testing of integrated ecosystem models and (2) multifactor, multilevel experiments for parameterization of process models across the critical range of interacting environmental factors (CO{sub 2}, temperature, water

  16. Microplastics in the Terrestrial Ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae).

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2016-03-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, microplastics in the litter than at 7% w/w and in the control (0%). Growth rate was significantly reduced at 28, 45, and 60% w/w microplastics, compared to the 7% and control treatments. Due to the digestion of ingested organic matter, microplastic was concentrated in cast, especially at the lowest dose (i.e., 7% in litter) because that dose had the highest proportion of digestible organic matter. Whereas 50 percent of the microplastics had a size of microplastics in the casts was microplastic in terrestrial ecosystems.

  17. Reduced terrestrial ecosystem carbon uptake under future climate

    Science.gov (United States)

    Beier, C.; Larsen, K. S.; Ambus, P.; Ibrom, A.; Arndal, M. F.; Schmidt, I. K.

    2014-12-01

    Elevated atmospheric carbon dioxide stimulates plant productivity and ecosystem carbon gain but may also stimulate respiratory processes and thereby ecosystem carbon loss with the net balance being generally uncertain. In addition, climate driven warming and altered precipitation regimes under future climate also affects both uptake and release of carbon from terrestrial ecosystems making the net effect of climate change on ecosystem carbon budgets highly uncertain. In order to understand the response of these climate change driven changes, a large number of ecosystem experiments with single climate change factors have been conducted providing insight into the response of processes as well as ecosystems. However, ecosystems may respond in a complex and interactive way when all drivers of biological activity change in concert, which may not be well covered by past experiments nor reflected in existing Earth System Models causing potential over-prediction of future ecosystem carbon storage. It is therefore critical for future climate projections to understand better how changes in climate will interact with the effects of elevated CO2. In a Danish climate change experiment, CLIMAITE, a shrubland ecosystem was exposed to all three main climate change factors, elevated CO2 and temperature and altered precipitation and the impacts on a range of ecosystem processes as well as the overall feedback to the atmosphere were studied and quantified. The measurements include direct measurements of carbon feedback from each experimental plot, which is almost never measured in elevated CO2 experiments for practical reasons. Our unique results show that long-term (seven years) simultaneous exposure to all climate change factors reduced the carbon storage of the shrubland ecosystem while in contrast, exposure to single factors individually led to either no change or increased carbon storage. This demonstrates significant interactions among climate change factors, especially when CO2

  18. Climate legacies drive global soil carbon stocks in terrestrial ecosystems.

    Science.gov (United States)

    Delgado-Baquerizo, Manuel; Eldridge, David J; Maestre, Fernando T; Karunaratne, Senani B; Trivedi, Pankaj; Reich, Peter B; Singh, Brajesh K

    2017-04-01

    Climatic conditions shift gradually over millennia, altering the rates at which carbon (C) is fixed from the atmosphere and stored in the soil. However, legacy impacts of past climates on current soil C stocks are poorly understood. We used data from more than 5000 terrestrial sites from three global and regional data sets to identify the relative importance of current and past (Last Glacial Maximum and mid-Holocene) climatic conditions in regulating soil C stocks in natural and agricultural areas. Paleoclimate always explained a greater amount of the variance in soil C stocks than current climate at regional and global scales. Our results indicate that climatic legacies help determine global soil C stocks in terrestrial ecosystems where agriculture is highly dependent on current climatic conditions. Our findings emphasize the importance of considering how climate legacies influence soil C content, allowing us to improve quantitative predictions of global C stocks under different climatic scenarios.

  19. Using Ant Communities For Rapid Assessment Of Terrestrial Ecosystem Health

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L

    2005-06-01

    relative health of the ecosystem. The IBI, though originally for Midwestern streams, has been successfully adapted to other ecoregions and taxa (macroinvertebrates, Lombard and Goldstein, 2004) and has become an important tool for scientists and regulatory agencies alike in determining health of stream ecosystems. The IBI is a specific type of a larger group of methods and procedures referred to as Rapid Bioassessment (RBA). These protocols have the advantage of directly measuring the organisms affected by system perturbations, thus providing an integrated evaluation of system health because the organisms themselves integrate all aspects of their environment and its condition. In addition to the IBI, the RBA concept has also been applied to seep wetlands (Paller et al. 2005) and terrestrial systems (O'Connell et al. 1998, Kremen et al. 1993, Rodriguez et al. 1998, Rosenberg et al. 1986). Terrestrial RBA methods have lagged somewhat behind those for aquatic systems because terrestrial systems are less distinctly defined and seem to have a less universal distribution of an all-inclusive taxon, such as fish in the IBI, upon which to base an RBA. In the last decade, primarily in Australia, extensive development of an RBA using ant communities has shown great promise. Ants have the same advantage for terrestrial RBAs that fish do for aquatic systems in that they are an essential and ubiquitous component of virtually all terrestrial ecosystems. They occupy a broad range of niches, functional groups, and trophic levels and they possess one very important characteristic that makes them ideal for RBA because, similar to the fishes, there is a wide range of tolerance to conditions within the larger taxa. Within ant communities there are certain groups, genera, or species that may be very robust and abundant under even the harshest impacts. There are also taxa that are very sensitive to disturbance and change and their presence or absence is also indicative of the local

  20. Factors influencing DOC leaching from terrestrial ecosystems: a database analysis

    Science.gov (United States)

    Camino Serrano, M.; Janssens, I.; Luyssaert, S.; Ciais, P.; Gielen, B.

    2012-04-01

    The lateral transport of dissolved organic carbon (DOC) is an important process linking terrestrial and aquatic ecosystems. Neglecting these fluxes can lead to biased of eddy covariance-based estimates of terrestrial ecosystem carbon sequestration. The necessity for integrating DOC leaching in carbon cycle models is thus clear, especially in view of future model development aiming at directly linking terrestrial, freshwater and ocean carbon cycles. However, to achieve this goal, more accurate information is needed in order to better understand and predict dissolved organic carbon dynamics. DOC concentrations mainly vary by geographical location, soil and vegetation types, topography, season and climate. Within this framework, we developed a database on DOC concentrations and fluxes with the aim of better understanding how those parameters determine DOC variations. This database compiles DOC concentrations and fluxes in soil solution and creeks at site or catchment level for different ecosystems around the world, but with special focus on the Northern Hemisphere and on peatland ecosystems. The database currently includes information from around 120 sites, gathered from published literature and datasets accessible on the internet. The database contains annual, seasonal and monthly data on DOC, dissolved inorganic carbon (DIC), dissolved organic nitrogen (DON) and dissolved inorganic nitrogen (DIN) and also includes other meta-data related to the site, such as land cover, soil properties, climate, annual water balance and other soil solution parameters. This compiled dataset allows to study the influence of several physical factors that determine DOC production in soils. We will present the observed relationships between drivers, such as precipitation, drainage flows, soil pH, soil texture, and DOC concentration/ DOC fluxes at different levels, ecosystem types, temporal scales (monthly versus annual or seasonal), and soil depths. The same relations will be analysed

  1. The roles of productivity and ecosystem size in determining food chain length in tropical terrestrial ecosystems.

    Science.gov (United States)

    Young, Hillary S; McCauley, Douglas J; Dunbar, Robert B; Hutson, Michael S; Ter-Kuile, Ana Miller; Dirzo, Rodolfo

    2013-03-01

    Many different drivers, including productivity, ecosystem size, and disturbance, have been considered to explain natural variation in the length of food chains. Much remains unknown about the role of these various drivers in determining food chain length, and particularly about the mechanisms by which they may operate in terrestrial ecosystems, which have quite different ecological constraints than aquatic environments, where most food chain length studies have been thus far conducted. In this study, we tested the relative importance of ecosystem size and productivity in influencing food chain length in a terrestrial setting. We determined that (1) there is no effect of ecosystem size or productive space on food chain length; (2) rather, food chain length increases strongly and linearly with productivity; and (3) the observed changes in food chain length are likely achieved through a combination of changes in predator size, predator behavior, and consumer diversity along gradients in productivity. These results lend new insight into the mechanisms by which productivity can drive changes in food chain length, point to potential for systematic differences in the drivers of food web structure between terrestrial and aquatic systems, and challenge us to consider how ecological context may control the drivers that shape food chain length.

  2. Cascading effects of induced terrestrial plant defences on aquatic and terrestrial ecosystem function.

    Science.gov (United States)

    Jackrel, Sara L; Wootton, J Timothy

    2015-04-22

    Herbivores induce plants to undergo diverse processes that minimize costs to the plant, such as producing defences to deter herbivory or reallocating limited resources to inaccessible portions of the plant. Yet most plant tissue is consumed by decomposers, not herbivores, and these defensive processes aimed to deter herbivores may alter plant tissue even after detachment from the plant. All consumers value nutrients, but plants also require these nutrients for primary functions and defensive processes. We experimentally simulated herbivory with and without nutrient additions on red alder (Alnus rubra), which supplies the majority of leaf litter for many rivers in western North America. Simulated herbivory induced a defence response with cascading effects: terrestrial herbivores and aquatic decomposers fed less on leaves from stressed trees. This effect was context dependent: leaves from fertilized-only trees decomposed most rapidly while leaves from fertilized trees receiving the herbivory treatment decomposed least, suggesting plants funnelled a nutritionally valuable resource into enhanced defence. One component of the defence response was a decrease in leaf nitrogen leading to elevated carbon : nitrogen. Aquatic decomposers prefer leaves naturally low in C : N and this altered nutrient profile largely explains the lower rate of aquatic decomposition. Furthermore, terrestrial soil decomposers were unaffected by either treatment but did show a preference for local and nitrogen-rich leaves. Our study illustrates the ecological implications of terrestrial herbivory and these findings demonstrate that the effects of selection caused by terrestrial herbivory in one ecosystem can indirectly shape the structure of other ecosystems through ecological fluxes across boundaries. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Terrestrial Ecosystems - Topographic Moisture Potential of the Conterminous United States

    Science.gov (United States)

    Cress, Jill J.; Sayre, Roger G.; Comer, Patrick; Warner, Harumi

    2009-01-01

    As part of an effort to map terrestrial ecosystems, the U.S. Geological Survey has generated topographic moisture potential classes to be used in creating maps depicting standardized, terrestrial ecosystem models for the conterminous United States, using an ecosystems classification developed by NatureServe. A biophysical stratification approach, developed for South America and now being implemented globally, was used to model the ecosystem distributions. Substrate moisture regimes strongly influence the differentiation and distribution of terrestrial ecosystems, and therefore topographic moisture potential is one of the key input layers in this biophysical stratification. The method used to produce these topographic moisture potential classes was based on the derivation of ground moisture potential using a combination of computed topographic characteristics (CTI, slope, and aspect) and mapped National Wetland Inventory (NWI) boundaries. This method does not use climate or soil attributes to calculate relative topographic moisture potential since these characteristics are incorporated into the ecosystem model though other input layers. All of the topographic data used for this assessment were derived from the USGS 30-meter National Elevation Dataset (NED ) including the National Compound Topographic Index (CTI). The CTI index is a topographically derived measure of slope for a raster cell and the contributing area from upstream raster cells, and thus expresses potential for water flow to a point. In other words CTI data are 'a quantification of the position of a site in the local landscape', where the lowest values indicate ridges and the highest values indicate stream channels, lakes and ponds. These CTI values were compared to independent estimates of water accumulation by obtaining geospatial data from a number of sample locations representing two types of NWI boundaries: freshwater emergent wetlands and freshwater forested/shrub wetlands. Where these shorelines

  4. Biomass Resources Distribution in the Terrestrial Ecosystem of China

    Directory of Open Access Journals (Sweden)

    Na Li

    2015-07-01

    Full Text Available In this study, Moderate Resolution Imaging Spectroradiometer (MODIS data and the multiple linear regression model were used to estimate distribution of biomass resources in 2010. The establishment of models, developed using different vegetation biomass sample data, normalized difference vegetation index (NDVI, leaf area index (LAI, meteorological data, coordinates, terrain data, and statistical data. Results based on a cross-validation approach show that the model can explain 95.6% of the variance in biomass, with a relative estimation error of 67 g·m−2 for a range of biomass between 0–73,875 g·m−2. Spatial statistic results were consistent with the practical condition in most cases. The above- and below-ground biomass (ABGB of China was estimated to be 31.1 Pg (1 Pg = 1015 g in 2010. The forest ecosystem has the largest total biomass, which represents about 70% of the whole terrestrial ecosystem. The desert ecosystem has minimum biomass value. The Belowground Endowment (BRE varied differently in spatial distribution, with the high values occurring in the southeast and northeast. The low values were primarily distributed in north and northwest regions, where it is mostly desert and few plants. Biomass per capita indicates the availability of natural resources per capita. Tibet had the maximum biomass per capita (807 tone in 2010. Shanghai and Tianjin had the minimum biomass per capita, less than 500 kg. Shanghai, Tianjin, Guangzhou, Beijing, and Hainan had negative growth of biomass per capita.

  5. Terrestrial ecosystem nowcasts and forecasts for North America

    Science.gov (United States)

    Nemani, R. R.; Votava, P.; Michaelis, A.; Ichii, K.; Hashimoto, H.; Milesi, C.; Dungan, J.; White, M.

    2006-12-01

    Understanding and predicting changes in carbon cycling of landscapes and adjacent oceans are important goals for the North American Carbon Program (NACP). Achieving these goals requires integration of a number of data sources that are both point-based and spatially explicit, as in the case of satellite data, and models to produce ecosystem fluxes at a variety of spatio-temporal scales. Here we show an adaptation of our data and modeling system, the Terrestrial Observation and Prediction System (TOPS) over North America to operationally produce nowcasts (daily) and forecasts (up to 7 days) of ecosystem fluxes including gross and net primary production and net ecosystem exchange. TOPS is a software system designed to seamlessly integrate data from satellite, aircraft, and ground sensors, and weather/climate models with application models to quickly and reliably produce operational nowcasts and forecasts of ecological conditions. The underlying technologies in TOPS are: 1) Ecosystem models of a variety of flavors ranging from process-based models that use satellite-derived inputs along with surface climate data, weather/climate forecasts to empirical models that rely on historical relationships between climate and ecological phenomenon such as fire risk, disease/pest outbreaks, etc.; 2) Planning and scheduling that facilitate a goal-based data collection and pre-processing so that all the necessary information is available in the required format for a given model run; and 3) Causality analysis and model generation using advances in data mining and machine learning. Nowcasts and forecasts are continuously evaluated using observations from diverse networks: SNOTEL for snow cover, USGS/Streamflow for runoff, USDA/SCAN for soil moisture, GLOBE for phenology and FLUXNET for carbon/water fluxes. Model parameters are optimized based on the spatio-temporal biases identified during model evaluation

  6. Statistical Classification of Terrestrial and Marine Ecosystems for Environmental Planning

    Directory of Open Access Journals (Sweden)

    W. Schröder

    2007-10-01

    Full Text Available E nvironmental planning is an instrument for the operationalisation of the precautionary principle in environmental law and, to this end, must rely on maps depicting the spatial patterns of ecological attributes of aquatic and terrestrial ecosystems and of environmental change effects, respectively. In this context, different mapping techniques are presented by example of three case studies covering terrestrial, coastal and marine environments. The first case study was selected to demonstrate how to compute an ecological land classification of Germany by means of CART. The resulting ecoregions were mapped by GIS. This CARTography enables to regionalise metal bioaccumulation data in terms of 21 ecological land categories and to prove the specifity of emission control measures as being part of environmental policies. The second investigation was chosen to applyfor the first time in Germany the regionalisation approach to the research of climate change effects in terms of past, recent and potential future incidences of Anopheles sp. and malaria in Lower Saxony. To investigate whether malaria might be transmitted due to increasing air temperatures, data sets on past and future air temperatures were used to spatially model malaria risk areas. The third example demonstrates the transfer of the CARTography approach presented in the first case study from terrestrial to marine environments. We analysed the statistical relations between data on benthic communities and physical properties of their marine environments by means of CART and applied these rules to geodata which only describe physical characteristics of the benthic habitats. By this, those parts of the sea ground could be predicted where certain benthic communities might occur.

  7. Function of Wildfire-Deposited Pyrogenic Carbon in Terrestrial Ecosystems

    Directory of Open Access Journals (Sweden)

    Melissa R. A. Pingree

    2017-08-01

    Full Text Available Fire is an important driver of change in most forest, savannah, and prairie ecosystems and fire-altered organic matter, or pyrogenic carbon (PyC, conveys numerous functions in soils of fire-maintained terrestrial ecosystems. Although an exceptional number of recent review articles and books have addressed agricultural soil application of charcoal or biochar, few reviews have addressed the functional role of naturally formed PyC in fire-maintained ecosystems. Recent advances in molecular spectroscopic techniques have helped strengthen our understanding of PyC as a ubiquitous, complex material that is capable of altering soil chemical, physical, and biological properties and processes. The uniquely recalcitrant nature of PyC in soils is partly a result of its stable C = C double-bonded, graphene-like structure and C-rich, N-poor composition. This attribute allows it to persist in soils for hundreds to thousands of years and represent net ecosystem C sequestration in fire-maintained ecosystems. The rapid formation of PyC during wildfire or anthropogenic fire events short-circuits the normally tortuous pathway of recalcitrant soil C formation. Existing literature also suggests that PyC provides an essential role in the cycling of certain nutrients, greatly extending the timeframe by which fires influence soil processes and facilitating recovery in ecosystems where organic matter inputs are low and post-fire surface soil bacterial and fungal activity is reduced. The high surface area of PyC allows for the adsorption a broad spectrum of organic compounds that directly or indirectly influence microbial processes after fire events. Adsorption capacity and microsite conditions created by PyC yields a “charosphere” effect in soil with heightened microbial activity in the vicinity of PyC. In this mini-review, we explore the function of PyC in natural and semi-natural settings, provide a mechanistic approach to understanding these functions, and examine

  8. USING ANT COMMUNITIES FOR RAPID ASSESSMENT OF TERRESTRIAL ECOSYSTEM HEALTH

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L; Doug Martin, D; Michael Paller, M; Eric Nelson, E

    2007-01-12

    Ecosystem health with its near infinite number of variables is difficult to measure, and there are many opinions as to which variables are most important, most easily measured, and most robust, Bioassessment avoids the controversy of choosing which physical and chemical parameters to measure because it uses responses of a community of organisms that integrate all aspects of the system in question. A variety of bioassessment methods have been successfully applied to aquatic ecosystems using fish and macroinvertebrate communities. Terrestrial biotic index methods are less developed than those for aquatic systems and we are seeking to address this problem here. This study had as its objective to examine the baseline differences in ant communities at different seral stages from clear cut back to mature pine plantation as a precursor to developing a bioassessment protocol. Comparative sampling was conducted at four seral stages; clearcut, 5 year, 15 year and mature pine plantation stands. Soil and vegetation data were collected at each site. All ants collected were preserved in 70% ethyl alcohol and identified to genus. Analysis of the ant data indicates that ants respond strongly to the habitat changes that accompany ecological succession in managed pine forests and that individual genera as well as ant community structure can be used as an indicator of successional change. Ants exhibited relatively high diversity in both early and mature seral stages. High ant diversity in the mature seral stages was likely related to conditions on the forest floor which favored litter dwelling and cool climate specialists.

  9. Direct and terrestrial vegetation-mediated effects of environmental change on aquatic ecosystem processes

    Science.gov (United States)

    Becky A. Ball; John S. Kominoski; Heather E. Adams; Stuart E. Jones; Evan S. Kane; Terrance D. Loecke; Wendy M. Mahaney; Jason P. Martina; Chelse M. Prather; Todd M.P. Robinson; Christopher T. Solomon

    2010-01-01

    Global environmental changes have direct effects on aquatic ecosystems, as well as indirect effects through alterations of adjacent terrestrial ecosystem structure and functioning. For example, shifts in terrestrial vegetation communities resulting from global changes can affect the quantity and quality of water, organic matter, and nutrient inputs to aquatic...

  10. Adaptation policies to increase terrestrial ecosystem resilience. Potential utility of a multicriteria approach

    Energy Technology Data Exchange (ETDEWEB)

    de Bremond, Ariane [Univ. of Maryland, College Park, MD (United States); Joint Global Change Research Inst., College Park, MD (United States); Engle, Nathan L. [World Bank, Washington, DC (United States)

    2014-01-30

    Climate change is rapidly undermining terrestrial ecosystem resilience and capacity to continue providing their services to the benefit of humanity and nature. Because of the importance of terrestrial ecosystems to human well-being and supporting services, decision makers throughout the world are busy creating policy responses that secure multiple development and conservation objectives- including that of supporting terrestrial ecosystem resilience in the context of climate change. This article aims to advance analyses on climate policy evaluation and planning in the area of terrestrial ecosystem resilience by discussing adaptation policy options within the ecology-economy-social nexus. The paper evaluates these decisions in the realm of terrestrial ecosystem resilience and evaluates the utility of a set of criteria, indicators, and assessment methods, proposed by a new conceptual multi-criteria framework for pro-development climate policy and planning developed by the United Nations Environment Programme. Potential applications of a multicriteria approach to climate policy vis-A -vis terrestrial ecosystems are then explored through two hypothetical case study examples. The paper closes with a brief discussion of the utility of the multi-criteria approach in the context of other climate policy evaluation approaches, considers lessons learned as a result efforts to evaluate climate policy in the realm of terrestrial ecosystems, and reiterates the role of ecosystem resilience in creating sound policies and actions that support the integration of climate change and development goals.

  11. Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations

    Science.gov (United States)

    Jingfeng Xiaoa; Qianlai Zhuang; Beverly E. Law; Dennis D. Baldocchi; Jiquan Chen; al. et.

    2011-01-01

    More accurate projections of future carbon dioxide concentrations in the atmosphere and associated climate change depend on improved scientific understanding of the terrestrial carbon cycle. Despite the consensus that U.S. terrestrial ecosystems provide a carbon sink, the size, distribution, and interannual variability of this sink remain uncertain. Here we report a...

  12. Isotopic identification of nitrogen hotspots across natural terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    E. Bai

    2012-08-01

    Full Text Available Nitrogen (N influences local biological processes, ecosystem productivity, the composition of the atmospheric-climate system, and the human endeavour as a whole. Here we use natural variations in N isotopes, coupled with two models, to trace global pathways of N loss from the land to the water and atmosphere. We show that denitrification accounts for approximately 35 % of total N losses from the natural soil, with NO, N2O, and N2 fluxes equal to 15.7 ± 4.7 Tg N yr−1, 10.2 ± 3.0 Tg N yr−1, and 21.0 ± 6.1 Tg N yr−1, respectively. Our analysis points to tropical regions as the major "hotspot" of nitrogen export from the terrestrial biosphere, accounting for 71 % of global N losses from the natural land surface. The poorly studied Congo Basin is further identified as one of the major natural sources of atmospheric N2O. Extra-tropical areas, by contrast, lose a greater fraction of N via leaching pathways (~77 % of total N losses than do tropical biomes, likely contributing to N limitations of CO2 uptake at higher latitudes. Our results provide an independent constraint on global models of the N cycle among different regions of the unfertilized biosphere.

  13. Nitrogen-induced terrestrial eutrophication: cascading effects and impacts on ecosystem services

    Science.gov (United States)

    Christopher M. Clark; Michael D. Bell; James W. Boyd; Jana E. Compton; Eric A. Davidson; Christine Davis; Mark E. Fenn; Linda Geiser; Laurence Jones; Tamara F. Blett

    2017-01-01

    Human activity has significantly increased the deposition of nitrogen (N) on terrestrial ecosystems over pre-industrial levels leading to a multitude of effects including losses of biodiversity, changes in ecosystem functioning, and impacts on human well-being. It is challenging to explicitly link the level of deposition on an ecosystem to the cascade of...

  14. Global Terrestrial Ecosystem Observations: Why, Where, What and How?

    NARCIS (Netherlands)

    Jongman, R.H.G.; Skidmore, A.K.; Mücher, C.A.; Bunce, R.G.H.; Metzger, M.

    2017-01-01

    This chapter covers the questions of ecosystem definition and the organisation of a monitoring system. It treats where and how ecosystems should be measured and the integration between in situ and RS observations. Ecosystems are characterised by composition, function and structure. The ecosystem

  15. The fate of mercury in Arctic terrestrial and aquatic ecosystems, a review

    DEFF Research Database (Denmark)

    Douglas, Thomas A.; Loseto, Lisa L.; MacDonald, Robie W.

    2012-01-01

    into the Arctic by oceanic, atmospheric and terrestrial pathways. Our focus is on the movement, transformation and bioaccumulation of Hg in aquatic (marine and fresh water) and terrestrial ecosystems. The processes most relevant to biological Hg uptake and the potential risk associated with Hg exposure...

  16. Relative abundance and species richness of terrestrial salamanders on hardwood ecosystem experiment sites before harvesting

    Science.gov (United States)

    Jami E. MacNeil; Rod N. Williams

    2013-01-01

    Terrestrial salamanders are ideal indicators of forest ecosystem integrity due to their abundance, their role in nutrient cycling, and their sensitivity to environmental change. To understand better how terrestrial salamanders are affected by forest management practices, we monitored species diversity and abundance before implementation of timber harvests within the...

  17. Benchmarking Terrestrial Ecosystem Models in the South Central US

    Science.gov (United States)

    Kc, M.; Winton, K.; Langston, M. A.; Luo, Y.

    2016-12-01

    Ecosystem services and products are the foundation of sustainability for regional and global economy since we are directly or indirectly dependent on the ecosystem services like food, livestock, water, air, wildlife etc. It has been increasingly recognized that for sustainability concerns, the conservation problems need to be addressed in the context of entire ecosystems. This approach is even more vital in the 21st century with formidable increasing human population and rapid changes in global environment. This study was conducted to find the state of the science of ecosystem models in the South-Central region of US. The ecosystem models were benchmarked using ILAMB diagnostic package developed as a result of International Land Model Benchmarking (ILAMB) project on four main categories; viz, Ecosystem and Carbon Cycle, Hydrology Cycle, Radiation and Energy Cycle and Climate forcings. A cumulative assessment was generated with weighted seven different skill assessment metrics for the ecosystem models. This synthesis on the current state of the science of ecosystem modeling in the South-Central region of US will be highly useful towards coupling these models with climate, agronomic, hydrologic, economic or management models to better represent ecosystem dynamics as affected by climate change and human activities; and hence gain more reliable predictions of future ecosystem functions and service in the region. Better understandings of such processes will increase our ability to predict the ecosystem responses and feedbacks to environmental and human induced change in the region so that decision makers can make an informed management decisions of the ecosystem.

  18. Reciprocal subsidies between freshwater and terrestrial ecosystems structure consumer resource dynamics.

    Science.gov (United States)

    Bartels, Pia; Cucherousset, Julien; Steger, Kristin; Eklöv, Peter; Tranvik, Lars J; Hillebrand, Helmut

    2012-05-01

    Cross-ecosystem movements of material and energy, particularly reciprocal resource fluxes across the freshwater-land interface, have received major attention. Freshwater ecosystems may receive higher amounts of subsidies (i.e., resources produced outside the focal ecosystem) than terrestrial ecosystems, potentially leading to increased secondary production in freshwaters. Here we used a meta-analytic approach to quantify the magnitude and direction of subsidy inputs across the freshwater-land interface and to determine subsequent responses in recipient animals. Terrestrial and freshwater ecosystems differed in the magnitude of subsidies they received, with aquatic ecosystems generally receiving higher subsidies than terrestrial ecosystems. Surprisingly, and despite the large discrepancy in magnitude, the contribution of these subsidies to animal carbon inferred from stable isotope composition did not differ between freshwater and terrestrial ecosystems, likely due to the differences in subsidy quality. The contribution of allochthonous subsidies was highest to primary consumers and predators, suggesting that bottom-up and top-down effects may be affected considerably by the input of allochthonous resources. Future work on subsidies will profit from a food web dynamic approach including indirect trophic interactions and propagating effects.

  19. Modeling coupled interactions of carbon, water, and ozone exchange between terrestrial ecosystems and the atmosphere

    Science.gov (United States)

    Ned Nikolova; Karl F. Zeller

    2003-01-01

    A new biophysical model (FORFLUX) is presented to study the simultaneous exchange of ozone, carbon dioxide, and water vapor between terrestrial ecosystems and the atmosphere. The model mechanistically couples all major processes controlling ecosystem flows trace gases and water implementing recent concepts in plant eco-physiology, micrometeorology, and soil hydrology....

  20. Carbon fluxes, evapotranspiration, and water use efficiency of terrestrial ecosystems in China

    Science.gov (United States)

    Jingfeng Xiao; Ge Sun; Jiquan Chen; Hui Chen; Shiping Chen; Gang Dong

    2013-01-01

    The magnitude, spatial patterns, and controlling factors of the carbon and water fluxes of terrestrial ecosystems in China are not well understood due to the lack of ecosystem-level flux observations. We synthesized flux and micrometeorological observations from 22 eddy covariance flux sites across China,and examined the carbon fluxes, evapotranspiration (ET), and...

  1. Microplastics in the terrestrial ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae)

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.D.; Salanki, T.E.; Ploeg, van der M.J.C.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2016-01-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, <150 μm)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-08-01

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

  3. Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

    Science.gov (United States)

    Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

    2013-01-01

    The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

  4. Identifying and prioritising services in European terrestrial and freshwater ecosystems

    NARCIS (Netherlands)

    Harrison, P.A.; Vandewalle, M.; Sykes, M.T.; Berry, P.M.; Bugter, R.J.F.; Bello, de F.; Feld, C.K.; Grandin, U.; Harrington, R.; Haslett, J.R.; Jongman, R.H.G.; Luck, G.W.; Martins da Silva, P.; Moora, M.; Settele, J.; Sousa, J.P.; Zobel, M.

    2010-01-01

    Ecosystems are multifunctional and provide humanity with a broad array of vital services. Effective management of services requires an improved evidence base, identifying the role of ecosystems in delivering multiple services, which can assist policy-makers in maintaining them. Here, information

  5. Regional terrestrial ecosystem dynamics and their interactions with the atmosphere

    Science.gov (United States)

    Ojima, D.; Schimel, D.; Parton, W.; McKeown, R.

    2003-04-01

    Integration of land use with human dimensions, biological, atmospheric and hydrological processes is necessary for us to estimate net carbon exchange from the terrestrial biota. However, proper handling of scale across a set of divergent processes interconnecting the atmosphere and the biosphere is critical to the success of this analysis. Development of the new IGBP “Land” Project will develop a structure to better integrate research that has advanced during the past decade. Our understanding of the long term changes in the terrestrial biosphere will provide greater insight to the environmental sustainability under different stresses and provide an indication of how different regions may respond to changes in climate, disturbance regimes, and land use. This insight will provide a framework to better develop earth system science over the coming decade and to better incorporate the human-environmental system perspective. Our understanding of the biological controls of carbon fluxes between the atmosphere and the land surface (referring to the soil, vegetation, water system) is critical to our estimation of net terrestrial carbon fluxes and the connection of key natural resources (e.g., water, vegetation, soils, etc) to climate and land use changes. Terrestrial biological processes respond strongly to atmospheric temperature, humidity, CO2 levels, N-deposition, precipitation, and radiative transfers. The development of this integrated science perspective to understand the scope of effects human activities on land are affecting the feedbacks to the earth system and the impacts on the terrestrial human-environment system. The presentation will focus on the development of this framework and highlight recent advances in our observational and analytical components of terrestrial biosphere research.

  6. Comparing marine and terrestrial ecosystems: Implications for the design of coastal marine reserves

    Science.gov (United States)

    Carr, M.H.; Neigel, J.E.; Estes, J.A.; Andelman, S.; Warner, R.R.; Largier, J. L.

    2003-01-01

    Concepts and theory for the design and application of terrestrial reserves is based on our understanding of environmental, ecological, and evolutionary processes responsible for biological diversity and sustainability of terrestrial ecosystems and how humans have influenced these processes. How well this terrestrial-based theory can be applied toward the design and application of reserves in the coastal marine environment depends, in part, on the degree of similarity between these systems. Several marked differences in ecological and evolutionary processes exist between marine and terrestrial ecosystems as ramifications of fundamental differences in their physical environments (i.e., the relative prevalence of air and water) and contemporary patterns of human impacts. Most notably, the great extent and rate of dispersal of nutrients, materials, holoplanktonic organisms, and reproductive propagules of benthic organisms expand scales of connectivity among near-shore communities and ecosystems. Consequently, the "openness" of marine populations, communities, and ecosystems probably has marked influences on their spatial, genetic, and trophic structures and dynamics in ways experienced by only some terrestrial species. Such differences appear to be particularly significant for the kinds of organisms most exploited and targeted for protection in coastal marine ecosystems (fishes and macroinvertebrates). These and other differences imply some unique design criteria and application of reserves in the marine environment. In explaining the implications of these differences for marine reserve design and application, we identify many of the environmental and ecological processes and design criteria necessary for consideration in the development of the analytical approaches developed elsewhere in this Special Issue.

  7. Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems

    CSIR Research Space (South Africa)

    Schimel, DS

    2001-11-08

    Full Text Available Knowledge of carbon exchange between the atmosphere, land and the oceans is important, given that the terrestrial and marine environments are currently absorbing about half of the carbon dioxide that is emitted by fossil-fuel combustion. This carbon...

  8. Biogeochemical cycling in terrestrial ecosystems - Modeling, measurement, and remote sensing

    Science.gov (United States)

    Peterson, D. L.; Matson, P. A.; Lawless, J. G.; Aber, J. D.; Vitousek, P. M.

    1985-01-01

    The use of modeling, remote sensing, and measurements to characterize the pathways and to measure the rate of biogeochemical cycling in forest ecosystems is described. The application of the process-level model to predict processes in intact forests and ecosystems response to disturbance is examined. The selection of research areas from contrasting climate regimes and sites having a fertility gradient in that regime is discussed, and the sites studied are listed. The use of remote sensing in determining leaf area index and canopy biochemistry is analyzed. Nitrous oxide emission is investigated by using a gas measurement instrument. Future research projects, which include studying the influence of changes on nutrient cycling in ecosystems and the effect of pollutants on the ecosystems, are discussed.

  9. Impacts of Climate Chnage on Terrestrial Ecosystems Functioning - An Overview

    OpenAIRE

    Beier, Claus; Ambus, Per; Amdal, M. F.; Christensen, Steen; Holmstrup, M.; Larsen, Klaus Steenberg; Michelsen, A.; Mikkelsen, Teis Nørgaard; Priemé, A.; Schmidt, I. K.; Pilegaard, Kim

    2015-01-01

    CLiMA!TE - backgroundThe concentration of CO2 in the atmosphere is increasing, globaltemperatures are increasing, and local precipitation patterns arechanging with increases in the intensity of rain events and droughtperiods. This is expected to affect the structure and functioning ofterrestrial ecosystems (IPCC, 2013) with major impacts on naturalenvironments as well as ecosystems used for agriculture or forestry. Over the past three decades, major efforts have been devoted to understandand ...

  10. Freshwater ecology. Experimental nutrient additions accelerate terrestrial carbon loss from stream ecosystems.

    Science.gov (United States)

    Rosemond, Amy D; Benstead, Jonathan P; Bumpers, Phillip M; Gulis, Vladislav; Kominoski, John S; Manning, David W P; Suberkropp, Keller; Wallace, J Bruce

    2015-03-06

    Nutrient pollution of freshwater ecosystems results in predictable increases in carbon (C) sequestration by algae. Tests of nutrient enrichment on the fates of terrestrial organic C, which supports riverine food webs and is a source of CO2, are lacking. Using whole-stream nitrogen (N) and phosphorus (P) additions spanning the equivalent of 27 years, we found that average terrestrial organic C residence time was reduced by ~50% as compared to reference conditions as a result of nutrient pollution. Annual inputs of terrestrial organic C were rapidly depleted via release of detrital food webs from N and P co-limitation. This magnitude of terrestrial C loss can potentially exceed predicted algal C gains with nutrient enrichment across large parts of river networks, diminishing associated ecosystem services. Copyright © 2015, American Association for the Advancement of Science.

  11. Soil microbial responses to disturbance events and consequences for carbon cycling in terrestrial ecosystems

    OpenAIRE

    Holden, Sandra Robin

    2014-01-01

    Understanding the response of soil microbial communities and decomposition to global environmental changes is central to our ability to accurately forecast future terrestrial carbon (C) storage and atmospheric CO2 levels. Increases in the frequency and severity of disturbance events are one element of global change in terrestrial ecosystems. The goal of this dissertation was to measure the response of soil microbial communities and decomposition to disturbance events and to examine the mechan...

  12. Using the CARDAMOM framework to retrieve global terrestrial ecosystem functioning properties

    Science.gov (United States)

    Exbrayat, Jean-François; Bloom, A. Anthony; Smallman, T. Luke; van der Velde, Ivar R.; Feng, Liang; Williams, Mathew

    2016-04-01

    Terrestrial ecosystems act as a sink for anthropogenic emissions of fossil-fuel and thereby partially offset the ongoing global warming. However, recent model benchmarking and intercomparison studies have highlighted the non-trivial uncertainties that exist in our understanding of key ecosystem properties like plant carbon allocation and residence times. It leads to worrisome differences in terrestrial carbon stocks simulated by Earth system models, and their evolution in a warming future. In this presentation we attempt to provide global insights on these properties by merging an ecosystem model with remotely-sensed global observations of leaf area and biomass through a data-assimilation system: the CARbon Data MOdel fraMework (CARDAMOM). CARDAMOM relies on a Markov Chain Monte Carlo algorithm to retrieve confidence intervals of model parameters that regulate ecosystem properties independently of any prior land-cover information. The MCMC method thereby enables an explicit representation of the uncertainty in land-atmosphere fluxes and the evolution of terrestrial carbon stocks through time. Global experiments are performed for the first decade of the 21st century using a 1°×1° spatial resolution. Relationships emerge globally between key ecosystem properties. For example, our analyses indicate that leaf lifespan and leaf mass per area are highly correlated. Furthermore, there exists a latitudinal gradient in allocation patterns: high latitude ecosystems allocate more carbon to photosynthetic carbon (leaves) while plants invest more carbon in their structural parts (wood and root) in the wet tropics. Overall, the spatial distribution of these ecosystem properties does not correspond to usual land-cover maps and are also partially correlated with disturbance regimes. For example, fire-prone ecosystems present statistically significant higher values of carbon use efficiency than less disturbed ecosystems experiencing similar climatic conditions. These results

  13. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders (ed.) (EcoAnalytica, Haegersten (Sweden))

    2010-12-15

    The ecosystem is in most cases the link between radionuclides released from a repository and the exposure of humans and other biota to them. This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing and performing cross-disciplinary analyses of data from a large number of reports produced during the site investigations, Figure 1-2. The report describes the terrestrial landscape, divided here into the three main categories: forests, wetlands and agriculture land, by identifying properties that are important for element accumulation and transport

  14. Do global change experiments overestimate impacts on terrestrial ecosystems?

    DEFF Research Database (Denmark)

    Leuzinger, Sebastian; Luo, Yiqi; Beier, Claus

    2011-01-01

    In recent decades, many climate manipulation experiments have investigated biosphere responses to global change. These experiments typically examined effects of elevated atmospheric CO2, warming or drought (driver variables) on ecosystem processes such as the carbon and water cycle (response...... variables). Because experiments are inevitably constrained in the number of driver variables tested simultaneously, as well as in time and space, a key question is how results are scaled up to predict net ecosystem responses. In this review, we argue that there might be a general trend for the magnitude...

  15. Terrestrial carbon and intraspecific size-variation shape lake ecosystems

    NARCIS (Netherlands)

    Jansson, M.; Persson, L.; de Roos, A.M.; I. Jones, R.; Tranvik, L.J.

    2007-01-01

    Conceptual models of lake ecosystem structure and function have generally assumed that energy in pelagic systems is derived from in situ photosynthesis and that its use by higher trophic levels depends on the average properties of individuals in consumer populations. These views are challenged by

  16. Impacts of Climate Chnage on Terrestrial Ecosystems Functioning - An Overview

    DEFF Research Database (Denmark)

    Beier, Claus; Ambus, Per; Amdal, M. F.

    CLiMA!TE - backgroundThe concentration of CO2 in the atmosphere is increasing, globaltemperatures are increasing, and local precipitation patterns arechanging with increases in the intensity of rain events and droughtperiods. This is expected to affect the structure and functioning ofterrestrial...... ecosystems (IPCC, 2013) with major impacts on naturalenvironments as well as ecosystems used for agriculture or forestry. Over the past three decades, major efforts have been devoted to understandand predict such impacts of climate change on ecosystemprocesses and functioning in order to understand...... mimicking future climate changes, and dynamicecosystem modelling (Beier, 2004; Rustad, 2008). Each of theseapproaches has their forces and drawbacks, but across all a generallimitation is that observations and experiments have focused on onesingle climate factor. For example, observations across gradients...

  17. Evaluation of the Terrestrial Ecosystem Formation and Diversity in a Modified Dynamic Global Vegetation Model

    Science.gov (United States)

    Zeng, X.; Shao, P.; Song, X.

    2010-12-01

    Terrestrial ecosystem formation and diversity have great impact on the stability and frangibility of ecosystem. It is important that Dynamic Global Vegetation Models (DGVMs) can capture these essential properties so that they can correctly simulate the succession and transition of terrestrial ecosystem in company with the global climate change. Previous studies have shown that DGVMs can roughly reproduce the spatial distributions of different vegetation types as well as the dependence of the vegetation distribution on climate conditions, however, the capability of DGVMs to reproduce the global vegetation distribution and ecosystem formation has not been fully evaluated. This study is based on our modified DGVM coupled with the Community Land Model (CLM-DGVM). The modified CLM-DGVM can simulate 12 plant functional types (PFTs) besides the bare soil. It allows two or more PFTs coexisting in a grid cell, in contrast to the DGVMs which tend to generate the ecosystem with single dominant plant functional type and hence lose the functional diversity of ecosystem. Our results show that the density distributions of fractional coverage (DDFC) of three vegetation categories (e.g., forest, grassland, and shrubland) and PFTs are different with the observation. In particular, the model overestimates the DDFC over regions with tree coverage larger than 70%, but underestimates the DDFC over regions with tree coverage less than 40%. Furthermore, the functional diversity of PFTs in each gridcell is generally lower than that in the observation. Sensitivity tests show that substantial changes in the terrestrial ecosystem usually occur within the areas where two or more PFTs coexist with comparable fractions, i.e., and the functional diversity is high. These results imply that current CLM-DGVM may not be able to appropriately produce the averaged amplitude and spatial pattern of the transition in global ecosystem. Therefore, we suggest that extensive studies are required to improve

  18. Late Permian (Lopingian) terrestrial ecosystems : A global comparison with new data from the low-latitude Bletterbach Biota

    NARCIS (Netherlands)

    Bernardi, M.; Massimo Petti, Fabio; Kustatscher, E.; Franz, M.; Hartkopf-Fröder, C.; Labandeira, Conrad C.; Wappler, Torsten; van Konijnenburg-van Cittert, Johanna H.A.; Peecook, Brandon R.; Angielczyk, Kenneth D.

    2017-01-01

    The late Palaeozoic is a pivotal period for the evolution of terrestrial ecosystems. Generalised warming and aridification trends resulted in profound floral and faunal turnover as well as increased levels of endemism. The patchiness of well-preserved, late Permian terrestrial ecosystems, however,

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

    Science.gov (United States)

    Lindsey E. Rustad

    2008-01-01

    Accumulating evidence points to an anthropogenic 'fingerprint' on the global climate change that has occurred in the last century. Climate change has, and will continue to have, profound effects on the structure and function of terrestrial ecosystems. As such, there is a critical need to continue to develop a sound scientific basis for national and...

  20. Effects of nitrogen deposition on carbon cycle in terrestrial ecosystems of China

    DEFF Research Database (Denmark)

    Chen, Hao; Li, Dejun; Gurmesa, Geshere Abdisa

    2015-01-01

    Nitrogen (N) deposition in China has increased greatly, but the general impact of elevated N deposition on carbon (C) dynamics in Chinese terrestrial ecosystems is not well documented. In this study we used a meta-analysis method to compile 88 studies on the effects of N deposition C cycling...

  1. Naturalization of host-dependent microbes after introduction into terrestrial ecosystems [Chapter 5

    Science.gov (United States)

    Geral I. McDonald; Paul J. Zambino; Ned B. Klopfenstein

    2005-01-01

    Introduction of plant pathogens, insects, parasites, and predators into terrestrial and marine ecosystems is second only to habitat loss among major threats to biodiversity (Torchin et. al. 2002), and the frequency of introductions continues to increase (Flather et al. 1998, Torchin et al. 2002, Wilcove et al. 1998). Despite their detrimental impacts, introductions can...

  2. A source of terrestrial organic carbon to investigate the browning of aquatic ecosystems.

    Science.gov (United States)

    Lennon, Jay T; Hamilton, Stephen K; Muscarella, Mario E; Grandy, A Stuart; Wickings, Kyle; Jones, Stuart E

    2013-01-01

    There is growing evidence that terrestrial ecosystems are exporting more dissolved organic carbon (DOC) to aquatic ecosystems than they did just a few decades ago. This "browning" phenomenon will alter the chemistry, physics, and biology of inland water bodies in complex and difficult-to-predict ways. Experiments provide an opportunity to elucidate how browning will affect the stability and functioning of aquatic ecosystems. However, it is challenging to obtain sources of DOC that can be used for manipulations at ecologically relevant scales. In this study, we evaluated a commercially available source of humic substances ("Super Hume") as an analog for natural sources of terrestrial DOC. Based on chemical characterizations, comparative surveys, and whole-ecosystem manipulations, we found that the physical and chemical properties of Super Hume are similar to those of natural DOC in aquatic and terrestrial ecosystems. For example, Super Hume attenuated solar radiation in ways that will not only influence the physiology of aquatic taxa but also the metabolism of entire ecosystems. Based on its chemical properties (high lignin content, high quinone content, and low C:N and C:P ratios), Super Hume is a fairly recalcitrant, low-quality resource for aquatic consumers. Nevertheless, we demonstrate that Super Hume can subsidize aquatic food webs through 1) the uptake of dissolved organic constituents by microorganisms, and 2) the consumption of particulate fractions by larger organisms (i.e., Daphnia). After discussing some of the caveats of Super Hume, we conclude that commercial sources of humic substances can be used to help address pressing ecological questions concerning the increased export of terrestrial DOC to aquatic ecosystems.

  3. Impacts of droughts on carbon sequestration by China's terrestrial ecosystems from 2000 to 2011

    Science.gov (United States)

    Liu, Y.; Zhou, Y.; Ju, W.; Wang, S.; Wu, X.; He, M.; Zhu, G.

    2014-05-01

    In recent years, China's terrestrial ecosystems have experienced frequent droughts. How these droughts have affected carbon sequestration by the terrestrial ecosystems is still unclear. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model, driven by remotely sensed vegetation parameters, was employed to assess the effects of droughts on net ecosystem productivity (NEP) of terrestrial ecosystems in China from 2000 to 2011. Droughts of differing severity, as indicated by a standard precipitation index (SPI), hit terrestrial ecosystems in China extensively in 2001, 2006, 2009, and 2011. The national total annual NEP exhibited the slight decline of -11.3 Tg C yr-2 during the aforementioned years of extensive droughts. The NEP reduction ranged from 61.1 Tg C yr-1 to 168.8 Tg C yr-1. National and regional total NEP anomalies were correlated with the annual mean SPI, especially in Northwest China, North China, Central China, and Southwest China. The reductions in annual NEP in 2001 and 2011 might have been caused by a larger decrease in annual gross primary productivity (GPP) than in annual ecosystem respiration (ER). The reductions experienced in 2009 might be due to a decrease in annual GPP and an increase in annual ER, while reductions in 2006 could stem from a larger increase in ER than in GPP. The effects of droughts on NEP lagged up to 3-6 months, due to different responses of GPP and ER. In eastern China, where is humid and warm, droughts have predominant and short-term lagged influences on NEP. In western regions, cold and arid, the drought effects on NEP were relatively weaker but prone to lasting longer.

  4. Sensitivity of global terrestrial ecosystems to climate variability

    Science.gov (United States)

    Seddon, Alistair W. R.; Macias-Fauria, Marc; Long, Peter R.; Benz, David; Willis, Kathy J.

    2016-03-01

    The identification of properties that contribute to the persistence and resilience of ecosystems despite climate change constitutes a research priority of global relevance. Here we present a novel, empirical approach to assess the relative sensitivity of ecosystems to climate variability, one property of resilience that builds on theoretical modelling work recognizing that systems closer to critical thresholds respond more sensitively to external perturbations. We develop a new metric, the vegetation sensitivity index, that identifies areas sensitive to climate variability over the past 14 years. The metric uses time series data derived from the moderate-resolution imaging spectroradiometer (MODIS) enhanced vegetation index, and three climatic variables that drive vegetation productivity (air temperature, water availability and cloud cover). Underlying the analysis is an autoregressive modelling approach used to identify climate drivers of vegetation productivity on monthly timescales, in addition to regions with memory effects and reduced response rates to external forcing. We find ecologically sensitive regions with amplified responses to climate variability in the Arctic tundra, parts of the boreal forest belt, the tropical rainforest, alpine regions worldwide, steppe and prairie regions of central Asia and North and South America, the Caatinga deciduous forest in eastern South America, and eastern areas of Australia. Our study provides a quantitative methodology for assessing the relative response rate of ecosystems—be they natural or with a strong anthropogenic signature—to environmental variability, which is the first step towards addressing why some regions appear to be more sensitive than others, and what impact this has on the resilience of ecosystem service provision and human well-being.

  5. Terrestrial and aquatic invertebrates as bioindicators for environmental monitoring, with particular reference to mountain ecosystems.

    Science.gov (United States)

    Hodkinson, Ian D; Jackson, John K

    2005-05-01

    The use of terrestrial and aquatic invertebrates as a management tool for monitoring change in ecosystems is reviewed and critically evaluated. Their suitability and value for assessing a range of environmental problems from pollution impacts, through habitat evaluation for conservation to the long-term degradation and recovery of ecosystems, is critically discussed. Guidelines are provided for the choice of appropriate bioindicators. Examples of the use of a broad spectrum of invertebrates to assess a variety of environmental problems are summarized. The particular potential of invertebrates for monitoring montane ecosystems is highlighted.

  6. A bottom-up evolution of terrestrial ecosystem modeling theory, and ideas toward global vegetation modeling

    Science.gov (United States)

    Running, Steven W.

    1992-01-01

    A primary purpose of this review is to convey lessons learned in the development of a forest ecosystem modeling approach, from it origins in 1973 as a single-tree water balance model to the current regional applications. The second intent is to use this accumulated experience to offer ideas of how terrestrial ecosystem modeling can be taken to the global scale: earth systems modeling. A logic is suggested where mechanistic ecosystem models are not themselves operated globally, but rather are used to 'calibrate' much simplified models, primarily driven by remote sensing, that could be implemented in a semiautomated way globally, and in principle could interface with atmospheric general circulation models (GCM's).

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-11-01

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

  8. User fees across ecosystem boundaries: Are SCUBA divers willing to pay for terrestrial biodiversity conservation?

    Science.gov (United States)

    Roberts, Michaela; Hanley, Nick; Cresswell, Will

    2017-09-15

    While ecological links between ecosystems have been long recognised, management rarely crosses ecosystem boundaries. Coral reefs are susceptible to damage through terrestrial run-off, and failing to account for this within management threatens reef protection. In order to quantify the extent to that coral reef users are willing to support management actions to improve ecosystem quality, we conducted a choice experiment with SCUBA divers on the island of Bonaire, Caribbean Netherlands. Specifically, we estimated their willingness to pay to reduce terrestrial overgrazing as a means to improve reef health. Willingness to pay was estimated using the multinomial, random parameter and latent class logit models. Willingness to pay for improvements to reef quality was positive for the majority of respondents. Estimates from the latent class model determined willingness to pay for reef improvements of between $31.17 - $413.18/year, dependent on class membership. This represents a significant source of funding for terrestrial conservation, and illustrates the potential for user fees to be applied across ecosystem boundaries. We argue that such across-ecosystem-boundary funding mechanisms are an important avenue for future investigation in many connected systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Integration of nitrogen dynamics into a global terrestrial ecosystem model

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaojuan [University of Illinois, Urbana-Champaign; Wittig, Victoria [University of Illinois, Urbana-Champaign; Jain, Atul [University of Illinois, Urbana-Champaign; Post, Wilfred M [ORNL

    2009-01-01

    A comprehensive model of terrestrial N dynamics has been developed and coupled with the geographically explicit terrestrial C cycle component of the Integrated Science Assessment Model (ISAM). The coupled C-N cycle model represents all the major processes in the N cycle and all major interactions between C and N that affect plant productivity and soil and litter decomposition. Observations from the LIDET data set were compiled for calibration and evaluation of the decomposition submodel within ISAM. For aboveground decomposition, the calibration is accomplished by optimizing parameters related to four processes: the partitioning of leaf litter between metabolic and structural material, the effect of lignin on decomposition, the climate control on decomposition and N mineralization and immobilization. For belowground decomposition, the calibrated processes include the partitioning of root litter between decomposable and resistant material as a function of litter quality, N mineralization and immobilization. The calibrated model successfully captured both the C and N dynamics during decomposition for all major biomes and a wide range of climate conditions. Model results show that net N immobilization and mineralization during litter decomposition are dominantly controlled by initial N concentration of litter and the mass remaining during decomposition. The highest and lowest soil organicNstorage are in tundra (1.24 KgNm2) and desert soil (0.06 Kg N m2). The vegetation N storage is highest in tropical forests (0.5 Kg N m2), and lowest in tundra and desert (<0.03 Kg N m2). N uptake by vegetation is highest in warm and moist regions, and lowest in cold and dry regions. Higher rates of N leaching are found in tropical regions and subtropical regions where soil moisture is higher. The global patterns of vegetation and soil N, N uptake and N leaching estimated with ISAM are consistent with measurements and previous modeling studies. This gives us confidence that ISAM

  10. Ecological Effects of Land Use Changes on European Terrestrial Mountain Ecosystems

    Directory of Open Access Journals (Sweden)

    Cernusca, Alexander

    1996-12-01

    Full Text Available As a contribution to the Terrestrial Ecosystem Research Initiative (TERI within Framework IV of the EU, ECOMONT aims at investigating ecological effects of land-use changes in European terrestrial mountain ecosystems. ECOMONT is coordinated by Prof Cernusca (University of Innsbruck and is carried out by eight European partner teams in the Eastern Alps, the Swiss Alps, the Spanish Pyrennees and the Scottish Highlands. ECOMONT focuses on an analysis of structures and processes in the context of land-use changes, scaling from the leaf to the landscape level. The following research topics are being investigated: Spatial distribution of vegetation and soil in the composite experimental sites; physical and chemical soil properties, SOM status and turnover; canopy structure, primary production, and litter decomposition; water relations of ecosystems and hydrology of catchment areas; microclimate and energy budget of ecosystems; gas exchange of single plants and ecosystems; gas exchange between the composite experimental sites and the atmosphere, population and plant biology of keyspecies, plant-animal interactions, potential risks through land-use changes; GIS; remote sensing - environmental mapping; modeling activities integrating from plant to ecosystem and landscape level. First results of ECOMONT show that land-use changes have strong impacts on vegetation composition, structure and processes, on soil physics and chemistry, and therefore strongly affect exchange processes with the atmosphere and biogeochemical cycles. Abandonment of traditional agricultural practices (grazing, mowing causes characteristic changes of the vegetation. In most cases a successional reversion over many decades reaches its climax with the vegetation growing naturally at the sites. Sometimes, however, abandonment can also lead fo a degradation of vegetation and soil. In spite of common principles of changes of vegetation, soils and related processes with altered land

  11. Challenges of deriving a complete biosphere greenhouse gas balance through integration of terrestrial and aquatic ecosystems

    Science.gov (United States)

    Peichl, Matthias

    2013-04-01

    Past research efforts have mostly focused on separately investigating the exchange of greenhouse gases (GHGs) within the limits of different terrestrial and aquatic ecosystem types. More recently however, it has been recognized that GHG exchanges and budgets are not limited to boundaries of the terrestrial or aquatic biosphere components and instead are often tightly linked amongst the different ecosystem types. Primarily the aquatic production and export of GHGs due to substrate supply or discharge from surrounding terrestrial ecosystems play a major role in regional GHG budgets. Understanding the mechanisms and drivers of this connectivity between different terrestrial and aquatic ecosystem GHG exchanges is therefore necessary to develop landscape-level GHG budgets and to understand their sensitivity to disturbances of the biosphere. Moreover, the exchange of carbon dioxide (CO2) as the most important GHG species has been the primary research objective with regards to obtaining better estimates of the carbon sequestration potential of the biosphere. However, methane (CH4) and nitrous oxide (N2O) emissions may offset CO2 sinks and considerably affect the complete GHG balance in both terrestrial and aquatic systems. Including their contribution and improved knowledge on the dynamics of these two gas species is therefore essential for complete GHG budget estimates. At present, the integration of terrestrial and aquatic GHG exchanges toward landscape GHG budgets poses numerous challenges. These include the need for a better knowledge of i) the contribution of CH4 and N2O to the GHG budgets within contrasting terrestrial (forests, peatlands, grasslands, croplands) and aquatic (lake, streams) ecosystems when integrated over a full year, ii) the effect of ecosystem properties (e.g. age and/or development stage, size of water body) on the GHG balance, iii) the impact of management effects (e.g. nitrogen fertilizer application), iv) differences among climate regions and v

  12. Impacts of Environmental Nanoparticles on Chemical, Biological and Hydrological Processes in Terrestrial Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla

    2012-01-01

    This chapter provides insights on nanoparticle (NP) influence or control on the extent and timescales of single or coupled physical, chemical, biological and hydrological reactions and processes that occur in terrestrial ecosystems. Examples taken from the literature that show how terrestrial NPs may determine the fate of the aqueous and sorbed (adsorbed or precipitated) chemical species of nutrients and contaminants, are also included in this chapter. Specifically, in the first section, chapter objectives, term definitions and discussions on size-dependent properties, the origin and occurrence of NP in terrestrial ecosystems and NP toxicity, are included. In the second section, the topic of the binary interactions of NPs of different sizes, shapes, concentrations and ages with the soil solution chemical species is covered, focusing on NP formation, stability, aggregation, ability to serve as sorbents, or surface-mediated precipitation catalysts, or electron donors and acceptors. In the third section, aspects of the interactions in the ternary systems composed of environmental NP, nutrient/contaminant chemical species, and the soil/sediment matrix are discussed, focusing on the inhibitory and catalytic effects of environmental NP on nutrient/contaminant advective mobility and mass transfer, adsorption and desorption, dissolution and precipitation and redox reactions that occur in terrestrial ecosystems. These three review sections are followed by a short summary of future research needs and directions, the acknowledgements, the list of the references, and the figures.

  13. Crossing the Threshold - Reviewed Evidence for Regime Shifts in Arctic Terrestrial Ecosystems

    Science.gov (United States)

    Mård Karlsson, J.; Destouni, G.; Peterson, G.; Gordon, L.

    2009-12-01

    The Arctic is rapidly changing, and the Arctic terrestrial ecosystems may respond to changing conditions in different ways. We review the evidence of regime shifts (ecosystem change from one set of mutually reinforcing feedbacks to another) in Arctic terrestrial ecosystems in relation to the hydrological cycle, as part of a larger interdisciplinary research project on Pan-Arctic ice-water-biogeochemical system responses and social-ecological resilience effects in a warming climate, which has in turn been part of the International Polar Year project Arctic-HYDRA. Such regime shifts may have implications for the Earth system as a whole, through changes in water flows and energy balance that yield feedbacks to hydrology and the local and global climate. Because the presence or absence of permafrost is a main control on local hydrological processes in the Arctic, we use the ecological response to permafrost warming to define three types of regime shifts: 1) Conversion of aquatic to terrestrial ecosystems due to draining of lakes and wetlands caused by permafrost degradation and thermokarst processes, which may have a large impact on local people and animals that depend on these ecosystems for food, domestic needs, and habitat, and on climate as the water conditions influence the direction of CO2 exchange. 2) Conversion of terrestrial to aquatic ecosystems as forests are being replaced by wet sedge meadows, bogs, and thermokarst ponds that favor aquatic birds and mammals, as thawing permafrost atop continuous permafrost undermines and destroys the root zone, leading to collapse and death of the trees. 3) Shifts in terrestrial ecosystems due to transition from tundra to shrubland and/or forest, caused by warming of air and soil, resulting in increased surface energy exchanges and albedo, which may in turn feed back to enhanced warming at the local-regional scale. We compare the impact, scale and key processes for each of these regime shifts, and assess the degree to

  14. Terrestrial Liming As a Restoration Technique for Acidified Forest Ecosystems

    Directory of Open Access Journals (Sweden)

    Sarah E. Pabian

    2012-01-01

    Full Text Available We studied the effects of liming on soils and forest songbirds as well as vegetation and calcium-rich invertebrate prey variables that were predicted to link birds to changes in soil conditions. We observed increases in soil pH, calcium, and magnesium, as well as in songbird abundances in response to lime application, with continuing increases through five years after liming. We observed an overall increase in snail abundance on limed sites, but an initial peak of a 23 fold increase three years after liming was reduced to an 11 fold increase five years after liming. We observed an increase in forb ground cover on limed sites, but liming had no effect on millipede abundance or other vegetation measures. Of the variables we measured, snail abundance was the most likely mechanism for the response in bird abundances. Because we observed continued benefits of liming up to five years post treatment, we concluded that liming is a very promising technique for restoring forest ecosystems impacted by acidic deposition.

  15. Biodiversity of Terrestrial Ecosystems in Tropical to Temperate Australia

    Directory of Open Access Journals (Sweden)

    Raymond L. Specht

    2012-01-01

    Full Text Available During the short period of annual foliage growth in evergreen plant communities, aerodynamic fluxes (frictional, thermal, evaporative in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and leaf attributes in overstorey and understorey strata. The number of leaves produced on each vertical foliage shoot depends on available soil water and nutrients during this growth period. The area of all leaves exposed to solar radiation determines net photosynthetic fixation of the plant community throughout the year. In turn, the species richness (number of species per hectare of both plants and resident vertebrates is determined. The species richness of unicellular algae and small multicellular isopods in permanent freshwater lagoons in Northern Australia may possibly have been increased by radiation released from nearby uranium deposits. Evolution of new angiosperms probably occurred in refugia during periods of extreme drought. When favourable climates were restored, the vegetation expanded to result in high Gamma Biodiversity (number of plant species per region but with each major plant community having essentially the same species richness (number of plant species per hectare. The probable effects of pollution and Global Warming on biodiversity in Australian ecosystems, that experience seasonal drought, are discussed.

  16. Effects of nitrogen deposition on carbon cycle in terrestrial ecosystems of China: A meta-analysis.

    Science.gov (United States)

    Chen, Hao; Li, Dejun; Gurmesa, Geshere A; Yu, Guirui; Li, Linghao; Zhang, Wei; Fang, Huajun; Mo, Jiangming

    2015-11-01

    Nitrogen (N) deposition in China has increased greatly, but the general impact of elevated N deposition on carbon (C) dynamics in Chinese terrestrial ecosystems is not well documented. In this study we used a meta-analysis method to compile 88 studies on the effects of N deposition C cycling on Chinese terrestrial ecosystems. Our results showed that N addition did not change soil C pools but increased above-ground plant C pool. A large decrease in below-ground plant C pool was observed. Our result also showed that the impacts of N addition on ecosystem C dynamics depend on ecosystem type and rate of N addition. Overall, our findings suggest that 1) decreased below-ground plant C pool may limit long-term soil C sequestration; and 2) it is better to treat N-rich and N-limited ecosystems differently in modeling effects of N deposition on ecosystem C cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Prediction of carbon exchanges between China terrestrial ecosystem and atmosphere in 21st century

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The projected changes in carbon exchange between China terrestrial ecosystem and the atmosphere and vegetation and soil carbon storage during the 21st century were investigated using an atmos-phere-vegetation interaction model (AVIM2). The results show that in the coming 100 a, for SRES B2 scenario and constant atmospheric CO2 concentration, the net primary productivity (NPP) of terrestrial ecosystem in China will be decreased slowly, and vegetation and soil carbon storage as well as net ecosystem productivity (NEP) will also be decreased. The carbon sink for China terrestrial ecosystem in the beginning of the 20th century will become totally a carbon source by the year of 2020, while for B2 scenario and changing atmospheric CO2 concentration, NPP for China will increase continuously from 2.94 GtC·a?1 by the end of the 20th century to 3.99 GtC·a?1 by the end of the 21st century, and vegetation and soil carbon storage will increase to 110.3 GtC. NEP in China will keep rising during the first and middle periods of the 21st century, and reach the peak around 2050s, then will decrease gradually and approach to zero by the end of the 21st century.

  18. Quantifying terrestrial ecosystem carbon dynamics in the Jinsha watershed, Upper Yangtze, China from 1975 to 2000

    Science.gov (United States)

    Zhao, Shuqing; Liu, Shuguang; Yin, Runsheng; Li, Zhengpeng; Deng, Yulin; Tan, Kun; Deng, Xiangzheng; Rothstein, David; Qi, Jiaguo

    2010-01-01

    Quantifying the spatial and temporal dynamics of carbon stocks in terrestrial ecosystems and carbon fluxes between the terrestrial biosphere and the atmosphere is critical to our understanding of regional patterns of carbon budgets. Here we use the General Ensemble biogeochemical Modeling System to simulate the terrestrial ecosystem carbon dynamics in the Jinsha watershed of China’s upper Yangtze basin from 1975 to 2000, based on unique combinations of spatial and temporal dynamics of major driving forces, such as climate, soil properties, nitrogen deposition, and land use and land cover changes. Our analysis demonstrates that the Jinsha watershed ecosystems acted as a carbon sink during the period of 1975–2000, with an average rate of 0.36 Mg/ha/yr, primarily resulting from regional climate variation and local land use and land cover change. Vegetation biomass accumulation accounted for 90.6% of the sink, while soil organic carbon loss before 1992 led to a lower net gain of carbon in the watershed, and after that soils became a small sink. Ecosystem carbon sink/source patterns showed a high degree of spatial heterogeneity. Carbon sinks were associated with forest areas without disturbances, whereas carbon sources were primarily caused by stand-replacing disturbances. It is critical to adequately represent the detailed fast-changing dynamics of land use activities in regional biogeochemical models to determine the spatial and temporal evolution of regional carbon sink/source patterns.

  19. Biogeochemical cycling in terrestrial ecosystems of the Caatinga Biome.

    Science.gov (United States)

    Menezes, R S C; Sampaio, E V S B; Giongo, V; Pérez-Marin, A M

    2012-08-01

    The biogeochemical cycles of C, N, P and water, the impacts of land use in the stocks and flows of these elements and how they can affect the structure and functioning of Caatinga were reviewed. About half of this biome is still covered by native secondary vegetation. Soils are deficient in nutrients, especially N and P. Average concentrations of total soil P and C in the top layer (0-20 cm) are 196 mg kg(-1) and 9.3 g kg(-1), corresponding to C stocks around 23 Mg ha(-1). Aboveground biomass of native vegetation varies from 30 to 50 Mg ha(-1), and average root biomass from 3 to 12 Mg ha(-1). Average annual productivities and biomass accumulation in different land use systems vary from 1 to 7 Mg ha(-1) year(-1). Biological atmospheric N2 fixation is estimated to vary from 3 to 11 kg N ha(-1) year-1 and 21 to 26 kg N ha(-1) year(-1) in mature and secondary Caatinga, respectively. The main processes responsible for nutrient and water losses are fire, soil erosion, runoff and harvest of crops and animal products. Projected climate changes in the future point to higher temperatures and rainfall decreases. In face of the high intrinsic variability, actions to increase sustainability should improve resilience and stability of the ecosystems. Land use systems based on perennial species, as opposed to annual species, may be more stable and resilient, thus more adequate to face future potential increases in climate variability. Long-term studies to investigate the potential of the native biodiversity or adapted exotic species to design sustainable land use systems should be encouraged.

  20. Advanced system demonstration for utilization of biomass as an energy source. Technical Appendix D: terrestrial ecosystems and forestry. Environmental report

    Energy Technology Data Exchange (ETDEWEB)

    McCollom, M. [ed.

    1979-01-01

    The existing terrestrial ecosystems at the plant site and impacts on them are described. The following are discussed for the fuelwood harvest region: forest soils, forest types and ecological succession, nutrient cycles in the forest ecosystem, fauna of the ecosystem, forest practices in the harvest region, and long-term productivity of the forest resource. (MHR)

  1. Trophic control of mesopredators in terrestrial ecosystems: top-down or bottom-up?

    Science.gov (United States)

    Elmhagen, Bodil; Rushton, Stephen P

    2007-03-01

    It has been argued that widespread extinctions of top predators have changed terrestrial ecosystem structures through mesopredator release, where increased abundances of medium-sized predators have detrimental effects on prey communities. This top-down concept has received much attention within conservation biology, but few studies have demonstrated the phenomenon. The concept has been criticized since alternative explanations involving bottom-up impacts from bioclimatic effects on ecosystem productivity and from anthropogenic habitat change are rarely considered. We analyse the response of a mesopredator (the red fox) to declines in top predators (wolf and Eurasian lynx) and agricultural expansion over 90 years in Sweden, taking bioclimatic effects into account. We show a top-down mesopredator release effect, but ecosystem productivity determined its strength. The impacts of agricultural activity were mediated by their effects on top predator populations. Thus, both top-down and bottom-up processes need to be understood for effective preservation of biodiversity in anthropogenically transformed ecosystems.

  2. Contributions of wildland fire to terrestrial ecosystem carbon dynamics in North America from 1990 to 2012

    Science.gov (United States)

    Chen, Guangsheng; Hayes, Daniel J.; McGuire, A. David

    2017-01-01

    Burn area and the frequency of extreme fire events have been increasing during recent decades in North America, and this trend is expected to continue over the 21st century. While many aspects of the North American carbon budget have been intensively studied, the net contribution of fire disturbance to the overall net carbon flux at the continental scale remains uncertain. Based on national scale, spatially explicit and long-term fire data, along with the improved model parameterization in a process-based ecosystem model, we simulated the impact of fire disturbance on both direct carbon emissions and net terrestrial ecosystem carbon balance in North America. Fire-caused direct carbon emissions were 106.55 ± 15.98 Tg C/yr during 1990–2012; however, the net ecosystem carbon balance associated with fire was −26.09 ± 5.22 Tg C/yr, indicating that most of the emitted carbon was resequestered by the terrestrial ecosystem. Direct carbon emissions showed an increase in Alaska and Canada during 1990–2012 as compared to prior periods due to more extreme fire events, resulting in a large carbon source from these two regions. Among biomes, the largest carbon source was found to be from the boreal forest, primarily due to large reductions in soil organic matter during, and with slower recovery after, fire events. The interactions between fire and environmental factors reduced the fire-caused ecosystem carbon source. Fire disturbance only caused a weak carbon source as compared to the best estimate terrestrial carbon sink in North America owing to the long-term legacy effects of historical burn area coupled with fast ecosystem recovery during 1990–2012.

  3. Conversion of native terrestrial ecosystems in Hawai‘i to novel grazing systems: a review

    Science.gov (United States)

    Leopold, Christina R.; Hess, Steven C.

    2017-01-01

    The remote oceanic islands of Hawai‘i exemplify the transformative effects that non-native herbivorous mammals can bring to isolated terrestrial ecosystems. We reviewed published literature containing systematically collected, analyzed, and peer-reviewed original data specifically addressing direct effects of non-native hoofed mammals (ungulates) on terrestrial ecosystems, and indirect effects and interactions on ecosystem processes in Hawai‘i. The effects of ungulates on native vegetation and ecosystems were addressed in 58 original studies and mostly showed strong short-term regeneration of dominant native trees and understory ferns after ungulate removal, but unassisted recovery was dependent on the extent of previous degradation. Ungulates were associated with herbivory, bark-stripping, disturbance by hoof action, soil erosion, enhanced nutrient cycling from the interaction of herbivory and grasses, and increased pyrogenicity and competition between native plants and pasture grasses. No studies demonstrated that ungulates benefitted native ecosystems except in short-term fire-risk reduction. However, non-native plants became problematic and continued to proliferate after release from herbivory, including at least 11 species of non-native pasture grasses that had become established prior to ungulate removal. Competition from non-native grasses inhibited native species regeneration where degradation was extensive. These processes have created novel grazing systems which, in some cases, have irreversibly altered Hawaii’s terrestrial ecology. Non-native plant control and outplanting of rarer native species will be necessary for recovery where degradation has been extensive. Lack of unassisted recovery in some locations should not be construed as a reason to not attempt restoration of other ecosystems.

  4. Contributions of wildland fire to terrestrial ecosystem carbon dynamics in North America from 1990 to 2012

    Science.gov (United States)

    Chen, Guangsheng; Hayes, Daniel J.; David McGuire, A.

    2017-05-01

    Burn area and the frequency of extreme fire events have been increasing during recent decades in North America, and this trend is expected to continue over the 21st century. While many aspects of the North American carbon budget have been intensively studied, the net contribution of fire disturbance to the overall net carbon flux at the continental scale remains uncertain. Based on national scale, spatially explicit and long-term fire data, along with the improved model parameterization in a process-based ecosystem model, we simulated the impact of fire disturbance on both direct carbon emissions and net terrestrial ecosystem carbon balance in North America. Fire-caused direct carbon emissions were 106.55 ± 15.98 Tg C/yr during 1990-2012; however, the net ecosystem carbon balance associated with fire was -26.09 ± 5.22 Tg C/yr, indicating that most of the emitted carbon was resequestered by the terrestrial ecosystem. Direct carbon emissions showed an increase in Alaska and Canada during 1990-2012 as compared to prior periods due to more extreme fire events, resulting in a large carbon source from these two regions. Among biomes, the largest carbon source was found to be from the boreal forest, primarily due to large reductions in soil organic matter during, and with slower recovery after, fire events. The interactions between fire and environmental factors reduced the fire-caused ecosystem carbon source. Fire disturbance only caused a weak carbon source as compared to the best estimate terrestrial carbon sink in North America owing to the long-term legacy effects of historical burn area coupled with fast ecosystem recovery during 1990-2012.

  5. Water use efficiency of China’s terrestrial ecosystems and responses to drought

    Science.gov (United States)

    Liu, Yibo; Xiao, Jingfeng; Ju, Weimin; Zhou, Yanlian; Wang, Shaoqiang; Wu, Xiaocui

    2015-01-01

    Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China’s terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg−1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. “Turning-points” were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity. PMID:26347998

  6. Water use efficiency of China's terrestrial ecosystems and responses to drought.

    Science.gov (United States)

    Liu, Yibo; Xiao, Jingfeng; Ju, Weimin; Zhou, Yanlian; Wang, Shaoqiang; Wu, Xiaocui

    2015-09-08

    Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China's terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg(-1) H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.

  7. The terrestrial ecosystems at Forsmark and Laxemar-Simpevarp. Site descriptive modelling SDM site

    Energy Technology Data Exchange (ETDEWEB)

    Loefgren, Anders (EcoAnalytica, Haegersten (Sweden)) (ed.)

    2008-12-15

    This report describes the terrestrial ecosystems in the Forsmark and Laxemar-Simpevarp areas by summarizing ecological data and data from disciplines such as hydrology, quaternary geology and chemistry. The description therefore includes a number of different processes that drive element fluxes in the ecosystems, such as net primary production, heterotrophic respiration, transpiration, and horizontal transport from land to streams and lakes. Moreover, the human appropriation of the landscape is described with regard to land use and potential and actual utilization of food resources both today and in a historical perspective

  8. Contrasting responses of water use efficiency to drought across global terrestrial ecosystems

    OpenAIRE

    Yang, Yuting; Guan, Huade; Batelaan, Okke; McVicar, Tim R.; Long, Di; Piao, Shilong; Liang, Wei; Liu, Bing; Jin, Zhao; Simmons, Craig T.

    2016-01-01

    Drought is an intermittent disturbance of the water cycle that profoundly affects the terrestrial carbon cycle. However, the response of the coupled water and carbon cycles to drought and the underlying mechanisms remain unclear. Here we provide the first global synthesis of the drought effect on ecosystem water use efficiency (WUE?=?gross primary production (GPP)/evapotranspiration (ET)). Using two observational WUE datasets (i.e., eddy-covariance measurements at 95 sites (526 site-years) an...

  9. Developments in deriving critical limits and modelling critical loads of nitrogen for terrestrial ecosystems in Europe

    OpenAIRE

    Vries, de, W.; Kros, H.; G. J. Reinds; Wamelink, W.; Mol, J.; Dobben, van, H.F.; Bobbink, R.; Emmett, B.; Smart, S.; Evans, C.; Schlutow, A.; Kraft, P.; Belyazid, S.; Sverdrup, H.; Hinsberg, van, A.

    2007-01-01

    This collaborative report of Alterra and the Coordination Center for Effects (MNP-CCE), in co-operation with various participants of the International Cooperative programme on Modelling and Mapping (ICP-MM) includes: 1. A summarizing overview of adverse nitrogen deposition effects on terrestrial ecosystems in terms of impacts on plant species and faunal biodiversity, forest nutrient status in relation to impacts on soil and solution chemistry and on ground water quality. 2. An overview of int...

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

    Energy Technology Data Exchange (ETDEWEB)

    Beier, Claus [RISO National Laboratory (Denmark)], E-mail: claus.beier@risoe.dk; Schmidt, Inger Kappel [Danish Forest and Landscape Research Institute (Denmark); Kristensen, Hanne Lakkenborg [Danish Institute of Agricultural Sciences, Dept. of Horticulture (Denmark)

    2004-06-15

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

  11. Bayesian calibration of terrestrial ecosystem models: a study of advanced Markov chain Monte Carlo methods

    Science.gov (United States)

    Lu, Dan; Ricciuto, Daniel; Walker, Anthony; Safta, Cosmin; Munger, William

    2017-09-01

    Calibration of terrestrial ecosystem models is important but challenging. Bayesian inference implemented by Markov chain Monte Carlo (MCMC) sampling provides a comprehensive framework to estimate model parameters and associated uncertainties using their posterior distributions. The effectiveness and efficiency of the method strongly depend on the MCMC algorithm used. In this work, a differential evolution adaptive Metropolis (DREAM) algorithm is used to estimate posterior distributions of 21 parameters for the data assimilation linked ecosystem carbon (DALEC) model using 14 years of daily net ecosystem exchange data collected at the Harvard Forest Environmental Measurement Site eddy-flux tower. The calibration of DREAM results in a better model fit and predictive performance compared to the popular adaptive Metropolis (AM) scheme. Moreover, DREAM indicates that two parameters controlling autumn phenology have multiple modes in their posterior distributions while AM only identifies one mode. The application suggests that DREAM is very suitable to calibrate complex terrestrial ecosystem models, where the uncertain parameter size is usually large and existence of local optima is always a concern. In addition, this effort justifies the assumptions of the error model used in Bayesian calibration according to the residual analysis. The result indicates that a heteroscedastic, correlated, Gaussian error model is appropriate for the problem, and the consequent constructed likelihood function can alleviate the underestimation of parameter uncertainty that is usually caused by using uncorrelated error models.

  12. The First Law of Thermodynamics for Ecosystems. Physical Processes in Terrestrial and Aquatic Ecosystems, Thermodynamics.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module and a comparison module are concerned with elementary concepts of thermodynamics as…

  13. Quantifying and mapping the human appropriation of net primary production in earth's terrestrial ecosystems.

    Science.gov (United States)

    Haberl, Helmut; Erb, K Heinz; Krausmann, Fridolin; Gaube, Veronika; Bondeau, Alberte; Plutzar, Christoph; Gingrich, Simone; Lucht, Wolfgang; Fischer-Kowalski, Marina

    2007-07-31

    Human appropriation of net primary production (HANPP), the aggregate impact of land use on biomass available each year in ecosystems, is a prominent measure of the human domination of the biosphere. We present a comprehensive assessment of global HANPP based on vegetation modeling, agricultural and forestry statistics, and geographical information systems data on land use, land cover, and soil degradation that localizes human impact on ecosystems. We found an aggregate global HANPP value of 15.6 Pg C/yr or 23.8% of potential net primary productivity, of which 53% was contributed by harvest, 40% by land-use-induced productivity changes, and 7% by human-induced fires. This is a remarkable impact on the biosphere caused by just one species. We present maps quantifying human-induced changes in trophic energy flows in ecosystems that illustrate spatial patterns in the human domination of ecosystems, thus emphasizing land use as a pervasive factor of global importance. Land use transforms earth's terrestrial surface, resulting in changes in biogeochemical cycles and in the ability of ecosystems to deliver services critical to human well being. The results suggest that large-scale schemes to substitute biomass for fossil fuels should be viewed cautiously because massive additional pressures on ecosystems might result from increased biomass harvest.

  14. High resolution measurement of light in terrestrial ecosystems using photodegrading dyes.

    Directory of Open Access Journals (Sweden)

    Javier Roales

    Full Text Available Incoming solar radiation is the main determinant of terrestrial ecosystem processes, such as primary production, litter decomposition, or soil mineralization rates. Light in terrestrial ecosystems is spatially and temporally heterogeneous due to the interaction among sunlight angle, cloud cover and tree-canopy structure. To integrate this variability and to know light distribution over time and space, a high number of measurements are needed, but tools to do this are usually expensive and limited. An easy-to-use and inexpensive method that can be used to measure light over time and space is needed. We used two photodegrading fluorescent organic dyes, rhodamine WT (RWT and fluorescein, for the quantification of light. We measured dye photodegradation as the decrease in fluorescence across an irradiance gradient from full sunlight to deep shade. Then, we correlated it to accumulated light measured with PAR quantum sensors and obtained a model for this behavior. Rhodamine WT and fluorescein photodegradation followed an exponential decay curve with respect to accumulated light. Rhodamine WT degraded slower than fluorescein and remained unaltered after exposure to temperature changes. Under controlled conditions, fluorescence of both dyes decreased when temperatures increased, but returned to its initial values after cooling to the pre-heating temperature, indicating no degradation. RWT and fluorescein can be used to measure light under a varying range of light conditions in terrestrial ecosystems. This method is particularly useful to integrate solar radiation over time and to measure light simultaneously at different locations, and might be a better alternative to the expensive and time consuming traditional light measurement methods. The accuracy, low price and ease of this method make it a powerful tool for intensive sampling of large areas and for developing high resolution maps of light in an ecosystem.

  15. Black spots for aquatic and terrestrial ecosystems: impact of a perennial cormorant colony on the environment.

    Science.gov (United States)

    Klimaszyk, Piotr; Brzeg, Andrzej; Rzymski, Piotr; Piotrowicz, Ryszard

    2015-06-01

    The global growth of populations of different cormorant species has raised concern on the consequences of their presence in the environment. This study examined the impact of a perennial colony (160 breeding pairs) of great cormorants on terrestrial and aquatic ecosystems. The deposition of bird-originating nutrients within the area of colony, their accumulation in soils and the fluxed of chemical substances to a nearby lake were investigated. The impact of cormorants on terrestrial vegetation and microbial pollution of the lake were also studied. The soils beneath the colony were found to contain extremely high concentrations of nitrogen and phosphorus. The overgrowing vegetation was largely limited with nitrophilous and invasive species being more abundant. Increased loads of organic matter, nitrogen and phosphorus were also found in groundwater and particularly, surface runoff. The colony area delivered significant amounts of nutrients to the lake also when the birds were absent. The lake water near colony was also characterized by increased nutrient content and additionally higher number of faecal bacteria. The present results demonstrate the complexity through which the effect of cormorant colonies can be manifested simultaneously in terrestrial and aquatic ecosystem. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. The response of terrestrial ecosystems to global climate change: towards an integrated approach.

    Science.gov (United States)

    Rustad, Lindsey E

    2008-10-15

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

  17. Software and Process Developments in the Functionally Assembled Terrestrial Ecosystem Simulator (FATES)

    Science.gov (United States)

    Knox, R. G.; Koven, C.; Fisher, R.; Andre, B. J.; Bisht, G.; Vertenstein, M.; Riley, W. J.; Sacks, W.; Kluzek, E. B.; Lawrence, D. M.

    2016-12-01

    The Functionally Assembled Terrestrial Ecosystem Simulator (FATES) represents processes related to the demographics and dynamics of aboveground vegetation, often in an earth systems model context. It serves as a focal component of the Model-Experiment (MODEX) approach to the Next Generation Ecosystem Experiment (NGEE-Tropics). This is a tool to probe our understanding of the terrestrial carbon sink and forest response to a changing climate and human activities. It is co-developed with scientific measurement experiments that are designed specifically to improve our understanding of model process and parameterization. FATES is a successor of the Ecosystem Demography model, and had originally been coupled with the Community Land Model, ie CLM-ED. The work presented here describes refactoring to isolate the FATES code into a standalone module and create a well documented public API. The API allows FATES to be incorporated into a range of host models, such as the land models in ACME and CESM, and the ATS. Some newly developed model processes and testing strategies for verifying model results are presented as well.

  18. Rare earth elements in freshwater, marine, and terrestrial ecosystems in the eastern Canadian Arctic.

    Science.gov (United States)

    MacMillan, Gwyneth Anne; Chételat, John; Heath, Joel P; Mickpegak, Raymond; Amyot, Marc

    2017-10-18

    Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. To understand how REEs behave in remote northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (∂ 15 N, ∂ 13 C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N = 339). Wildlife harvesting and tissue sampling was partly conducted by local hunters through a community-based monitoring project. Results show that REEs generally follow a coherent bioaccumulation pattern for sample tissues, with some anomalies for redox-sensitive elements (Ce, Eu). Highest REE concentrations were found at low trophic levels, especially in vegetation and aquatic invertebrates. Terrestrial herbivores, ringed seal, and fish had low total REE levels in muscle tissue (∑REE for 15 elements Age- and length-dependent REE accumulation also suggest that REE uptake is faster than elimination for some species. Overall, REE bioaccumulation patterns appear to be species- and tissue-specific, with limited potential for biomagnification. This study provides novel data on the behaviour of REEs in ecosystems and will be useful for environmental impact assessment of REE enrichment in northern regions.

  19. Contrasting responses of water use efficiency to drought across global terrestrial ecosystems.

    Science.gov (United States)

    Yang, Yuting; Guan, Huade; Batelaan, Okke; McVicar, Tim R; Long, Di; Piao, Shilong; Liang, Wei; Liu, Bing; Jin, Zhao; Simmons, Craig T

    2016-03-17

    Drought is an intermittent disturbance of the water cycle that profoundly affects the terrestrial carbon cycle. However, the response of the coupled water and carbon cycles to drought and the underlying mechanisms remain unclear. Here we provide the first global synthesis of the drought effect on ecosystem water use efficiency (WUE = gross primary production (GPP)/evapotranspiration (ET)). Using two observational WUE datasets (i.e., eddy-covariance measurements at 95 sites (526 site-years) and global gridded diagnostic modelling based on existing observation and a data-adaptive machine learning approach), we find a contrasting response of WUE to drought between arid (WUE increases with drought) and semi-arid/sub-humid ecosystems (WUE decreases with drought), which is attributed to different sensitivities of ecosystem processes to changes in hydro-climatic conditions. WUE variability in arid ecosystems is primarily controlled by physical processes (i.e., evaporation), whereas WUE variability in semi-arid/sub-humid regions is mostly regulated by biological processes (i.e., assimilation). We also find that shifts in hydro-climatic conditions over years would intensify the drought effect on WUE. Our findings suggest that future drought events, when coupled with an increase in climate variability, will bring further threats to semi-arid/sub-humid ecosystems and potentially result in biome reorganization, starting with low-productivity and high water-sensitivity grassland.

  20. The stoichiometry of nutrient release by terrestrial herbivores and its ecosystem consequences

    Science.gov (United States)

    Sitters, Judith; Bakker, Elisabeth S.; Veldhuis, Michiel P.; Veen, G. F.; Olde Venterink, Harry; Vanni, Michael J.

    2017-04-01

    It is widely recognized that the release of nutrients by herbivores via their waste products strongly impacts nutrient availability for autotrophs. The ratios of nitrogen (N) and phosphorus (P) recycled through herbivore release (i.e., waste N:P) are mainly determined by the stoichiometric composition of the herbivore’s food (food N:P) and its body nutrient content (body N:P). Waste N:P can in turn impact autotroph nutrient limitation and productivity. Herbivore-driven nutrient recycling based on stoichiometric principles is dominated by theoretical and experimental research in freshwater systems, in particular interactions between algae and invertebrate herbivores. In terrestrial ecosystems, the impact of herbivores on nutrient cycling and availability is often limited to studying carbon (C ):N and C:P ratios, while the role of terrestrial herbivores in mediating N:P ratios is also likely to influence herbivore-driven nutrient recycling. In this review, we use rules and predictions on the stoichiometry of nutrient release originating from algal-based aquatic systems to identify the factors that determine the stoichiometry of nutrient release by herbivores. We then explore how these rules can be used to understand the stoichiometry of nutrient release by terrestrial herbivores, ranging from invertebrates to mammals, and its impact on plant nutrient limitation and productivity. Future studies should focus on measuring both N and P when investigating herbivore-driven nutrient recycling in terrestrial ecosystems, while also taking the form of waste product (urine or feces) and other pathways by which herbivores change nutrients into account, to be able to quantify the impact of waste stoichiometry on plant communities.

  1. Increases in terrestrially derived carbon stimulate organic carbon processing and CO2 emissions in boreal aquatic ecosystems

    Science.gov (United States)

    Lapierre, Jean-François; Guillemette, François; Berggren, Martin; Del Giorgio, Paul A.

    2013-12-01

    The concentrations of terrestrially derived dissolved organic carbon have been increasing throughout northern aquatic ecosystems in recent decades, but whether these shifts have an impact on aquatic carbon emissions at the continental scale depends on the potential for this terrestrial carbon to be converted into carbon dioxide. Here, via the analysis of hundreds of boreal lakes, rivers and wetlands in Canada, we show that, contrary to conventional assumptions, the proportion of biologically degradable dissolved organic carbon remains constant and the photochemical degradability increases with terrestrial influence. Thus, degradation potential increases with increasing amounts of terrestrial carbon. Our results provide empirical evidence of a strong causal link between dissolved organic carbon concentrations and aquatic fluxes of carbon dioxide, mediated by the degradation of land-derived organic carbon in aquatic ecosystems. Future shifts in the patterns of terrestrial dissolved organic carbon in inland waters thus have the potential to significantly increase aquatic carbon emissions across northern landscapes.

  2. Modeling gross primary production and ecosystem respiration for terrestrial ecosystems in North China and Tibet Plateau using MODIS imagery

    Science.gov (United States)

    Gao, Y.; Yu, G.; Yan, H.; Zhu, X.; Li, S.; Wang, Q.; Zhang, J.; Wang, Y.; Li, Y.; Zhao, L.; Shi, P.

    2013-12-01

    Gross primary production (GPP) and ecosystem respiration (Re) are two large components in the studying of regional and global carbon cycles. Accurate quantification of spatio-temporal variations of GPP and Re for terrestrial ecosystems is of great importance to research carbon budget on regional and global scales. In this study, we proposed two satellite-based models, i.e. Photosynthetic Capacity Model (PCM) and Ecosystem Respiration Model (ERM), to simulate GPP and Re of terrestrial ecosystems, respectively. Multi-year eddy CO2 flux data from five vegetation types in North China (temperate mixed forest, temperate steppe) and Tibet Plateau (alpine shrubland, alpine marsh and alpine meadow-steppe) were used for assessing the model performances. The PCM model was driven by the Enhanced Vegetation Index (EVI) and the Land Surface Water Index (LSWI) from MODIS imagery. In most cases, the PCM-simulated GPP and the observed GPP displayed very consistent seasonal and inter-seasonal variability regardless of vegetation types. The PCM predicted versus observed GPP performed better than the MODIS GPP products, and was compatible with the Vegetation Photosynthesis Model (VPM). Moreover, the model parameter of the PCM could be gained from the linear function of mean annual remote sensing data. Based on this linear function, the PCM model simulated 93% variations of the observed GPP across all five vegetation types. The ERM model was developed based on both GPP and temperature, and was driven by EVI, LSWI and the Land Surface Temperature (LST) from MODIS imagery. In most cases, the seasonal and interannual variations of the simulated Re matched well with the observed Re. Compared with the model driven by temperature, and the model further added GPP in the reference respiration, the ERM model was optimal in each vegetation type. The model parameters of the ERM could also be presented by the liner functions of mean annual remote sensing data. Based on these linear functions, 90

  3. Nitrogen feedbacks increase future terrestrial ecosystem carbon uptake in an individual-based dynamic vegetation model

    Science.gov (United States)

    Wårlind, D.; Smith, B.; Hickler, T.; Arneth, A.

    2014-11-01

    Recently a considerable amount of effort has been put into quantifying how interactions of the carbon and nitrogen cycle affect future terrestrial carbon sinks. Dynamic vegetation models, representing the nitrogen cycle with varying degree of complexity, have shown diverging constraints of nitrogen dynamics on future carbon sequestration. In this study, we use LPJ-GUESS, a dynamic vegetation model employing a detailed individual- and patch-based representation of vegetation dynamics, to evaluate how population dynamics and resource competition between plant functional types, combined with nitrogen dynamics, have influenced the terrestrial carbon storage in the past and to investigate how terrestrial carbon and nitrogen dynamics might change in the future (1850 to 2100; one representative "business-as-usual" climate scenario). Single-factor model experiments of CO2 fertilisation and climate change show generally similar directions of the responses of C-N interactions, compared to the C-only version of the model as documented in previous studies using other global models. Under an RCP 8.5 scenario, nitrogen limitation suppresses potential CO2 fertilisation, reducing the cumulative net ecosystem carbon uptake between 1850 and 2100 by 61%, and soil warming-induced increase in nitrogen mineralisation reduces terrestrial carbon loss by 31%. When environmental changes are considered conjointly, carbon sequestration is limited by nitrogen dynamics up to the present. However, during the 21st century, nitrogen dynamics induce a net increase in carbon sequestration, resulting in an overall larger carbon uptake of 17% over the full period. This contrasts with previous results with other global models that have shown an 8 to 37% decrease in carbon uptake relative to modern baseline conditions. Implications for the plausibility of earlier projections of future terrestrial C dynamics based on C-only models are discussed.

  4. Interdisciplinary research in global biogeochemical cycling Nitrous oxide in terrestrial ecosystems

    Science.gov (United States)

    Norman, S. D.; Peterson, D. L.

    1984-01-01

    NASA has begun an interdisciplinary research program to investigate various aspects of Global Biology and Global Habitability. An important element selected for the study of global phenomena is related to biogeochemical cycling. The studies involve a collaboration with recognized scientists in the areas of plant physiology, microbiology, nutrient cycling theory, and related areas. Selected subjects of study include nitrogen cycling dynamics in terrestrial ecosystems with special attention to biosphere/atmosphere interactions, and an identification of sensitive response variables which can be used in ecosystem models based on parameters derived from remotely sensed variables. A description is provided of the progress and findings over the past two years. Attention is given to the characteristics of nitrous oxide emissions, the approach followed in the investigations, the selection of study sites, radiometric measurements, and research in Sequoia.

  5. The characteristics of soil N transformations regulate the composition of hydrologic N export from terrestrial ecosystem

    Science.gov (United States)

    Zhang, Jinbo; Tian, Peng; Tang, Jialiang; Yuan, Lei; Ke, Yun; Cai, Zucong; Zhu, Bo; Müller, Christoph

    2016-06-01

    It is important to clarify the quantity and composition of hydrologic N export from terrestrial ecosystem and its primary controlling factors, because it affected N availability, productivity, and C storage in natural ecosystems. The most previous investigations were focused on the effects of N deposition and human disturbance on the composition of hydrologic N export. However, few studies were aware of whether there were significant differences in the concentrations and composition of hydrologic N export from natural ecosystems in different climate zones and what is the primary controlling factor. In the present study, three natural forest ecosystems and one natural grassland ecosystem that were located in different climate zones and with different soil pH range were selected. The concentrations of total dissolved N, dissolved organic nitrogen (DON), NH4+, NO3- in soil solution and stream water, soil properties, and soil gross N transformation rates were measured to answer above questions. Our results showed that NO3- concentrations and the composition pattern of hydrologic N export from natural ecosystems varied greatly in the different climate zones. The NO3- concentrations in stream water varied largely, ranging from 0.1 mg N L-1 to 1.6 mg N L-1, while DON concentration in stream water, ranging from 0.1 to 0.9 mg N L-1, did not differ significantly, and the concentrations of NH4+ were uniformly low (average 0.1 mg N L-1) in all studied sites. There was a trade-off relationship between the proportions of NO3- and DON to total dissolved N in stream water. In subtropical strongly acidic forests soil site, DON was the dominance in total dissolved N in stream water, while NO3--N became dominance in temperate acidic forests soil site, subtropical alkaline forests soil region, and the alpine meadow sites on the Tibetan Plateau. The proportions of NO3- to total dissolved N in both soil solution and stream water significantly increased with the increasing of the gross

  6. Transfer parameters for ICRP's Reference Animals and Plants in a terrestrial Mediterranean ecosystem.

    Science.gov (United States)

    Guillén, J; Beresford, N A; Baeza, A; Izquierdo, M; Wood, M D; Salas, A; Muñoz-Serrano, A; Corrales-Vázquez, J M; Muñoz-Muñoz, J G

    2018-06-01

    A system for the radiological protection of the environment (or wildlife) based on Reference Animals and Plants (RAPs) has been suggested by the International Commission on Radiological Protection (ICRP). To assess whole-body activity concentrations for RAPs and the resultant internal dose rates, transfer parameters are required. However, transfer values specifically for the taxonomic families defined for the RAPs are often sparse and furthermore can be extremely site dependent. There is also a considerable geographical bias within available transfer data, with few data for Mediterranean ecosystems. In the present work, stable element concentrations (I, Li, Be, B, Na, Mg, Al, P, S, K. Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Cs, Ba, Tl, Pb and U) in terrestrial RAPs, and the corresponding whole-body concentration ratios, CR wo , were determined in two different Mediterranean ecosystems: a Pinewood and a Dehesa (grassland with disperse tree cover). The RAPs considered in the Pinewood ecosystem were Pine Tree and Wild Grass; whereas in the Dehesa ecosystem those considered were Deer, Rat, Earthworm, Bee, Frog, Duck and Wild Grass. The CR wo values estimated from these data are compared to those reported in international compilations and databases. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Development of an Unmanned Aerial System (UAS) for Scaling Terrestrial Ecosystem Traits

    Science.gov (United States)

    Meng, R.; McMahon, A. M.; Serbin, S.; Rogers, A.

    2015-12-01

    The next generation of Ecosystem and Earth System Models (EESMs) will require detailed information on ecosystem structure and function, including properties of vegetation related to carbon (C), water, and energy cycling, in order to project the future state of ecosystems. High spatial-temporal resolution measurements of terrestrial ecosystem are also important for EESMs, because they can provide critical inputs and benchmark datasets for evaluation of EESMs simulations across scales. The recent development of high-quality, low-altitude remote sensing platforms or small UAS (traits. To do this we are developing an integrated software workflow and hardware package using off-the-shelf instrumentation including a high-resolution digital camera for Structure from Motion, spectroradiometer, and a thermal infrared camera. Our workflow includes platform design, measurement, image processing, data management, and information extraction. The fusion of 3D structure information, thermal-infrared imagery, and spectroscopic measurements, will provide a foundation for the development of ecological scaling and mapping algorithms. Our initial focus is in temperate forests but near-term research will expand into the high-arctic and eventually tropical systems. The results of this prototype study show that off-the-shelf technology can be used to develop a low-cost alternative for mapping plant traits and three-dimensional structure for ecological research.

  8. Biological nitrogen fixation: rates, patterns and ecological controls in terrestrial ecosystems

    Science.gov (United States)

    Vitousek, Peter M.; Menge, Duncan N.L.; Reed, Sasha C.; Cleveland, Cory C.

    2013-01-01

    New techniques have identified a wide range of organisms with the capacity to carry out biological nitrogen fixation (BNF)—greatly expanding our appreciation of the diversity and ubiquity of N fixers—but our understanding of the rates and controls of BNF at ecosystem and global scales has not advanced at the same pace. Nevertheless, determining rates and controls of BNF is crucial to placing anthropogenic changes to the N cycle in context, and to understanding, predicting and managing many aspects of global environmental change. Here, we estimate terrestrial BNF for a pre-industrial world by combining information on N fluxes with 15N relative abundance data for terrestrial ecosystems. Our estimate is that pre-industrial N fixation was 58 (range of 40–100) Tg N fixed yr−1; adding conservative assumptions for geological N reduces our best estimate to 44 Tg N yr−1. This approach yields substantially lower estimates than most recent calculations; it suggests that the magnitude of human alternation of the N cycle is substantially larger than has been assumed.

  9. Determination of volatile halogenated organic compounds in the tropical terrestrial ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Quintana, A.; Lopez-Garriga, J. [Univ. of Puerto Rico, Mayaguez (Puerto Rico)

    1995-12-01

    Volatile Halogenated Organic Compounds are discharged into our biosphere by plants, marine organisms, fungi and by other natural processes. Due to the high rate of evaporation of the tropical terrestrial ecosystem, the production of VHOC by fungi, higher plants and other organisms may be one of the most important sources of the total amount of VHOC released to the atmosphere from biogenic origin. The main goal of this research was to determine the VHOC`s released to the surroundings from biogenic origin in the tropical terrestrial ecosystem. Using vacuum distillation with cryogenic trapping and a thermal desorption unit coupled to a GC-ECD, we found that samples of air, water and soil contains 36.418 ng/L, 0.222 ng/mL and 9.156 ng/g (wet) of chloroform. Microorganisms such as the Actinomycetes and Halobacterium salinarium were also analyzed for VHOC`S contents. Carbontetrachloride, 1,1-dichloroethene, dichlorodifluoromethane, trichlorofluoromethane and other VHOC`S of environmental importance were determined. This is the first time that the presence of VHOC`S is reported in pure cultured bacteria.

  10. The greenhouse gas balance of Italy. An insight on managed and natural terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, Riccardo [Tuscia Univ., Viterbo (Italy). Dept. for Innovation in Biological, Agro-Food and Forest System (DIBAF); Euro-Mediterranean Center on Climate Changes (CMCC), Viterbo (Italy). Impacts on Agriculture, Forest and Natural Ecosystem Division (IAFENT); Miglietta, Franco (ed.) [National Research Council of Italy (CNR) and Edmund Mach Foundation, San Michele all' Adige (Italy). FoxLab Inst. of Biometeorology

    2015-04-01

    Comprehensively addresses the full greenhouse gases budget of the Italian landscape. Presents the results of the national project CARBOITALY. Provides new data and analyses in the framework of climate policies. The book addresses in a comprehensive way the full greenhouse gases budget of the Italian landscape, focusing on land use and terrestrial ecosystems. In recent years there has been a growing interest in the role of terrestrial ecosystems with regard to the carbon cycle and only recently a regional approach has been considered for its specificity in terms of new methodologies for observations and models and its relevance for national policies on mitigation and adaptation to climate changes. In terms of methods this book describes the role of flux networks and data-driven models, airborne regional measurements of fluxes and specific sectoral approaches related to important components of the human and natural landscapes. There is also a growing need on the part of institutions, agencies and policy stakeholders for new data and analyses enabling them to improve their national inventories of greenhouse gases and their compliance with the UNFCCC process. In this respect the data presented is a basis for a full carbon accounting and available to relevant stakeholders for improvements and/or verification of national inventories. The wealth of research information is the result of a national project, CARBOITALY, which involved 15 Italian institutions and several researchers to provide new data and analyses in the framework of climate policies.

  11. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

    Science.gov (United States)

    McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

    2012-01-01

    Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts

  12. Biogenic and non-biogenic Si pools in terrestrial ecosystems: results from a novel analysis method

    Science.gov (United States)

    Barao, Lucia; Vandevenne, Floor; Clymans, Wim; Meire, Patrick; Frings, Patrick; Conley, Daniel; Struyf, Eric

    2015-04-01

    Silicon (Si) is a chemical element frequently associated with highly abundant silicate minerals in the Earth crust. Over millions of years, the interaction of such minerals with the atmosphere and hydrosphere produces a myriad of processed compounds, and the mineral weathering consumes CO2 during the process. The weathering of minerals also triggers the export of dissolved Si (DSi) to coastal waters and the ocean. Here, DSi is deposited in diatom frustules, in an amorphous biogenic form (BSi). Diatoms account for 50% of the primary production and are crucial for the export of carbon into the deep sea. In recent years, it was acknowledged that terrestrial systems filter the Si transition from the terrestrial mineral to the marine and coastal biological pool, by the incorporation of DSi into plants. In this process, DSi is taken up by roots together with other nutrients and precipitates in plant cells in amorphous structures named phytoliths. After dead, plant tissues become mixed in the top soil, where BSi is available for dissolution and will control the DSi availability in short time scales. Additionally, Si originated from soil forming processes can also significantly interfere with the global cycle. The Si cycle in terrestrial ecosystems is a key factor to coastal ecology, plant ecology, biogeochemistry and agro-sciences, but the high variability of different biogenic and non-biogenic Si pools remains as an obstacle to obtain accurate measurements. The traditional methods, developed to isolate diatoms in ocean sediments, only account for simple mineral corrections. In this dissertation we have adapted a novel continuous analysis method (during alkaline extraction) that uses Si-Al ratios and reactivity to differ biogenic from non-biogenic fractions. The method was originally used in marine sediments, but we have developed it to be applicable in a wide range of terrestrial, aquatic and coastal ecosystems. We first focused on soils under strong human impact in

  13. Green Ocean Amazon 2014/15 Terrestrial Ecosystem Project (Geco) Field Campaign Report

    Energy Technology Data Exchange (ETDEWEB)

    Jardine, Kolby [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-06-01

    In conjunction with the U.S. Department of Energy (DOE)’s Atmospheric Radiation Measurement (ARM) Climate Research Facility GoAmazon campaign, the Terrestrial Ecosystem Science (TES)-funded Green Ocean Amazon (GoAmazon 2014/15) terrestrial ecosystem project (Geco) was designed to: • evaluate the strengths and weaknesses of leaf-level algorithms for biogenic volatile organic compounds (BVOCs) emissions in Amazon forests near Manaus, Brazil, and • conduct mechanistic field studies to characterize biochemical and physiological processes governing leaf- and landscape-scale tropical forest BVOC emissions, and the influence of environmental drivers that are expected to change with a warming climate. Through a close interaction between modeling and observational activities, including the training of MS and PhD graduate students, post-doctoral students, and technicians at the National Institute for Amazon Research (INPA), the study aimed at improving the representation of BVOC-mediated biosphere-atmosphere interactions and feedbacks under a warming climate. BVOCs can form cloud condensation nuclei (CCN) that influence precipitation dynamics and modify the quality of down welling radiation for photosynthesis. However, our ability to represent these coupled biosphere-atmosphere processes in Earth system models suffers from poor understanding of the functions, identities, quantities, and seasonal patterns of BVOC emissions from tropical forests as well as their biological and environmental controls. The Model of Emissions of Gases and Aerosols from Nature (MEGAN), the current BVOC sub-model of the Community Earth System Model (CESM), was evaluated to explore mechanistic controls over BVOC emissions. Based on that analysis, a combination of observations and experiments were studied in forests near Manaus, Brazil, to test existing parameterizations and algorithm structures in MEGAN. The model was actively modified as needed to improve tropical BVOC emission simulations on

  14. Unmanned Aircraft Systems Used over Western U.S. Rangelands to Characterize Terrestrial Ecosystems

    Science.gov (United States)

    Rango, A.

    2015-12-01

    New remote sensing methods to quantify terrestrial ecosystems have developed rapidly over the past 10 years. New platforms with improved aeronautical capabilities have become known as Unmanned Aircraft Systems (UAS). In addition to the new aircraft, sensors are becoming smaller and some can fit into limited payload bays. The miniaturization process is well underway, but much remains to be done. Rather than using a wide variety of sensors, a limited number of instruments is recommended. At the moment we fly 2-3 instruments (digital SLR camera, 6-band multispectral camera, and single video camera). Our flights are primarily over low population density western U.S. rangeland with objectives to assess rangeland health, active erosion, vegetation change, phenology, livestock movement, and vegetation type consumed by grazing animals. All of our UAS flights are made using a serpentine flight path with overlapping images at an altitude of 700 ft (215 m). This altitude allows hyperspatial imagery with a resolution of 5-15 cm depending upon the sensor being used, and it allows determination of vegetation type based on the plant structure and vegetation geometries, or by multispectral analysis. In addition to advances in aircraft and sensor technology, image processing software has become more sophisticated. Future development is necessary, and we can expect improvement in sensors, aircraft, data collection, and application to terrestrial ecosystems. Of 17 ARS research laboratories across the country four laboratories are interested in future UAS applications and another 13 already have at least one UAS. In 2015 the Federal Aviation Administration proposed a framework of recommendations that would allow routine use of certain small UAS (those weighing less than 55 lb (25 kg)). Although these new regulations will provide increased flexibility in how flights are made, other operations will still require the use of a Certificate of Authorization.

  15. Pterosaur diversity and faunal turnover in Cretaceous terrestrial ecosystems in China.

    Science.gov (United States)

    Wang, Xiaolin; Kellner, Alexander W A; Zhou, Zhonghe; Campos, Diogenes de Almeida

    2005-10-06

    New specimens and an analysis of the Jehol pterosaur faunae of northeastern China show an unexpected diversity of flying reptile groups in terrestrial Cretaceous ecosystems. Here we report two new pterosaurs that are referred to European groups previously unknown in deposits of northeastern China. Feilongus youngi, from the Yixian Formation, is closely related to the Gallodactylidae and is distinguished by the presence of two independent sagittal crests and a protruding upper jaw. Nurhachius ignaciobritoi, from the Jiufotang Formation, has teeth formed by labiolingually compressed triangular crowns, only previously reported in Istiodactylus latidens from England. With these new discoveries, the Jehol pterosaurs show a wide range of groups including both primitive and derived forms that are not matched by any other deposit in the world. The discoveries also document the turnover of pterosaur faunae, with the primitive Anurognathidae and early archaeopterodactyloids being replaced by derived pterodactyloids. Furthermore, these deposits offer an opportunity to examine the interaction and competition between birds and pterosaurs--it indicates that the avian fauna during the Lower Cretaceous (and possibly most of the Mesozoic) dominated terrestrial, inland regions, whereas pterosaurs were more abundant in coastal areas.

  16. Modelling accumulation of radionuclides in terrestrial ecosystems originating from a long-term groundwater contamination

    Energy Technology Data Exchange (ETDEWEB)

    Gaerdenaes, Annemieke I. [Dept. of Soil and Environment, Swedish University of Agricultural Sciences (SLU), P.O. Box 7001, 750 07 Uppsala (Sweden); Eckersten, Henrik [Dept. of Ecology and Crop Production, SLU, P.O. Box 7042, 750 07 Uppsala (Sweden); Reinlert, Andre [Dept. of Physical Geography and Ecosystems Analysis, Lund University, 223 62 Lund (Sweden); MMT, Sven Kaellfelts Gata 11 SE 426 71 Vaestra Froelunda (Sweden); Gustafsson, David; Jansson, Per-Erik [Dept. Land and Water Resources, KTH, SE 100 44, Stockholm (Sweden); Ekstroem, Per-Anders [Facilia AB, Gustavlundsvaegen 151A, 167 51 Bromma (Sweden); Greger, Maria [Dept. of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm (Sweden)

    2014-07-01

    This study was conducted as part of the risk assessment of final deposits of nuclear fuel waste. The overall objective is to assess the possible accumulation of radionuclides in terrestrial ecosystems after an eventual long-term groundwater contamination. The specific objectives are to assess: i) What proportion of the contamination will accumulate in the soil-plant-system? ii) Where in the soil-plant- system will it accumulate? iii) Which ecosystem characteristics and radionuclides properties are important for the accumulation? and iv) Under which circumstances do losses from the ecosystems occur? We developed the dynamic model Tracey (Gaerdenaes et al. 2009) describing cycling of radionuclides in terrestrial ecosystems with high temporal resolution (1 day). The model is a multi-compartmental model in which fluxes and storage of radionuclides are described for different plant parts and soil pools in each of the 10 soil layers. The radionuclide fluxes are driven either by water or carbon fluxes. The water and the carbon fluxes are simulated with the dynamic, bio-geophysical Coup Model (Jansson and Karlberg, 2004). Tracey includes two root uptake approaches of radionuclides; (i) passive uptake driven by root water uptake and (ii) active uptake driven by plant growth. A linear approach describes the adsorption of radionuclides to soil particles and organic matter. Tracey was applied on two ecosystems with contrasting hydrology, the mixed Pinus-Picea forests found in the dry, elevated areas and the Alnus forests found in the wet, low-land areas of Uppland in central east Sweden. Different varieties of the two forest types were created by varying the root depth and radiation use efficiency. The climate was cold-temperate and based on 30-year daily weather data from Uppsala. The assumed groundwater contamination was close to 1 mg of an unspecified radionuclide per m2 and year. This load corresponds to 1 Bq per m{sup 2} and year of {sup 238}U, a common long

  17. How well does your model capture the terrestrial ecosystem dynamics of the Arctic-Boreal Region?

    Science.gov (United States)

    Stofferahn, E.; Fisher, J. B.; Hayes, D. J.; Huntzinger, D. N.; Schwalm, C.

    2016-12-01

    The Arctic-Boreal Region (ABR) is a major source of uncertainties for terrestrial biosphere model (TBM) simulations. These uncertainties are precipitated by a lack of observational data from the region, affecting the parameterizations of cold environment processes in the models. Addressing these uncertainties requires a coordinated effort of data collection and integration of the following key indicators of the ABR ecosystem: disturbance, flora / fauna and related ecosystem function, carbon pools and biogeochemistry, permafrost, and hydrology. We are developing a model-data integration framework for NASA's Arctic Boreal Vulnerability Experiment (ABoVE), wherein data collection for the key ABoVE indicators is driven by matching observations and model outputs to the ABoVE indicators. The data are used as reference datasets for a benchmarking system which evaluates TBM performance with respect to ABR processes. The benchmarking system utilizes performance metrics to identify intra-model and inter-model strengths and weaknesses, which in turn provides guidance to model development teams for reducing uncertainties in TBM simulations of the ABR. The system is directly connected to the International Land Model Benchmarking (ILaMB) system, as an ABR-focused application.

  18. Deriving Vegetation Dynamics of Natural Terrestrial Ecosystems from MODIS NDVI/EVI Data over Turkey.

    Science.gov (United States)

    Evrendilek, Fatih; Gulbeyaz, Onder

    2008-09-01

    The 16-day composite MODIS vegetation indices (VIs) at 500-m resolution for the period between 2000 to 2007 were seasonally averaged on the basis of the estimated distribution of 16 potential natural terrestrial ecosystems (NTEs) across Turkey. Graphical and statistical analyses of the time-series VIs for the NTEs spatially disaggregated in terms of biogeoclimate zones and land cover types included descriptive statistics, correlations, discrete Fourier transform (DFT), time-series decomposition, and simple linear regression (SLR) models. Our spatio-temporal analyses revealed that both MODIS VIs, on average, depicted similar seasonal variations for the NTEs, with the NDVI values having higher mean and SD values. The seasonal VIs were most correlated in decreasing order for: barren/sparsely vegetated land > grassland > shrubland/woodland > forest; (sub)nival > warm temperate > alpine > cool temperate > boreal = Mediterranean; and summer > spring > autumn > winter. Most pronounced differences between the MODIS VI responses over Turkey occurred in boreal and Mediterranean climate zones and forests, and in winter (the senescence phase of the growing season). Our results showed the potential of the time-series MODIS VI datasets in the estimation and monitoring of seasonal and interannual ecosystem dynamics over Turkey that needs to be further improved and refined through systematic and extensive field measurements and validations across various biomes.

  19. Mechanisms of Biogeochemical Influence on Phosphorus Bioavailablity in Cold Terrestrial Ecosystems

    Science.gov (United States)

    Kearns, J. P.; Cervini-Silva, J.; Fournelle, J.; Schloss, P.; Williamson, L.; Reuss, R.; Handlesman, J.; Banfield, J. F.

    2003-12-01

    The Bonanza Creek LTER site along the Tanana River near Fairbanks, Alaska is a phosphorus-limited ecosystem. Our research combines microbiological and geochemical approaches to understand factors controlling phosphorus bioavailability at this site. Our first objective was to identify the phosphate minerals within the sediment and soils of vegetated islands in the river. Detailed electron microprobe studies revealed that the predominant inorganic phosphate source is fluorapatite. Thus, we are conducting microbial and abiotic experiments to evaluate the role of organic ligands in fluorapatite dissolution. Kinetic data are obtained in flow through reaction vessels as a function of apatite variety and ligand type. Batch experiments are used to investigate organic adsorption to apatite surfaces to test a hypothesized relationship between the propensity of a ligand to adsorb and its influence on dissolution rates. These data will contribute to understanding of biological impact on mineral weathering and nutrient cycling in terrestrial environments. At Bonanza Creek, and in many other soils, phosphorus released by apatite weathering is sequestered into secondary lanthanide, aluminum, and iron phosphate minerals. These represent important, highly insoluble phosphate reservoirs in some phosphorus-limited ecosystems. We have studied the selectivity of biogenic organic ligands in promoting mineral dissolution through strong metal ion complexation. Of particular interest are siderophores, which modeling results indicate have the potential to influence both iron and phosphorus bioavailability.

  20. Terrestrial Carbon Sinks in the Brazilian Amazon and Cerrado Region Predicted from MODIS Satellite Data and Ecosystem Modeling

    Science.gov (United States)

    A simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate monthly carbon fluxes in terrestrial ecosystems of Brazilian Amazon and Cerrado regions over the period 2000-2004. Pr...

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

    Science.gov (United States)

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

    2015-01-01

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

  2. Diagnosing phosphorus limitations in natural terrestrial ecosystems in carbon cycle models

    Science.gov (United States)

    Sun, Yan; Peng, Shushi; Goll, Daniel S.; Ciais, Philippe; Guenet, Bertrand; Guimberteau, Matthieu; Hinsinger, Philippe; Janssens, Ivan A.; Peñuelas, Josep; Piao, Shilong; Poulter, Benjamin; Violette, Aurélie; Yang, Xiaojuan; Yin, Yi; Zeng, Hui

    2017-07-01

    Most of the Earth System Models (ESMs) project increases in net primary productivity (NPP) and terrestrial carbon (C) storage during the 21st century. Despite empirical evidence that limited availability of phosphorus (P) may limit the response of NPP to increasing atmospheric CO2, none of the ESMs used in the previous Intergovernmental Panel on Climate Change assessment accounted for P limitation. We diagnosed from ESM simulations the amount of P need to support increases in carbon uptake by natural ecosystems using two approaches: the demand derived from (1) changes in C stocks and (2) changes in NPP. The C stock-based additional P demand was estimated to range between -31 and 193 Tg P and between -89 and 262 Tg P for Representative Concentration Pathway (RCP) 2.6 and RCP8.5, respectively, with negative values indicating a P surplus. The NPP-based demand, which takes ecosystem P recycling into account, results in a significantly higher P demand of 648-1606 Tg P for RCP2.6 and 924-2110 Tg P for RCP8.5. We found that the P demand is sensitive to the turnover of P in decomposing plant material, explaining the large differences between the NPP-based demand and C stock-based demand. The discrepancy between diagnosed P demand and actual P availability (potential P deficit) depends mainly on the assumptions about availability of the different soil P forms. Overall, future P limitation strongly depends on both soil P availability and P recycling on ecosystem scale.

  3. Modeling extreme drought impacts on terrestrial ecosystems when thresholds are exceeded

    Science.gov (United States)

    Holm, J. A.; Rammig, A.; Smith, B.; Medvigy, D.; Lichstein, J. W.; Dukes, J. S.; Allen, C. D.; Beier, C.; Larsen, K. S.; Ficken, C. D.; Pockman, W.; Anderegg, W.; Luo, Y.

    2016-12-01

    Recent IPCC Assessment Reports suggest that with predicted climate changes future precipitation- and heat-related extreme events are becoming stronger and more frequent with potential for prolonged droughts. To prepare for these changes and their impacts, we need to develop a better understanding of terrestrial ecosystem responses to extreme drought events. In particular, we focus here on large-extent and long-lasting extreme drought events with noticeable impacts on the functioning of forested ecosystems. While most of ecosystem manipulative experiments have been motivated by ongoing and predicted climate change, the majority only applied relatively moderate droughts, not addressing the "very" extreme tail of these scenarios, i.e. "extreme extremes (EEs)". We explore the response of forest ecosystems to EEs using two demographic-based dynamic global vegetation models (DGVMs) (i.e. ED2, LPJ-GUESS) in which the abundances of different plant functional types, as well as tree size- and age-class structure, are emergent properties of resource competition. We evaluate the model's capabilities to represent extreme drought scenarios (i.e., 50% and 90% reduction in precipitation for 1-year, 2-year, and 4-year drought scenarios) at two dry forested sites: Palo Verde, Costa Rica (i.e. tropical) and EucFACE, Australia (i.e. temperate). Through the DGVM modeling outcomes we determine the following five testable hypotheses for future experiments: 1) EEs cannot be extrapolated from mild extremes due to plant plasticity and functional composition. 2) Response to EEs depends on functional diversity, trait combinations, and phenology, such that both models predicted even after 100 years plant biomass did not recover. 3) Mortality from drought reduces the pressure on resources and prevents further damage by subsequent years of drought. 4) Early successional stands are more vulnerable to extreme droughts while older stand are more resilient. 5) Elevated atmospheric CO2 alleviates

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

    Science.gov (United States)

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

    2015-06-01

    facilitate mechanistic understanding of the carbon-water interactions over terrestrial ecosystems under global change. © 2015 John Wiley & Sons Ltd.

  5. Effects of active forest fire on terrestrial ecosystem production and greenhouse gas emissions

    Science.gov (United States)

    Sannigrahi, Srikanta; Rahmat, Shahid; Bhatt, Sandeep; Rana, Virendra

    2017-04-01

    The forest fire is one of the most catalysing agents which degrade an ecosystems leading to the loss of net and gross primary productivity (NPP & GPP) and carbon sequestration service. Additionally, it can suppress the efficiency of service providing capacity of an ecosystem throughout the time and space. Remote sensing-based forest fire estimation in a diverse ecosystem is very much essential for mitigating the biodiversity and productivity losses due to the forest fire. Satellite-based Land Surface Temperature (LST) has been calculated for the pre-fire and fire years to identify the burn severity hotspot across all eco-regions in the Lower Himalaya region. Several burn severity indices: Normalized Burn Ratio (NBR), Burnt Area Index (BAI), Normalized Multiband Drought Index (NMDI), Soil Adjusted Vegetation Index (SAVI), Global Environmental Monitoring Index (GEMI), Enhance Vegetation Index (EVI) have been used in this study to quantify the spatial and temporal changes (delta) of the selected indices. Two Light Use Efficiency (LUE) models: Carnegie- Ames-Stanford-Approach (CASA) and Vegetation Photosynthesis Model (VPM) have been used to quantify the terrestrial Net Primary Productivity (NPP) in the pre-fire and fire years across all biomes of the region. A novel approach has been preceded in this field to demonstrate the correlation between forest fire density (FFD) and NPP. A strong positive correlation was found between burn severity indices and predicted NPP: BAI and NPP (r = 0.49), NBR and NPP: (r = 0.58), EVI and NPP: (r = 0.72), SAVI and NPP: (r = 0.67), whereas, a negative association has noted between the NMDI and NPP: (r = -0.36) during the both studied years. Results have shown that the NPP is highly correlated with the forest fire density (R2 = 0.75, RMSE = 5.03 gC m-2 month-1). The estimated LST of the individual fire days has witnessed a sharp temperature increase by > 6oC - 9oC in comparison to the non-fire days clearly indicates high fire risk (in

  6. A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur

    Directory of Open Access Journals (Sweden)

    Jorge O. Calvo

    2007-09-01

    Full Text Available A unique site at the northern area of Patagonia (Neuquén, Argentina reveals a terrestrial ecosystem preserved in a detail never reported before in a Late Cretaceous deposit. An extraordinary diversity and abundance of fossils was found concentrated in a 0.5 m horizon in the same quarry, including a new titanosaur sauropod, Futalognkosaurus dukei n.gen., n.sp, which is the most complete giant dinosaur known so far. Several plant leaves, showing a predominance of angiosperms over gymnosperms that likely constituted the diet of F. dukei were found too. Other dinosaurs (sauropods, theropods, ornithopods, crocodylomorphs, pterosaurs, and fishes were also discovered, allowing a partial reconstruction of this Gondwanan continental ecosystem.Um depósito fóssil na região norte da Patagônia (Neuquén, Argentina revela um ecossistema nunca antes registrado a este nível de detalhes em depósitos do Cretáceo Superior. Uma diversidade e abundância extraordinária de fósseis encontra-se concentrada em uma camada de 0,5 m no mesmo sítio, incluindo um novo saurópodo titanossaurídeo, Futalognkosaurus dukei n. gen, n. sp., que é o mais completo dinossauro gigante encontrado até a presente data. Foram descobertas váriasfolhas de plantas indicando a predominância de angiospermas sobre gimnospermas que possivelmente formavam a base da dieta de F. dukei. Outros dinossauros (saurópodes, terópodes, ornitópodes, crocodilomorfos, pterossauros e peixes foram também encontrados possibilitando a reconstrução parcialdeste ecossistema continental do Gondwana.

  7. Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica

    Science.gov (United States)

    Quesada, A.; Camacho, A.; Rochera, C.; Velázquez, D.

    2009-11-01

    This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, ponds, rivers and wetlands; microbiology of microbial mats, ecology of microbial food webs and viral effects on aquatic ecosystems; ornithology, with investigations on a Gentoo penguin rookery ( Pygoscelis papua) as well as the flying ornithofauna; biocomplexity and life cycles of species from different taxonomic groups; analysis of a complete watershed unit from a landscape perspective; and human impacts, specifically the effect of trampling on soil characteristics and biota. Byers Peninsula offers many features as an international reference site given it is one of the largest ice-free areas in the Antarctic Peninsula region, it has a variety of different landscape units, and it hosts diverse aquatic ecosystems. Moreover, the Byers Peninsula is a hotspot for Antarctic biodiversity, and because of its high level of environmental protection, it has been very little affected by human activities. Finally, the proximity to the Spanish polar installations on Livingston Island and the experience derived from previous expeditions to the site make it logistically feasible as a site for ongoing monitoring and research.

  8. Experimental terrestrial soil-core microcosm test protocol. A method for measuring the potential ecological effects, fate, and transport of chemicals in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Van Voris, P.; Tolle, D.A.; Arthur, M.F.

    1985-06-01

    In order to protect the environment properly and have a realistic appraisal of how a chemical will act in the environment, tests of ecological effects and chemical fate must be performed on complex assemblages of biotic and abiotic components (i.e., microcosms) as well as single species. This protocol is one which could be added to a series of tests recently developed as guidelines for Section 4 of the Toxic Substances Control Act (P.L. 94-469; U.S.C., Section 2601-2629). The terrestrial soil-core microcosm is designed to supply site-specific and possibly regional information on the probable chemical fate and ecological effects resulting from release of a chemical substance to a terrestrial ecosystem. The EPA will use the data resulting from this test system to compare the potential hazards of a chemical with others that have been previously evaluated.

  9. The SMAP Level 4 Carbon PRODUCT for Monitoring Terrestrial Ecosystem-Atmosphere CO2 Exchange

    Science.gov (United States)

    Jones, L. A.; Kimball, J. S.; Madani, N.; Reichle, R. H.; Glassy, J.; Ardizzone, J/

    2016-01-01

    The NASA Soil Moisture Active Passive (SMAP) mission Level 4 Carbon (L4_C) product provides model estimates of Net Ecosystem CO2 exchange (NEE) incorporating SMAP soil moisture information as a primary driver. The L4_C product provides NEE, computed as total respiration less gross photosynthesis, at a daily time step and approximate 14-day latency posted to a 9-km global grid summarized by plant functional type. The L4_C product includes component carbon fluxes, surface soil organic carbon stocks, underlying environmental constraints, and detailed uncertainty metrics. The L4_C model is driven by the SMAP Level 4 Soil Moisture (L4_SM) data assimilation product, with additional inputs from the Goddard Earth Observing System, Version 5 (GEOS-5) weather analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data. The L4_C data record extends from March 2015 to present with ongoing production. Initial comparisons against global CO2 eddy flux tower measurements, satellite Solar Induced Canopy Florescence (SIF) and other independent observation benchmarks show favorable L4_C performance and accuracy, capturing the dynamic biosphere response to recent weather anomalies and demonstrating the value of SMAP observations for monitoring of global terrestrial water and carbon cycle linkages.

  10. Levels and transfer of {sup 210}Po and {sup 210}Pb in Nordic terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.E., E-mail: justin.brown@nrpa.n [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Gjelsvik, R. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Roos, P. [RISO-DTU P.O. Box 49 DK-4000 Roskilde (Denmark); Kalas, J.A. [Norwegian Institute for Nature Research (NINA), Tungasletta 2, 7485 Trondheim (Norway); Outola, I. [STUK, Laippatie 4/P.O. BOX 14, 00881 Helsinki (Finland); Holm, E. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway)

    2011-05-15

    Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides {sup 210}Po and {sup 210}Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in {sup 210}Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of {sup 210}Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg{sup -1} d.w. and in plants and lichens between 20 and 138 Bq kg{sup -1} d.w. The results showed that soil humus is an important reservoir for {sup 210}Po and {sup 210}Pb and that fauna in close contact with this media may also exhibit elevated levels of {sup 210}Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of {sup 210}Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of {sup 210}Po in this system.

  11. Organochlorine Turnover in Forest Ecosystems: The Missing Link in the Terrestrial Chlorine Cycle

    Energy Technology Data Exchange (ETDEWEB)

    A Leri; S Myneni

    2011-12-31

    Research in the last 20 years has shown that chlorine undergoes transformations between inorganic and organic forms as part of a complex biogeochemical cycle in terrestrial systems. Natural organochlorine production appears to be associated with the decomposition of plant material on the soil surface, though the chlorine cycle budget implies that a proportion of natural organochlorine enters soil through plant litter and atmospheric deposition as well. Organochlorine compounds may form through biotic and abiotic pathways, but the rates and magnitude of production in the field remain undefined. We have performed a time-dependent trace of chlorine concentration through forest ecosystems, revealing distinct fractions of naturally produced organochlorine in plant biomass. Aliphatic organochlorine constitutes an intrinsic component of healthy leaves that persists through senescence and humification of the plant material, making a substantial contribution to the pool of soil organochlorine. Plant leaves also contain soluble aromatic organochlorine compounds that leach from leaf litter during early decay stages. As decay progresses, high concentrations of insoluble aromatic organochlorine accrue in the humus, through de novo production as well as adsorption. The rates of aromatic organochlorine production and degradation vary seasonally and conversely. This study presents the first unambiguous evidence that there exist multiple pools of chlorinated organic matter in the soil environment and that leaf litter deposition makes a significant and refractory contribution to the soil organochlorine pool, providing key insights into the biogeochemical chlorine cycle.

  12. Global Monthly CO2 Flux Inversion Based on Results of Terrestrial Ecosystem Modeling

    Science.gov (United States)

    Deng, F.; Chen, J.; Peters, W.; Krol, M.

    2008-12-01

    Most of our understanding of the sources and sinks of atmospheric CO2 has come from inverse studies of atmospheric CO2 concentration measurements. However, the number of currently available observation stations and our ability to simulate the diurnal planetary boundary layer evolution over continental regions essentially limit the number of regions that can be reliably inverted globally, especially over continental areas. In order to overcome these restrictions, a nested inverse modeling system was developed based on the Bayesian principle for estimating carbon fluxes of 30 regions in North America and 20 regions for the rest of the globe. Inverse modeling was conducted in monthly steps using CO2 concentration measurements of 5 years (2000 - 2005) with the following two models: (a) An atmospheric transport model (TM5) is used to generate the transport matrix where the diurnal variation n of atmospheric CO2 concentration is considered to enhance the use of the afternoon-hour average CO2 concentration measurements over the continental sites. (b) A process-based terrestrial ecosystem model (BEPS) is used to produce hourly step carbon fluxes, which could minimize the limitation due to our inability to solve the inverse problem in a high resolution, as the background of our inversion. We will present our recent results achieved through a combination of the bottom-up modeling with BEPS and the top-down modeling based on TM5 driven by offline meteorological fields generated by the European Centre for Medium Range Weather Forecast (ECMFW).

  13. Relaxation Biodynamics: Experimental Studies and Modeling of Biogeochemical Processes in Northern Terrestrial Ecosystems

    Science.gov (United States)

    Panikov, N. S.; Pankratov, T.

    2001-12-01

    Relaxation phenomenon in physics and chemistry stands for delay between the application of an external stress to a system and its response. When an equilibrated nuclear, atomic or molecular system is subjected to an abrupt physical change (sudden rise in temperature or pressure), it takes time for the system to re-equilibrate under the new conditions. This period (relaxation time) can provide a powerful insight into mechanisms of chemical reaction. Our intention is to extend such approach to analysis of the complex biological phenomena related mainly to microbial growth and activity in the soil. We will show how this information can be used for better understanding the biogeochemical processes in northern terrestrial ecosystems such as aerobic and anaerobic decomposition of organic matter, gas (CO2 and CH4) emission to atmosphere, migration and transformation of biogenic elements, etc. The major source of experimental data is laboratory soil incubation under controlled environmental conditions with abrupt changes in one of the key parameters: temperature (including the water-to-ice phase transition), soil moisture, light (illumination of planted soil), supply of organic substrate and mineral nutrients. The state of biological component before and after abrupt changes was followed by continuous recording of gas (CO2, CH4) exchange rate and (in some special experiments), chemical analysis of the soil solution, and the characterization of soil community (microbial and plants biomass, species composition, change of life forms, etc.) The obtained dynamic data were fit to simulation models (sets of differential equations) describing the C- and energy flow through the studied microcosm systems. The comparison of predicted and observed relaxation dynamics allowed us to discard wrong assumptions on the nature of regulatory mechanisms involved in the functioning of the soil community. Finally, the conclusions derived from the lab experiments are projected to field

  14. How do persistent organic pollutants be coupled with biogeochemical cycles of carbon and nutrients in terrestrial ecosystems under global climate change?

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Ying [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation; Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Xu, Zhihong; Reverchon, Frederique [Griffith Univ., Nathan, QLD (Australia). Environmetnal Futures Centre and School of Biomolecular and Physical Sciences; Luo, Yongming [Chinese Academy of Sciences, Nanjing (China). Key Lab. of Soil Environment and Pollution Remediation

    2012-03-15

    Global climate change (GCC), especially global warming, has affected the material cycling (e.g., carbon, nutrients, and organic chemicals) and the energy flows of terrestrial ecosystems. Persistent organic pollutants (POPs) were regarded as anthropogenic organic carbon (OC) source, and be coupled with the natural carbon (C) and nutrient biogeochemical cycling in ecosystems. The objective of this work was to review the current literature and explore potential coupling processes and mechanisms between POPs and biogeochemical cycles of C and nutrients in terrestrial ecosystems induced by global warming. Global warming has caused many physical, chemical, and biological changes in terrestrial ecosystems. POPs environmental fate in these ecosystems is controlled mainly by temperature and biogeochemical processes. Global warming may accelerate the re-emissions and redistribution of POPs among environmental compartments via soil-air exchange. Soil-air exchange is a key process controlling the fate and transportation of POPs and terrestrial ecosystem C at regional and global scales. Soil respiration is one of the largest terrestrial C flux induced by microbe and plant metabolism, which can affect POPs biotransformation in terrestrial ecosystems. Carbon flow through food web structure also may have important consequences for the biomagnification of POPs in the ecosystems and further lead to biodiversity loss induced by climate change and POPs pollution stress. Moreover, the integrated techniques and biological adaptation strategy help to fully explore the coupling mechanisms, functioning and trends of POPs and C and nutrient biogeochemical cycling processes in terrestrial ecosystems. There is increasing evidence that the environmental fate of POPs has been linked with biogeochemical cycles of C and nutrients in terrestrial ecosystems under GCC. However, the relationships between POPs and the biogeochemical cycles of C and nutrients are still not well understood. Further

  15. Competition between plant functional types in the Canadian Terrestrial Ecosystem Model (CTEM) v. 2.0

    Science.gov (United States)

    Melton, J. R.; Arora, V. K.

    2016-01-01

    The Canadian Terrestrial Ecosystem Model (CTEM) is the interactive vegetation component in the Earth system model of the Canadian Centre for Climate Modelling and Analysis. CTEM models land-atmosphere exchange of CO2 through the response of carbon in living vegetation, and dead litter and soil pools, to changes in weather and climate at timescales of days to centuries. Version 1.0 of CTEM uses prescribed fractional coverage of plant functional types (PFTs) although, in reality, vegetation cover continually adapts to changes in climate, atmospheric composition and anthropogenic forcing. Changes in the spatial distribution of vegetation occur on timescales of years to centuries as vegetation distributions inherently have inertia. Here, we present version 2.0 of CTEM, which includes a representation of competition between PFTs based on a modified version of the Lotka-Volterra (L-V) predator-prey equations. Our approach is used to dynamically simulate the fractional coverage of CTEM's seven natural, non-crop PFTs, which are then compared with available observation-based estimates. Results from CTEM v. 2.0 show the model is able to represent the broad spatial distributions of its seven PFTs at the global scale. However, differences remain between modelled and observation-based fractional coverage of PFTs since representing the multitude of plant species globally, with just seven non-crop PFTs, only captures the large-scale climatic controls on PFT distributions. As expected, PFTs that exist in climate niches are difficult to represent either due to the coarse spatial resolution of the model, and the corresponding driving climate, or the limited number of PFTs used. We also simulate the fractional coverage of PFTs using unmodified L-V equations to illustrate its limitations. The geographic and zonal distributions of primary terrestrial carbon pools and fluxes from the versions of CTEM that use prescribed and dynamically simulated fractional coverage of PFTs compare

  16. [Characteristics of terrestrial ecosystem primary productivity in East Asia based on remote sensing and process-based model].

    Science.gov (United States)

    Zhang, Fang-Min; Ju, Wei-Min; Chen, Jing-Ming; Wang, Shao-Qiang; Yu, Gui-Rui; Han, Shi-Jie

    2012-02-01

    Based on the bi-linearly interpolated meteorological reanalysis data from National Centers for Environmental Prediction, USA and by using the leaf area index data derived from the GIMMS NDVI to run the process-based Boreal Ecosystems Productivity Simulator (BEPS) model, this paper simulated and analyzed the spatiotemporal characteristics of the terrestrial ecosystem gross primary productivity (GPP) and net primary productivity (NPP) in East Asia in 2000-2005. Before regional simulating and calculating, the observation GPP data of different terrestrial ecosystem in 15 experimental stations of AsiaFlux network and the inventory measurements of NPP at 1300 sampling sites were applied to validate the BEPS GPP and NPP. The results showed that BEPS could well simulate the changes in GPP and NPP of different terrestrial ecosystems, with the R2 ranging from 0.86 to 0.99 and the root mean square error (RMSE) from 0.2 to 1.2 g C x m(-2) x d(-1). The simulated values by BEPS could explain 78% of the changes in annual NPP, and the RMSE was 118 g C x m(-2) x a(-1). In 2000-2005, the averaged total GPP and total NPP of the terrestrial ecosystems in East Asia were 21.7 and 10.5 Pg C x a(-1), respectively, and the GPP and NPP exhibited similar spatial and temporal variation patterns. During the six years, the total NPP of the terrestrial ecosystems varied from 10.2 to 10.7 Pg C x a(-1), with a coefficient of variation being 2. 2%. High NPP (above 1000 g C x m(-2) x a(-1)) occurred in the southeast island countries, while low NPP (below 30 g C x m(-2) x a(-1)) occurred in the desert area of Northwest China. The spatial patterns of NPP were mainly attributed to the differences in the climatic variables across East Asia. The NPP per capita also varied greatly among different countries, which was the highest (70217 kg C x a(-1)) in Mongolia, far higher than that (1921 kg C x a(-1)) in China, and the lowest (757 kg C x a(-1)) in India.

  17. [Effects and mechanism of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem].

    Science.gov (United States)

    Wang, Li-qin; Qi, Yu-chun; Dong, Yun-she; Peng, Qin; Guo, Shu-fang; He, Yun-long; Yan, Zhong-qing

    2015-11-01

    As a widespread natural phenomenon in the soil of middle and high latitude as well as high altitude, freeze-thawing cycles have a great influence on the nitrogen cycle of terrestrial ecosystem in non-growing season. Freeze-thawing cycles can alter the physicochemical and biological properties of the soil, which thereby affect the migration and transformation of soil nitrogen. The impacts of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem found in available studies remain inconsistent, the mechanism is still not clear, and the research methods also need to be further explored and innovated. So it is necessary to sum up and analyze the existing achievements in order to better understand the processes of soil nitrogen cycle subjected to freeze-thawing cycles. This paper reviewed the research progress in China and abroad about the effects and mechanisms of freeze-thawing cycles on key processes of nitrogen cycle in terrestrial ecosystem, including mineralization, immobilization, nitrification and denitrification, N leakage and gaseous loss, and analyzed the deficiencies of extant research. The possible key research topics that should be urgently paid more attention to in the future were also discussed.

  18. An organic record of terrestrial ecosystem collapse and recovery at the Triassic-Jurassic boundary in East Greenland

    Science.gov (United States)

    Williford, Kenneth H.; Grice, Kliti; Holman, Alexander; McElwain, Jennifer C.

    2014-02-01

    Terrestrial ecosystem collapse at the end of the Triassic Period coincided with a major mass extinction in the marine realm and has been linked to increasing atmospheric carbon dioxide, global warming, and fire activity. Extractable hydrocarbons in samples from the fluvial Triassic-Jurassic boundary section at Astartekløft, East Greenland were analyzed to investigate the molecular and isotopic organic record of biotic and environmental change during this event. Carbon isotopic compositions of individual plant wax lipids show a >4‰ negative excursion coinciding with peak extinction and a further decrease of 2‰ coinciding with peak pCO2 as estimated from the stomatal indices of fossil Gingkoales. An increase of ˜30‰ in the hydrogen isotopic compositions of the same plant wax lipids coincides with ecosystem collapse, suggesting that the biotic crisis was accompanied by strong hydrologic change. Concentrations of polycyclic aromatic hydrocarbons related to combustion also increase together with abrupt plant diversity loss and peak with fossil charcoal abundance and maximum plant turnover, supporting the role of fire in terrestrial extinctions. Anomalously high concentrations of a monoaromatic diterpenoid related to gymnosperm resin derivatives (and similar to dehydroabietane) occur uniquely in samples from the boundary bed, indicating that environmental stress factors leading to peak plant extinction stimulated increased resin production, and that plant resin derivatives may be effective biomarkers of terrestrial ecosystem stress.

  19. Intercomparison of Terrestrial Laser Scanning Instruments for Assessing Forested Ecosystems: A Brisbane Field Experiment

    Science.gov (United States)

    Armston, J.; Newnham, G.; Strahler, A. H.; Schaaf, C.; Danson, M.; Gaulton, R.; Zhang, Z.; Disney, M.; Sparrow, B.; Phinn, S. R.; Schaefer, M.; Burt, A.; Counter, S.; Erb, A.; Goodwin, N.; Hancock, S.; Howe, G.; Johansen, K.; Li, Z.; Lollback, G.; Martel, J.; Muir, J.; Paynter, I.; Saenz, E.; Scarth, P.; Tindall, D.; Walker, L.; Witte, C.; Woodgate, W.; Wu, S.

    2013-12-01

    During 28th July - 3rd August, 2013, an international group of researchers brought five terrestrial laser scanners (TLS) to long-term monitoring plots in three eucalyptus-dominated woodland sites near Brisbane, Queensland, Australia, to acquire scans at common locations for calibration and intercomparison.They included: DWEL - a dual-wavelength full-waveform laser scanner (Boston U., U. Massachusetts Lowell, U. Massachusetts Boston, USA) SALCA - a dual-wavelength full-waveform laser scanner (U. Salford, UK) CBL - a canopy biomass lidar, a small ultraportable low-cost multiple discrete return scanner (U. Massachusetts Boston, USA) Riegl VZ400 - a survey-grade commercial waveform scanner (Queensland Government and TERN, U. Queensland, Australia) FARO Focus 3D - a lightweight commercial phase-shift ranging laser scanner (U. Southern Queensland) Two plots were scanned at Karawatha Forest Park, a Terrestrial Ecosystem Research Network (TERN) Supersite, and one plot at D'Aguilar National Park. At each 50 x 100 m plot, a center scan point was surrounded by four scan points located 25 m away in a cross pattern allowing for 3-D reconstructions of scan sites in the form of point clouds. At several center points, multiple instrument configurations (i.e. different beam divergence, angular resolution, pulse rate) were acquired to test the impact of instrument specifications on separation of woody and non-woody materials and estimation of vegetation structure parameters. Three-dimensional Photopoint photographic panoramas were also acquired, providing reconstructions of stems in the form of point clouds using photogrammetric correlation methods. Calibrated reflectance targets were also scanned to compare instrument geometric and radiometric performance. Ancillary data included hemispherical photos, TRAC LAI/clumping measurements, spectra of leaves, bark, litter, and other target components. Wet and dry leaf weights determined water content. Planned intercomparison topics and

  20. Quantifying GHG Emissions From Terrestrial Ecosystems In Africa - The Crucial Role Of Livestock Systems

    Science.gov (United States)

    Butterbach-Bahl, K.; Pelster, D.; Goopy, J.

    2015-12-01

    Knowledge on GHG fluxes from terrestrial ecosystems in Africa remains limited. Published field trials on soil GHG fluxes are summarized in approx. 10 research papers. Emissions related to livestock production, which are dominating most current estimates, rely on modelling work. Thus, uncertainties for African GHG fluxes are likely the highest at continental scale. Even though total GHG fluxes from agricultural soils seem to be low (insufficient fertilizer use/ soil degradation) the opposite might be true for livestock systems. Emissions per kg edible milk protein in SSA are a magnitude higher as for Europe (>100 kg CO2eq kg-1). Differences are related to feed intake, quality and availability, species and breeds, etc. Besides, handling of animal wastes is often less sophisticated, resulting in high nutrient losses and GHG fluxes. Estimates remain unconstrained, since in-situ measurements are missing and emission factors, developed elsewhere, are applied without verification to the African situation. To support African countries to improve emission reporting, to improve productivity of the agricultural sector while minimizing GHG fluxes and to allow them to play a vital role in emission trading, , requires to build in-continent research capacity. The International Livestock Research Institute (ILRI), has recently established a state-of-the art GHG laboratory in East Africa, which is envisioned to build a knowledge hub for environmental research. First measurement results indicate that EF for excreta applications to rangelands might be largely overestimated, mainly due to its rather low N concentrations. On the other hand, EF for ruminant CH4 emissions might be strongly underestimated, since those do not consider that livestock is often held at sub-maintenance levels. Thus, an international initiative is needed to support African countries to learn about land based GHG fluxes and to build research capacity. When do we start?

  1. Terrestrial ecosystem collapse associated to the K-Pg boundary and dinosaur extinction: palynological evidences

    Science.gov (United States)

    Bercovici, A.; Vajda, V.; Lyson, T. R.; Chester, S. G. B.; Sargis, E. J.; Pearson, D. A.; Joyce, W. G.

    2012-04-01

    We report here the discovery of the stratigraphically youngest in situ dinosaur specimen. This ceratopsian brow horn was found in southeastern Montana, in the Western Interior of the United States in a poorly rooted, silty mudstone floodplain deposit and only 13 centimeters below the palynologically defined K-Pg boundary. The boundary is identified using three criteria: 1) substantial decrease in diversity and abundance of Cretaceous pollen and spore taxa that completely disappear from the palynological record a few meters above the boundary, 2) the presence of a "fern spike", and 3) palynostratigraphical correlation to a nearby section where primary extraterrestrial impact markers are present (e.g., iridium anomaly, spherules and shocked quartz). The palynological record in the rock sequence immediately following the K-Pg boundary consistently indicates a sudden and major loss of the Cretaceous components across the North American record. During this rapid decline, the palynological assemblages are dominated by freshwater ferns (Azolla) and algae (usually Pediastrum sp. and Penetetrapites sp.) indicating generalized flooding in the area. The onset of the Paleocene sedimentation is subsequently announced by the presence of variegated beds, multiple lignite seams and small scale meandering river systems, starting with palynological associations that attest for reworking and erosion. The destabilization of terrestrial ecosystems is coincident with the markers of the K-Pg boundary, supporting a catastrophic event taking place over a very short duration. The in situ ceratopsian brow horn demonstrates that a gap devoid of non-avian dinosaur fossils in the last meters of the Cretaceous is artificial and thus inconsistent with the hypothesis that non-avian dinosaurs were extinct prior to the K-Pg boundary asteroid impact event.

  2. The role of UV-B radiation in aquatic and terrestrial ecosystems - an experimental and functional analysis of the evolution of UV-absorbing componist.

    NARCIS (Netherlands)

    Rozema, J.; Bjorn, L.O.; Bornman, J.F.; Gaberscik, A.; Hader, D.P.; Trost, T.; Germ, M.; Klisch, M.; Groniger, A.; Sinha, R.P.; Lebert, M.; He, Y.Y.; Buffoni-Hall, R.; Bakker, N.; van de Staaij, J.W.M.; Meijkamp, B.B.

    2002-01-01

    We analysed and compared the functioning of UV-B screening pigments in plants from marine, fresh water and terrestrial ecosystems, along the evolutionary line of cyanobacteria, unicellular algae, primitive multicellular algae, charophycean algae, lichens, mosses and higher plants, including

  3. Organic carbon stock modelling for the quantification of the carbon sinks in terrestrial ecosystems

    Science.gov (United States)

    Durante, Pilar; Algeet, Nur; Oyonarte, Cecilio

    2017-04-01

    Given the recent environmental policies derived from the serious threats caused by global change, practical measures to decrease net CO2 emissions have to be put in place. Regarding this, carbon sequestration is a major measure to reduce atmospheric CO2 concentrations within a short and medium term, where terrestrial ecosystems play a basic role as carbon sinks. Development of tools for quantification, assessment and management of organic carbon in ecosystems at different scales and management scenarios, it is essential to achieve these commitments. The aim of this study is to establish a methodological framework for the modeling of this tool, applied to a sustainable land use planning and management at spatial and temporal scale. The methodology for carbon stock estimation in ecosystems is based on merger techniques between carbon stored in soils and aerial biomass. For this purpose, both spatial variability map of soil organic carbon (SOC) and algorithms for calculation of forest species biomass will be created. For the modelling of the SOC spatial distribution at different map scales, it is necessary to fit in and screen the available information of soil database legacy. Subsequently, SOC modelling will be based on the SCORPAN model, a quantitative model use to assess the correlation among soil-forming factors measured at the same site location. These factors will be selected from both static (terrain morphometric variables) and dynamic variables (climatic variables and vegetation indexes -NDVI-), providing to the model the spatio-temporal characteristic. After the predictive model, spatial inference techniques will be used to achieve the final map and to extrapolate the data to unavailable information areas (automated random forest regression kriging). The estimated uncertainty will be calculated to assess the model performance at different scale approaches. Organic carbon modelling of aerial biomass will be estimate using LiDAR (Light Detection And Ranging

  4. Terrestrial ecosystem destabilization at the K/T boundary in southwestern North Dakota, USA.

    Science.gov (United States)

    Bercovici, Antoine; Pearson, Dean; Villanueva-Amadoz, Uxue

    2010-05-01

    stratigraphical interval, when preserved. 3) Within or just above the formation contact coal, the relative abundance of palynological taxa indicative of the Cretaceous (K-taxa) drop significantly without significant subsequent recovery. 4) Above the formation contact lignite, lithology systematically the lithology consistently appears as a 1-2 m thick dark mudstone sequence. The palynological record of this interval is dominated by freshwater taxa (Pediastrum sp. and Penetetrapites sp.) indicating general flooding in the study area. 5) Change in the sedimentation style in comparison of the Hell Creek is reflected by the preservation of variegated beds, multiple lignite seams and small scale meandering river systems. The palynological content attest for reworking and erosion. Conclusions shows that both palaeoenviroments and biodiversity patterns stay consistent throughout the Hell Creek Formation, with the exception of its uppermost part. The vertebrate and plant communities underwent a significant change at this time coincident with the evidence for a impact scenario or catastrophic event of massive scale. Beginning at the very end of the Cretaceous and continuing up into the overlying Fort Union Formation, the area was experiencing the onset of a transgression cycle which contributed to widespread ponding. Following the impact, modifications in the environment caused by land denudation, changes in sea level and drainage patterns promoted run-off and reworking. The destabilization of terrestrial ecosystems in southwestern North Dakota is coincident with markers of the K/T boundary that supports a catastrophic event taking place over a very short duration.

  5. Possible Cretaceous Arctic terrestrial ecosystem dynamics based on a rich dinosaur record from Alaska

    Science.gov (United States)

    Fiorillo, A. R.; McCarthy, P. J.; Flaig, P. P.

    2010-12-01

    The widespread occurrence of large-bodied herbivores, specifically hadrosaurian and ceratopsian dinosaurs, in the Cretaceous of Alaska presents a proxy for understanding polar terrestrial ecosystem biological productivity in a warm Arctic world. These dinosaurs lived in Alaska at time when this region was at or near current latitudes. Thus these dinosaurs present a paradox. The warmer Cretaceous high-latitude climate, likely related to higher levels of CO2, may have increased plant productivity but the polar light regime fluctuations must have limited the available food during the winter months. The most detailed sedimentological data available regarding the paleoenvironments supporting these dinosaurs are from the Prince Creek Formation of northern Alaska and to a lesser extent the Cantwell Formation of the Alaska Range. The sediments of the Late Cretaceous Prince Creek Formation represent a continental succession deposited on a high-latitude, low-gradient, alluvial/coastal plain. The Prince Creek Formation records numerous paleosols that are consistent with seasonality and successional vegetative cover. Drab colors in fine-grained sediments, abundant carbonaceous plant material, and common siderite nodules and jarosite suggest widespread reducing conditions on poorly-drained floodplains influenced in more distal areas by marine waters. In addition, these rocks contain high levels of organic carbon and charcoal. Carbonaceous root-traces found ubiquitously within all distributary channels and most floodplain facies, along with common Fe-oxide mottles, indicate that the alluvial system likely experienced flashy, seasonal, or ephemeral flow and a fluctuating water table. The flashy nature of the alluvial system may have been driven by recurring episodes of vigorous seasonal snowmelt in the Brooks Range orogenic belt as a consequence of the high paleolatitude of northern Alaska in the Late Cretaceous. The presence of dinosaurian megaherbivores suggests that water was

  6. Drought dominates the interannual variability in global terrestrial net primary production by controlling semi-arid ecosystems.

    Science.gov (United States)

    Huang, Ling; He, Bin; Chen, Aifang; Wang, Haiyan; Liu, Junjie; Lű, Aifeng; Chen, Ziyue

    2016-04-19

    Drought is a main driver of interannual variation in global terrestrial net primary production. However, how and to what extent drought impacts global NPP variability is unclear. Based on the multi-timescale drought index SPEI and a satellite-based annual global terrestrial NPP dataset, we observed a robust relationship between drought and NPP in both hemispheres. In the Northern Hemisphere, the annual NPP trend is driven by 19-month drought variation, whereas that in the Southern Hemisphere is driven by 16-month drought variation. Drought-dominated NPP, which mainly occurs in semi-arid ecosystems, explains 29% of the interannual variation in global NPP, despite its 16% contribution to total global NPP. More surprisingly, drought prone ecosystems in the Southern Hemisphere, which only account for 7% of the total global NPP, contribute to 33% of the interannual variation in global NPP. Our observations support the leading role of semi-arid ecosystems in interannual variability in global NPP and highlight the great impacts of long-term drought on the global carbon cycle.

  7. There's no place like home? An exploration of the mechanisms behind plant litter-decomposer affinity in terrestrial ecosystems.

    Science.gov (United States)

    Austin, Amy T; Vivanco, Lucía; González-Arzac, Adelia; Pérez, Luis I

    2014-08-08

    Litter decomposition in terrestrial ecosystems is an important first step for carbon and nutrient cycling, as senescent plant material is degraded and consequently incorporated, along with microbial products, into soil organic matter. The identification of litter affinity effects, whereby decomposition is accelerated in its home environment (home-field advantage, HFA), highlights the importance of plant-soil interactions that have consequences for biogeochemical cycling. While not universal, these affinity effects have been identified in a range of ecosystems, particularly in forests without disturbance. The optimization of the local decomposer community to degrade a particular combination of litter traits is the most oft-cited explanation for HFA effects, but the ways in which this specialized community can develop are only beginning to be understood. We explore ways in which HFA, or more broadly litter affinity effects, could arise in terrestrial ecosystems. Plant-herbivore interactions, microbial symbiosis, legacies from phyllosphere communities and attractors of specific soil fauna could contribute to spatially defined affinity effects for litter decomposition. Pyrosequencing soil communities and functional linkages of soil fauna provide great promise in advancing our mechanistic understanding of these interactions, and could lead to a greater appreciation of the role of litter-decomposer affinity in the maintenance of soil functional diversity. © 2014 The Authors New Phytologist © 2014 New Phytologist Trust.

  8. Terrestrial ecosystems of the Osa-Golfito region: one component of an integrative cross-disciplinary initiative for sustainability

    Science.gov (United States)

    Broadbent, E. N.; Dirzo, R.; Morales Barquero, L.

    2012-12-01

    Sustainability science seeks to develop approaches incorporating simultaneous human and environmental well-being. The Osa-Golfito Initiative (InOGo), as described in the previous presentation by Dr. Hunt et al. in this session, represents a cutting edge project seeking to develop both a fundamental framework for linking interdisciplinary components to address this objective with the creation of an applied approach for a sustainable future in this area of exceptional cultural and environmental diversity. In this presentation we describe the terrestrial ecosystems component of InOGo. This component incorporates four primary research approaches: (a) an extensive literature review; (b) spatial and non-spatial data aggregation; (c) change analysis via remote sensing; and (d) a questionnaire and participatory mapping survey with relevant experts. Integrating these approaches we seek to: (a) establish a detailed baseline understanding of the terrestrial ecosystems and their spatial distribution in the study region; (b) quantify temporal changes in their extent, connectivity, and ecosystem services; (c) identify the principal conservation priorities and threats in the region; and (d) isolate specific actions to address identified threats. We highlight both the overall approach developed for this component, which is broadly applicable throughout similar tropical regions, as well as results specific to the initiative.;

  9. Early Cretaceous terrestrial ecosystems in East Asia based on food-web and energy-flow models

    Science.gov (United States)

    Matsukawa, M.; Saiki, K.; Ito, M.; Obata, I.; Nichols, D.J.; Lockley, M.G.; Kukihara, R.; Shibata, K.

    2006-01-01

    In recent years, there has been global interest in the environments and ecosystems around the world. It is helpful to reconstruct past environments and ecosystems to help understand them in the present and the future. The present environments and ecosystems are an evolving continuum with those of the past and the future. This paper demonstrates the contribution of geology and paleontology to such continua. Using fossils, we can make an estimation of past population density as an ecosystem index based on food-web and energy-flow models. Late Mesozoic nonmarine deposits are distributed widely on the eastern Asian continent and contain various kinds of fossils such as fishes, amphibians, reptiles, dinosaurs, mammals, bivalves, gastropods, insects, ostracodes, conchostracans, terrestrial plants, and others. These fossil organisms are useful for late Mesozoic terrestrial ecosystem reconstruction using food-web and energy-flow models. We chose Early Cretaceous fluvio-lacustrine basins in the Choyr area, southeastern Mongolia, and the Tetori area, Japan, for these analyses and as a potential model for reconstruction of other similar basins in East Asia. The food-web models are restored based on taxa that occurred in these basins. They form four or five trophic levels in an energy pyramid consisting of rich primary producers at its base and smaller biotas higher in the food web. This is the general energy pyramid of a typical ecosystem. Concerning the population densities of vertebrate taxa in 1 km2 in these basins, some differences are recognized between Early Cretaceous and the present. For example, Cretaceous estimates suggest 2.3 to 4.8 times as many herbivores and 26.0 to 105.5 times the carnivore population. These differences are useful for the evaluation of past population densities of vertebrate taxa. Such differences may also be caused by the different metabolism of different taxa. Preservation may also be a factor, and we recognize that various problems occur in

  10. Biome-BGC: Terrestrial Ecosystem Process Model, Version 4.1.1

    Data.gov (United States)

    National Aeronautics and Space Administration — Biome-BGC is a computer program that estimates fluxes and storage of energy, water, carbon, and nitrogen for the vegetation and soil components of terrestrial...

  11. Modeled responses of terrestrial ecosystems to elevated atmospheric CO2: a comparison of simulations by the biogeochemistry models of the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP).

    Science.gov (United States)

    Pan, Yude; Melillo, Jerry M; McGuire, A David; Kicklighter, David W; Pitelka, Louis F; Hibbard, Kathy; Pierce, Lars L; Running, Steven W; Ojima, Dennis S; Parton, William J; Schimel, David S

    1998-04-01

    Although there is a great deal of information concerning responses to increases in atmospheric CO2 at the tissue and plant levels, there are substantially fewer studies that have investigated ecosystem-level responses in the context of integrated carbon, water, and nutrient cycles. Because our understanding of ecosystem responses to elevated CO2 is incomplete, modeling is a tool that can be used to investigate the role of plant and soil interactions in the response of terrestrial ecosystems to elevated CO2. In this study, we analyze the responses of net primary production (NPP) to doubled CO2 from 355 to 710 ppmv among three biogeochemistry models in the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP): BIOME-BGC (BioGeochemical Cycles), Century, and the Terrestrial Ecosystem Model (TEM). For the conterminous United States, doubled atmospheric CO2 causes NPP to increase by 5% in Century, 8% in TEM, and 11% in BIOME-BGC. Multiple regression analyses between the NPP response to doubled CO2 and the mean annual temperature and annual precipitation of biomes or grid cells indicate that there are negative relationships between precipitation and the response of NPP to doubled CO2 for all three models. In contrast, there are different relationships between temperature and the response of NPP to doubled CO2 for the three models: there is a negative relationship in the responses of BIOME-BGC, no relationship in the responses of Century, and a positive relationship in the responses of TEM. In BIOME-BGC, the NPP response to doubled CO2 is controlled by the change in transpiration associated with reduced leaf conductance to water vapor. This change affects soil water, then leaf area development and, finally, NPP. In Century, the response of NPP to doubled CO2 is controlled by changes in decomposition rates associated with increased soil moisture that results from reduced evapotranspiration. This change affects nitrogen availability for plants, which influences NPP. In

  12. Comprehensive Evaluation of Machine Learning Techniques for Estimating the Responses of Carbon Fluxes to Climatic Forces in Different Terrestrial Ecosystems

    Directory of Open Access Journals (Sweden)

    Xianming Dou

    2018-02-01

    Full Text Available Accurately estimating the carbon budgets in terrestrial ecosystems ranging from flux towers to regional or global scales is particularly crucial for diagnosing past and future climate change. This research investigated the feasibility of two comparatively advanced machine learning approaches, namely adaptive neuro-fuzzy inference system (ANFIS and extreme learning machine (ELM, for reproducing terrestrial carbon fluxes in five different types of ecosystems. Traditional artificial neural network (ANN and support vector machine (SVM models were also utilized as reliable benchmarks to measure the generalization ability of these models according to the following statistical metrics: coefficient of determination (R2, index of agreement (IA, root mean square error (RMSE, and mean absolute error (MAE. In addition, we attempted to explore the responses of all methods to their corresponding intrinsic parameters in terms of the generalization performance. It was found that both the newly proposed ELM and ANFIS models achieved highly satisfactory estimates and were comparable to the ANN and SVM models. The modeling ability of each approach depended upon their respective internal parameters. For example, the SVM model with the radial basis kernel function produced the most accurate estimates and performed substantially better than the SVM models with the polynomial and sigmoid functions. Furthermore, a remarkable difference was found in the estimated accuracy among different carbon fluxes. Specifically, in the forest ecosystem (CA-Obs site, the optimal ANN model obtained slightly higher performance for gross primary productivity, with R2 = 0.9622, IA = 0.9836, RMSE = 0.6548 g C m−2 day−1, and MAE = 0.4220 g C m−2 day−1, compared with, respectively, 0.9554, 0.9845, 0.4280 g C m−2 day−1, and 0.2944 g C m−2 day−1 for ecosystem respiration and 0.8292, 0.9306, 0.6165 g C m−2 day−1, and 0.4407 g C m−2 day−1 for net ecosystem exchange

  13. Fate, behavior, and bioavailability of metal and metal oxide nanomaterials in terrestrial ecosystems

    Science.gov (United States)

    Bertsch, P. M.; Unrine, J. M.; Judy, J.; Tsyusko, O.

    2012-12-01

    Despite the benefits that are currently being manifested and those transformative breakthroughs that will undoubtedly result from advances in nanotechnology, concerns surrounding the potential negative impacts to the environment and human health and welfare continue to emerge. Information on the transport and fate of manufactured nanomaterials (MNMs) in the environment and on their potential effects to human and ecological receptors is emerging at an increasing rate. Notwithstanding these developments, the research enterprise focused on the environmental implications of nanotechnology is in its infancy and few unifying principles have yet to emerge. This lack of unanimity is related to many factors including, the vast diversity in chemical composition, size, shape, and surface chemical properties of MNMs, as well as the range of receptor species and cell lines investigated. Additionally, the large variation in exposure methodologies employed by various investigators as well as the discrepancies in the amount and quality of characterization data collected to support specific conclusions, provide major challenges for developing unifying concepts and principles. As the utilization of MNMs for a large variety of applications is currently in an exponential growth phase, there is great urgency to develop information that can be used to identify priority areas for assessing risks to humans and the environment, as well as in developing potential mitigation strategies. We have been investigating the fate, behavior, and potential impacts of MNMs released into terrestrial ecosystems by examining the bioavailability and toxicity as well as the trophic transfer of a range of metal and metal oxide nanoparticles (Ag, Au, Cu, TiO2, ZnO, CeO2) to microorganisms, detritivores, and plants. Interdisciplinary studies include the characterization of the nanoparticles and aged nanoparticles in complex media, the distribution of nanoparticles in biological tissues, nanoparticle toxicity

  14. Spatial distribution of caesium-137 in soil cover of background terrestrial ecosystems, Central European Russia

    Energy Technology Data Exchange (ETDEWEB)

    Paramonova, Tatiana A. [Radioecology and Ecotoxicology Department of Soil Science Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation); Shamshurina, Evgenia N. [Laboratory of soil erosion and fluvial processes of Geography Faculty, Moscow State Lomonosov University, 119234 Moscow (Russian Federation)

    2014-07-01

    ¹³⁷Cs - the main long-living anthropogenic radionuclide - arrived in mass at Russian terrestrial ecosystems after nuclear tests in the atmosphere in 1960-yy. and after Chernobyl accident in 1986 y., but in spite of a long period since these events soil cover contamination by ¹³⁷Cs is considered as extremely resistant due to its firmly fixation by soil solid matter and a long half-life of the radionuclide. Wide-scale investigation in maximal diversity of natural, semi-natural and anthropogenic landscapes of Central European Russia (more than 400 soils samples from Vologda, Yaroslavl, Ivanovo, Tver regions which are representative for the southern taiga zone) demonstrates that modern average specific activity of ¹³⁷Cs in the upper 15-cm layer of soil is 11±3 Bq/kg (contamination density 0.05±0.01 Ci/km²), that is fully ecologically acceptable. It is important that the average concentrations of ¹³⁷Cs in the soil cover of individual regions are close to each other. The most likely these average values are approximate assessment of background radioactive contamination of soils in central European Russia outside of the immediate Chernobyl trace. At the same time approximately 3% of soils are characterized by elevated ¹³⁷Cs content - 62-98 Bq/kg (0.24-0.43 Ci/km²), that indicates the presence of low radioactive spots on the territory and may be considered as local Chernobyl fallout. All of them attribute with forest soils which are commonly characterized by considerably more high accumulation of ¹³⁷Cs (18±5 Bq/kg, 0.06±0.01 Ci/km²) due to advanced absorbing surface of trees. Agricultural lands (plagued or under meadows) and soils of industrial plots with scarce vegetation contain only 6±2 Bq/kg (0.03±0.01 Ci/km²) of ¹³⁷Cs. About 84-92% of ¹³⁷Cs are concentrated in the upper 15-cm layer of natural soils or in Ap horizon of plagued soils, thus vertical migration of radionuclide is very slow in spite of ~30 years after Chernobyl

  15. Ecosystem responses to reduced and oxidised nitrogen inputs in European terrestrial habitats

    NARCIS (Netherlands)

    Stevens, C.J.; Manning, P.; Berg, van den L.J.L.; Graaf, de M.C.C.; Wamelink, G.W.W.; Boxman, A.W.; Bleeker, A.; Vergeer, P.; Arroniz-Crespo, M.; Limpens, J.; Lamers, L.P.M.; Bobbink, R.; Dorland, E.

    2011-01-01

    While it is well established that ecosystems display strong responses to elevated nitrogen deposition, the importance of the ratio between the dominant forms of deposited nitrogen (NHx and NOy) in determining ecosystem response is poorly understood. As large changes in the ratio of oxidised and

  16. Mapping and Quantifying Biodiversity and Ecosystem Services Related to Terrestrial Vertebrates: A National Approach

    Science.gov (United States)

    Biodiversity is crucial for the functioning of ecosystems and the products and services from which we transform natural assets of the Earth for human survival, security, and well-being. The ability to assess, report, map, and forecast the life support functions of ecosystems is a...

  17. How is water-use efficiency of terrestrial ecosystems distributed and changing on Earth?

    DEFF Research Database (Denmark)

    Tang, Xuguang; Li, Hengpeng; Desai, Ankur R.

    2015-01-01

    A better understanding of ecosystem water-use efficiency (WUE) will help us improve ecosystem management for mitigation as well as adaption to global hydrological change. Here, long-term flux tower observations of productivity and evapotranspiration allow us to detect a consistent latitudinal tre...

  18. A National Approach to Map and Quantify Terrestrial Vertebrate Biodiversity within an Ecosystem Services Framework

    Science.gov (United States)

    Biodiversity is crucial for the functioning of ecosystems and the products and services from which we transform natural assets of the Earth for human survival, security, and well-being. The ability to assess, report, map, and forecast the life support functions of ecosystems is a...

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

    Directory of Open Access Journals (Sweden)

    Junjiong Shao

    2016-08-01

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

  20. Global Trends in Exposure to Light Pollution in Natural Terrestrial Ecosystems

    Directory of Open Access Journals (Sweden)

    Jonathan Bennie

    2015-03-01

    Full Text Available The rapid growth in electric light usage across the globe has led to increasing presence of artificial light in natural and semi-natural ecosystems at night. This occurs both due to direct illumination and skyglow - scattered light in the atmosphere. There is increasing concern about the effects of artificial light on biological processes, biodiversity and the functioning of ecosystems. We combine intercalibrated Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS images of stable night-time lights for the period 1992 to 2012 with a remotely sensed landcover product (GLC2000 to assess recent changes in exposure to artificial light at night in 43 global ecosystem types. We find that Mediterranean-climate ecosystems have experienced the greatest increases in exposure, followed by temperate ecosystems. Boreal, Arctic and montane systems experienced the lowest increases. In tropical and subtropical regions, the greatest increases are in mangroves and subtropical needleleaf and mixed forests, and in arid regions increases are mainly in forest and agricultural areas. The global ecosystems experiencing the greatest increase in exposure to artificial light are already localized and fragmented, and often of particular conservation importance due to high levels of diversity, endemism and rarity. Night time remote sensing can play a key role in identifying the extent to which natural ecosystems are exposed to light pollution.

  1. Changes of evapotranspiration and water yield in China's terrestrial ecosystems during the period from 2000 to 2010

    Science.gov (United States)

    Liu, Y.; Zhou, Y.; Ju, W.; Chen, J.; Wang, S.; He, H.; Wang, H.; Guan, D.; Zhao, F.; Li, Y.; Hao, Y.

    2013-04-01

    Terrestrial carbon and water cycles are interactively linked at various spatial and temporal scales. Evapotranspiration (ET) plays a key role in the terrestrial water cycle and altering carbon sequestration of terrestrial ecosystems. The study of ET and its response to climate and vegetation changes is critical in China since water availability is a limiting factor for the functioning of terrestrial ecosystems in vast arid and semiarid regions. In this study, the process-based Boreal Ecosystem Productivity Simulator (BEPS) model was employed in conjunction with a newly developed leaf area index (LAI) dataset and other spatial data to simulate daily ET and water yield at a spatial resolution of 500 m over China for the period from 2000 to 2010. The spatial and temporal variations of ET and water yield and influences of temperature, precipitation, land cover types, and LAI on ET were analyzed. The validations with ET measured at 5 typical ChinaFLUX sites and inferred using statistical hydrological data in 10 basins showed that the BEPS model was able to simulate daily and annual ET well at site and basin scales. Simulated annual ET exhibited a distinguishable southeast to northwest decreasing gradient, corresponding to climate conditions and vegetation types. It increased with the increase of LAI in 74% of China's landmass and was positively correlated with temperature in most areas of southwest, south, east, and central China and with precipitation in the arid and semiarid areas of northwest and north China. In the Tibet Plateau and humid southeast China, the increase in precipitation might cause ET to decrease. The national mean annual ET varied from 345.5 mm yr-1 in 2001 to 387.8 mm yr-1 in 2005, with an average of 369.8 mm yr-1 during the study period. The overall increase rate of 1.7 mm yr-2 (r = 0.43 p = 0.19) was mainly driven by the increase of total ET in forests. During the period from 2006 to 2009, precipitation and LAI decreased widely and consequently

  2. Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders, Belgium

    NARCIS (Netherlands)

    D'Hollander, W.; De Bruyn, L.; Hagenaars, A; de Voogt, P.; Bervoets, L.

    2014-01-01

    Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical

  3. Patterns and controls of the variability of radiation use efficiency and primary productivity across terrestrial ecosystems

    NARCIS (Netherlands)

    Garbulsky, M.F.; Peñuelas, J.; Papale, D.; Ardö, J.; Goulden, M.L.; Kiely, G.; Richardson, A.D.; Rotenberg, E.; Veenendaal, E.M.; Filella, I.

    2010-01-01

    Aim The controls of gross radiation use efficiency (RUE), the ratio between gross primary productivity (GPP) and the radiation intercepted by terrestrial vegetation, and its spatial and temporal variation are not yet fully understood. Our objectives were to analyse and synthesize the spatial

  4. Developing Conceptual Models for Assessing Climate Change Impacts to Contaminant Availability in Terrestrial Ecosystems

    Science.gov (United States)

    2015-03-01

    about climate change, contaminant availability, and TER-S conservation on installations. CONCEPTUAL MODEL BACKGROUND: Conceptual models are...criteria were terrestrially based bats, reptiles, amphibians , and birds and were therefore used for developing CMs. Developing Conceptual Models. A...models for the following topics: contaminant availability, bats, birds, non-bat mammals, reptiles, and amphibians . To maintain consistency in the

  5. Developments in deriving critical limits and modelling critical loads of nitrogen for terrestrial ecosystems in Europe

    NARCIS (Netherlands)

    Vries, de W.; Kros, H.; Reinds, G.J.; Wamelink, W.; Mol, J.; Dobben, van H.F.; Bobbink, R.; Emmett, B.; Smart, S.; Evans, C.; Schlutow, A.; Kraft, P.; Belyazid, S.; Sverdrup, H.; Hinsberg, van A.; Posch, M.; Hettelingh, J.P.

    2007-01-01

    This collaborative report of Alterra and the Coordination Center for Effects (MNP-CCE), in co-operation with various participants of the International Cooperative programme on Modelling and Mapping (ICP-MM) includes: 1. A summarizing overview of adverse nitrogen deposition effects on terrestrial

  6. Merging paleobiology with conservation biology to guide the future of terrestrial ecosystems.

    Science.gov (United States)

    Barnosky, Anthony D; Hadly, Elizabeth A; Gonzalez, Patrick; Head, Jason; Polly, P David; Lawing, A Michelle; Eronen, Jussi T; Ackerly, David D; Alex, Ken; Biber, Eric; Blois, Jessica; Brashares, Justin; Ceballos, Gerardo; Davis, Edward; Dietl, Gregory P; Dirzo, Rodolfo; Doremus, Holly; Fortelius, Mikael; Greene, Harry W; Hellmann, Jessica; Hickler, Thomas; Jackson, Stephen T; Kemp, Melissa; Koch, Paul L; Kremen, Claire; Lindsey, Emily L; Looy, Cindy; Marshall, Charles R; Mendenhall, Chase; Mulch, Andreas; Mychajliw, Alexis M; Nowak, Carsten; Ramakrishnan, Uma; Schnitzler, Jan; Das Shrestha, Kashish; Solari, Katherine; Stegner, Lynn; Stegner, M Allison; Stenseth, Nils Chr; Wake, Marvalee H; Zhang, Zhibin

    2017-02-10

    Conservation of species and ecosystems is increasingly difficult because anthropogenic impacts are pervasive and accelerating. Under this rapid global change, maximizing conservation success requires a paradigm shift from maintaining ecosystems in idealized past states toward facilitating their adaptive and functional capacities, even as species ebb and flow individually. Developing effective strategies under this new paradigm will require deeper understanding of the long-term dynamics that govern ecosystem persistence and reconciliation of conflicts among approaches to conserving historical versus novel ecosystems. Integrating emerging information from conservation biology, paleobiology, and the Earth sciences is an important step forward on the path to success. Maintaining nature in all its aspects will also entail immediately addressing the overarching threats of growing human population, overconsumption, pollution, and climate change. Copyright © 2017, American Association for the Advancement of Science.

  7. Modeling coupled interactions of carbon, water, and ozone exchange between terrestrial ecosystems and the atmosphere. I: model description.

    Science.gov (United States)

    Nikolov, Ned; Zeller, Karl F

    2003-01-01

    A new biophysical model (FORFLUX) is presented to study the simultaneous exchange of ozone, carbon dioxide, and water vapor between terrestrial ecosystems and the atmosphere. The model mechanistically couples all major processes controlling ecosystem flows trace gases and water implementing recent concepts in plant eco-physiology, micrometeorology, and soil hydrology. FORFLUX consists of four interconnected modules-a leaf photosynthesis model, a canopy flux model, a soil heat-, water- and CO2- transport model, and a snow pack model. Photosynthesis, water-vapor flux and ozone uptake at the leaf level are computed by the LEAFC3 sub-model. The canopy module scales leaf responses to a stand level by numerical integration of the LEAFC3model over canopy leaf area index (LAI). The integration takes into account (1) radiative transfer inside the canopy, (2) variation of foliage photosynthetic capacity with canopy depth, (3) wind speed attenuation throughout the canopy, and (4) rainfall interception by foliage elements. The soil module uses principles of the diffusion theory to predict temperature and moisture dynamics within the soil column, evaporation, and CO2 efflux from soil. The effect of soil heterogeneity on field-scale fluxes is simulated employing the Bresler-Dagan stochastic concept. The accumulation and melt of snow on the ground is predicted using an explicit energy balance approach. Ozone deposition is modeled as a sum of three fluxes- ozone uptake via plant stomata, deposition to non-transpiring plant surfaces, and ozone flux into the ground. All biophysical interactions are computed hourly while model projections are made at either hourly or daily time step. FORFLUX represents a comprehensive approach to studying ozone deposition and its link to carbon and water cycles in terrestrial ecosystems.

  8. Geospatial Analysis of Climate-Related Changes in North American Arctic Ecosystems and Implications for Terrestrial Flora and Fauna

    Science.gov (United States)

    Amirazodi, S.; Griffin, R.

    2016-12-01

    Climate change induces range shifts among many terrestrial species in Arctic regions. At best, warming often forces poleward migration if a stable environment is to be maintained. At worst, marginal ecosystems may disappear entirely without a contiguous shift allowing migratory escape to similar environs. These changing migration patterns and poleward range expansion push species into higher latitudes where ecosystems are less stable and more sensitive to change. This project focuses on ecosystem geography and interspecies relationships and interactions by analyzing seasonality and changes over time in variables including the following: temperature, precipitation, vegetation, physical boundaries, population demographics, permafrost, sea ice, and food and water availability. Publicly available data from remote sensing platforms are used throughout, and processed with both commercially available and open sourced GIS tools. This analysis describes observed range changes for selected North American species, and attempts to provide insight into the causes and effects of these phenomena. As the responses to climate change are complex and varied, the goal is to produce the aforementioned results in an easily understood set of geospatial representations to better support decision making regarding conservation prioritization and enable adaptive responses and mitigation strategies.

  9. Quantifying regional changes in terrestrial carbon storage by extrapolation from local ecosystem models

    Energy Technology Data Exchange (ETDEWEB)

    King, A W

    1991-12-31

    A general procedure for quantifying regional carbon dynamics by spatial extrapolation of local ecosystem models is presented Monte Carlo simulation to calculate the expected value of one or more local models, explicitly integrating the spatial heterogeneity of variables that influence ecosystem carbon flux and storage. These variables are described by empirically derived probability distributions that are input to the Monte Carlo process. The procedure provides large-scale regional estimates based explicitly on information and understanding acquired at smaller and more accessible scales.Results are presented from an earlier application to seasonal atmosphere-biosphere CO{sub 2} exchange for circumpolar ``subarctic`` latitudes (64{degree}N-90{degree}N). Results suggest that, under certain climatic conditions, these high northern ecosystems could collectively release 0.2 Gt of carbon per year to the atmosphere. I interpret these results with respect to questions about global biospheric sinks for atmospheric CO{sub 2} .

  10. Example for the importance of interface biogeochemistry for C and N fluxes from terrestrial to open aquatic ecosystems

    Science.gov (United States)

    Fiedler, S.; Jungkunst, H.

    2009-04-01

    Boundaries between terrestrial and aquatic ecosystems play a critical role in regulating terrestrial export. Understanding of biogeochemical cycling within this zone is urgently needed to unravel controls of matter transfer between terrestrial and aquatic ecosystems. This knowledge is needed to support decisions for optimizing mitigation options of water loading of "pollutants". Our investigation focused on the fate of carbon (C) and nitrogen (N) species at the interface between soil and spring, know as critical transition zone (CTZ). We present long-term monitoring data from a temperate spruce forest ecosystems (‘Wildmooswald') in Southwest Germany (MAP 1,600 mm, MAT 6°C). The investigated catena which is little more than 200 m long, includes common forest soils (n = 4) of three redox categories: Soils are represented by anaerobic Histosol, oxic Cambisols, Histosol with degraded peatlayers and Stagnosols having intermediate redox state. Measured C and N species were DOC, dissolved CO2, CH4, dissolved N2O, NH4, and NO3 in soil solutions along a hydrological pathway and in the adjacent aquatic system. Our results demonstrated that DOC dominance in soil solution throughout a catena can instantaneously shift to DIC (dissolved CO2) dominance when this soil water leaves the system at a spring outlet. This can be interpreted as a result of adsorption or oxidative turnover. At the presence of O2 extremely rapid shifts in N species (NH4+ → NO3-) can be observed. This was found at the spring. This rapid nitrification process apparently produced N2O: The N2O concentrations at the spring were three times higher than the N2O concentrations in the soil solutions. Oxidative turnover is also an important process for dissolved CH4. Although soil solutions were highly CH4-oversaturate, low concentrations in the aquatic system were found. Dissolved gases were discharged to the atmosphere, when the soil solution crossed the CTZ, whereas direct degassing at the spring was

  11. Simulated sensitivity of African terrestrial ecosystem photosynthesis to rainfall frequency, intensity, and rainy season length

    Science.gov (United States)

    Guan, Kaiyu; Good, Stephen P.; Caylor, Kelly K.; Medvigy, David; Pan, Ming; Wood, Eric F.; Sato, Hisashi; Biasutti, Michela; Chen, Min; Ahlström, Anders; Xu, Xiangtao

    2018-02-01

    There is growing evidence of ongoing changes in the statistics of intra-seasonal rainfall variability over large parts of the world. Changes in annual total rainfall may arise from shifts, either singly or in a combination, of distinctive intra-seasonal characteristics –i.e. rainfall frequency, rainfall intensity, and rainfall seasonality. Understanding how various ecosystems respond to the changes in intra-seasonal rainfall characteristics is critical for predictions of future biome shifts and ecosystem services under climate change, especially for arid and semi-arid ecosystems. Here, we use an advanced dynamic vegetation model (SEIB-DGVM) coupled with a stochastic rainfall/weather simulator to answer the following question: how does the productivity of ecosystems respond to a given percentage change in the total seasonal rainfall that is realized by varying only one of the three rainfall characteristics (rainfall frequency, intensity, and rainy season length)? We conducted ensemble simulations for continental Africa for a realistic range of changes (‑20% ~ +20%) in total rainfall amount. We find that the simulated ecosystem productivity (measured by gross primary production, GPP) shows distinctive responses to the intra-seasonal rainfall characteristics. Specifically, increase in rainfall frequency can lead to 28% more GPP increase than the same percentage increase in rainfall intensity; in tropical woodlands, GPP sensitivity to changes in rainy season length is ~4 times larger than to the same percentage changes in rainfall frequency or intensity. In contrast, shifts in the simulated biome distribution are much less sensitive to intra-seasonal rainfall characteristics than they are to total rainfall amount. Our results reveal three major distinctive productivity responses to seasonal rainfall variability—‘chronic water stress’, ‘acute water stress’ and ‘minimum water stress’ - which are respectively associated with three broad spatial patterns

  12. Representation of ecosystem services by terrestrial protected areas: Chile as a case study.

    Science.gov (United States)

    Durán, América P; Casalegno, Stefano; Marquet, Pablo A; Gaston, Kevin J

    2013-01-01

    Protected areas are increasingly considered to play a key role in the global maintenance of ecosystem processes and the ecosystem services they provide. It is thus vital to assess the extent to which existing protected area systems represent those services. Here, for the first time, we document the effectiveness of the current Chilean protected area system and its planned extensions in representing both ecosystem services (plant productivity, carbon storage and agricultural production) and biodiversity. Additionally, we evaluate the effectiveness of protected areas based on their respective management objectives. Our results show that existing protected areas in Chile do not contain an unusually high proportion of carbon storage (14.9%), agricultural production (0.2%) or biodiversity (11.8%), and also represent a low level of plant productivity (Normalized Difference Vegetation Index of 0.38). Proposed additional priority sites enhance the representation of ecosystem services and biodiversity, but not sufficiently to attain levels of representation higher than would be expected for their area of coverage. Moreover, when the species groups were assessed separately, amphibians was the only one well represented. Suggested priority sites for biodiversity conservation, without formal protection yet, was the only protected area category that over-represents carbon storage, agricultural production and biodiversity. The low representation of ecosystem services and species' distribution ranges by the current protected area system is because these protected areas are heavily biased toward southern Chile, and contain large extents of ice and bare rock. The designation and management of proposed priority sites needs to be addressed in order to increase the representation of ecosystem services within the Chilean protected area system.

  13. Representation of ecosystem services by terrestrial protected areas: Chile as a case study.

    Directory of Open Access Journals (Sweden)

    América P Durán

    Full Text Available Protected areas are increasingly considered to play a key role in the global maintenance of ecosystem processes and the ecosystem services they provide. It is thus vital to assess the extent to which existing protected area systems represent those services. Here, for the first time, we document the effectiveness of the current Chilean protected area system and its planned extensions in representing both ecosystem services (plant productivity, carbon storage and agricultural production and biodiversity. Additionally, we evaluate the effectiveness of protected areas based on their respective management objectives. Our results show that existing protected areas in Chile do not contain an unusually high proportion of carbon storage (14.9%, agricultural production (0.2% or biodiversity (11.8%, and also represent a low level of plant productivity (Normalized Difference Vegetation Index of 0.38. Proposed additional priority sites enhance the representation of ecosystem services and biodiversity, but not sufficiently to attain levels of representation higher than would be expected for their area of coverage. Moreover, when the species groups were assessed separately, amphibians was the only one well represented. Suggested priority sites for biodiversity conservation, without formal protection yet, was the only protected area category that over-represents carbon storage, agricultural production and biodiversity. The low representation of ecosystem services and species' distribution ranges by the current protected area system is because these protected areas are heavily biased toward southern Chile, and contain large extents of ice and bare rock. The designation and management of proposed priority sites needs to be addressed in order to increase the representation of ecosystem services within the Chilean protected area system.

  14. Carbon dioxide exchange in the High Arctic - examples from terrestrial ecosystems

    DEFF Research Database (Denmark)

    Grøndahl, L.

    of the growing season, which in combination with high temperatures increased uptake rates. The dry heath ecosystem in general gained carbon during the summer season in the order of magnitude -1.4 gCm-2 up to 32 gCm-2. This result is filling out a gap of knowledge on the response of high Arctic ecosystems...... the measurements conducted in the valley to a regional level. Including information on temporal and spatial variability in air temperature and radiation, together with NDVI and a vegetation map a regional estimate of the CO2 exchange during the summer was provided, elaborating the NDVI based estimate on net carbon...

  15. Aspects of the carbon cycle in terrestrial ecosystems of Northeastern Smaaland

    Energy Technology Data Exchange (ETDEWEB)

    Tagesson, Torbern [Lund Univ., Geobiosphere Science Centre (Sweden). Physical Geography and Ecosystems Analysis

    2006-02-15

    Boreal and temperate ecosystems of the northern hemisphere are important for the future development of global climate. In this study, the carbon cycle has been studied in a pine forest, a meadow, a spruce forest and two deciduous forests in the Simpevarp investigation area in southern Sweden (57 deg 5 min N, 34 deg 55 min E). Ground respiration and ground Gross Primary Production (GPP) has been measured three times during spring 2004 with the closed chamber technique. Soil temperature, soil moisture and Photosynthetically Active Radiation (PAR) were also measured. An exponential regression with ground respiration against soil temperature was used to extrapolate respiration over spring 2004. A logarithmic regression with ground GPP against PAR was used to extrapolate GPP in meadow over spring 2004. Ground respiration is affected by soil temperature in all ecosystems but pine, but still it only explains a small part of the variation in respiration and this indicates that other abiotic factors also have an influence. Soil moisture affects respiration in spruce and one of the deciduous ecosystems. A comparison between measured and extrapolated ground respiration indicated that soil temperature could be used to extrapolate ground respiration. PAR is the main factor influencing GPP in all ecosystems but pine, still it could not be used to extrapolate GPP in meadow since too few measurements were done and they were from different periods of spring. Soil moisture did not have any significant effect on GPP. A Dynamic Global Vegetation Model, a DGVM called LPJ-GUESS, was downscaled to the Simpevarp investigation area. The downscaled DGVM was evaluated against measured respiration and soil organic acids for all five ecosystems. In meadow, it was evaluated against Net Primary Production, NPP. For the forest ecosystems, it was evaluated against tree layer carbon pools. The evaluation indicated that the DGVM is reasonably well downscaled to the Simpevarp investigation area and

  16. Spatial and temporal patterns of CH4 and N2O fluxes in terrestrial ecosystems of North America during 1979–2008: application of a global biogeochemistry model

    Directory of Open Access Journals (Sweden)

    C. Lu

    2010-09-01

    Full Text Available Continental-scale estimations of terrestrial methane (CH4 and nitrous oxide (N2O fluxes over a long time period are crucial to accurately assess the global balance of greenhouse gases and enhance our understanding and prediction of global climate change and terrestrial ecosystem feedbacks. Using a process-based global biogeochemical model, the Dynamic Land Ecosystem Model (DLEM, we quantified simultaneously CH4 and N2O fluxes in North America's terrestrial ecosystems from 1979 to 2008. During the past 30 years, approximately 14.69 ± 1.64 T g C a−1 (1 T g = 1012 g of CH4, and 1.94 ± 0.1 T g N a−1 of N2O were released from terrestrial ecosystems in North America. At the country level, both the US and Canada acted as CH4 sources to the atmosphere, but Mexico mainly oxidized and consumed CH4 from the atmosphere. Wetlands in North America contributed predominantly to the regional CH4 source, while all other ecosystems acted as sinks for atmospheric CH4, of which forests accounted for 36.8%. Regarding N2O emission in North America, the US, Canada, and Mexico contributed 56.19%, 18.23%, and 25.58%, respectively, to the continental source over the past 30 years. Forests and croplands were the two ecosystems that contributed most to continental N2O emission. The inter-annual variations of CH4 and N2O fluxes in North America were mainly attributed to year-to-year climatic variability. While only annual precipitation was found to have a significant effect on annual CH4 flux, both mean annual temperature and annual precipitation were significantly correlated to annual N2O flux. The regional estimates and spatiotemporal patterns of terrestrial ecosystem CH4 and N2O fluxes in North America generated in this study provide useful information for global change research and policy making.

  17. Applications of the First Law to Ecological Systems. Physical Processes in Terrestrial and Aquatic Ecosystems, Thermodynamics.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This report describes concepts presented in another module called "The First Law of…

  18. Modelling carbon and water flows in terrestrial ecosystems in the boreal zone - examples from Oskarshamn

    Energy Technology Data Exchange (ETDEWEB)

    Karlberg, Louise [Stockholm Environment Institute (SEI), Stockholm (Sweden); Gu stafsson, David; Jansson, Per-Erik [Royal Inst. of Technology, Dept. of Land and Water Resources Engineering, Stockholm (Sweden)

    2007-12-15

    Carbon budgets and mean residence times were estimated in four hypothetical ecosystems. The greatest uncertainties in the estimations lie in the calculation of fluxes to and from the field layer. A parametrisation method based on multiple criteria, synthesising a wide range of empirical knowledge on ecosystem behaviour, proved to be useful both in the estimation of unknown parameters, to demonstrate model sensitivity, and to identify processes where our current knowledge is limited. The parameterizations derived from the study of the hypothetical systems were used to estimate site-specific carbon and water budgets for four ecosystems located within the Oskarshamn study-area. Measured soil respiration was used to calibrate the simulations. An analysis of the simulated carbon fluxes indicated that two of the ecosystems, namely the grassland and the spruce forest, were net sources of carbon dioxide, while the alder and the pine forest were net sinks of CO{sub 2}. In the former case, this was interpreted as a result of recent drainage of the organogenic soils and the concurrent increase in decomposition. The results from the study conformed rather well with results from a previous study on carbon budgets from the Oskarshamn study area.

  19. Climate change impacts on terrestrial ecosystems in metropolitan Chicago and its surrounding, multi-state region

    Science.gov (United States)

    Jessica J. Hellmann; Knute J. Nadelhoffer; Louis R. Iverson; Lewis H. Ziska; Stephen N. Matthews; Philip Myers; Anantha M. Prasad; Matthew P. Peters

    2010-01-01

    This paper describes the potential impacts of warming temperatures and changing precipitation on plants, wildlife, invasive species, pests, and agricultural ecosystems across the multi-state region centered on Chicago, Illinois. We examine a geographic area that captures much of Lake Michigan, including a complex mosaic of urbanization and agriculture surrounding...

  20. The vulnerability of a groundwater dependent terrestrial ecosystem to chemical and quantitative anthropogenic pressures: case study from southern Poland

    Science.gov (United States)

    Zurek, Anna J.; Wachniew, Przemyslaw; Witczak, Stanislaw

    2016-04-01

    The protected Wielkie Bloto fen in southern Poland is a Groundwater Depended Terrestrial Ecosystem (GDTE). The vulnerability of this GDTE was assessed in the contexts of both quality and quantity of groundwater supporting the fen. The qualitative aspect of vulnerability was assessed with an approach based on evaluation of timescales of pollution transport in the aquifer supporting the ecosystem with groundwater. Assessment of the quantitative aspect was based on the conceptualization of the relations of the Wielkie Bloto fen to the underlying groundwater system. The fen relies on groundwater from a shallow Quaternary aquifer and from the deeper Neogene aquifer. Upward leakage from the Neogene to the Quaternary aquifer and to the fen was confirmed by multidisciplinary research (Zurek et al. 2015). In July 2009 a cluster of new pumping wells abstracting water from the Neogene aquifer was commissioned 1 km north of the edge of Wielkie Bloto fen. Consequently, lowering of water levels occurred in this aquifer. However, it remains unclear whether the fen ecosystem will be affected by the pumping. The objective of the study was to assess the dependence of the fen on groundwater. The spatial distribution of physico-chemical parameters of water (pH, conductivity, Na/Cl ratio) in the fen area suggests that the degree of dependence on groundwater is strongly heterogeneous spatially and the recharge rate from the deeper aquifer varies considerably. Groundwater contributions to the fen, which can be used as an indicator of GDTE vulnerability, were quantified and mapped. Acknowledgements. The work was carried out as part of the statutory funds of the AGH University of Science and Technology (project No.11.11.140.026 and 11.11.220.01). References: Zurek A.J., Witczak S., Dulinski M., Wachniew P., Rozanski K., Kania J., Postawa A., Karczewski J., and Moscicki W.J.: 2015. Quantification of anthropogenic impact on groundwater dependent terrestrial ecosystem using geochemical and

  1. Terrestrial ecosystem model performance in simulating productivity and its vulnerability to climate change in the northern permafrost region

    DEFF Research Database (Denmark)

    Xia, Jianyang; McGuire, A. David; Lawrence, David

    2017-01-01

    Realistic projection of future climate-carbon (C) cycle feedbacks requires better understanding and an improved representation of the C cycle in permafrost regions in the current generation of Earth system models. Here we evaluated 10 terrestrial ecosystem models for their estimates of net primary...... productivity (NPP) and responses to historical climate change in permafrost regions in the Northern Hemisphere. In comparison with the satellite estimate from the Moderate Resolution Imaging Spectroradiometer (MODIS; 246 ± 6 g C m−2 yr−1), most models produced higher NPP (309 ± 12 g C m−2 yr−1) over...... the permafrost region during 2000–2009. By comparing the simulated gross primary productivity (GPP) with a flux tower-based database, we found that although mean GPP among the models was only overestimated by 10% over 1982–2009, there was a twofold discrepancy among models (380 to 800 g C m−2 yr−1), which mainly...

  2. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River site

    Energy Technology Data Exchange (ETDEWEB)

    Friday, G.P.; Cummins, C.L.; Schwartzman, A.L.

    1996-12-31

    Since the early 1950s, the Savannah River Site (SRS) released over 50 radionuclides into the environment while producing nuclear defense materials. These releases directly exposed aquatic and terrestrial biota to ionizing radiation from surface water, soil, and sediment, and also indirectly by the ingestion of items in the food chain. As part of new missions to develop waste management strategies and identify cost-effective environmental restoration options, knowledge concerning the uptake and distribution of these radionuclides is essential. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at SRS.

  3. Implications of climate change for northern Canada: freshwater, marine, and terrestrial ecosystems.

    Science.gov (United States)

    Prowse, Terry D; Furgal, Chris; Wrona, Fred J; Reist, James D

    2009-07-01

    Climate variability and change is projected to have significant effects on the physical, chemical, and biological components of northern Canadian marine, terrestrial, and freshwater systems. As the climate continues to change, there will be consequences for biodiversity shifts and for the ranges and distribution of many species with resulting effects on availability, accessibility, and quality of resources upon which human populations rely. This will have implications for the protection and management of wildlife, fish, and fisheries resources; protected areas; and forests. The northward migration of species and the disruption and competition from invading species are already occurring and will continue to affect marine, terrestrial, and freshwater communities. Shifting environmental conditions will likely introduce new animal-transmitted diseases and redistribute some existing diseases, affecting key economic resources and some human populations. Stress on populations of iconic wildlife species, such as the polar bear, ringed seals, and whales, will continue as a result of changes in critical sea-ice habitat interactions. Where these stresses affect economically and culturally important species, they will have significant effects on people and regional economies. Further integrated, field-based monitoring and research programs, and the development of predictive models are required to allow for more detailed and comprehensive projections of change to be made, and to inform the development and implementation of appropriate adaptation, wildlife, and habitat conservation and protection strategies.

  4. Integration of Long term experiments on terrestrial ecosystem in AnaEE-France Research Infrastructure : concept and adding value

    Science.gov (United States)

    Chanzy, André; Chabbi, Abad; Houot, Sabine; Lafolie, François; Pichot, Christian; Raynal, Hélène; Saint-André, Laurent; Clobert, Jean; Greiveldinger, Lucile

    2015-04-01

    Continental ecosystems represent a critical zone that provide key ecological services to human populations like biomass production, that participate to the regulation of the global biogeochemical cycles and contribute and contribute to the maintenance of air and water quality. Global changes effects on continental ecosystems are likely to impact the fate of humanity, which is thus facing numerous challenges, such as an increasing demand for food and energy, competition for land and water use, or rapid climate warming. Hence, scientific progress in our understanding of the continental critical zone will come from studies that address how biotic and abiotic processes react to global changes. Long term experiments are required to take into account ecosystem inertia and feedback loops and to characterize trends and threshold in ecosystem dynamics. In France, 20 long-term experiments on terrestrial ecosystems are gathered within a single Research Infrastructure: ANAEE-France (http://www.anaee-s.fr), which is a part of AnaEE-Europe (http://www.anaee.com/). Each experiment consist in applying differentiated pressures on different plot over a long period (>20 years) representative of a range of management options. The originality of such infrastructure is a combination of experimental set up and long-term monitoring of simultaneous measurements of key ecosystem variables and parameters through a multi-disciplinary approach and replications of each treatment that improve the statistical strength of the results. The sites encompass gradients of climate conditions, ecosystem complexity and/or management, and can be used for calibration/validation of ecosystem functioning models as well as for the design of ecosystem management strategies. Gathering those experiments in a single research infrastructure is an important issue to enhance their visibility and increase the number of hosting scientific team by offering a range of services. These are: • Access to the ongoing long

  5. Ecosystem responses to reduced and oxidised nitrogen inputs in European terrestrial habitats

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, C.J. [Department of Life Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); Manning, P. [School of Agriculture Food and Rural Development, Newcastle University, Newcastle upon Tyne, Tyne and Wear, NE1 7RU (United Kingdom); Van den Berg, L.J.L. [Environment Department, University of York, Heslington, York, YO 5DD (United Kingdom); De Graaf, M.C.C. [University of Applied Sciences, HAS Den Bosch, PO BOX 90108, 5200 MA ' s-Hertogenbosch (Netherlands); Wieger Wamelink, G.W. [Alterra, Droevendaalsesteeg 3a, P.O. Box 47, 6700 AA Wageningen (Netherlands); Boxman, A.W.; Vergeer, P.; Lamers, L.P.M. [Department of Aquatic Ecology and Environmental Biology, University of Nijmegen, P.O. Box 9010, NL-6500 GL, Nijmegen (Netherlands); Bleeker, A. [Energy research Centre of the Netherlands, Petten, NH, 1755 ZG (Netherlands); Arroniz-Crespo, M. [Departamento de Biologia Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, 28040, Madrid (Spain); Limpens, J. [Nature Conservation and Plant Ecology Group, Wageningen University, Bornsesteeg 69, 6708 PD Wageningen (Netherlands); Bobbink, R. [Ware Research Centre, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen (Netherlands); Dorland, E. [Staatsbosbeheer, PO Box 1300, 3970 BH, Driebergen (Netherlands)

    2011-03-15

    While it is well established that ecosystems display strong responses to elevated nitrogen deposition, the importance of the ratio between the dominant forms of deposited nitrogen (NHx and NOy) in determining ecosystem response is poorly understood. As large changes in the ratio of oxidised and reduced nitrogen inputs are occurring, this oversight requires attention. One reason for this knowledge gap is that plants experience a different NHx:NOy ratio in soil to that seen in atmospheric deposits because atmospheric inputs are modified by soil transformations, mediated by soil pH. Consequently species of neutral and alkaline habitats are less likely to encounter high NH4+ concentrations than species from acid soils. We suggest that the response of vascular plant species to changing ratios of NHx:NOy deposits will be driven primarily by a combination of soil pH and nitrification rates. Testing this hypothesis requires a combination of experimental and survey work in a range of systems.

  6. Quantifying the role of fire in the Earth system - Part 2: Impact on the net carbon balance of global terrestrial ecosystems for the 20th century

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fang; Bond-Lamberty, Benjamin; Levis, Samuel

    2014-03-07

    Fire is the primary terrestrial ecosystem disturbance agent on a global scale. It affects carbon balance of global terrestrial ecosystems by emitting carbon to atmosphere directly and immediately from biomass burning (i.e., fire direct effect), and by changing net ecosystem productivity and land-use carbon loss in post-fire regions due to biomass burning and fire-induced vegetation mortality (i.e., fire indirect effect). Here, we provide the first quantitative assessment about the impact of fire on the net carbon balance of global terrestrial ecosystems for the 20th century, and investigate the roles of fire direct and indirect effects. This study is done by quantifying the difference between the 20th century fire-on and fire-off simulations with NCAR community land model CLM4.5 as the model platform. Results show that fire decreases net carbon gain of the global terrestrial ecosystems by 1.0 Pg C yr-1 average across the 20th century, as a results of fire direct effect (1.9 Pg C yr-1) partly offset by indirect effect (-0.9 Pg C yr-1). Fire generally decreases the average carbon gains of terrestrial ecosystems in post-fire regions, which are significant over tropical savannas and part of forests in North America and the east of Asia. The general decrease of carbon gains in post-fire regions is because fire direct and indirect effects have similar spatial patterns and the former (to decrease carbon gain) is generally stronger. Moreover, the effect of fire on net carbon balance significantly declines prior to ~1970 with trend of 8 Tg C yr-1 due to increasing fire indirect effect and increases afterward with trend of 18 Tg C yr-1 due to increasing fire direct effect.

  7. Enhanced water use efficiency in global terrestrial ecosystems under increasing aerosol loadings

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaoliang; Chen, Min; Liu, Yaling; Miralles, Diego G.; Wang, Faming

    2017-05-01

    Aerosols play a crucial role in the climate system, affecting incoming radiation and cloud formation. Based on a modelling framework that couples ecosystem processes with the atmospheric transfer of radiation, we analyze the effect of aerosols on surface incoming radiation, gross primary productivity (GPP), water losses from ecosystems through evapotranspiration (ET) and ecosystem water use efficiency (WUE, defined as GPP/ET) for 2003–2010 and validate them at global FLUXNET sites. The total diffuse radiation increases under relatively low or intermediate aerosol loadings, but decreases under more polluted conditions. We find that aerosol-induced changes in GPP depend on leaf area index, aerosol loading and cloudiness. Specifically, low and moderate aerosol loadings cause increases in GPP for all plant types, while heavy aerosol loadings result in enhancement (decrease) in GPP for dense (sparse) vegetation. On the other hand, ET is mainly negatively affected by aerosol loadings due to the reduction in total incoming radiation. Finally, WUE shows a consistent rise in all plant types under increasing aerosol loadings. Overall, the simulated daily WUE compares well with observations at 43 eddy-covariance tower sites (R2=0.84 and RMSE=0.01gC (kg H2O)-1) with better performance at forest sites. In addition to the increasing portions of diffuse light, the rise in WUE is also favored by the reduction in radiation- and heat-stress caused by the aerosols, especially for wet and hot climates.

  8. Carbon dioxide emission and soil microbial respiration activity of Chernozems under anthropogenic transformation of terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    Nadezhda D. Ananyeva

    2016-04-01

    Full Text Available The total soil CO2 emission (EM and portion of microbial respiration were measured (in situ; May, June, July 2015 in Chernozems typical of virgin steppe, oak forest, bare fallow and urban ecosystems (Kursk region, Russia. In soil samples (upper 10 cm layer, the soil microbial biomass carbon (Cmic, basal respiration (BR and fungi-to-bacteria ratio were determined and the specific microbial respiration (BR / Cmic = qCO2 was calculated. The EM was varied from 2.0 (fallow to 23.2 (steppe g СО2 m-2 d-1. The portion of microbial respiration in EM was reached in average 83, 51 and 60% for forest, steppe and urban, respectively. The soil Cmic and BR were decreased along a gradient of ecosystems transformation (by 4 and 2 times less, respectively, while the qCO2 of urban soil was higher (in average by 42% compared to steppe, forest and fallow. In urban soil the Cmic portion in soil Сorg and Сfungi-to-Сorg ratio were by 2.6 and 2.4 times less than those for steppe. The relationship between microbial respiration and BR values in Chernozems of various ecosystems was significant (R2 = 0.57.

  9. Impacts of urbanization on carbon balance in terrestrial ecosystems of the Southern United States.

    Science.gov (United States)

    Zhang, Chi; Tian, Hanqin; Chen, Guangsheng; Chappelka, Arthur; Xu, Xiaofeng; Ren, Wei; Hui, Dafeng; Liu, Mingliang; Lu, Chaoqun; Pan, Shufen; Lockaby, Graeme

    2012-05-01

    Using a process-based Dynamic Land Ecosystem Model, we assessed carbon dynamics of urbanized/developed lands in the Southern United States during 1945-2007. The results indicated that approximately 1.72 (1.69-1.77) Pg (1P = 10(15)) carbon was stored in urban/developed lands, comparable to the storage of shrubland or cropland in the region. Urbanization resulted in a release of 0.21 Pg carbon to the atmosphere during 1945-2007. Pre-urbanization vegetation type and time since land conversion were two primary factors determining the extent of urbanization impacts on carbon dynamics. After a rapid decline of carbon storage during land conversion, an urban ecosystem gradually accumulates carbon and may compensate for the initial carbon loss in 70-100 years. The carbon sequestration rate of urban ecosystem diminishes with time, nearly disappearing in two centuries after land conversion. This study implied that it is important to take urbanization effect into account for assessing regional carbon balance. Published by Elsevier Ltd.

  10. Terrestrial ecosystem process model Biome-BGCMuSo v4.0: summary of improvements and new modeling possibilities

    Science.gov (United States)

    Hidy, Dóra; Barcza, Zoltán; Marjanović, Hrvoje; Zorana Ostrogović Sever, Maša; Dobor, Laura; Gelybó, Györgyi; Fodor, Nándor; Pintér, Krisztina; Churkina, Galina; Running, Steven; Thornton, Peter; Bellocchi, Gianni; Haszpra, László; Horváth, Ferenc; Suyker, Andrew; Nagy, Zoltán

    2016-12-01

    The process-based biogeochemical model Biome-BGC was enhanced to improve its ability to simulate carbon, nitrogen, and water cycles of various terrestrial ecosystems under contrasting management activities. Biome-BGC version 4.1.1 was used as a base model. Improvements included addition of new modules such as the multilayer soil module, implementation of processes related to soil moisture and nitrogen balance, soil-moisture-related plant senescence, and phenological development. Vegetation management modules with annually varying options were also implemented to simulate management practices of grasslands (mowing, grazing), croplands (ploughing, fertilizer application, planting, harvesting), and forests (thinning). New carbon and nitrogen pools have been defined to simulate yield and soft stem development of herbaceous ecosystems. The model version containing all developments is referred to as Biome-BGCMuSo (Biome-BGC with multilayer soil module; in this paper, Biome-BGCMuSo v4.0 is documented). Case studies on a managed forest, cropland, and grassland are presented to demonstrate the effect of model developments on the simulation of plant growth as well as on carbon and water balance.

  11. Effects of long-range transported acidification on the bio-diversity in terrestrial ecosystems; Effekter av langtransporterte forsuringer paa biodiversitet i terrestriske oekosystemer

    Energy Technology Data Exchange (ETDEWEB)

    Hoeiland, K. [Oslo Univ. (Norway)

    1996-01-01

    The conference paper deals with the environmental effects of long-range transported pollutants on the biodiversity in the terrestrial ecosystems. The paper discusses different chemical substances existing in the atmosphere and their influence on vegetation together with the effects on biodiversity from acidification. 4 refs.

  12. The use of the multivariate Principal Response Curve (PRC) for community analysis: a case study on the effects of carbendazim on enchytraeids in Terrestrial Model Ecosystems (TME).

    NARCIS (Netherlands)

    Moser, T.; Römbke, J.; Schallnass, H.-J.; van Gestel, C.A.M.

    2007-01-01

    The effects of the fungicide carbendazim (formulation Derosal®) on enchytraeids were determined in Terrestrial Model Ecosystem (TME) tests. TMEs consisted of intact soil columns (diameter 17.5 cm; length 40 cm) taken from three grassland sites (Amsterdam (The Netherlands), Bangor (Wales, England)

  13. Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Cummins, C.L.

    1994-09-01

    As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentration factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms.

  14. Field perturbation experiments, an alternate approach to the assessment of human effects in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Suter, II, G W

    1980-01-01

    The National Environmental Policy Act of 1969 (NEPA) was initially interpreted as requiring full disclosure of the environmental impacts of a federal action. Because of the limitations of time, money, and manpower, this requirement that all impacts be considered has led to superficial analysis of many important impacts. Data collection has largely been limited to the enumeration of species because this information can be applied to the analysis of any problem. The President's Council on Environmental Quality (CEQ) has provided a solution to this problem by reinterpreting NEPA as requiring analysis of those impacts which have significant bearing on decision making. Because assessment resources can now be concentrated on a few critical issues, it should be possible to perform field perturbation experiments to provide direct evidence of the effects of a specific mixture of pollutants or physical disturbances on the specific mixture of pollutants or physical disturbances on the specific receiving ecosystem. Techniques are described for field simulation of gaseous and particulate air pollution, soil pollutants, disturbance of the earth's surface, and disturbance of wildlife. These techniques are discussed in terms of their realism, cost, and the restrictions which they place on the measurement of ecological parameters. Development and use of these field perturbation techniques should greatly improve the accuracy of predictive assessments and further our understanding of ecosystem processes.

  15. A model of the coupled dynamics of climate, vegetation and terrestrial ecosystem biogeochemistry for regional applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Benjamin; Wramneby, Anna (Dept. of Earth and Ecosystem Sciences, Lund Univ., Geocentrum II, Lund (Sweden)), e-mail: ben.smith.lu@gmail.com; Samuelsson, Patrick (Rossby Centre, Swedish Meteorological and Hydrological Inst., SE-60176, Norrkoeping (Sweden)); Rummukainen, Markku (Dept. of Earth and Ecosystem Sciences, Lund Univ., Geocentrum II, SE-22362, Lund (Sweden); Rossby Centre, Swedish Meteorological and Hydrological Inst., SE-60176, Norrkoeping (Sweden))

    2011-01-15

    Regional climate models (RCMs) primarily represent physical components of the climate system, omitting vegetation dynamics, ecosystem biogeochemistry and their associated feedbacks. To account for such feedbacks, we implemented a novel plant individual-based vegetation dynamics-ecosystem biogeochemistry scheme within the RCA3 RCM. Variations in leaf area index (LAI) of seven plant functional type (PFTs) in response to physical forcing and evolving vegetation state feed back to climate via adjustments in surface energy fluxes and surface properties. In an ERA-40-driven simulation over Europe, the model reproduces the recent past climate with comparable accuracy to the standard RCM. Large-scale patterns of LAI, net primary production and vegetation composition were comparable with observations, although winter LAI was systematically overestimated compared to satellite estimates. Analysis of the ERA-40 simulation and an A1B climate-change simulation revealed considerable covariation among dynamic variables of the physical climate and vegetation. At a Mediterranean site, periodic soil water limitation led to fluctuations in leaf cover and a likely positive feedback to near-surface temperature. At an alpine site, rising temperatures led to forest advance onto tundra areas, reducing albedo and effecting a likely positive feedback on temperature. Climate vegetation coupling was less pronounced but still apparent at intermediate temperate and boreal sites

  16. The Cretaceous Tetori biota in Japan and its evolutionary significance for terrestrial ecosystems in Asia

    Science.gov (United States)

    Matsukawa, M.; Ito, M.; Nishida, N.; Koarai, K.; Lockley, M.G.; Nichols, D.J.

    2006-01-01

    Cretaceous nonmarine deposits are widely distributed on the Asian continent and include various kinds of zoo- and phyto-assemblages. The Tetori Group is one of the most important Mesozoic terrestrial deposits in East Asia, and for this reason its geology, stratigraphy, and biota have been studied intensively by our group for more than a decade. We present the main results herein. We confirm that formations as lithostratigraphic units are the best geological correlation tools for the Tetori Group and the best tools for a geological mapping of the group. Although subgroups have previously been used for correlation, proper designation and evaluation of subgroups is required if they are to be used effectively, and we show that previous geological correlation of the Tetori Group has been confused by inappropriate definition of these subgroups. We located fossil localities including reported zoo- and phyto-assemblages in the framework of formations correlated by our stratigraphy. The occurrence of zoo-assemblages was probably controlled by environments (i.e., most are in situ), but phyto-assemblages were mostly transported and rapidly buried by high-energy river systems. Although two distinct dinosaur faunas and four floras have been named for the zoo- and phyto-assemblages in the Tetori Group, in reality there is only one Tetori Dinosaur Fauna and one Tetori Flora, as proved by careful correlation. Two types of zoo-assemblages co-occur in the Tetori Group: vertebrate species whose ancestors flourished in the Jurassic (as found in China), and their descendants from the Late Cretaceous. As the latter modern type of assemblage is more abundant than the former, changeable environments at the continental margin probably accelerated evolution of more modern species. We can employ nonmarine molluscan species as geological correlation tools in some cases, i.e., when their taxon ranges are well-confirmed by independent evidence. However, because freshwater molluscan species and

  17. Partition of some key regulating services in terrestrial ecosystems: Meta-analysis and review

    Energy Technology Data Exchange (ETDEWEB)

    Viglizzo, E.F., E-mail: evigliz@cpenet.com.ar [INTA, EEA Anguil, Grupo de Investigaciones en Gestión Ambiental (GIGA), Av. Spinetto 785, 6300 Santa Rosa, La Pampa (Argentina); INCITAP-CONICET, Ruta 35, km 335, 6300 Santa Rosa, La Pampa (Argentina); UNLPam, Facultad de Ciencias Exactas y Naturales, Av. Uruguay 151, 6300 Santa Rosa, La Pampa (Argentina); Jobbágy, E.G. [CONICET, Andes 950, 5700 San Luis, San Luis (Argentina); Grupo de Estudios Ambientales IMASL, Ejército de los, Andes 950, 5700 San Luis, San Luis (Argentina); Ricard, M.F. [INCITAP-CONICET, Ruta 35, km 335, 6300 Santa Rosa, La Pampa (Argentina); UNLPam, Facultad de Ciencias Exactas y Naturales, Av. Uruguay 151, 6300 Santa Rosa, La Pampa (Argentina); Paruelo, J.M. [Laboratorio de Análisis Regional y Teledetección, Departamento de Métodos Cuantitativos Sistemas de información, Facultad de Agronomía and IFEVA, Universidad de Buenos Aires and CONICET, Av. San Martín 4453, 1417 Buenos Aires (Argentina)

    2016-08-15

    Our knowledge about the functional foundations of ecosystem service (ES) provision is still limited and more research is needed to elucidate key functional mechanisms. Using a simplified eco-hydrological scheme, in this work we analyzed how land-use decisions modify the partition of some essential regulatory ES by altering basic relationships between biomass stocks and water flows. A comprehensive meta-analysis and review was conducted based on global, regional and local data from peer-reviewed publications. We analyzed five datasets comprising 1348 studies and 3948 records on precipitation (PPT), aboveground biomass (AGB), AGB change, evapotranspiration (ET), water yield (WY), WY change, runoff (R) and infiltration (I). The conceptual framework was focused on ES that are associated with the ecological functions (e.g., intermediate ES) of ET, WY, R and I. ES included soil protection, carbon sequestration, local climate regulation, water-flow regulation and water recharge. To address the problem of data normality, the analysis included both parametric and non-parametric regression analysis. Results demonstrate that PPT is a first-order biophysical factor that controls ES release at the broader scales. At decreasing scales, ES are partitioned as result of PPT interactions with other biophysical and anthropogenic factors. At intermediate scales, land-use change interacts with PPT modifying ES partition as it the case of afforestation in dry regions, where ET and climate regulation may be enhanced at the expense of R and water-flow regulation. At smaller scales, site-specific conditions such as topography interact with PPT and AGB displaying different ES partition formats. The probable implications of future land-use and climate change on some key ES production and partition are discussed. - Highlights: • The partition of regulatory services in ecosystems poses a major policy challenge. • We examined how partitions occur at the hydrosphere

  18. Novel approaches to study climate change effects on terrestrial ecosystems in the field

    DEFF Research Database (Denmark)

    Beier, C.; Emmett, B.; Gundersen, P.

    2004-01-01

    mimicked the way climate change, caused by increased cloudiness and increased greenhouse gas emissions, alters the heat balance of ecosystems. Drought conditions were created by automatically covering the vegetation with transparent curtains during rain events over a 2-5-month period. The experimental...... approach has been evaluated at four European sites across a climate gradient. All sites were dominated (more than 50%) by shrubs of the ericaceous family. Within each site, replicated 4-m X 5-m plots were established for control, warming, and drought treatments and the effect on climate variables recorded....... Results over a two-year period indicate that the warming treatment was successful in achieving an increase of the minimum temperatures by 0.4-1.2degreesC in the air and soil. The drought treatment resulted in a soil moisture reduction of 33%-82% at the peak of the drought. The data presented demonstrate...

  19. Divergent ecological effects of oceanographic anomalies on terrestrial ecosystems of the Mexican Pacific coast

    Science.gov (United States)

    Caso, Margarita; González-Abraham, Charlotte; Ezcurra, Exequiel

    2007-01-01

    Precipitation pulses are essential for the regeneration of drylands and have been shown to be related to oceanographic anomalies. However, whereas some studies report increased precipitation in drylands in northern Mexico during El Niño years, others report increased drought in the southern drylands. To elucidate the effect of oceanographic/atmospheric anomalies on moisture pulses along the whole Pacific coast of Mexico, we correlated the average Southern Oscillation Index values with total annual precipitation for 117 weather stations. We also analyzed this relationship for three separate rainfall signals: winter-spring, summer monsoon, and fall precipitation. The results showed a distinct but divergent seasonal pattern: El Niño events tend to bring increased rainfall in the Mexican northwest but tend to increase aridity in the ecosystems of the southern tropical Pacific slope. The analysis for the separated rainfall seasons showed that El Niño conditions produce a marked increase in winter rainfall above 22° latitude, whereas La Niña conditions tend to produce an increase in the summer monsoon-type rainfall that predominates in the tropical south. Because these dryland ecosystems are dependent on rainfall pulses for their renewal, understanding the complex effect of ocean conditions may be critical for their management in the future. Restoration ecology, grazing regimes, carrying capacities, fire risks, and continental runoff into the oceans could be predicted from oceanographic conditions. Monitoring the coupled atmosphere–ocean system may prove to be important in managing and mitigating the effects of large-scale climatic change on coastal drylands in the future. PMID:17563355

  20. Metagenomic insights into S(0 precipitation in a terrestrial subsurface lithoautotrophic ecosystem

    Directory of Open Access Journals (Sweden)

    Trinity eHamilton

    2015-01-01

    Full Text Available The Frasassi and Acquasanta Terme cave systems in Italy host isolated lithoautotrophic ecosystems characterized by sulfur-oxidizing biofilms with up to 50% S(0 by mass. The net contributions of microbial taxa in the biofilms to production and consumption of S(0 are poorly understood and have implications for understanding the formation of geological sulfur deposits as well as the ecological niches of sulfur-oxidizing autotrophs. Filamentous Epsilonproteobacteria are among the principal biofilm architects in Frasassi and Acquasanta Terme streams, colonizing high-sulfide, low-oxygen niches relative to other major biofilm-forming populations. Metagenomic sequencing of eight biofilm samples indicated the presence of diverse and abundant Epsilonproteobacteria. Populations of Sulfurovum-like organisms were the most abundant Epsilonproteobacteria regardless of differences in biofilm morphology, temperature, or water chemistry. After assembling and binning the metagenomic data, we retrieved four nearly-complete genomes of Sulfurovum-like organisms as well as a Sulfuricurvum spp. Analyses of the binned and assembled metagenomic data indicate that the Epsilonproteobacteria are autotrophic and therefore provide organic carbon to the isolated subsurface ecosystem. Multiple homologs of sulfide-quinone oxidoreductase (Sqr, together with incomplete or absent Sox pathways, suggest that cave Sulfurovum-like Epsilonproteobacteria oxidize sulfide incompletely to S(0 using either O2 or nitrate as a terminal electron acceptor, consistent with previous evidence that they are most successful in niches with high dissolved sulfide to oxygen ratios. In contrast, we recovered homologs of the complete complement of Sox proteins affiliated Gammaproteobacteria and with less abundant Sulfuricurvum spp. and Arcobacter spp., suggesting that these populations are capable of the complete oxidation of sulfide to sulfate. These and other genomic data presented here offer new clues

  1. Responses of terrestrial herpetofauna to persistent, novel ecosystems resulting from mountaintop removal mining

    Science.gov (United States)

    Williams, Jennifer M.; Brown, Donald J.; Wood, Petra

    2017-01-01

    Mountaintop removal mining is a large-scale surface mining technique that removes entire floral and faunal communities, along with soil horizons located above coal seams. In West Virginia, the majority of this mining occurs on forested mountaintops. However, after mining ceases the land is typically reclaimed to grasslands and shrublands, resulting in novel ecosystems. In this study, we examined responses of herpetofauna to these novel ecosystems 10–28 y postreclamation. We quantified differences in species-specific habitat associations, (sub)order-level abundances, and habitat characteristics in four habitat types: reclaimed grassland, reclaimed shrubland, forest fragments in mined areas, and nonmined intact forest. Habitat type accounted for 33.2% of the variation in species-specific captures. With few exceptions, forest specialists were associated with intact forest and fragmented forest sites, while habitat generalists were either associated with grassland and shrubland sites or were distributed among all habitat types. At the (sub)order level, salamander (Order Urodela) captures were highest at fragmented and intact forest sites, frog and toad (Order Anura) captures were lowest at intact forest sites, and snake (Suborder Serpentes) captures were highest at shrubland sites. Habitat type was a strong predictor for estimated total abundance of urodeles, but not for anurans or snakes. Tree stem densities in grasslands differed from the other three habitat types, and large trees (>38 cm diameter at breast height) were only present at forest sites. Overstory vegetation cover was greater in forested than in reclaimed habitat types. Ground cover in reclaimed grasslands was distinct from forest treatments with generally less woody debris and litter cover and more vegetative cover. It is important to consider the distributions of habitat specialists of conservation concern when delineating potential mountaintop mine sites, as these sites will likely contain unsuitable

  2. Modelling of plant-soil carbon, nitrogen and phosphorus cycling in semi-natural terrestrial ecosystems

    Science.gov (United States)

    Davies, Jessica; Quinton, John; Rowe, Ed; Tipping, Ed

    2013-04-01

    In recent centuries pools and fluxes of C, N and P in natural and semi-natural UK ecosystems have been transformed by atmospheric pollution leading to: acidification; eutrophication of surface waters; loss of biodiversity; and increased greenhouse gas emissions. In addition, climate change now threatens to perturb these systems further. Understanding in this field is vital in determining the consequences of artificial nutrient enrichment and land use and climate change, and mitigating against their effects. The N14CP model has been recently developed to assess the temporal responses of soil C, N and P pools to nutrient enrichment in semi-natural ecosystems, and explore the connections between these nutrients. It is a dynamic, mechanistic model, driven by: climate; CO2, N (fixation and pollutant deposition), and P (weathering and atmospheric deposition) inputs; and plant cover type. It explicitly links C, N, and P in both plants and soils, using plant element stoichiometry as the primary constraint. Net primary production, and plant/soil element pools, are calculated over time, and output fluxes of dissolved organic and inorganic, and gaseous, forms of C, N, and P produced. Radiocarbon data are used to constrain Soil Organic Matter (SOM) turnover. The SOM is represented as three pools, undergoing first-order decomposition reactions with turn-over rates ranging from 2 to 1000 years. The N14CP modelling methodology is discussed and its calibration and verification using observations from 200 northern European sites presented. Whilst the primary period of interest with respect to nutrient enrichment is from the industrial revolution onwards, plant-soil C, N and P are simulated at these sites for a period spanning from the start of the Holocene (to provide a spin-up period) to the present day. Clearly, during this time span land cover and usage will have changed at these sites, and histories of these changes are used as an input to the model. The influence of these land

  3. The age and diversification of terrestrial New World ecosystems through Cretaceous and Cenozoic time.

    Science.gov (United States)

    Graham, Alan

    2011-03-01

    Eight ecosystems that were present in the Cretaceous about 100 Ma (million years ago) in the New World eventually developed into the 12 recognized for the modern Earth. Among the forcing mechanisms that drove biotic change during this interval was a decline in global temperatures toward the end of the Cretaceous, augmented by the asteroid impact at 65 Ma and drainage of seas from continental margins and interiors; separation of South America from Africa beginning in the south at ca. 120 Ma and progressing northward until completed 90-100 Ma; the possible emission of 1500 gigatons of methane and CO(2) attributed to explosive vents in the Norwegian Sea at ca. 55 Ma, resulting in a temperature rise of 5°-6°C in an already warm world; disruption of the North Atlantic land bridge at ca. 45 Ma at a time when temperatures were falling; rise of the Andes Mountains beginning at ca. 40 Ma; opening of the Drake Passage between South America and Antarctica at ca. 32 Ma with formation of the cold Humboldt at ca. 30 Ma; union of North and South America at ca. 3.5 Ma; and all within the overlay of evolutionary processes. These processes generated a sequence of elements (e.g., species growing in moist habitats within an overall dry environment; gallery forests), early versions (e.g., mangrove communities without Rhizophora until the middle Eocene), and essentially modern versions of present-day New World ecosystems. As a first approximation, the fossil record suggests that early versions of aquatic communities (in the sense of including a prominent angiosperm component) appeared early in the Middle to Late Cretaceous, the lowland neotropical rainforest at 64 Ma (well developed by 58-55 Ma), shrubland/chaparral-woodland-savanna and grasslands around the middle Miocene climatic optimum at ca. 15-13 Ma, deserts in the middle Miocene/early Pliocene at ca. 10 Ma, significant tundra at ca. 7-5 Ma, and alpine tundra (páramo) shortly thereafter when cooling temperatures were augmented

  4. Can ecosystem-scale translocations mitigate the impact of climate change on terrestrial biodiversity? Promises, pitfalls, and possibilities [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Stéphane Boyer

    2016-02-01

    Full Text Available Because ecological interactions are the first components of the ecosystem to be impacted by climate change, future forms of threatened-species and ecosystem management should aim at conserving complete, functioning communities rather than single charismatic species. A possible way forward is the deployment of ecosystem-scale translocation (EST, where above- and below-ground elements of a functioning terrestrial ecosystem (including vegetation and topsoil are carefully collected and moved together. Small-scale attempts at such practice have been made for the purpose of ecological restoration. By moving larger subsets of functioning ecosystems from climatically unstable regions to more stable ones, EST could provide a practical means to conserve mature and complex ecosystems threatened by climate change. However, there are a number of challenges associated with EST in the context of climate change mitigation, in particular the choice of donor and receptor sites. With the aim of fostering discussion and debate about the EST concept, we  1 outline the possible promises and pitfalls of EST in mitigating the impact of climate change on terrestrial biodiversity and 2 use a GIS-based approach to illustrate how  potential source and receptor sites, where EST could be trialed and evaluated globally, could be identified.

  5. Comparing the influence of wildfire and prescribed burns on watershed nitrogen biogeochemistry using 15N natural abundance in terrestrial and aquatic ecosystem components.

    Science.gov (United States)

    Stephan, Kirsten; Kavanagh, Kathleen L; Koyama, Akihiro

    2015-01-01

    We evaluated differences in the effects of three low-severity spring prescribed burns and four wildfires on nitrogen (N) biogeochemistry in Rocky Mountain headwater watersheds. We compared paired (burned/unburned) watersheds of four wildfires and three spring prescribed burns for three growing seasons post-fire. To better understand fire effects on the entire watershed ecosystem, we measured N concentrations and δ15N in both the terrestrial and aquatic ecosystems components, i.e., soil, understory plants in upland and riparian areas, streamwater, and in-stream moss. In addition, we measured nitrate reductase activity in foliage of Spiraea betulifolia, a dominant understory species. We found increases of δ15N and N concentrations in both terrestrial and aquatic ecosystem N pools after wildfire, but responses were limited to terrestrial N pools after prescribed burns indicating that N transfer from terrestrial to aquatic ecosystem components did not occur in low-severity prescribed burns. Foliar δ15N differed between wildfire and prescribed burn sites; the δ15N of foliage of upland plants was enriched by 2.9 ‰ (difference between burned and unburned watersheds) in the first two years after wildfire, but only 1.3 ‰ after prescribed burns. In-stream moss δ15N in wildfire-burned watersheds was enriched by 1.3 ‰, but there was no response by moss in prescription-burned watersheds, mirroring patterns of streamwater nitrate concentrations. S. betulifolia showed significantly higher nitrate reductase activity two years after wildfires relative to corresponding unburned watersheds, but no such difference was found after prescribed burns. These responses are consistent with less altered N biogeochemistry after prescribed burns relative to wildfire. We concluded that δ15N values in terrestrial and aquatic plants and streamwater nitrate concentrations after fire can be useful indicators of the magnitude and duration of fire effects and the fate of post

  6. Comparing the influence of wildfire and prescribed burns on watershed nitrogen biogeochemistry using 15N natural abundance in terrestrial and aquatic ecosystem components.

    Directory of Open Access Journals (Sweden)

    Kirsten Stephan

    Full Text Available We evaluated differences in the effects of three low-severity spring prescribed burns and four wildfires on nitrogen (N biogeochemistry in Rocky Mountain headwater watersheds. We compared paired (burned/unburned watersheds of four wildfires and three spring prescribed burns for three growing seasons post-fire. To better understand fire effects on the entire watershed ecosystem, we measured N concentrations and δ15N in both the terrestrial and aquatic ecosystems components, i.e., soil, understory plants in upland and riparian areas, streamwater, and in-stream moss. In addition, we measured nitrate reductase activity in foliage of Spiraea betulifolia, a dominant understory species. We found increases of δ15N and N concentrations in both terrestrial and aquatic ecosystem N pools after wildfire, but responses were limited to terrestrial N pools after prescribed burns indicating that N transfer from terrestrial to aquatic ecosystem components did not occur in low-severity prescribed burns. Foliar δ15N differed between wildfire and prescribed burn sites; the δ15N of foliage of upland plants was enriched by 2.9 ‰ (difference between burned and unburned watersheds in the first two years after wildfire, but only 1.3 ‰ after prescribed burns. In-stream moss δ15N in wildfire-burned watersheds was enriched by 1.3 ‰, but there was no response by moss in prescription-burned watersheds, mirroring patterns of streamwater nitrate concentrations. S. betulifolia showed significantly higher nitrate reductase activity two years after wildfires relative to corresponding unburned watersheds, but no such difference was found after prescribed burns. These responses are consistent with less altered N biogeochemistry after prescribed burns relative to wildfire. We concluded that δ15N values in terrestrial and aquatic plants and streamwater nitrate concentrations after fire can be useful indicators of the magnitude and duration of fire effects and the fate of

  7. Nitrogen Availability Dampens the Positive Impacts of CO2 Fertilization on Terrestrial Ecosystem Carbon and Water Cycles

    Science.gov (United States)

    He, Liming; Chen, Jing M.; Croft, Holly; Gonsamo, Alemu; Luo, Xiangzhong; Liu, Jane; Zheng, Ting; Liu, Ronggao; Liu, Yang

    2017-11-01

    The magnitude and variability of the terrestrial CO2 sink remain uncertain, partly due to limited global information on ecosystem nitrogen (N) and its cycle. Without N constraint in ecosystem models, the simulated benefits from CO2 fertilization and CO2-induced increases in water use efficiency (WUE) may be overestimated. In this study, satellite observations of a relative measure of chlorophyll content are used as a proxy for leaf photosynthetic N content globally for 2003-2011. Global gross primary productivity (GPP) and evapotranspiration are estimated under elevated CO2 and N-constrained model scenarios. Results suggest that the rate of global GPP increase is overestimated by 85% during 2000-2015 without N limitation. This limitation is found to occur in many tropical and boreal forests, where a negative leaf N trend indicates a reduction in photosynthetic capacity, thereby suppressing the positive vegetation response to enhanced CO2 fertilization. Based on our carbon-water coupled simulations, enhanced CO2 concentration decreased stomatal conductance and hence increased WUE by 10% globally over the 1982 to 2015 time frame. Due to increased anthropogenic N application, GPP in croplands continues to grow and offset the weak negative trend in forests due to N limitation. Our results also show that the improved WUE is unlikely to ease regional droughts in croplands because of increases in evapotranspiration, which are associated with the enhanced GPP. Although the N limitation on GPP increase is large, its associated confidence interval is still wide, suggesting an urgent need for better understanding and quantification of N limitation from satellite observations.

  8. Process-based estimates of terrestrial ecosystem isoprene emissions: incorporating the effects of a direct CO2-isoprene interaction

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2007-01-01

    increase of ecosystem isoprene emission in a future, warmer atmosphere with higher CO2 levels; this effect raises important questions for projections of future atmospheric chemistry, and its connection to the terrestrial vegetation and carbon cycle.

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

    Directory of Open Access Journals (Sweden)

    Xuhui Zhou

    2012-10-01

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

  10. Proceedings of the international workshop on the effects of acid precipitation on vegetation, soils, and terrestrial ecosystems, Brookhaven National Laboratory, June 12 to 14, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Evans, L.S.; Hendrey, G.R. (eds.)

    1979-01-01

    The objectives of the workshop were to determine the levels of current knowledge of the effects of acid precipitation on vegetation, soils, and terrestrial ecosystems; research needed in these areas to understand the environmental impacts of acid rain; and to help coordinate research groups to avoid excessive duplication of research. The workshop was designed so that researchers in the areas of effects of acid precipitation on vegetation, soils, and whole ecosystem approaches could communicate effectively. There was a general consensus that acid rain at extreme ambient levels, or in artificial systems that simulate extreme ambient levels, causes injury to plant tissues. A major area of concern of acid rain injury was thought to be plant reproduction. The overall levels of significance of plant injury among various plant species remain unknown. The most important priorities in the area of effects of acid rain on crops were an evaluation of effects on crop yields and interaction of acid rain in combination with pollutants on various plants. Few participants thought that ambient acid rain loadings have altered soils to such a degree that plants are affected at present, but many thought that acid rain could cause some alterations in soils. The most important research priorities were in the areas of the effects of acid rain on increased leaching of exchangeable plant nutrients and alterations in phosphorous availability. All participants agreed that there are alterations in terrestrial ecosystems from acid precipitation. However, no demonstrated harmful effects were presented from natural ecosystems. Further research on the effects of acid rain on terrestrial ecosystems should be directed mostly toward the interaction of acid rain with toxic elements such as Al, Fe, and Mn and on the effects on nutrient cycling, especially that of nitrogen.

  11. Terrestrial ecosystem model performance in simulating productivity and its vulnerability to climate change in the northern permafrost region

    Science.gov (United States)

    Xia, Jianyang; McGuire, A. David; Lawrence, David; Burke, Eleanor J.; Chen, Guangsheng; Chen, Xiaodong; Delire, Christine; Koven, Charles; MacDougall, Andrew; Peng, Shushi; Rinke, Annette; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Gouttevin, Isabelle; Hajima, Tomohiro; Hayes, Daniel J.; Huang, Kun; Ji, Duoying; Krinner, Gerhard; Lettenmaier, Dennis P.; Miller, Paul A.; Moore, John C.; Smith, Benjamin; Sueyoshi, Tetsuo; Shi, Zheng; Yan, Liming; Liang, Junyi; Jiang, Lifen; Zhang, Qian; Luo, Yiqi

    2017-01-01

    Realistic projection of future climate-carbon (C) cycle feedbacks requires better understanding and an improved representation of the C cycle in permafrost regions in the current generation of Earth system models. Here we evaluated 10 terrestrial ecosystem models for their estimates of net primary productivity (NPP) and responses to historical climate change in permafrost regions in the Northern Hemisphere. In comparison with the satellite estimate from the Moderate Resolution Imaging Spectroradiometer (MODIS; 246 ± 6 g C m−2 yr−1), most models produced higher NPP (309 ± 12 g C m−2 yr−1) over the permafrost region during 2000–2009. By comparing the simulated gross primary productivity (GPP) with a flux tower-based database, we found that although mean GPP among the models was only overestimated by 10% over 1982–2009, there was a twofold discrepancy among models (380 to 800 g C m−2 yr−1), which mainly resulted from differences in simulated maximum monthly GPP (GPPmax). Most models overestimated C use efficiency (CUE) as compared to observations at both regional and site levels. Further analysis shows that model variability of GPP and CUE are nonlinearly correlated to variability in specific leaf area and the maximum rate of carboxylation by the enzyme Rubisco at 25°C (Vcmax_25), respectively. The models also varied in their sensitivities of NPP, GPP, and CUE to historical changes in climate and atmospheric CO2 concentration. These results indicate that model predictive ability of the C cycle in permafrost regions can be improved by better representation of the processes controlling CUE and GPPmax as well as their sensitivity to climate change.

  12. Terrestrial ecosystem model performance in simulating productivity and its vulnerability to climate change in the northern permafrost region

    Science.gov (United States)

    Xia, Jianyang; McGuire, A. David; Lawrence, David; Burke, Eleanor; Chen, Guangsheng; Chen, Xiaodong; Delire, Christine; Koven, Charles; MacDougall, Andrew; Peng, Shushi; Rinke, Annette; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Gouttevin, Isabelle; Hajima, Tomohiro; Hayes, Daniel J.; Huang, Kun; Ji, Duoying; Krinner, Gerhard; Lettenmaier, Dennis P.; Miller, Paul A.; Moore, John C.; Smith, Benjamin; Sueyoshi, Tetsuo; Shi, Zheng; Yan, Liming; Liang, Junyi; Jiang, Lifen; Zhang, Qian; Luo, Yiqi

    2017-02-01

    Realistic projection of future climate-carbon (C) cycle feedbacks requires better understanding and an improved representation of the C cycle in permafrost regions in the current generation of Earth system models. Here we evaluated 10 terrestrial ecosystem models for their estimates of net primary productivity (NPP) and responses to historical climate change in permafrost regions in the Northern Hemisphere. In comparison with the satellite estimate from the Moderate Resolution Imaging Spectroradiometer (MODIS; 246 ± 6 g C m-2 yr-1), most models produced higher NPP (309 ± 12 g C m-2 yr-1) over the permafrost region during 2000-2009. By comparing the simulated gross primary productivity (GPP) with a flux tower-based database, we found that although mean GPP among the models was only overestimated by 10% over 1982-2009, there was a twofold discrepancy among models (380 to 800 g C m-2 yr-1), which mainly resulted from differences in simulated maximum monthly GPP (GPPmax). Most models overestimated C use efficiency (CUE) as compared to observations at both regional and site levels. Further analysis shows that model variability of GPP and CUE are nonlinearly correlated to variability in specific leaf area and the maximum rate of carboxylation by the enzyme Rubisco at 25°C (Vcmax_25), respectively. The models also varied in their sensitivities of NPP, GPP, and CUE to historical changes in climate and atmospheric CO2 concentration. These results indicate that model predictive ability of the C cycle in permafrost regions can be improved by better representation of the processes controlling CUE and GPPmax as well as their sensitivity to climate change.

  13. Terrestrial Subsurface Ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Fredrickson, Jim K.

    2015-10-15

    The Earth’s crust is a solid cool layer that overlays the mantle, with a varying thickness of between 30-50 km on continental plates, and 5-10 km on oceanic plates. Continental crust is composed of a variety of igneous, metamorphic, and sedimentary rocks that weather and re-form over geologic cycles lasting millions to billions of years. At the crust surface, these weathered minerals and organic material combine to produce a variety of soils types that provide suitable habitats and niches for abundant microbial diversity (see Chapter 4). Beneath this soil zone is the subsurface. Once thought to be relatively free of microorganisms, recent estimates have calculated that between 1016-1017 g C biomass (2-19% of Earth’s total biomass) may be present in this environment (Whitman et al., 1998;McMahon and Parnell, 2014). Microbial life in the subsurface exists across a wide range of habitats: in pores associated with relatively shallow unconsolidated aquifer sediments to fractures in bedrock formations that are more than a kilometer deep, where extreme lithostatic pressures and temperatures are encountered. While these different environments contain varying physical and chemical conditions, the absence of light is a constant. Despite this, diverse physiologies and metabolisms enable microorganisms to harness energy and carbon for growth in water-filled pore spaces and fractures. Carbon and other element cycles are driven by microbial activity, which has implications for both natural processes and human activities in the subsurface, e.g., bacteria play key roles in both hydrocarbon formation and degradation. Hydrocarbons are a major focus for human utilization of the subsurface, via oil and gas extraction and potential geologic CO2 sequestration. The subsurface is also utilized or being considered for sequestered storage of high-level radioactive waste from nuclear power generation and residual waste from past production of weapons grade nuclear materials. While our understanding of the subsurface is continually improving, it is clear that only a small fraction of microbial habitats have been sampled and studied. In this chapter, we will discuss these studies in the context of the distribution of microbial life in the subsurface, the stresses that microorganisms must overcome to survive in these environments, and the metabolic strategies that are employed to harness energy in a region of the planet far-removed from sunlight. Finally, we will consider both beneficial and deleterious effects of microbial activity in the subsurface on human activities in this environment.

  14. Quantifying Terrestrial Ecosystem Carbon Stocks for Future GHG Mitigation, Sustainable Land-Use Planning and Adaptation to Climate Change in Quebec, Canada.

    Science.gov (United States)

    Garneau, M.; van Bellen, S.

    2016-12-01

    Based on various databases, carbon stocks of terrestrial ecosystems in the boreal and arctic biomes of Quebec were quantified as part of an evaluation of their capacity to mitigate anthropogenic greenhouse gas (GHG) emissions and estimate their vulnerability with respect to recent climate change and land use changes. The results of this project are contributing to the establishment of the Strategy for Climate Change Adaptation as well as the 2013-2020 Climate Change Action Plan of the Quebec Ministry of Environment, which aim to adapt the Quebec society to the effects of climate change and the reduction of GHG emissions. The total carbon stock of the soils of the forest and peatland ecosystems of Quebec was quantified at 18.00 Gt C or 66.0 Gt CO2-equivalent, of which 95% corresponds to the boreal and arctic regions. The mean carbon mass per unit area (kg C m-2) of peatlands is about nine times higher than that of forests, with values of 100,0 kg C m-2 for peatlands and 10,9 kg C m-2 for forest stands. In 2013, total anthropogenic emissions in Quebec were quantified at 82.6 Mt CO2-equivalent (Environment Canada, 2015), or 1.25‰ of the total Quebec ecosystem carbon stock. The total stock thus represents the equivalent of about 800 years of anthropogenic emissions at the current rate, divided between 478 years for peatlands and 321 years for forest soils. Future GHG mitigation policies and sustainable land-use planning should be supported by scientific data on terrestrial ecosystems carbon stocks. An increase in investments in peatland, wetland and forest conservation, management and rehabilitation may contribute to limit greenhouse gas emissions. It is therefore essential, that, following the objectives of multiple international organisations, the management of terrestrial carbon stocks becomes part of the national engagement to reduce GHG emissions.

  15. Outdoor Terrestrial Model Ecosystems are suitable to detect pesticide effects on soil fauna: design and method development.

    Science.gov (United States)

    Scholz-Starke, B; Nikolakis, A; Leicher, T; Lechelt-Kunze, C; Heimbach, F; Theissen, B; Toschki, A; Ratte, H T; Schäffer, A; Ross-Nickoll, M

    2011-11-01

    Terrestrial Model Ecosystems (TME) were developed as one higher-tier option to detect and assess effects of pesticides on soil communities in a 1 year study using lindane (gamma-HCH) as a persistent and toxic reference pesticide. TME contained intact soil cores (diameter 300 mm, height 400 mm) including indigenous soil communities of undisturbed grassland. Forty units were placed outdoors between spring 2005 and 2006. The TME experiment was designed to provide data that fulfill the requirements of the revised European regulation on plant protection products (regulation 1107/2009/EEC replacing guideline 91/414/EC) with a focus on structural endpoints such as soil organisms and their community structure in case higher-tier evaluation is triggered. The key objective was to evaluate the dynamics and stability of species-diverse microarthropod communities of undisturbed grassland over at least 1 year after application. In grassland soils, less selection pressure towards insensitive species compared to arable land was presumed. Sufficient numbers of organisms and numerous TME replicates ensured that a statistical evaluation could be performed to estimate the sensitivity of the organisms upon application of lindane applied at high rates of 7.5 and 75 kg ai/ha. The application rates resulted in nominal concentrations of 10 and 100 mg ai/kg dry soil referred to the top 5 cm soil layer of 10 TME each; 20 untreated TME served as controls and were used to study the natural dynamics and the variability of populations under field conditions. Results showed that the grassland from which the soil cores were sampled contained communities of soil organisms marked by typical diversity of improved grassland. Lindane applied at excessive rates caused clear dose-related and long-lasting effects on the communities of microarthropods. On the contrary, lumbricids, the total feeding activity (bait lamina) and the growth of plant biomass were not affected up to 1 year after application

  16. Impacts of Diffuse Radiation on Light Use Efficiency across Terrestrial Ecosystems Based on Eddy Covariance Observation in China

    Science.gov (United States)

    Huang, Kun; Wang, Shaoqiang; Zhou, Lei; Wang, Huimin; Zhang, Junhui; Yan, Junhua; Zhao, Liang; Wang, Yanfen; Shi, Peili

    2014-01-01

    Ecosystem light use efficiency (LUE) is a key factor of production models for gross primary production (GPP) predictions. Previous studies revealed that ecosystem LUE could be significantly enhanced by an increase on diffuse radiation. Under large spatial heterogeneity and increasing annual diffuse radiation in China, eddy covariance flux data at 6 sites across different ecosystems from 2003 to 2007 were used to investigate the impacts of diffuse radiation indicated by the cloudiness index (CI) on ecosystem LUE in grassland and forest ecosystems. Our results showed that the ecosystem LUE at the six sites was significantly correlated with the cloudiness variation (0.24≤R2≤0.85), especially at the Changbaishan temperate forest ecosystem (R2 = 0.85). Meanwhile, the CI values appeared more frequently between 0.8 and 1.0 in two subtropical forest ecosystems (Qianyanzhou and Dinghushan) and were much larger than those in temperate ecosystems. Besides, cloudiness thresholds which were favorable for enhancing ecosystem carbon sequestration existed at the three forest sites, respectively. Our research confirmed that the ecosystem LUE at the six sites in China was positively responsive to the diffuse radiation, and the cloudiness index could be used as an environmental regulator for LUE modeling in regional GPP prediction. PMID:25393629

  17. Multiproxy evidence for terrestrial and aquatic ecosystem responses during the 8.2 ka cold event as recorded at Højby Sø, Denmark

    Science.gov (United States)

    Hede, Mikkel Ulfeldt; Rasmussen, Peter; Noe-Nygaard, Nanna; Clarke, Annemarie L.; Vinebrooke, Rolf D.; Olsen, Jesper

    2010-05-01

    A sediment succession from Højby Sø, a lake in eastern Denmark, covering the time period 9400-7400 cal yr BP was studied using high-resolution geochemistry, magnetic susceptibility, pollen, macrofossil, diatom, and algal pigment analysis to investigate responses of the terrestrial and aquatic ecosystems to the 8.2 ka cold event. A reduced pollen production by thermophilous deciduous tree taxa in the period c. 8250-8000 cal yr BP reveal that the forest ecosystem was affected by low temperatures during the summer and winter/early-spring seasons. This finding is consistent with the timing of the 8.2 ka cold event as registered in the Greenland ice cores. At Højby Sø, the climate anomaly appears to have started 200-250 yr earlier than the 8.2 ka cold event as the lake proxy data provide strong evidence for a precipitation-induced distinct increase in catchment soil erosion beginning around 8500 cal yr BP. Alteration of the terrestrial environment then resulted in a major aquatic ecosystem change with nutrient enrichment of the lake and enhanced productivity, which lasted until c. 7900 cal yr BP.

  18. A strategy to study regional hydrology and terrestrial ecosystem processes using satellite remote sensing, ground-based data and computer modeling

    Science.gov (United States)

    Vorosmarty, C.; Grace, A.; Moore, B.; Choudhury, B.; Willmott, C. J.

    1990-01-01

    A strategy is presented for integrating scanning multichannel microwave radiometer data from the Nimbus-7 satellite with meteorological station records and computer simulations of land surface hydrology, terrestrial nutrient cycling, and trace gas emission. Analysis of the observations together with radiative transfer analysis shows that in the tropics the temporal and spatial variations of the polarization difference are determined primarily by the structure and phenology of vegetation and seasonal inundations of major rivers and wetlands. It is concluded that the proposed surface hydrology model, along with climatological records, and, potentially, 37-GHz data for phenology, will provide inputs to a terrestrial ecosystem model that predicts regional net primary production and CO2 gas exchange.

  19. Ecological risk assessment for the terrestrial ecosystem under chronic radioactive pollution - Ecological risk assessment for the biota on regional radioactive waste storage

    Energy Technology Data Exchange (ETDEWEB)

    Lavrentyeva, G.V.; Synzynys, B.I.; Shoshina, R.R.; Mirzeabasov, O.A. [Obninsk Institute for Nuclear Power Engineering, branch of the National Research Nuclear University MEPhI, Department of Ecology, Studgorodok,1, 249040 Obninsk, Kaluga region (Russian Federation)

    2014-07-01

    Now the methods of ecological regulation of a radiation factor from risk assessment are developed poorly. The paper attempts to assess and forecast the terrestrial ecosystem conditions under chronic ionizing radiation by calculating the critical loads. The paper is aimed at developing a methodology to assess the ecological risk for a terrestrial ecosystem under chronic radioactive pollution in a biotope of a regional radioactive waste storage. Objects and Methods: Biotope monitoring of a radioactive waste storage makes clear that the radioecological situation in this territory is stipulated by technogenic {sup 90}Sr found in soil, ground water and biota. Terrestrial mollusks of a shrubby Snail type (Bradybaena fruticum) were chosen as reference species due to their activity to accumulate {sup 90}Sr in shells and the number of colony-forming soil units (CFU) as reference indices. The number of CFU was determined by inoculation of solid medium. Soil and mollusk samples have been collected at most representative sites identified in the previous studies. To assess {sup 90}Sr content in the samples collected, radiochemical separation was used with further radionuclide activity measurements by a 'BETA-01C' scintillation beta-ray spectrometer according to a standard procedure of {sup 90}Sr content assessment from beta-radiation of its daughter radionuclide {sup 90}Y. Ecological risk was calculated from analyzed critical loads using a 'dose-effect' dependence. Statistical data processing was realized with Excell 2007 and R software programs [R Development Core Team, 2010]. The software R was also used for GIS creation. Results and Discussion: A methodology of ecological risk assessment for the terrestrial ecosystem under chronic radioactive pollution of a biotope near a regional radioactive waste storage has been developed in terms of the critical environmental loads analyzed. It consists of five stages: determination of effect indicators and assessment

  20. Drought dominates the interannual variability in global terrestrial net primary production by controlling semi-arid ecosystems

    OpenAIRE

    Ling Huang; Bin He; Aifang Chen; Haiyan Wang; Junjie Liu; Aifeng Lű; Ziyue Chen

    2016-01-01

    Drought is a main driver of interannual variation in global terrestrial net primary production. However, how and to what extent drought impacts global NPP variability is unclear. Based on the multi-timescale drought index SPEI and a satellite-based annual global terrestrial NPP dataset, we observed a robust relationship between drought and NPP in both hemispheres. In the Northern Hemisphere, the annual NPP trend is driven by 19-month drought variation, whereas that in the Southern Hemisphere ...

  1. Application of Terrestrial Ecosystem Monitoring under the CAFF Circumpolar Biodiversity Monitoring Program: Designing and Implementing Terrestrial Monitoring to Establish the Canadian High Arctic Research Station as a Flagship Arctic Environmental Monitoring Site

    Science.gov (United States)

    McLennan, D.; Kehler, D.

    2016-12-01

    The Canadian High Arctic Research Station (CHARS) is scheduled for completion in July 2017 and is the northern science component of Polar Knowledge Canada (POLAR). A mandated goal for POLAR is to establish the adjacent Experimental and Reference Area (ERA) as an Arctic Flagship monitoring site that will track change in Arctic terrestrial, freshwater and marine ecosystems. Situated in the community of Cambridge Bay, CHARS provides the opportunity to draw on the Indigenous Knowledge of local residents to help design and conduct the monitoring, and to operate 12 months a year. Monitoring at CHARS will be linked to networks nationally and internationally, and is being designed so that change in key indicators can be understood in terms of drivers and processes, modeled and scaled up regionally, and used to predict important changes in critical indicators. As a partner in the Circumpolar Biodiversity Monitoring Program (CBMP), the monitoring design for terrestrial ecosystems follows approaches outlined by the CBMP Terrestrial Expert Monitoring Group, who have listed key monitoring questions and identified a list of important Focal Ecosystem Components (FECs). To link drivers to FECs we are proposing a multi-scaled approach: 1) an Intensive Monitoring Area to establish replicated monitoring plots that track change in snow depth and condition, active layer depth, soil temperature, soil moisture, and soil solution chemistry that are spatially and temporally linked to changes in microbiological activity, CO2/CH4 net ecosystem flux, vegetation relative frequency, species composition, growth and foliar nutrient concentration, arthropod abundance, lemming abundance and health, and shorebird/songbird abundance and productivity. 2) These intensive observations are supported by watershed scale measures that will monitor, during the growing season, lemming winter nest abundance, songbird, shorebird and waterfowl staging and nesting, and other observations; in the winter we will

  2. Terrestrial ecosystem recovery - Modelling the effects of reduced acidic inputs and increased inputs of sea-salts induced by global change

    DEFF Research Database (Denmark)

    Beier, C.; Moldan, F.; Wright, R.F.

    2003-01-01

    The reduced emissions of acidifying sulfur and nitrogen in Europe since the late 1970s will be further reduced when the Gothenburg protocol is fully implemented by 2010. Here we address the consequences for the recovery of acidified terrestrial ecosystems using the acidification model MAGIC applied...... and base saturation increases less than 5% over the next 30 years. A climate-induced increase in storm severity will increase the sea-salt input to the ecosystems. This will provide additional base cations to the soils and more than double the rate of the recovery, but also lead to strong acid pulses...... following high sea-salt inputs as the deposited base cations exchange with the acidity stored in the soil. Future recovery of soils and runoff at acidified catchments will thus depend on the amount and rate of reduction of acid deposition, and in the case of systems near the coast, the frequency...

  3. Exploring industry specific social welfare maximizing rates of water pollution abatement in linked terrestrial and marine ecosystems

    NARCIS (Netherlands)

    Roebeling, P.C.; Hendrix, E.M.T.; Grieken, van M.E.

    2009-01-01

    Marine ecosystems are severely affected by water pollution originating from coastal catchments, while these ecosystems are of vital importance from an environmental as well as an economic perspective. To warrant sustainable economic development of coastal regions, we need to balance the marginal

  4. Wild food in Europe: a synthesis of knowledge and data of terrestrial wild food as an ecosystem service

    NARCIS (Netherlands)

    Schulp, C.J.E.; Thuiller, W.; Verburg, P.H.

    2014-01-01

    Wild food is an iconic ecosystem service that receives little attention in quantifying, valuating and mapping studies, due to the perceived low importance or due to lack of data. Here, we synthesize available data on the importance of wild food as ecosystem service, its spatial distribution and

  5. Linking terrestrial and estuarine ecosystems: Organic matter sources supporting the high secondary production of a non-indigenous bivalve

    Science.gov (United States)

    The Asian clam Corbicula fluminea is one of the most pervasive species in freshwater ecosystems. Our objective was to characterize the trophic interactions of C. fluminea in the Minho river estuary (NW-Iberian Peninsula, Europe), an estuarine ecosystem in which C. fluminea presen...

  6. Model estimates of net primary productivity, evaportranspiration, and water use efficiency in the terrestrial ecosystems of the southern United States

    Science.gov (United States)

    Hanqin Tian; Guangsheng Chen; Mingliang Liu; Chi Zhang; Ge Sun; Chaoqun Lu; Xiaofeng Xu; Wei Ren; Shufen Pan; Arthur. Chappelka

    2010-01-01

    The effects of global change on ecosystem productivity and water resources in the southern United States (SUS), a traditionally ‘water-rich’ region and the ‘timber basket’ of the country, are not well quantified. We carried out several simulation experiments to quantify ecosystem net primary productivity (NPP), evapotranspiration (ET)...

  7. Uptake of Cadmium, Copper, Lead, and Zinc from Sediments by an Aquatic Macrophyte and by Terrestrial Arthropods in a Freshwater Wetland Ecosystem.

    Science.gov (United States)

    Kim, Heung-Tae; Kim, Jae Geun

    2016-08-01

    The objective of this study was to investigate trace-metal [cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn)] biotransference and biomagnification in terrestrial biota at different trophic levels (primary producer-top predator) of a wetland ecosystem. We investigated whether metal concentrations in the sediment are reflected in terrestrial arthropods and aquatic plants. We sampled the floating-leaved plant Trapa japonica; its species-specific primary consumer, the leaf beetle Galerucella nipponensis; and two predatory arthropods (the water strider Gerris sp. and the wolf spider Arctosa sp.) from three wetlands with different sedimentary metal concentrations. The δ(13)C and δ(15)N signatures in the trophic link between the plants and the leaf beetles supported the specificity of their feeding relationship. The stable isotope signatures indicate that the leaf beetle could be an important link in the trophic transfer of the metals. Transference factors (TFs) were Cu and Zn had TF >1 for all biota, and the concentrations were positively correlated with the trophic levels. Thus, there may be Cu and Zn biomagnification in the arthropods. We noted TF 1 among the arthropods. Therefore, Cd is probably not biomagnified between T. japonica and G. nipponensis, but it might be biomagnified in the arthropods. The metal burden in terrestrial arthropods may also be influenced by uptake from the sediment by aquatic plants.

  8. Quantification of terrestrial ecosystem carbon dynamics in the conterminous United States combining a process-based biogeochemical model and MODIS and AmeriFlux data

    Directory of Open Access Journals (Sweden)

    M. Chen

    2011-09-01

    Full Text Available Satellite remote sensing provides continuous temporal and spatial information of terrestrial ecosystems. Using these remote sensing data and eddy flux measurements and biogeochemical models, such as the Terrestrial Ecosystem Model (TEM, should provide a more adequate quantification of carbon dynamics of terrestrial ecosystems. Here we use Moderate Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Index (EVI, Land Surface Water Index (LSWI and carbon flux data of AmeriFlux to conduct such a study. We first modify the gross primary production (GPP modeling in TEM by incorporating EVI and LSWI to account for the effects of the changes of canopy photosynthetic capacity, phenology and water stress. Second, we parameterize and verify the new version of TEM with eddy flux data. We then apply the model to the conterminous United States over the period 2000–2005 at a 0.05° × 0.05° spatial resolution. We find that the new version of TEM made improvement over the previous version and generally captured the expected temporal and spatial patterns of regional carbon dynamics. We estimate that regional GPP is between 7.02 and 7.78 Pg C yr−1 and net primary production (NPP ranges from 3.81 to 4.38 Pg C yr−1 and net ecosystem production (NEP varies within 0.08–0.73 Pg C yr−1 over the period 2000–2005 for the conterminous United States. The uncertainty due to parameterization is 0.34, 0.65 and 0.18 Pg C yr−1 for the regional estimates of GPP, NPP and NEP, respectively. The effects of extreme climate and disturbances such as severe drought in 2002 and destructive Hurricane Katrina in 2005 were captured by the model. Our study provides a new independent and more adequate measure of carbon fluxes for the conterminous United States, which will benefit studies of carbon-climate feedback and facilitate policy-making of carbon management and climate.

  9. Quantification of terrestrial ecosystem carbon dynamics in the conterminous United States combining a process-based biogeochemical model and MODIS and AmeriFlux data

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Min; Zhuang, Qianlai; Cook, D.; Coulter, Richard L.; Pekour, Mikhail S.; Scott, Russell L.; Munger, J. W.; Bible, Ken

    2011-08-31

    Satellite remote sensing provides continuous temporal and spatial information of terrestrial ecosystems. Using these remote sensing data and eddy flux measurements and biogeochemical models, such as the Terrestrial Ecosystem Model (TEM), should provide a more adequate quantification of carbon dynamics of terrestrial ecosystems. Here we use Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI), Land Surface Water Index (LSWI) and carbon flux data of AmeriFlux to conduct such a study. We first modify the gross primary production (GPP) modeling in TEM by incorporating EVI and LSWI to account for the effects of the changes of canopy photosynthetic capacity, phenology and water stress. Second, we parameterize and verify the new version of TEM with eddy flux data. We then apply the model to the conterminous United States over the period 2000-2005 at a 0.05-0.05 spatial resolution. We find that the new version of TEM made improvement over the previous version and generally captured the expected temporal and spatial patterns of regional carbon dynamics. We estimate that regional GPP is between 7.02 and 7.78 PgC yr{sup -1} and net primary production (NPP) ranges from 3.81 to 4.38 Pg Cyr{sup -1} and net ecosystem production (NEP) varies within 0.08- 0.73 PgC yr{sup -1} over the period 2000-2005 for the conterminous United States. The uncertainty due to parameterization is 0.34, 0.65 and 0.18 PgC yr{sup -1} for the regional estimates of GPP, NPP and NEP, respectively. The effects of extreme climate and disturbances such as severe drought in 2002 and destructive Hurricane Katrina in 2005 were captured by the model. Our study provides a new independent and more adequate measure of carbon fluxes for the conterminous United States, which will benefit studies of carbon-climate feedback and facilitate policy-making of carbon management and climate.

  10. Quantification of Terrestrial Ecosystem Carbon Dynamics in the Conterminous United States Combining a Process-Based Biogeochemical Model and MODIS and AmeriFlux data

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Min; Zhuang, Qianlai; Cook, David R.; Coulter, Richard L.; Pekour, Mikhail S.; Scott, Russell L.; Munger, J. W.; Bible, Ken

    2011-09-21

    Satellite remote sensing provides continuous temporal and spatial information of terrestrial 24 ecosystems. Using these remote sensing data and eddy flux measurements and biogeochemical 25 models, such as the Terrestrial Ecosystem Model (TEM), should provide a more adequate 26 quantification of carbon dynamics of terrestrial ecosystems. Here we use Moderate Resolution 27 Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI), Land Surface Water Index 28 (LSWI) and carbon flux data of AmeriFlux to conduct such a study. We first modify the gross primary 29 production (GPP) modeling in TEM by incorporating EVI and LSWI to account for the effects of the 30 changes of canopy photosynthetic capacity, phenology and water stress. Second, we parameterize and 31 verify the new version of TEM with eddy flux data. We then apply the model to the conterminous 32 United States over the period 2000-2005 at a 0.05o ×0.05o spatial resolution. We find that the new 33 version of TEM generally captured the expected temporal and spatial patterns of regional carbon 34 dynamics. We estimate that regional GPP is between 7.02 and 7.78 Pg C yr-1 and net primary 35 production (NPP) ranges from 3.81 to 4.38 Pg C yr-1 and net ecosystem production (NEP) varies 36 within 0.08-0.73 Pg C yr-1 over the period 2000-2005 for the conterminous United States. The 37 uncertainty due to parameterization is 0.34, 0.65 and 0.18 Pg C yr-1 for the regional estimates of GPP, 38 NPP and NEP, respectively. The effects of extreme climate and disturbances such as severe drought in 39 2002 and destructive Hurricane Katrina in 2005 were captured by the model. Our study provides a 40 new independent and more adequate measure of carbon fluxes for the conterminous United States, 41 which will benefit studies of carbon-climate feedback and facilitate policy-making of carbon 42 management and climate.

  11. The Phanerozoic diversification of silica-cycling testate amoebae and its possible links to changes in terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    Daniel J.G. Lahr

    2015-09-01

    Full Text Available The terrestrial cycling of Si is thought to have a large influence on the terrestrial and marine primary production, as well as the coupled biogeochemical cycles of Si and C. Biomineralization of silica is widespread among terrestrial eukaryotes such as plants, soil diatoms, freshwater sponges, silicifying flagellates and testate amoebae. Two major groups of testate (shelled amoebae, arcellinids and euglyphids, produce their own silica particles to construct shells. The two are unrelated phylogenetically and acquired biomineralizing capabilities independently. Hyalosphenids, a group within arcellinids, are predators of euglyphids. We demonstrate that hyalosphenids can construct shells using silica scales mineralized by the euglyphids. Parsimony analyses of the current hyalosphenid phylogeny indicate that the ability to “steal” euglyphid scales is most likely ancestral in hyalosphenids, implying that euglyphids should be older than hyalosphenids. However, exactly when euglyphids arose is uncertain. Current fossil record contains unambiguous euglyphid fossils that are as old as 50 million years, but older fossils are scarce and difficult to interpret. Poor taxon sampling of euglyphids has also prevented the development of molecular clocks. Here, we present a novel molecular clock reconstruction for arcellinids and consider the uncertainties due to various previously used calibration points. The new molecular clock puts the origin of hyalosphenids in the early Carboniferous (∼370 mya. Notably, this estimate coincides with the widespread colonization of land by Si-accumulating plants, suggesting possible links between the evolution of Arcellinid testate amoebae and the expansion of terrestrial habitats rich in organic matter and bioavailable Si.

  12. Do high levels of diffuse and chronic metal pollution in sediments of Rhine and Meuse floodplains affect structure and functioning of terrestrial ecosystems?

    Energy Technology Data Exchange (ETDEWEB)

    Rozema, Jelte [Department of Systems Ecology, Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: jelte.rozema@ecology.falw.vu.nl; Notten, Martje J.M.; Aerts, Rien [Department of Systems Ecology, Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Gestel, Cornelis A.M. van; Hobbelen, Peter H.F. [Department of Animal Ecology, Institute of Ecological Science, Vrije Universiteit, Amsterdam (Netherlands); Hamers, Timo H.M. [Institute for Environmental Studies (IVM), Vrije Universiteit, Amsterdam (Netherlands)

    2008-12-01

    This paper (re)considers the question if chronic and diffuse heavy metal pollution (cadmium, copper, lead and zinc) affects the structure and functioning of terrestrial ecosystems of Biesbosch National Park, the floodplain area of rivers Meuse and Rhine. To reach this aim, we integrated the results of three projects on: 1. the origin, transfer and effects of heavy metals in a soil-plant-snail food chain; 2. the impact of bioavailability on effects of heavy metals on the structure and functioning of detritivorous communities; 3. the risk assessment of heavy metals for an herbivorous and a carnivorous small mammal food chain. Metal pollution levels of the Biesbosch floodplain soils are high. The bioavailability of metals in the soils is low, causing low metal levels in plant leaves. Despite this, metal concentrations in soil dwelling detritivores and in land snails at polluted locations are elevated in comparison to animals from 'non-polluted' reference sites. However, no adverse effects on ecosystem structure (species richness, density, biomass) and functioning (litter decomposition, leaf consumption, reproduction) have been found. Sediment metal pollution may pose a risk to the carnivorous small mammal food chain, in which earthworms with elevated metal concentrations are eaten by the common shrew. Additional measurements near an active metal smelter, however, show reduced leaf consumption rates and reduced reproduction by terrestrial snails, reflecting elevated metal bioavailability at this site. Since future management may also comprise reintroduction of tidal action in the Biesbosch area, changes in metal bioavailability, and as a consequence future ecosystem effects, cannot be excluded.

  13. The rise of fire: Fossil charcoal in late Devonian marine shales as an indicator of expanding terrestrial ecosystems, fire, and atmospheric change

    Science.gov (United States)

    Rimmer, Susan M.; Hawkins, Sarah J.; Scott, Andrew C.; Cressler, Walter L.

    2015-01-01

    Fossil charcoal provides direct evidence for fire events that, in turn, have implications for the evolution of both terrestrial ecosystems and the atmosphere. Most of the ancient charcoal record is known from terrestrial or nearshore environments and indicates the earliest occurrences of fire in the Late Silurian. However, despite the rise in available fuel through the Devonian as vascular land plants became larger and trees and forests evolved, charcoal occurrences are very sparse until the Early Mississippian where extensive charcoal suggests well-established fire systems. We present data from the latest Devonian and Early Mississippian of North America from terrestrial and marine rocks indicating that fire became more widespread and significant at this time. This increase may be a function of rising O2 levels and the occurrence of fire itself may have contributed to this rise through positive feedback. Recent atmospheric modeling suggests an O2 low during the Middle Devonian (around 17.5%), with O2 rising steadily through the Late Devonian and Early Mississippian (to 21–22%) that allowed for widespread burning for the first time. In Devonian-Mississippian marine black shales, fossil charcoal (inertinite) steadily increases up-section suggesting the rise of widespread fire systems. There is a concomitant increase in the amount of vitrinite (preserved woody and other plant tissues) that also suggests increased sources of terrestrial organic matter. Even as end Devonian glaciation was experienced, fossil charcoal continued to be a source of organic matter being introduced into the Devonian oceans. Scanning electron and reflectance microscopy of charcoal from Late Devonian terrestrial sites indicate that the fires were moderately hot (typically 500–600 °C) and burnt mainly surface vegetation dominated by herbaceous zygopterid ferns and lycopsids, rather than being produced by forest crown fires. The occurrence and relative abundance of fossil charcoal in

  14. Abundance, biomass production, nutrient content, and the possible role of terrestrial salamanders in Missouri Ozark forest ecosystems

    Science.gov (United States)

    R.D. Semlitsch; K.M. O' Donnell; F.R. Thompson

    2014-01-01

    The transfer of energy and nutrients largely depends on the role of animals in the movement of biomass between trophic levels and ecosystems. Despite the historical recognition that amphibians could play an important role in the movement of biomass and nutrients, very few studies have provided reliable estimates of abundance and density of amphibians to reveal their...

  15. Animal Thermoregulation and the Operative Environmental (Equivalent) Temperature. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Process.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Thermoregulation is defined as the ability of an organism to modify its body temperature. This…

  16. Vertical structure and pH as factors for chitinolytic and pectinolytic microbial community of soils and terrestrial ecosystems of different climatic zones

    Science.gov (United States)

    Lukacheva, Evgeniya; Natalia, Manucharova

    2016-04-01

    Chitin is a naturally occurring fibre-forming polymer that plays a protective role in many lower animals similar to that of cellulose in plants. Also it's a compound of cell walls of fungi. Chemically it is a long-chain unbranched polysaccharide made of N-acetylglucosamine residues; it is the second most abundant organic compound in nature, after cellulose. Pectin is a structural heteropolysaccharide contained in the primary cell walls of terrestrial plants. Roots of the plants and root crops contain pectin. Chitin and pectin are widely distributed throughout the natural world. Structural and functional features of the complex microbial degradation of biopolymers one of the most important direction in microbial ecology. But there is no a lot of data concerns degradation in vertical structure of terrestrial ecosystems and detailed studies concerning certain abiotic features as pH. Microbial complexes of natural areas were analyzed only as humus horizons (A1) of the soil profile. Only small part of microbial community could be studied with this approach. It is known that ecosystems have their own structure. It is possible to allocate some vertical tiers: phylloplane, litter (soil covering), soil. We investigated chitinolytic and pectinolytic microbial communities dedicated to different layers of the ecosystems. Also it was described depending on pH dominated in certain ecosystem with certain conditions. Quantity of eukaryote and procaryote organisms increased in the test samples with chitin and pectin. Increasing of eukaryote in samples with pectin was more then in samples with chitin. Also should be noted the significant increasing of actinomycet's quantity in the samples with chitin in comparison with samples with pectin. The variety and abundance of bacteria in the litter samples increased an order of magnitude as compared to other probes. Further prokaryote community was investigated by method FISH (fluorescence in situ hybridization). FISH is a cytogenetic

  17. Radioecology of natural systems in Colordao. Fourteenth annual progress report, May 1, 1975--July 31, 1976. [Pu diffusion in terrestrial ecosystems at Rocky Flats Plant

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, F.W.

    1976-08-01

    This report summarizes project activities during the period May 1, 1975 through July 31, 1976. The major study on the distribution and levels of Pu in major components of the terrestrial ecosystem at Rocky Flats was completed. Supportive studies on the ecology and pathology of small mammals and their role in Pu transport were essentially completed as well. Detailed studies on mule deer food habits, population dynamics, and movements at Rocky Flats are progressing. These studies are designed to measure the potential of mule deer in transporting Pu to uncontrolled areas. Alpha autoradiographic studies designed to measure Pu particle size and distribution and spatial patterns in soil were initiated. Field and greenhouse transport pathways from soil to vegetation are in progress and some early results reported. The status of studies on seasonal kinetics of Cs in a montane lake and stable lead geochemistry in an alpine lake watershed are also reported.

  18. EcoDoses improving radiological assessment of doses to man from terrestrial ecosystems. A status report for the NKS-B project 2003

    Energy Technology Data Exchange (ETDEWEB)

    Bergan, T. [Lavrans Skuterud, Haevard Thoerring (Norway); Liland, A. [Norwegian Radiation Protection Authority (NRPA) (Denmark)] (eds.)

    2004-05-01

    The NKS B-programme EcoDoses project started in 2003 as a collaboration between all the Nordic countries. The aim of the project is to improve the radiological assessments of doses to man from terrestrial ecosystems. The first part, conducted in 2003, has focussed on an extensive collation and review of both published and unpublished data from all the Nordic countries for the nuclear weapons fallout period and the post-Chemobyl period. This included data on radionuclides in air filters, precipitation, soil samples, milk and reindeer. Based on this, an improved model for estimating radioactive fallout based on precipitation data during the nuclear weapons fallout period has been developed. Effective ecological half- lives for 137Cs and 90Sr in milk have been calculated for the nuclear weapons fallout period. For reindeer the ecological half- lives for 137Cs have been calculated for both the nuclear weapons fallout period and the post-Chemobyl period. The data were also used to compare modelling results with observed concentrations. This was done at a workshop where the radioecological food-and-dose module in the ARGOS decision support system was used to predict transfer of deposited radionuclides to foodstuffs and subsequent radiation doses to man. The work conducted the first year is presented in this report and gives interesting, new results relevant for terrestrial radioecology. (au)

  19. Characterization of field margins in intensified agro-ecosystems-why narrow margins should matter in terrestrial pesticide risk assessment and management.

    Science.gov (United States)

    Hahn, Melanie; Lenhardt, Patrick P; Brühl, Carsten A

    2014-07-01

    Field margins are important seminatural habitats in agro-ecosystems, but they can be negatively affected by pesticide inputs via direct overspray and spray drift. In Germany, risk mitigation measures (like buffer zones) to reduce pesticide inputs in terrestrial noncrop habitats do not have to be put in place by farmers next to narrow field margins (Hedgerows were only occasionally recorded. Hence, narrow grassy field margins can represent a large part of the available seminatural habitats adjoining agricultural sites and potentially act as corridors between further habitat patches. For this reason, these margins should be protected from pesticide inputs, at least in landscapes under intensive agricultural use. Field margins are also the main, so-called nontarget habitat protected by the terrestrial risk assessment for plants and arthropods. With many (narrow) margins not considered relevant for risk management, the current practice for protecting the biodiversity from negative effects of pesticides seems questionable. More data on field margin constitution in Germany and other European countries is necessary to critically assess the current practice of pesticide risk assessment and management on a larger scale. © 2014 SETAC.

  20. Mapping of critical loads of acidity for the Italian terrestrial ecosystems; Mappa dei carichi critici di acidita' totale riferita al territorio italiano

    Energy Technology Data Exchange (ETDEWEB)

    Bonanni, P.; Brini, S.; Delmonaco, G.; Liburdi, C.; Trocciola, A.; Vetrella, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1999-07-01

    In this report the mapping of critical loads of acidity for the Italian terrestrial ecosystems is presented. The level 0 method (Stockholm Environment Institute) has been used to determine sensitivity to acid deposition; this semi-quantitative method has been modified to address some Italian characteristics. The sensitivity of the Italian soils to acidification is not particularly elevated: there are really only few small areas with poor tolerance to acid depositions in the north-east Italy, Alpine and Prealpine region. [Italian] Nel presente relazione vengono riportati i risultati della mappatura riferita ad ecosistemi terrestri del territorio italiano, dei carichi critici per l'acidita' totale. Il calcolo dei carichi e' stato eseguito sulla base della metodologia messa a punto dallo Stockholm Environment Institute con alcune modifiche per adattarlo meglio alle caratteristiche del territorio italiano. Si dimostra che la sensibilita' dei suoli italiani all'acidificazione non sia particolarmente elevata: sono state riscontrate infatti solo alcune aree, peraltro con superficie limitata, con una scarsa tolleranza alle deposizioni acide nelle zone del Nord Est, in zona alpina e prealpina.

  1. Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. Implications for the structure of Paleocene terrestrial ecosystems

    Science.gov (United States)

    Angst, D.; Lécuyer, C.; Amiot, R.; Buffetaut, E.; Fourel, F.; Martineau, F.; Legendre, S.; Abourachid, A.; Herrel, A.

    2014-04-01

    The mode of life of the early Tertiary giant bird Gastornis has long been a matter of controversy. Although it has often been reconstructed as an apex predator feeding on small mammals, according to other interpretations, it was in fact a large herbivore. To determine the diet of this bird, we analyze here the carbon isotope composition of the bone apatite from Gastornis and contemporaneous herbivorous mammals. Based on 13C-enrichment measured between carbonate and diet of carnivorous and herbivorous modern birds, the carbonate δ13C values of Gastornis bone remains, recovered from four Paleocene and Eocene French localities, indicate that this bird fed on plants. This is confirmed by a morphofunctional study showing that the reconstructed jaw musculature of Gastornis was similar to that of living herbivorous birds and unlike that of carnivorous forms. The herbivorous Gastornis was the largest terrestrial tetrapod in the Paleocene biota of Europe, unlike the situation in North America and Asia, where Gastornis is first recorded in the early Eocene, and the largest Paleocene animals were herbivorous mammals. The structure of the Paleocene terrestrial ecosystems of Europe may have been similar to that of some large islands, notably Madagascar, prior to the arrival of humans.

  2. Increased light-use efficiency in northern terrestrial ecosystems indicated by CO 2 and greening observations: INCREASE IN NH LIGHT USE EFFICIENCY

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Rebecca T. [Science and Solutions for a Changing Planet DTP, Imperial College London, London UK; AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, London UK; Department of Physics, Imperial College London, London UK; Prentice, Iain Colin [AXA Chair Programme in Biosphere and Climate Impacts, Department of Life Sciences, Imperial College London, London UK; Grantham Institute: Climate Change and the Environment, Imperial College London, London UK; Graven, Heather [Department of Physics, Imperial College London, London UK; Grantham Institute: Climate Change and the Environment, Imperial College London, London UK; Ciais, Philippe [Laboratoire des Sciences du Climat et de l' Environnement, Saint-Aubin France; Fisher, Joshua B. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Hayes, Daniel J. [School of Forest Resources, University of Maine, Orono Maine USA; Huang, Maoyi [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Huntzinger, Deborah N. [School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff Arizona USA; Ito, Akihiko [Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba Japan; Jain, Atul [Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana Illinois USA; Mao, Jiafu [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Michalak, Anna M. [Department of Global Ecology, Carnegie Institution for Science, Stanford California USA; Peng, Shushi [Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing China; Poulter, Benjamin [Department of Ecology, Montana State University, Bozeman Montana USA; Ricciuto, Daniel M. [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Shi, Xiaoying [Climate Change Science Institute and Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee USA; Schwalm, Christopher [Woods Hole Research Center, Falmouth Massachusetts USA; Tian, Hanqin [International Center for Climate and Global Change Research, School of Forestry and Wildlife Sciences, Auburn University, Auburn Alabama USA; Zeng, Ning [Department of Atmospheric and Oceanic Science and Earth System Science Interdisciplinary Center, University of Maryland, College Park Maryland USA

    2016-11-04

    Observations show an increasing amplitude in the seasonal cycle of CO2 (ASC) north of 45°N of 56 ± 9.8% over the last 50 years and an increase in vegetation greenness of 7.5–15% in high northern latitudes since the 1980s. However, the causes of these changes remain uncertain. Historical simulations from terrestrial biosphere models in the Multiscale Synthesis and Terrestrial Model Intercomparison Project are compared to the ASC and greenness observations, using the TM3 atmospheric transport model to translate surface fluxes into CO2 concentrations. We find that the modeled change in ASC is too small but the mean greening trend is generally captured. Modeled increases in greenness are primarily driven by warming, whereas ASC changes are primarily driven by increasing CO2. We suggest that increases in ecosystem-scale light use efficiency (LUE) have contributed to the observed ASC increase but are underestimated by current models. We highlight potential mechanisms that could increase modeled LUE.

  3. Assessment of regional-scale primary production in terrestrial ecosystems to estimate the possible influence of future climate change on biodiversity

    Science.gov (United States)

    Noda, Hibiki; Nishina, Kazuya; Ito, Akihiko

    2015-04-01

    In recent decades, climate change including global warming has progressed worldwide and their influences on ecosystem structure and function that provide various goods and services to humans' well-being are of the greatest concerns. The ecosystem function and services are tightly coupled with the biodiversity particularly via food web and biogeochemical cycles, and here carbon is one of the central elements that also affect atmospheric CO2 concentration. Therefore mechanistic and quantitative understandings of the consequences among on-going climate change, ecosystem function, and biodiversity are urgent issues for seeking a better adaptation strategy. In order to tackle such tasks in the current environmental and ecological sciences, efforts have been made by numerous scientists and/or organizations to clarify the current status of and threats to biodiversity, responses of biogeochemical cycles to meteorological variables, and to construct climate change scenarios considering economic activities. However, to gain insights into the possible influence of climate change on biodiversity via altered ecosystem functions over broad temporal and spatial scales ranging from past to near-future periods and from landscape to global scales, further efforts to find the consequences are required, since the assessment of the influence of climate change on biodiversity is straightforward but difficult. For decades in climate change science, carbon flux between the atmosphere and terrestrial ecosystems has attracted intensive attention as it connects the atmosphere and biosphere. Carbon flux in the biosphere is not only a process of biogeochemical material flux but also is an element to drive biological and ecological processes in ecosystems via food web beginning from photosynthetic carbon fixation by plants. Therefore focusing on photosynthetic production by plants, i.e. primary production of the ecosystem, may help us to estimate the possible influence of climate change on

  4. Using the Terrestrial Observation and Prediction System (TOPS) to Analyze Impacts of Climate Change on Ecosystems within Northern California Climate Regions

    Science.gov (United States)

    Pitts, K.; Little, M.; Loewenstein, M.; Iraci, L. T.; Milesi, C.; Schmidt, C.; Skiles, J. W.

    2011-12-01

    The projected impacts of climate change on Northern California ecosystems using model outputs from the Terrestrial Observation and Prediction System (TOPS) for the period 1950-2099 based on 1km downscaled climate data from the Geophysical Fluid Dynamics Laboratory (GFDL) model are analyzed in this study. The impacts are analyzed for the Special Report Emissions Scenarios (SRES) A1B and A2, both maintaining present levels of urbanization constant and under projected urban expansion. The analysis is in support of the Climate Adaptation Science Investigation at NASA Ames Research Center. A statistical analysis is completed for time series of temperature, precipitation, gross primary productivity (GPP), evapotranspiration, soil runoff, and vapor pressure deficit. Trends produced from this analysis show that increases in maximum and minimum temperatures lead to declines in peak GPP, length of growing seasons, and overall declines in runoff within the watershed. For Northern California, GPP is projected under the A2 scenario to decrease by 18-25% by the 2090 decade as compared to the 2000 decade. These trends indicate a higher risk to crop production and other ecosystem services, as conditions would be less hospitable to vegetation growth. The increase in dried out vegetation would then lead to a higher risk of wildfire and mudslides in the mountainous regions.

  5. Source-pathway-receptor investigation of the fate of trace elements derived from shotgun pellets discharged in terrestrial ecosystems managed for game shooting

    Energy Technology Data Exchange (ETDEWEB)

    Sneddon, Jennifer [School of Natural Sciences and Psychology, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom); Clemente, Rafael, E-mail: rclemente@cebas.csic.e [School of Natural Sciences and Psychology, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom); Riby, Philip [School of Pharmacy and Chemistry, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); Lepp, Nicholas W., E-mail: n.w.lepp@ljmu.ac.u [School of Natural Sciences and Psychology, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom)

    2009-10-15

    Spent shotgun pellets may contaminate terrestrial ecosystems. We examined the fate of elements originating from shotgun pellets in pasture and woodland ecosystems. Two source-receptor pathways: i) soil-soil pore water-plant and ii) whole earthworm/worm gut contents - washed and unwashed small mammal hair were investigated. Concentrations of Pb and associated contaminants were higher in soils from shot areas than controls. Arsenic and lead concentrations were positively correlated in soils, soil pore water and associated biota. Element concentrations in biota were below statutory levels in all locations. Bioavailability of lead to small mammals, based on concentrations in washed body hair was low. Lead movement from soil water to higher trophic levels was minor compared to lead adsorbed onto body surfaces. Lead was concentrated in earthworm gut and some plants. Results indicate that managed game shooting presents minimal risk in terms of element transfer to soils and their associated biota. - Source-receptor pathway analysis of a managed game shooting site showed no environmental risk of trace element transfer.

  6. The relative roles of climate and land use in the degradation of a terrestrial ecosystem: a case study from Kjarardalur, West Iceland

    Science.gov (United States)

    Erlendsson, Egill; Gísladóttir, Guðrún

    2016-04-01

    Around AD 870 the virgin environment of Iceland became populated by humans and mammal land herbivores. Since then, the island has lost nearly all of its native birch woodland, resulting in dramatic degradation of landscapes and ecosystems, attributed mainly to over-exploitation of woodlands and late-medieval climate deterioration. As part of policy making in agriculture, a heated debate is ongoing over limitations to sheep grazing in pastures suffering from long-term degradation. In this context the history of climate and land use is of great importance. Those who consider grazing a minimal attribute to land degradation argue that the harsh climate conditions of the little ice age are the primary mechanism behind the current degraded landscape. Others err on the side of caution and propose a careful approach to grazing. This study forms a contribution to the historical context of the impact of grazing upon the Icelandic terrestrial ecosystem. Using the analyses of pollen and spores from coprophilous fungi as principal methods, we present data about historical environmental change from within two different land holdings in Kjarardalur Valley, West Iceland. One dataset comes from within a landholding governed by the chieftain farm Reykholt, the other comes from within the land of the indipendent farm, Norðtunga. In the past the valley was used primarily as a pasture, associated with shielings (organised seasonal grazing). Pollen data from the pasture in Kjarardalur Valley, West Iceland, demonstrate a rapid loss of birch (Betula pubescens) woodland from grazing areas owned by the major farm and institution, Reykholt. The suppressive nature of grazing is demonstrated by the expansion of woodland as soon when animal stocks are reduced, probably as a consequence of the bubonic plague after AD 1402. Resumed exploitation of resources eventually depleted all birch woodland from the Reykholt landholding and precipitated soil erosion. The trajectory of environmental change

  7. Description, calibration and sensitivity analysis of the local ecosystem submodel of a global model of carbon and nitrogen cycling and the water balance in the terrestrial biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kercher, J.R. [Lawrence Livermore National Lab., CA (United States); Chambers, J.Q. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Santa Barbara, CA (United States). Dept. of Biological Sciences

    1995-10-01

    We have developed a geographically-distributed ecosystem model for the carbon, nitrogen, and water dynamics of the terrestrial biosphere TERRA. The local ecosystem model of TERRA consists of coupled, modified versions of TEM and DAYTRANS. The ecosystem model in each grid cell calculates water fluxes of evaporation, transpiration, and runoff; carbon fluxes of gross primary productivity, litterfall, and plant and soil respiration; and nitrogen fluxes of vegetation uptake, litterfall, mineralization, immobilization, and system loss. The state variables are soil water content; carbon in live vegetation; carbon in soil; nitrogen in live vegetation; organic nitrogen in soil and fitter; available inorganic nitrogen aggregating nitrites, nitrates, and ammonia; and a variable for allocation. Carbon and nitrogen dynamics are calibrated to specific sites in 17 vegetation types. Eight parameters are determined during calibration for each of the 17 vegetation types. At calibration, the annual average values of carbon in vegetation C, show site differences that derive from the vegetation-type specific parameters and intersite variation in climate and soils. From calibration, we recover the average C{sub v} of forests, woodlands, savannas, grasslands, shrublands, and tundra that were used to develop the model initially. The timing of the phases of the annual variation is driven by temperature and light in the high latitude and moist temperate zones. The dry temperate zones are driven by temperature, precipitation, and light. In the tropics, precipitation is the key variable in annual variation. The seasonal responses are even more clearly demonstrated in net primary production and show the same controlling factors.

  8. Final Report on "Rising CO2 and Long-term Carbon Storage in Terrestrial Ecosystems: An Empirical Carbon Budget Validation"

    Energy Technology Data Exchange (ETDEWEB)

    J. Patrick Megonigal; Bert G. Drake

    2010-08-27

    The primary goal of this report is to report the results of Grant DE-FG02-97ER62458, which began in 1997 as Grant DOE-98-59-MP-4 funded through the TECO program. However, this project has a longer history because DOE also funded this study from its inception in 1985 through 1997. The original grant was focused on plant responses to elevated CO2 in an intact ecosystem, while the latter grant was focused on belowground responses. Here we summarize the major findings across the 25 years this study has operated, and note that the experiment will continue to run through 2020 with NSF support. The major conclusions of the study to date are: (1 Elevated CO2 stimulated plant productivity in the C3 plant community by ~30% during the 25 year study. The magnitude of the increase in productivity varied interannually and was sometime absent altogether. There is some evidence of down-regulation at the ecosystem level across the 25 year record that may be due to interactions with other factors such as sea-level rise or long-term changes in N supply; (2) Elevated CO2 stimulated C4 productivity by <10%, perhaps due to more efficient water use, but C3 plants at elevated CO2 did not displace C4 plants as predicted; (3) Increased primary production caused a general stimulation of microbial processes, but there were both increases and decreases in activity depending on the specific organisms considered. An increase in methanogenesis and methane emissions implies elevated CO2 may amplify radiative forcing in the case of wetland ecosystems; (4) Elevated CO2 stimulated soil carbon sequestration in the form of an increase in elevation. The increase in elevation is 50-100% of the increase in net ecosystem production caused by elevated CO2 (still under analysis). The increase in soil elevation suggests the elevated CO2 may have a positive outcome for the ability of coastal wetlands to persist despite accelerated sea level rise; (5) Crossing elevated CO2 with elevated N causes the elevated CO

  9. Component modeling in ecological risk assessment: Disturbance in interspecific interactions caused by air toxics introduced into terrestrial ecosystems

    Science.gov (United States)

    Swider, Jan Zenon

    The human health risk assessment (HRA), initiated by the onset of nuclear industry, has been a well established methodology for assessing the impacts of human created contamination on an individual human being and entire population. The wide spread of applications and tools grown upon this methodology allows one not only to identify the hazards, but also to manage the risks. Recently, there has existed an increased awareness of the need to conduct ecological risk assessments (ERA) in addition to HRAs. The ERAs are, by and large, more complex than typical HRAs and involve not only different species but whole ecological systems. Such complex analyses require a thorough understanding of the processes underway in the ecosystem, including the contaminant transport through the food web, population dynamics as well as intra- and inter-specific relationships. The exposure pathways change radically depending on the consumer tier. Plants produce their nutriment from the sunlight and raw inorganic compounds. Animals and other living forms obtain energy by eating plants, other animals and detritus. Their double role as food consumers and food producers causes a trophic structure of the ecological system, where nutrients and energy are transferred from one trophic level to another. This is a dynamic process of energy flow, mostly in the form of food, varying with time and space. In order to conduct an efficient ERA, a multidisciplinary framework is needed. This framework can be enhanced by analyzing predator-prey interactions during the environmental disturbances caused by a pollutant emission, and by assessing the consequences of such disturbances. It is necessary to develop a way to describe how human industrial activity affects the ecosystems. Existing ecological studies have mostly been focused either on pure ecological interdependencies or on limited perspectives of human activities. In this study, we discuss the issues of air pollution and its ecological impacts from the

  10. Field calibration of soil-core microcosms for evaluating fate and effects of genetically engineered microorganisms in terrestrial ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, H Jr; Fredrickson, J K; Bentjen, S A; Workman, D J; Li, S W; Thomas, J M

    1991-04-01

    Pacific Northwest Laboratory compared intact soil-core microcosms and the field for ecosystem structural and functional properties after the introduction of a model genetically engineered microorganism (GEM). This project used two distinct microbial types as model GEMs, Gram-negative Pseudomonas sp. RC1, which was an aggressive root colonizer, and Gram-positive Streptomyces lividans TK24. The model GEMs were added to surface soil in separate studies, with RC1 studied throughout the growth of winter wheat (Triticum aestivum), while TK24 was studied throughout a ten month period. Also, RC1 was used in studies conducted during two consecutive field seasons (1988 to 1990) to determine how year-to-year field variability influenced the calibration of microcosms with the field. The main conclusions of this research were that intact soil-core microcosms can be useful to simulate the field for studies of microbial fate and effects on ecosystem structural and functional properties. In general, microcosms in the growth chamber, which simulated average field variations, were similar to the field for most parameters or differences could be attributed to the great extremes in temperature that occurred in the field compared to the microcosms. Better controls of environmental variables including temperature and moisture will be necessary to more closely simulate the field for future use of microcosms for risk assessment. 126 refs., 13 figs., 12 tabs.

  11. Characteristic of pollution with groundwater inflow (90)Sr natural waters and terrestrial ecosystems near a radioactive waste storage.

    Science.gov (United States)

    Lavrentyeva, G V

    2014-09-01

    The studies were conducted in the territory contaminated by (90)Sr with groundwater inflow as a result of leakage from the near-surface trench-type radioactive waste storage. The vertical soil (90)Sr distribution up to the depth of 2-3 m is analyzed. The area of radioactive contamination to be calculated with a value which exceeds the minimum significant activity 1 kBq/kg for the tested soil layers: the contaminated area for the 0-5 cm soil layer amounted to 1800 ± 85 m(2), for the 5-10 cm soil layer amounted to 300 ± 12 m(2), for the 10-15 cm soil layer amounted to 180 ± 10 m(2). It is found that (90)Sr accumulation proceeds in a natural sorption geochemical barrier of the marshy terrace near flood plain. The exposure doses for terrestrial mollusks Bradybaena fruticum are presented. The excess (90)Sr interference level was registered both in the ground and surface water during winter and summer low-water periods and autumn heavy rains. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Neoarchean paleoweathering of tonalite and metabasalt: Implications for reconstructions of 2.69Ga early terrestrial ecosystems and paleoatmospheric chemistry

    Science.gov (United States)

    Driese, S.G.; Jirsa, M.A.; Ren, M.; Brantley, S.L.; Sheldon, N.D.; Parker, Dana C.; Schmitz, M.

    2011-01-01

    primitive microbial community) during weathering. Cu metal in the profile may document lower pO2 than present day at the surface. Comparison with previous studies of weathered tonalite and basalt (Denison, 2.45-2.22Ga) in Ontario, Canada, reveal general similarities in paleoweathering with our study, as well as important differences related to lower paleoatmospheric pO2 and terrestrial biosignature for the older Minnesota profile. A falling water table in the Alpine Lake locality is presumed to have promoted formation of this gossan-like deep-weathering system that extends to 50-m depth. ?? 2011 Elsevier B.V.

  13. Biodiversity, Community and Trophic Structure of the Suprabenthos of the Gulf of Cádiz-Guadalquivir Estuary Coupled System: Linking Pelagic-Benthic and Terrestrial-Marine Ecosystems.

    Science.gov (United States)

    Vilas, C.

    2016-02-01

    Suprabenthos biodiversity and species densities on both offshore and coastal systems are largely unknown. Main components like mysids, euphasiids or amphipods are omnivorous and constitute a major dietary component for many benthic and pelagic fishes, mammals, cephalopods and decapods. Despite their relevant ecological role linking pelagic-benthic food webs, suprabenthos have been chronically undersampled and their components underrepresented and underestimated in food web models. Many pelagic and demersal species of high commercial and ecological interest at the Gulf of Cádiz (GoC) feed at a bottom scattering layer identified from 0 to 200 m depth and up to 50 km from coast, related to the Guadalquivir Estuary (GE) influence coastal area, and present life history cycles based on a sequential use of habitats from GoC to GE nursery area, may be adapted to match the horizontal migrations of key suprabenthos prey species. In order to understand the ecological mechanisms through which the GE-GoC coupled ecosystem would influence the recruitment of these fishery resources, the suprabenthos was sampled by suprabenthic sldege (200 μm) from the shallow estuary to 75 m depth during June, August and November of 2013. We identified up to 300 species (H index 0.4-2-9 and Beta diversity 0.55), being copepods, molluscs, cumacea, cladocera, poliquets, decapods, mysids and amphipods the most important groups by biomass (mg/m3), finding densities up to 32.9 mg/m3 for copepods, 6 for mysids and up to 100 mg/m3 for decapods. Multivariate analysis determines depth as the most important variable explaining community structure, decreasing biodiversity with depth, while for sites at depths < 30 m the community changes seasonal. Fatty acid analysis of different group sizes is revealing interesting trophic links. Some prey copepods and mysid species show seasonal horizontal migrations between GoC and GE, connecting terrestrial and marine ecosystems.

  14. Introduction - The impacts of the 2008 eruption of Kasatochi Volcano on terrestrial and marine ecosystems in the Aleutian Islands, Alaska

    Science.gov (United States)

    DeGange, Anthony R.; Byrd, G. Vernon; Walker, Lawrence R.; Waythomas, C.F.

    2010-01-01

    The Aleutian Islands are situated on the northern edge of the so-called “Pacific Ring of Fire,” a 40,000-km-long horseshoe-shaped assemblage of continental landmasses and islands bordering the Pacific Ocean basin that contains many of the world's active and dormant volcanoes. Schaefer et al. (2009) listed 27 historically active volcanoes in the Aleutian Islands, of which nine have had at least one major eruptive event since 1990. Volcanic eruptions are often significant natural disturbances, and ecosystem responses to volcanic eruptions may vary markedly with eruption style (effusive versus explosive), frequency, and magnitude of the eruption as well as isolation of the disturbed sites from potential colonizing organisms (del Moral and Grishin, 1999). Despite the relatively high frequency of volcanic activity in the Aleutians, the response of island ecosystems to volcanic disturbances is largely unstudied because of the region's isolation. The only ecological studies in the region that address the effects of volcanic activity were done on Bogoslof Island, a remote, highly active volcanic island in the eastern Aleutians, which grew from a submarine eruption in 1796 (Merriam, 1910; Byrd et al., 1980; Byrd and Williams, 1994). Nevertheless, in the 214 years of Bogoslof's existence, the island has been visited only intermittently.Kasatochi Island is a small (2.9 km by 2.6 km, 314 m high) volcano in the central Aleutian Islands of Alaska (52.17°N latitude, 175.51°W longitude; Fig. 1) that erupted violently on 7-8 August 2008 after a brief, but intense period of precursory seismic activity (Scott et al., 2010 [this issue]; Waythomas et al., in review). The island is part of the Aleutian arc volcanic front, and is an isolated singular island. Although the immediate offshore areas are relatively shallow (20–50 m water depth), the island is about 10 km south of the 2000 m isobath, north of which, ocean depths increase markedly. Kasatochi is located between the

  15. Temperature and Snow-Mediated Moisture Controls of Summer Photosynthetic Activity in Northern Terrestrial Ecosystems between 1982 and 2011

    Directory of Open Access Journals (Sweden)

    Jonathan Barichivich

    2014-02-01

    ecosystem responses to the projected warming and increase in evapotranspiration demand during the coming decades.

  16. Carbon isotopic record of terrestrial ecosystems spanning the Late Miocene extinction of Oreopithecus bambolii, Baccinello Basin (Tuscany, Italy).

    Science.gov (United States)

    Matson, Samuel D; Rook, Lorenzo; Oms, Oriol; Fox, David L

    2012-07-01

    Oreopithecus bambolii is a Late Miocene hominoid with an extensive fossil record in the Baccinello Basin (Tuscany, Italy), and was the only western European hominoid to survive a major extinction event ca. 9.6 Ma (millions of years ago). Oreopithecus lived in the insular Tusco-Sardinian paleobioprovince, where it evolved many unique anatomical specializations that make it important for understanding the mechanisms and history of Late Miocene hominoid evolution. The eventual extinction of Oreopithecus and its associated fauna ca. 6.5 Ma has generally been attributed to interaction with species that arrived from continental Europe following tectonic collision of the Tusco-Sardinian province with mainland Italy, but palynological, paleontological, and sedimentological records indicate an environmental shift toward more variable climate across the extinction event. To explore the possibility of environmental change as a contributing factor in the extinction of Oreopithecus, we developed a stable carbon and oxygen isotope record from organic matter in paleosols from the Baccinello Basin. These data show very low temporal and spatial variability (indicating plant ecosystem stability through time and space) and provide no evidence for ecologically significant changes in floral composition spanning the extinction event, suggesting that environmental change was not an underlying cause for the extinction of Oreopithecus and its associated fauna. The carbon isotope values fall entirely within the range of isotopic variability for modern plants following the C(3) photosynthetic pathway (trees, shrubs, cool-season grasses), indicating that C(4) vegetation (warm-season grasses) was not an important component of biomass. When corrected for temporal variation in the carbon isotopic composition of atmospheric carbon dioxide, the paleosol carbon isotope values are consistent with predicted values based on modern plants and the Baccinello palynoflora, supporting the reliability of

  17. Effects of modified UV-B radiation on terrestrial ecosystems; Auswirkungen veraenderter UV-B-Strahlung auf terrestrische Oekosysteme

    Energy Technology Data Exchange (ETDEWEB)

    Tevini, M. [Karlsruhe Univ. (T.H.) (Germany). Botanisches Inst. 2

    1994-10-01

    The author describes the effects of anthropogenically modified UV-B radiation on plants and aquatic ecosystems. The modified radiation may cause reduced growth of leaves and shoots, partial reduction of the photosynthesis activity, and reduced biomass production (i.e. a loss of yield). Although the UV damage may be compensated to a certain degree by a synthesis of protective pigments (cinnamonic acids and flavonoids) or by UV repair mechanisms via the enyzme photolyase, the upper limit of this adapability seems to have already been reached. One frequently observed effect of the increase in UV radiation in aquatic systems is the loss of phytoplancton biomass by 6 - 10%.Since phytoplancton is the basis of the marine food chain, this may have long-term effects on the number and distribution of species and on fish protein for the human diet. Further, the loss of biomass causes a reduction of carbon dioxide fixation, which may have consequences for the global carbon cycle. (orig.) [Deutsch] Der Autor beschreibt die Auswirkungen anthropogen veraenderter UV-B-Strahlung auf Pflanzen und aquatische Oekosysteme. Durch die veraenderte Strahlung kann es zu vermindertem Blatt- und Sprosswachstum, zur partiellen Reduktion der Photosyntheseaktivitaet und zu verringerter Biomasseproduktion, d.h. zu einem Ertragsverlust kommen. Die UV-Schaedigung kann zwar durch die Synthese von Schutzpigmenten (Zimtsaeuren und Flavonoide) oder durch UV-Reparaturmechanismen ueber das Enzym Photolyase in gewissem Masse kompensiert werden, die obere Grenze dieser Adaptationsfaehigkeit scheint aber bereits erreicht zu sein. Ein beobachteter Effekt des UV-Strahlungsanstiegs in aquatischen Systemen ist der Verlust der Phytoplankton-Biomasse um 6% - 10%. Da das Phytoplankton die Grundlage der marinen Nahrungskette bildet, sind Rueckwirkungen auf die Artenzusammensetzung und die menschliche Ernaehrung mit Fischprotein moeglich. Weiterhin fuehrt der Verlust an Biomasse zu einer Reduzierung der

  18. Correlations between interannual variations of simulated global and regional CO{sub 2} fluxes from terrestrial ecosystems and El Nino Southern Oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Takao (Disaster Prevention Research Inst., Kyoto Univ., Gokasho (Japan)), e-mail: iguchi@dpac.dpri.kyoto-u.ac.jp

    2011-04-15

    Using a terrestrial ecosystem model (Sim-CYCLE), CO{sub 2} exchange between the biosphere and the atmosphere was simulated for the period of 1980-2000. As a result, the biosphere was totally a sink of CO{sub 2}, and the phase of the interannual variation of the global annual CO{sub 2} flux from the biosphere was similar to that of the annual increase of the global atmospheric CO{sub 2}. The interannual variation of the global annual CO{sub 2} flux showed high correlation with that of the annual mean ENSO index (NINO.3 monitoring index) for a time lag of 1 yr. As for the regional annual carbon fluxes, some showed high correlation with the annual mean ENSO index for a time lag of 1 yr and some without time lag. Among the regional carbon fluxes those showed high correlations with ENSO index without time lag, some showed positive correlations and some showed negative correlations, and they canceled out each other in total. These negative correlations were found in tropical regions. All the regional carbon fluxes those showed high correlations with ENSO index for a time lag of 1 yr showed positive correlations

  19. Application of zonality conceptual model of chronic effects of ionizing radiation for studying the behavior of Sr-90 in terrestrial ecosystems

    Directory of Open Access Journals (Sweden)

    R.R. Shoshina

    2015-12-01

    It was discovered that dose rates of irradiation of molluscs Bradybaena Fruticicola fruticum are within 0.03–1.60 Gy/year. Structuring of experimental data was implemented based on the obtained data on the specific activity of Sr-90 in the system under study in accordance with model by G.G.Polikarpov. Three ecological zones were identified on the experimental site with regular variation of specific activity of Sr-90 in mollusс shells. In the zone of physiological masking concentration of radionuclide in mollusc shells can be by one order of magnitude and even more higher than in the plant. In the zone of ecological masking and the zone of pronounced environmental effects specific activities of the radionuclide are reduced as compared to its concentration in plants by 8 and 40 times, respectively (no decrease of specific activities of the radionuclide in the plant is regisrered. The implemented studies allow formulating the conclusion on the possibility of adaptation of indicators of Sr-90 migration in terrestrial ecosystems.

  20. Depletion of stratospheric ozone over the Antarctic and Arctic: responses of plants of polar terrestrial ecosystems to enhanced UV-B, an overview.

    Science.gov (United States)

    Rozema, Jelte; Boelen, Peter; Blokker, Peter

    2005-10-01

    Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to experimentally varied UV-B through supplementation or exclusion. In supplementation studies comparing ambient and above ambient UV-B, no effect on growth occurred. UV-B-induced DNA damage, as measured in polar bryophytes, is repaired overnight by photoreactivation. With UV exclusion, growth at near ambient may be less than at below ambient UV-B levels, which relates to the UV response curve of polar plants. UV-B screening foils also alter PAR, humidity, and temperature and interactions of UV with environmental factors may occur. Plant phenolics induced by solar UV-B, as in pollen, spores and lignin, may serve as a climate proxy for past UV. Since the Antarctic and Arctic terrestrial ecosystems differ essentially, (e.g. higher species diversity and more trophic interactions in the Arctic), generalization of polar plant responses to UV-B needs caution.

  1. EcoDoses. Improving radiological assessment of doses to man from terrestrial ecosystems. A status report for the NKS-B project 2004

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Sven P.; Isaksson, M.; Nilsson, Elisabeth (and others)

    2005-07-01

    The NKS B-programme EcoDoses project started in 2003 as a collaboration between all the Nordic countries. The aim of the project is to improve the radiological assessments of doses to man from terrestrial ecosystems. The present report sums up the work performed in the second phase of the project. The main topics in 2004 have been: (i) A continuation of previous work with a better approach for estimating global fallout on a regional or national scale, based on a correlation between precipitation and deposition rates. (ii) Fur-ther extension of the EcoDoses milk database. Estimation of effective ecological half lives of {sup 137}Cs in cows milk focussing on suitable post-Chernobyl time-series. Modelling integrated transfer of {sup 13}7{sup C}s to cow's milk from Nordic countries. (iii) Determination of effective ecological half lives for fresh water fish from Nordic lakes. (iv) Investigate ra-dioecological sensitivity for Nordic populations. (v) Food-chain modelling using the Eco-sys-model, which is the underlying food- and dose-module in several computerised deci-sion-making systems. (au)

  2. Ent: A global dynamic terrestrial ecosystem model for climate interactions at seasonal to century time scales through coupled water, carbon, and nitrogen dynamics

    Science.gov (United States)

    Kiang, N. Y.; Koster, R. D.; Moorcroft, P. R.; Ni-Meister, W.; Rind, D. H.; Aleinov, I.; Kharecha, P.

    2006-12-01

    Ent is a dynamic global terrestrial ecosystem model (DGTEM) under development at the NASA GISS for coupling with atmospheric general circulation models (GCMs). Ent will be capable of predicting the fast time scale fluxes of water, carbon, nitrogen and energy between the land-surface and the atmosphere and the resulting diurnal surface fluxes, seasonal and inter-annual vegetation growth, and decadal to century scale alterations in vegetation structure and soil carbon and nitrogen. Canopy radiative transfer, biophysics, biogeochemistry, and ecological dynamics will be integrated in a consistent, prognostic, process-based manner, in a way that is both biologically realistic and computationally efficient, and suitable for two-way coupling and parallel computing in GCMs. Canopy radiative transfer is derived from the Geometric-Optical Radiative Transfer (GORT) model (Ni, et al., JGR, 102(D24): 9,555-29,566, 1997); biophysics combines the dynamic construction/destruction of the photosynthetic apparatus of Kull and Kruijt (Adv. Water Resources Res, 24:745-762, 1998) with stomatal conductance of Ball and Berry (Plant Phys., 77(Suppl. 4):91, 1985); dynamic allocation of plant carbon and nitrogen; CASA soil biogeochemistry with extended soil depth (Potter, et al., GBC, 7(4):811-841); and community dynamics of Moorcroft, et al. (Ecol. Monographs, 71(4):557-586, 2001). The model can be used for both assimilation of satellite data and with the GISS GCM for long-term climate studies. Ent will be a standalone set of modules that can be used by the climate modeling community to couple with land surface models and atmospheric GCMs for studies on seasonal weather evolution, vegetation phenology, the carbon budget, climate variability, paleoclimate, global change, vegetation-climate feedbacks, and astronomical biosignatures. Ent is envisioned as a tool for understanding the conditions and signatures of habitability of the Earth, ancient, modern, and future.

  3. The role of UV-B radiation in aquatic and terrestrial ecosystems--an experimental and functional analysis of the evolution of UV-absorbing compounds.

    Science.gov (United States)

    Rozema, J; Björn, L O; Bornman, J F; Gaberscik, A; Häder, D-P; Trost, T; Germ, M; Klisch, M; Gröniger, A; Sinha, R P; Lebert, M; He, Y-Y; Buffoni-Hall, R; de Bakker, N V J; van de Staaij, J; Meijkamp, B B

    2002-02-01

    We analysed and compared the functioning of UV-B screening pigments in plants from marine, fresh water and terrestrial ecosystems, along the evolutionary line of cyanobacteria, unicellular algae, primitive multicellular algae, charophycean algae, lichens, mosses and higher plants, including amphibious macrophytes. Lichens were also included in the study. We were interested in the following key aspects: (a) does the water column function effectively as an 'external UV-B filter'?; (b) do aquatic plants need less 'internal UV-B screening' than terrestrial plants?; (c) what role does UV screening play in protecting the various plant groups from UV-B damage, such as the formation of thymine dimers?; and (d) since early land 'plants' (such as the predecessors of present-day cyanobacteria, lichens and mosses) experienced higher UV-B fluxes than higher plants, which evolved later, are primitive aquatic and land organisms (cyanobacteria, algae, lichens, mosses) better adapted to present-day levels of UV-B than higher plants? Furthermore, polychromatic action spectra for the induction of UV screening pigments of aquatic organisms have been determined. This is relevant for translating 'physical' radiation measurements of solar UV-B into 'biological' and 'ecological' effects. From the action spectra, radiation amplification factors (RAFs) have been calculated. These action spectra allow us to determine any mitigating or antagonistic effects in the ecosystems and therefore qualify the damage prediction for the ecosystems under study. We summarize and discuss the main results based on three years of research of four European research groups. The central theme of the work was the investigation of the effectiveness of the various screening compounds from the different species studied in order to gain some perspective of the evolutionary adaptations from lower to higher plant forms. The induction of mycosporine-like amino acids (MAAs) was studied in the marine dinoflagellate

  4. Guidelines for Terrestrial Ecosystem Survey.

    Science.gov (United States)

    1980-05-01

    34Two Methods for Estimating Populations of Mammals From Trapping Records," J. Mammal., Vol 30 (1949), pp 399-411. Hesse , P. R., A Textbook of Soil...Missouri Quail and Quail Hunting, 1939-1948, Missouri Conservation Commission, Technical Bulletin 2 Bennitt, Rudolf and Werner 0. Nagel, "A Survey of

  5. Estimation of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem in China using real-time remote sensing data

    Science.gov (United States)

    Li, M.; Huang, X.; Li, J.; Song, Y.

    2012-04-01

    Because of the high emission intensity and reactivity, biogenic volatile organic compounds (BVOCs) play a significant role in the terrestrial ecosystems, human health, secondary pollution, global climate change and the global carbon cycle. Past estimations of BVOC emissions in China were based on outdated algorithms and limited meteorological data, and there have been significant inconsistences between the land surface parameters of dynamic models and those of BVOC estimation models, leading to large inaccuracies in the estimated results. To refine BVOC emission estimations for China and to further explore the role of BVOCs in atmospheric chemical processes, we used the latest algorithms of MEGAN (Model of Emissions of Gases and Aerosols from Nature) with MM5 (the Fifth-Generation Mesoscale Model) providing highly resolved meteorological data, to estimate the biogenic emissions of isoprene (C5H8) and seven monoterpene species (C10H16) in 2006. Real-time MODIS (Moderate Resolution Imaging Spectroradiometer) data were introduced to update the land surface parameters and improve the simulation performance of MM5, and to modify the influence of leaf area index (LAI) and leaf age deviation from standard conditions. In this study, the annual BVOC emissions for the whole country totaled 12.97 Tg C, a relevant value much lower than that given in global estimations but higher than the past estimations in China. Therein, the most important individual contributor was isoprene (9.36 Tg C), followed by α-pinene (1.24 Tg C yr-1) and β-pinene (0.84 Tg C yr-1). Due to the considerable regional disparity in plant distributions and meteorological conditions across China, BVOC emissions presented significant spatial-temporal variations. Spatially, isoprene emission was concentrated in South China, which is covered by large areas of broadleaf forests and shrubs. On the other hand, Southeast China was the top-ranking contributor of monoterpenes, in which the dominant vegetation

  6. Coupling the Canadian Terrestrial Ecosystem Model (CTEM v. 2.0 to Environment and Climate Change Canada's greenhouse gas forecast model (v.107-glb

    Directory of Open Access Journals (Sweden)

    B. Badawy

    2018-02-01

    Full Text Available The Canadian Land Surface Scheme and the Canadian Terrestrial Ecosystem Model (CLASS-CTEM together form the land surface component in the family of Canadian Earth system models (CanESMs. Here, CLASS-CTEM is coupled to Environment and Climate Change Canada (ECCC's weather and greenhouse gas forecast model (GEM-MACH-GHG to consistently model atmosphere–land exchange of CO2. The coupling between the land and the atmospheric transport model ensures consistency between meteorological forcing of CO2 fluxes and CO2 transport. The procedure used to spin up carbon pools for CLASS-CTEM for multi-decadal simulations needed to be significantly altered to deal with the limited availability of consistent meteorological information from a constantly changing operational environment in the GEM-MACH-GHG model. Despite the limitations in the spin-up procedure, the simulated fluxes obtained by driving the CLASS-CTEM model with meteorological forcing from GEM-MACH-GHG were comparable to those obtained from CLASS-CTEM when it is driven with standard meteorological forcing from the Climate Research Unit (CRU combined with reanalysis fields from the National Centers for Environmental Prediction (NCEP to form CRU-NCEP dataset. This is due to the similarity of the two meteorological datasets in terms of temperature and radiation. However, notable discrepancies in the seasonal variation and spatial patterns of precipitation estimates, especially in the tropics, were reflected in the estimated carbon fluxes, as they significantly affected the magnitude of the vegetation productivity and, to a lesser extent, the seasonal variations in carbon fluxes. Nevertheless, the simulated fluxes based on the meteorological forcing from the GEM-MACH-GHG model are consistent to some extent with other estimates from bottom-up or top-down approaches. Indeed, when simulated fluxes obtained by driving the CLASS-CTEM model with meteorological data from the GEM-MACH-GHG model are used as

  7. Radioecology of natural systems. Fifteenth annual progress report, August 1, 1976--July 31, 1977. [Plutonium transport in terrestrial ecosystems at Rocky Flats Plant with emphasis on biological effects on mule deer and coyotes

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, F.W.

    1977-08-01

    This report summarizes project activities during the period August 1, 1976 through July 31, 1977. Four major areas of effort are reported, namely plutonium behavior in a terrestrial ecosystem at Rocky Flats, mule deer and coyote studies at Rocky Flats, ecological consequences of transuranics in the terrestrial environment, and lead geochemistry of an alpine lake ecosystem. Much of the first area of effort involved the synthesis of data and preparation of manuscripts, although some new data are reported on plutonium levels in small mammals, plant uptake of plutonium from contaminated soil, and plutonium deposition rates on macroplot 1. The mule deer studies generated a substantial body of new information which will permit quantitative assessment of plutonium dispersion by deer that utilize contaminated areas. These studies involve population dynamics, movement and use patterns, food habits, ingestion rates of contaminated soil and vegetation and plutonium burdens of deer tissues. A related study of coyote food habits in summer at Rocky Flats is reported. A manuscript dealing with the question of ecological effects of transuranics was prepared. This manuscript incorporates data from Rocky Flats on characteristics of natural populations which occupy ecologically similar areas having differing levels of plutonium contamination. The lead geochemistry studies continued to generate new data but the data are not yet reported.

  8. Multiproxy evidence for terrestrial and aquatic ecosystem responses during the 8.2 ka cold event as recorded at Højby Sø, Denmark

    DEFF Research Database (Denmark)

    Hede, Mikkel U.; Rasmussen, Peter; Noe-Nygaard, Nanna

    2010-01-01

    A sediment succession from Højby Sø, a lake in eastern Denmark, covering the time period 9400–7400 cal yr BP was studied using high-resolution geochemistry, magnetic susceptibility, pollen, macrofossil, diatom, and algal pigment analysis to investigate responses of the terrestrial and aquatic......; Algal pigments; Diatoms; Holocene; Denmark...

  9. The role of amoeboid protists and the microbial community in moss-rich terrestrial ecosystems: biogeochemical implications for the carbon budget and carbon cycle, especially at higher latitudes.

    Science.gov (United States)

    Anderson, O Roger

    2008-01-01

    Moss-rich terrestrial communities are widely distributed in low- and high-latitude environments, covering vast surface areas in the boreal forests and tundra. The microbial biota in these organic-rich communities may contribute substantially to the carbon budget of terrestrial communities and the carbon cycle on a global scale. Recent research is reported on the carbon content of microbial communities in some temperate and high-latitude moss communities. The total carbon content and potential respiratory carbon dioxide (CO(2)) efflux is reported for bacteria, microflagellates, naked amoebae, and testate amoebae within sampling sites at a northeastern forest and the tundra at Toolik, Alaska. Quantitative models of the predicted total CO(2) efflux from the microbes, based on microscopic observations and enumeration of the microbiota in samples from the research sites, are described and predictions are compared with published field-based data of CO(2) efflux. The significance of the predictions for climate change and global warming are discussed.

  10. Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems.

    Science.gov (United States)

    Krusor, Colin; Smith, Woutrina A; Tinker, M Tim; Silver, Mary; Conrad, Patricia A; Shapiro, Karen

    2015-11-01

    The parasite Toxoplasma gondii is an environmentally persistent pathogen that can cause fatal disease in humans, terrestrial warm-blooded animals and aquatic mammals. Although an association between T. gondii exposure and prey specialization on marine snails was identified in threatened California sea otters, the ability of kelp-dwelling snails to transmit terrestrially derived pathogens has not been previously investigated. The objective of this study was to measure concentration and retention of T. gondii by marine snails in laboratory aquaria, and to test for natural T. gondii contamination in field-collected snails. Following exposure to T. gondii-containing seawater, oocysts were detected by microscopy in snail faeces and tissues for 10 and 3 days respectively. Nested polymerase chain reaction was also applied as a method for confirming putative T. gondii oocysts detected in snail faeces and tissues by microscopy. Toxoplasma gondii was not detected in field-collected snails. Results suggest that turban snails are competent transport hosts for T. gondii. By concentrating oocysts in faecal pellets, snails may facilitate entry of T. gondii into the nearshore marine food web. This novel mechanism also represents a general pathway by which marine transmission of terrestrially derived microorganisms can be mediated via pathogen concentration and retention by benthic invertebrates. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  11. Concentration and retention of Toxoplasma gondii oocysts by marine snails demonstrate a novel mechanism for transmission of terrestrial zoonotic pathogens in coastal ecosystems

    Science.gov (United States)

    Krusor, Colin; Smith, Woutrina A.; Tinker, M. Tim; Silver, Mary; Conrad, Patricia A.; Shapiro, Karen

    2015-01-01

    The parasite Toxoplasma gondii is an environmentally persistent pathogen that can cause fatal disease in humans, terrestrial warm-blooded animals and aquatic mammals. Although an association between T. gondii exposure and prey specialization on marine snails was identified in threatened California sea otters, the ability of kelp-dwelling snails to transmit terrestrially derived pathogens has not been previously investigated. The objective of this study was to measure concentration and retention of T. gondii by marine snails in laboratory aquaria, and to test for natural T. gondii contamination in field-collected snails. Following exposure to T. gondii-containing seawater, oocysts were detected by microscopy in snail faeces and tissues for 10 and 3 days respectively. Nested polymerase chain reaction was also applied as a method for confirming putative T. gondii oocysts detected in snail faeces and tissues by microscopy. Toxoplasma gondiiwas not detected in field-collected snails. Results suggest that turban snails are competent transport hosts for T. gondii. By concentrating oocysts in faecal pellets, snails may facilitate entry of T. gondii into the nearshore marine food web. This novel mechanism also represents a general pathway by which marine transmission of terrestrially derived microorganisms can be mediated via pathogen concentration and retention by benthic invertebrates.

  12. The Climate Space Concept: Analysis of the Steady State Heat Energy Budget of Animals. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Stevenson, R. D.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. Several modules in the thermodynamic series considered the application of the First Law to…

  13. Trace metallic elements in Helix aspersa terrestrial snails of a semiarid ecosystem; Elementos metalicos traza en caracoles terrestres Helix aspersa de un ecosistema semiarido

    Energy Technology Data Exchange (ETDEWEB)

    Gaso P, M.I.; Segovia, N.; Zarazua, G.; Montes, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Morton, O.; Armienta, M.A.; Hernandez, E. [IGF-UNAM, Ciudad Universitaria, 04510 Mexico D.F. (Mexico)

    2001-07-01

    The concentration of some major elements and traces in soil samples and of Helix aspersa eatable terrestrial snails were analysed at the Radioactive Wastes Storage Center (CADER) and in other reference sites. The methodology includes the use of an atomic absorption spectrophotometer, an X-ray fluorescence equipment and an Icp-mass spectroscope. The concentrations of some toxic elements (Ba, Cd, Cr, Ni, Pb and V) in the soft tissue of the snails were greater than the toxic levels reported in the literature for such trace elements. The snails compared with another wild eatable foods present transfer coefficients soil-snail high relatively. (Author)

  14. RADIATION DOSE ASSESSMENT FOR THE BIOTA OF TERRESTRIAL ECOSYSTEMS IN THE SHORELINE ZONE OF THE CHERNOBYL NUCLEAR POWER PLANT COOLING POND

    Energy Technology Data Exchange (ETDEWEB)

    Farfan, E.; Jannik, T.

    2011-10-01

    Radiation exposure of the biota in the shoreline area of the Chernobyl Nuclear Power Plant Cooling Pond was assessed to evaluate radiological consequences from the decommissioning of the Cooling Pond. The article addresses studies of radioactive contamination of the terrestrial faunal complex and radionuclide concentration ratios in bodies of small birds, small mammals, amphibians, and reptiles living in the area. The data were used to calculate doses to biota using the ERICA Tool software. Doses from {sup 90}Sr and {sup 137}Cs were calculated using the default parameters of the ERICA Tool and were shown to be consistent with biota doses calculated from the field data. However, the ERICA dose calculations for plutonium isotopes were much higher (2-5 times for small mammals and 10-14 times for birds) than the doses calculated using the experimental data. Currently, the total doses for the terrestrial biota do not exceed maximum recommended levels. However, if the Cooling Pond is allowed to drawdown naturally and the contaminants of the bottom sediments are exposed and enter the biological cycle, the calculated doses to biota may exceed the maximum recommended values. The study is important in establishing the current exposure conditions such that a baseline exists from which changes can be documented following the lowering of the reservoir water. Additionally, the study provided useful radioecological data on biota concentration ratios for some species that are poorly represented in the literature.

  15. Ecological impacts of atmospheric pollution and interactions with climate change in terrestrial ecosystems of the Mediterranean Basin: Current research and future directions.

    Science.gov (United States)

    Ochoa-Hueso, Raúl; Munzi, Silvana; Alonso, Rocío; Arróniz-Crespo, María; Avila, Anna; Bermejo, Victoria; Bobbink, Roland; Branquinho, Cristina; Concostrina-Zubiri, Laura; Cruz, Cristina; Cruz de Carvalho, Ricardo; De Marco, Alessandra; Dias, Teresa; Elustondo, David; Elvira, Susana; Estébanez, Belén; Fusaro, Lina; Gerosa, Giacomo; Izquieta-Rojano, Sheila; Lo Cascio, Mauro; Marzuoli, Riccardo; Matos, Paula; Mereu, Simone; Merino, José; Morillas, Lourdes; Nunes, Alice; Paoletti, Elena; Paoli, Luca; Pinho, Pedro; Rogers, Isabel B; Santos, Arthur; Sicard, Pierre; Stevens, Carly J; Theobald, Mark R

    2017-08-01

    Mediterranean Basin ecosystems, their unique biodiversity, and the key services they provide are currently at risk due to air pollution and climate change, yet only a limited number of isolated and geographically-restricted studies have addressed this topic, often with contrasting results. Particularities of air pollution in this region include high O 3 levels due to high air temperatures and solar radiation, the stability of air masses, and dominance of dry over wet nitrogen deposition. Moreover, the unique abiotic and biotic factors (e.g., climate, vegetation type, relevance of Saharan dust inputs) modulating the response of Mediterranean ecosystems at various spatiotemporal scales make it difficult to understand, and thus predict, the consequences of human activities that cause air pollution in the Mediterranean Basin. Therefore, there is an urgent need to implement coordinated research and experimental platforms along with wider environmental monitoring networks in the region. In particular, a robust deposition monitoring network in conjunction with modelling estimates is crucial, possibly including a set of common biomonitors (ideally cryptogams, an important component of the Mediterranean vegetation), to help refine pollutant deposition maps. Additionally, increased attention must be paid to functional diversity measures in future air pollution and climate change studies to establish the necessary link between biodiversity and the provision of ecosystem services in Mediterranean ecosystems. Through a coordinated effort, the Mediterranean scientific community can fill the above-mentioned gaps and reach a greater understanding of the mechanisms underlying the combined effects of air pollution and climate change in the Mediterranean Basin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Technical progress report of biological research on the Volcanic Island Surtsey and environment for the year 1976. [Recovery of terrestrial ecosystem on volcanic island following volcano eruption

    Energy Technology Data Exchange (ETDEWEB)

    Fridriksson, S.

    1976-01-01

    The study involves the terrestrial biological research on the volcanic island, Surtsey, off the coast of Iceland and the neighbouring islands and environs of the Westman Islands, which are situated on the Mid-Atlantic Ridge. An eruption of the volcano in 1973 is studied. The topographical changes on Surtsey were studied in August 1976. It is evident that the southwestern side is constantly being eroded and that the island decreases in area of some 7.5 hectares per year. Results are reported from studies of microorganisms, algae, lichens, moss, vascular plants, insects, birds, and soil, and the nitrogen cycle. Emphasis was placed on revegetation and recolonization of plants, insects, and sea birds.

  17. Ecosystem CO2 Exchange Across Semiarid Southwestern North America: A Synthesis of Multi-Year Flux Site Observations and its Comparison with Estimates from Terrestrial Biome Models and Remote Sensing

    Science.gov (United States)

    Biederman, J. A.; Scott, R. L.; Goulden, M.; Litvak, M. E.; Kolb, T.; Yepez, E. A.; Garatuza, J.; Oechel, W. C.; Krofcheck, D. J.; Ponce-Campos, G. E.; Bowling, D. R.; Meyers, T. P.; Maurer, G.

    2016-12-01

    Global carbon cycle studies reveal that semiarid ecosystems dominate the increasing trend and interannual variability of the land CO2 sink. However, the regional terrestrial biome models (TBM) and remote sensing products (RSP) used in large-scale analyses are poorly constrained by ecosystem flux measurements in semiarid regions, which are under-represented in global flux datasets. Here we present eddy covariance measurements from 25 diverse ecosystems in semiarid southwestern North America with ranges in annual precipitation of 100 - 1000 mm, annual temperatures of 2 - 25 °C, and records of 3 - 10 years each (150 site-years in total). We identified seven subregions with unique seasonal dynamics in climate and ecosystem-atmosphere exchange, including net and gross CO2 exchange (photosynthesis and respiration) and evapotranspiration (ET), and we evaluated how well measured dynamics were captured by satellite-based greenness observations of the Enhanced Vegetation Index (EVI). Annual flux integrals were calculated based on site-appropriate ecohydrologic years. Net ecosystem production (NEP) varied between -550 and + 420 g C m-2, highlighting the wide range of regional sink/source function. Annual photosynthesis and respiration were positively related to water availability but were suppressed in warmer years at a given site and at climatically warmer sites, in contrast to positive temperature responses at wetter sites. When precipitation anomalies were spatially coherent across sites (e.g. related to El Niño Southern Oscillation), we found large regional annual anomalies in net and gross CO2 uptake. TBM and RSP were less effective in capturing spatial gradients in mean ET and CO2 exchange across this semiarid region as compared to wetter regions. Measured interannual variability of ET and gross CO2 exchange was 3 - 5 times larger than estimates from TBM or RSP. These results suggest that semiarid regions play an even larger role in regulating interannual variability

  18. Woody plant encroachment, and its removal, impact bacterial and fungal communities across stream and terrestrial habitats in a tallgrass prairie ecosystem.

    Science.gov (United States)

    Veach, Allison M; Dodds, Walter K; Jumpponen, Ari

    2015-10-01

    Woody plant encroachment has become a global threat to grasslands and has caused declines in aboveground richness and changes in ecosystem function; yet we have a limited understanding on the effects of these phenomena on belowground microbial communities. We completed riparian woody plant removals at Konza Prairie Biological Station, Kansas and collected soils spanning land-water interfaces in removal and woody vegetation impacted areas. We measured stream sediments and soils for edaphic variables (C and N pools, soil water content, pH) and bacterial (16S rRNA genes) and fungal (ITS2 rRNA gene repeat) communities using Illumina MiSeq metabarcoding. Bacterial richness and diversity decreased with distance from streams. Fungal richness decreased with distance from the stream in wooded areas, but was similar across landscape position while Planctomycetes and Basidiomycota relative abundance was lower in removal areas. Cyanobacteria, Ascomycota, Chytridiomycota and Glomeromycota relative abundance was greater in removal areas. Ordination analyses indicated that bacterial community composition shifted more across land-water interfaces than fungi yet both were marginally influenced by treatment. This study highlights the impacts of woody encroachment restoration on grassland bacterial and fungal communities which likely subsequently affects belowground processes and plant health in this ecosystem. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. The influence of grain size, grain color, and suspended-sediment concentration on light attenuation: why fine-grained terrestrial sediment is bad for coral reef ecosystems

    Science.gov (United States)

    Storlazzi, Curt; Norris, Benjamin; Rosenberger, Kurt

    2015-01-01

    Sediment has been shown to be a major stressor to coral reefs globally. Although many researchers have tested the impact of sedimentation on coral reef ecosystems in both the laboratory and the field and some have measured the impact of suspended sediment on the photosynthetic response of corals, there has yet to be a detailed investigation on how properties of the sediment itself can affect light availability for photosynthesis. We show that finer-grained and darker-colored sediment at higher suspended-sediment concentrations attenuates photosynthetically active radiation (PAR) significantly more than coarser, lighter-colored sediment at lower concentrations and provide PAR attenuation coefficients for various grain sizes, colors, and suspended-sediment concentrations that are needed for biophysical modeling. Because finer-grained sediment particles settle more slowly and are more susceptible to resuspension, they remain in the water column longer, thus causing greater net impact by reducing light essential for photosynthesis over a greater duration. This indicates that coral reef monitoring studies investigating sediment impacts should concentrate on measuring fine-grained lateritic and volcanic soils, as opposed to coarser-grained siliceous and carbonate sediment. Similarly, coastal restoration efforts and engineering solutions addressing long-term coral reef ecosystem health should focus on preferentially retaining those fine-grained soils rather than coarse silt and sand particles.

  20. The terrestrial silica pump.

    Directory of Open Access Journals (Sweden)

    Joanna C Carey

    Full Text Available Silicon (Si cycling controls atmospheric CO(2 concentrations and thus, the global climate, through three well-recognized means: chemical weathering of mineral silicates, occlusion of carbon (C to soil phytoliths, and the oceanic biological Si pump. In the latter, oceanic diatoms directly sequester 25.8 Gton C yr(-1, accounting for 43% of the total oceanic net primary production (NPP. However, another important link between C and Si cycling remains largely ignored, specifically the role of Si in terrestrial NPP. Here we show that 55% of terrestrial NPP (33 Gton C yr(-1 is due to active Si-accumulating vegetation, on par with the amount of C sequestered annually via marine diatoms. Our results suggest that similar to oceanic diatoms, the biological Si cycle of land plants also controls atmospheric CO(2 levels. In addition, we provide the first estimates of Si fixed in terrestrial vegetation by major global biome type, highlighting the ecosystems of most dynamic Si fixation. Projected global land use change will convert forests to agricultural lands, increasing the fixation of Si by land plants, and the magnitude of the terrestrial Si pump.

  1. Evaluating the effects of terrestrial ecosystems, climate and carbon dioxide on weathering over geological time: a global-scale process-based approach.

    Science.gov (United States)

    Taylor, Lyla L; Banwart, Steve A; Valdes, Paul J; Leake, Jonathan R; Beerling, David J

    2012-02-19

    Global weathering of calcium and magnesium silicate rocks provides the long-term sink for atmospheric carbon dioxide (CO(2)) on a timescale of millions of years by causing precipitation of calcium carbonates on the seafloor. Catchment-scale field studies consistently indicate that vegetation increases silicate rock weathering, but incorporating the effects of trees and fungal symbionts into geochemical carbon cycle models has relied upon simple empirical scaling functions. Here, we describe the development and application of a process-based approach to deriving quantitative estimates of weathering by plant roots, associated symbiotic mycorrhizal fungi and climate. Our approach accounts for the influence of terrestrial primary productivity via nutrient uptake on soil chemistry and mineral weathering, driven by simulations using a dynamic global vegetation model coupled to an ocean-atmosphere general circulation model of the Earth's climate. The strategy is successfully validated against observations of weathering in watersheds around the world, indicating that it may have some utility when extrapolated into the past. When applied to a suite of six global simulations from 215 to 50 Ma, we find significantly larger effects over the past 220 Myr relative to the present day. Vegetation and mycorrhizal fungi enhanced climate-driven weathering by a factor of up to 2. Overall, we demonstrate a more realistic process-based treatment of plant fungal-geosphere interactions at the global scale, which constitutes a first step towards developing 'next-generation' geochemical models.

  2. Role of CO2, climate and land use in regulating the seasonal amplitude increase of carbon fluxes in terrestrial ecosystems: a multimodel analysis

    Science.gov (United States)

    Zhao, Fang; Zeng, Ning; Asrar, Ghassem; Friedlingstein, Pierre; Ito, Akihiko; Jain, Atul; Kalnay, Eugenia; Kato, Etsushi; Koven, Charles D.; Poulter, Ben; Rafique, Rashid; Sitch, Stephen; Shu, Shijie; Stocker, Beni; Viovy, Nicolas; Wiltshire, Andy; Zaehle, Sonke

    2016-09-01

    We examined the net terrestrial carbon flux to the atmosphere (FTA) simulated by nine models from the TRENDY dynamic global vegetation model project for its seasonal cycle and amplitude trend during 1961-2012. While some models exhibit similar phase and amplitude compared to atmospheric inversions, with spring drawdown and autumn rebound, others tend to rebound early in summer. The model ensemble mean underestimates the magnitude of the seasonal cycle by 40 % compared to atmospheric inversions. Global FTA amplitude increase (19 ± 8 %) and its decadal variability from the model ensemble are generally consistent with constraints from surface atmosphere observations. However, models disagree on attribution of this long-term amplitude increase, with factorial experiments attributing 83 ± 56 %, -3 ± 74 and 20 ± 30 % to rising CO2, climate change and land use/cover change, respectively. Seven out of the nine models suggest that CO2 fertilization is the strongest control - with the notable exception of VEGAS, which attributes approximately equally to the three factors. Generally, all models display an enhanced seasonality over the boreal region in response to high-latitude warming, but a negative climate contribution from part of the Northern Hemisphere temperate region, and the net result is a divergence over climate change effect. Six of the nine models show that land use/cover change amplifies the seasonal cycle of global FTA: some are due to forest regrowth, while others are caused by crop expansion or agricultural intensification, as revealed by their divergent spatial patterns. We also discovered a moderate cross-model correlation between FTA amplitude increase and increase in land carbon sink (R2 = 0.61). Our results suggest that models can show similar results in some benchmarks with different underlying mechanisms; therefore, the spatial traits of CO2 fertilization, climate change and land use/cover changes are crucial in determining the right mechanisms in

  3. Application of the 15N-Gas Flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    Science.gov (United States)

    Sgouridis, F.; Ullah, S.; Stott, A.

    2015-08-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilised agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps, a copper based reduction furnace, and allows the analysis of small gas injection volumes (4 μL) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Pre-concentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N Gas-Flux method was adapted for application in natural and semi-natural land use types (peatlands, forests and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. For our chamber design (volume / surface = 8:1) and a 20 h incubation period, the minimum detectable flux rates were 4 μg N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. The N2 flux ranged between 2.4 and 416.6 μg N m-2 h-1, and the grassland soils showed on average 3 and 14 times higher denitrification rates than the woodland and organic soils respectively. The N2O flux was on average 20 to 200 times lower than the N2 flux, while the denitrification product ratio (N2O/N2 + N2O) was low, ranging between 0.03 and 13 %. Total denitrification rates measured by the acetylene inhibition technique under the same field conditions

  4. Application of the 15N gas-flux method for measuring in situ N2 and N2O fluxes due to denitrification in natural and semi-natural terrestrial ecosystems and comparison with the acetylene inhibition technique

    Science.gov (United States)

    Sgouridis, Fotis; Stott, Andrew; Ullah, Sami

    2016-03-01

    Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N2 flux measurements, particularly in natural and semi-natural terrestrial ecosystems. 15N tracer approaches can provide in situ measurements of both N2 and N2O simultaneously, but their use has been limited to fertilized agro-ecosystems due to the need for large 15N additions in order to detect 15N2 production against the high atmospheric N2. For 15N-N2 analyses, we have used an "in-house" laboratory designed and manufactured N2 preparation instrument which can be interfaced to any commercial continuous flow isotope ratio mass spectrometer (CF-IRMS). The N2 prep unit has gas purification steps and a copper-based reduction furnace, and allows the analysis of small gas injection volumes (4 µL) for 15N-N2 analysis. For the analysis of N2O, an automated Tracegas Preconcentrator (Isoprime Ltd) coupled to an IRMS was used to measure the 15N-N2O (4 mL gas injection volume). Consequently, the coefficient of variation for the determination of isotope ratios for N2 in air and in standard N2O (0.5 ppm) was better than 0.5 %. The 15N gas-flux method was adapted for application in natural and semi-natural land use types (peatlands, forests, and grasslands) by lowering the 15N tracer application rate to 0.04-0.5 kg 15N ha-1. The minimum detectable flux rates were 4 µg N m-2 h-1 and 0.2 ng N m-2 h-1 for the N2 and N2O fluxes respectively. Total denitrification rates measured by the acetylene inhibition technique in the same land use types correlated (r = 0.58) with the denitrification rates measured under the 15N gas-flux method, but were underestimated by a factor of 4, and this was partially attributed to the incomplete inhibition of N2O reduction to N2, under a relatively high soil moisture content, and/or the catalytic NO decomposition in the presence of acetylene. Even though relatively robust for in situ denitrification measurements, methodological

  5. Role of CO2, climate and land use in regulating the seasonal amplitude increase of carbon fluxes in terrestrial ecosystems: a multimodel analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fang; Zeng, Ning; Akihiko, Ito; Asrar, Ghassam; Friedlingstein, Pierre; Jain, Atul; Kalnay, Eugenia; Kato, Etsushi; Koven, Charles D.; Poulter, Ben; Rafique, Rashid; Sitch, Stephen; Shu, Shijie; Stocker, Beni; Viovy, Nicolas; Wiltshire, Andy; Zaehle, Sonke

    2016-04-11

    We examined the net terrestrial carbon flux to the atmosphere (FTA) simulated by nine models from the TRENDY dynamic global vegetation model project during 1961–2012 for its seasonal cycle and amplitude trend. While some models exhibit similar phase and amplitude compared to atmospheric inversions, with spring drawdown and autumn rebound, others tend to rebound early in summer. The model ensemble mean underestimates the magnitude of the seasonal cycle by 40 % compared to atmospheric inversions. Global FTA amplitude increase (19 ± 8 %) and its decadal variability from the model ensemble are generally consistent with constraints from surface atmosphere observations. However, models disagree on attribution of this long-term amplitude increase, with factorial experiments attributing 83 ± 56 %, −3 ± 74 % and 20 ± 30 % to rising CO2, climate change and land use/cover change, respectively. Seven out of the nine models suggest that CO2 fertilization is a stronger control — with the notable exception of VEGAS, which attributes approximately equally to the three factors. Generally, all models display an enhanced seasonality over the boreal region in response to high-latitude warming, but a negative climate contribution from part of the Northern Hemisphere temperate region, and the net result is a divergence over climate change effect. Six of the nine models show land use/cover change amplifies the seasonal cycle of global FTA: some are due to forest regrowth while others are caused by crop expansion or agricultural intensification, as revealed by their divergent spatial patterns. We also discovered a moderate cross-model correlation between FTA amplitude increase and increase in land carbon sink (R2 = 0.61). Our results suggest that models can show similar results in some benchmarks with different underlying mechanisms, therefore the spatial traits of CO2 fertilization

  6. Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

    Science.gov (United States)

    Hayes, Daniel J.; Turner, David P.; Stinson, Graham; McGuire, A. David; Wei, Yaxing; West, Tristram O.; Heath, Linda S.; de Jong, Bernardus; McConkey, Brian G.; Birdsey, Richard A.; Kurz, Werner A.; Jacobson, Andrew R.; Huntzinger, Deborah N.; Pan, Yude; Post, W. Mac; Cook, Robert B.

    2012-01-01

    We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2, while accounting for lateral transfers of forest and crop products as well as their eventual emissions. The total NEE estimate of a -327 ± 252 TgC yr-1 sink for NA was driven primarily by CO2 uptake in the Forest Lands sector (-248 TgC yr-1), largely in the Northwest and Southeast regions of the US, and in the Crop Lands sector (-297 TgC yr-1), predominantly in the Midwest US states. These sinks are counteracted by the carbon source estimated for the Other Lands sector (+218 TgC yr-1), where much of the forest and crop products are assumed to be returned to the atmosphere (through livestock and human consumption). The ecosystems of Mexico are estimated to be a small net source (+18 TgC yr-1) due to land use change between 1993 and 2002. We compare these inventory-based estimates with results from a suite of terrestrial biosphere and atmospheric inversion models, where the mean continental-scale NEE estimate for each ensemble is -511 TgC yr-1 and -931 TgC yr-1, respectively. In the modeling approaches, all sectors, including Other Lands, were generally estimated to be a carbon sink, driven in part by assumed CO2 fertilization and/or lack of consideration of carbon sources from disturbances and product emissions. Additional fluxes not measured by the inventories, although highly uncertain, could add an additional -239 TgC yr-1 to the inventory-based NA sink estimate, thus suggesting some convergence with the modeling approaches.

  7. Water use efficiency of net primary production in global terrestrial ...

    Indian Academy of Sciences (India)

    The carbon and water cycles of terrestrial ecosystems, which are strongly coupled via water use efficiency (WUE), are influenced by global climate change. To explore the relationship between the carbon and water cycles and predict the effect of climate change on terrestrial ecosystems, it is necessary to study the WUE in ...

  8. MODIS-derived terrestrial primary production [chapter 28

    Science.gov (United States)

    Maosheng Zhao; Steven Running; Faith Ann Heinsch; Ramakrishna Nemani

    2011-01-01

    Temporal and spatial changes in terrestrial biological productivity have a large impact on humankind because terrestrial ecosystems not only create environments suitable for human habitation, but also provide materials essential for survival, such as food, fiber and fuel. A recent study estimated that consumption of terrestrial net primary production (NPP; a list of...

  9. Dynamic belowground ecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Harris, W. F.; Santantonio, D.; McGinty, D.

    1979-01-01

    Roots comprise the primary interface between plant and soil for uptake of water and nutrients. Much is known about the biochemistry, cell physiology and membrane physics associated with these important processes. In this paper we discuss the role of the belowground ecosystem, especially the autotrophic root component, in the structure and function of forest ecosystems. Beyond recognizing roles of anchoring terrestrial plants and uptake of water and nutrients, this component of the forest has been largely neglected in an ecosystem context. In order to focus discussion on the properties of the belowground ecosystem, we use the term rhizosphere to include roots, mycorrhizae, microbes, and rhizophagus invertebrates.

  10. Conservación de la biodiversidad en Chile: Nuevos desafíos y oportunidades en ecosistemas terrestres y marinos costeros Biodiversity conservation in Chile: New challenges and opportunities in terrestrial and marine coastal ecosystems

    Directory of Open Access Journals (Sweden)

    CARMEN JORQUERA-JARAMILLO

    2012-09-01

    Full Text Available La pérdida de la biodiversidad producida por el crecimiento demográfico, la demanda por recursos y la actividad productiva es contradictoria con el reconocimiento de su importancia. En ecosistemas terrestres, el Sistema Nacional de Áreas Protegidas del Estado (SNASPE contiene cerca del 19 % del territorio de Chile continental; aunque no representa todos los ecosistemas con especies amenazadas, puede ser complementado implementando nuevas áreas protegidas públicas (AP y privadas (APP. El desarrollo de áreas marinas protegidas (AMP es incipiente, y algunas iniciativas comparten la responsabilidad de conservación con los usuarios locales. En Chile, un conjunto de reglamentos, normas legales y tratados internacionales promueven distintas oportunidades de conservación en ecosistemas terrestres y marinos costeros, de las cuales emergen nuevos desafíos. Entre estos destacan, estandarizar la clasificación de especies según categorías de conservación en un protocolo internacional y optimizar las metodologías para seleccionar áreas prioritarias, ambos criterios indispensables para decidir qué y dónde conservar. Otro desafío es integrar el valor intrínseco de la biodiversidad con los servicios ecosistémicos que presta para instaurar una cultura participativa. Esto mejoraría la efectividad de las distintas estrategias de protección y uso sustentable de la biodiversidad al incorporar la educación y la participación ciudadana desde una perspectiva biocultural. La educación fomenta la conservación de la naturaleza al hacernos conscientes de nuestro entorno; mientras que la participación involucra a los ciudadanos como un actor más en la toma de decisiones, procurando la aplicación efectiva de las estrategias de conservación de la biodiversidad.Biodiversity loss caused by population growth, the demand of resources and productive activities is inconsistent with the recognition of its importance. In terrestrial ecosystems, the

  11. Terrestrial biogeochemical cycles - Global interactions with the atmosphere and hydrology

    Science.gov (United States)

    Schimel, David S.; Parton, William J.; Kittel, Timothy G. F.

    1991-01-01

    A review is presented of developments in ecosystem theory, remote sensing, and geographic information systems that support new endeavors in spatial modeling. A paradigm has emerged to predict ecosystem behavior based on understanding responses to multiple resources. Ecosystem models couple primary production to decomposition and nutrient availability utilizing this paradigm. It is indicated that coupling of transport and ecosystem processes alters the behavior of earth system components (terrestrial ecosystems, hydrology, and the atmosphere) from that of an uncoupled model.

  12. Pacific Salmon in aquatic and terrestrial ecosystem.

    Science.gov (United States)

    S.M. Gende; R.T. Edwards; M.F. Willson; M.S. Wipfli

    2002-01-01

    almon runs in the Pacific Northwest have been declining for decades, so much so that many runs are threatened or endangered; others have been completely extirpated (Nehlsen et al. 1991). This "salmon crisis" looms large in the public eye, because it has serious and wideranging economic, cultural, and ecological repercussions. Billions of dollars have gone...

  13. The circumpolar biodiversity monitoring program - Terrestrial plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    and attributes to monitor in the plan related to soil invertebrates. Focal Ecosystem Components (FECs) of the soil decomposer system include the soil living invertebrates such as microarthropods, enchytraeids and earthworms and the functions performed by microorganisms such as nitrification, decomposition......The Circumpolar Biodiversity Monitoring Program, CBMP, Terrestrial Plan, www.caff.is/terrestrial, is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders......, northern communities, and scientists to detect, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity. This presentation will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based...

  14. WOODS, THE MOST COMPLEX TERRESTRIAL ECOSISTEM

    OpenAIRE

    BLAJ Robert; SAND Camelia; Gligor CIORTEA

    2012-01-01

    A forest ecosystem is a terrestrial unit of living organisms (plants, animals and microorganisms), all interacting among themselves and with the environment (soil, climate, water and light) in which they live. The environmental "common denominator" of that forest ecological community is a tree, who most faithfully obeys the ecological cycles of energy, water, carbon and nutrients. A forest ecosystem would be considered having boundaries and would include a forest of trees out to the limit of ...

  15. Predictability of the terrestrial carbon cycle.

    Science.gov (United States)

    Luo, Yiqi; Keenan, Trevor F; Smith, Matthew

    2015-05-01

    Terrestrial ecosystems sequester roughly 30% of anthropogenic carbon emission. However this estimate has not been directly deduced from studies of terrestrial ecosystems themselves, but inferred from atmospheric and oceanic data. This raises a question: to what extent is the terrestrial carbon cycle intrinsically predictable? In this paper, we investigated fundamental properties of the terrestrial carbon cycle, examined its intrinsic predictability, and proposed a suite of future research directions to improve empirical understanding and model predictive ability. Specifically, we isolated endogenous internal processes of the terrestrial carbon cycle from exogenous forcing variables. The internal processes share five fundamental properties (i.e., compartmentalization, carbon input through photosynthesis, partitioning among pools, donor pool-dominant transfers, and the first-order decay) among all types of ecosystems on the Earth. The five properties together result in an emergent constraint on predictability of various carbon cycle components in response to five classes of exogenous forcing. Future observational and experimental research should be focused on those less predictive components while modeling research needs to improve model predictive ability for those highly predictive components. We argue that an understanding of predictability should provide guidance on future observational, experimental and modeling research. © 2014 John Wiley & Sons Ltd.

  16. Activities of the National Programmes for Ecosystem and Aquaculture Research 1983 - 1985

    CSIR Research Space (South Africa)

    Auret, EW

    1986-01-01

    Full Text Available Activities of the National Programmes for Ecosystem and Aquaculture Research of the CSIR Foundation for Research Development are reviewed, within the programmes on Inland Water Ecosystems, Terrestrial Ecosystems, Nature Conservation Research, Human...

  17. Functional Valuation of Ecosystem Services on Bonaire: an ecological analysis of ecosystem functions provided by coral reefs

    NARCIS (Netherlands)

    Beek, van I.J.M.

    2011-01-01

    This research is a semi-quantitative analysis of the functional value of coral reef habitats on Bonaire to support ecosystem services. It is part of an economic valuation study of marine and terrestrial ecosystem services on Bonaire.

  18. Millennium Ecosystem Assessment: MA Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — The Millennium Ecosystem Assessment: MA Ecosystems provides data and information on the extent and classification of ecosystems circa 2000, including coastal,...

  19. Water use efficiency of net primary production in global terrestrial ...

    Indian Academy of Sciences (India)

    Water use efficiency; global terrestrial ecosystems; MODIS; net primary production; evapotranspiration;. Köppen–Geiger climate classification. ... Terrestrial plants fix or trap carbon dioxide via photosynthesis to produce the material ...... S W 2007 Evaluating water stress controls on primary production in biogeochemical and ...

  20. Climate control of terrestrial carbon exchange across biomes and continents

    Science.gov (United States)

    Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

  1. Pathways to bridge the biophysical realism gap in ecosystem services mapping approaches

    NARCIS (Netherlands)

    Lavorel, Sandra; Bayer, Anita; Bondeau, Alberte; Lautenbach, Sven; Ruiz-Frau, Ana; Schulp, Nynke; Seppelt, Ralf; Verburg, P.H.; Teeffelen, Astrid van; Vannier, Clémence; Arneth, Almut; Cramer, Wolfgang; Marba, Nuria

    2017-01-01

    The mapping of ecosystem service supply has become quite common in ecosystem service assessment practice for terrestrial ecosystems, but land cover remains the most common indicator for ecosystems ability to deliver ecosystem services. For marine ecosystems, practice is even less advanced, with a

  2. Terrestrial Carbon Cycle Variability.

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2 , temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1 ) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1 ), and

  3. The Circumpolar Biodiversity Monitoring Program Terrestrial Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments in terrestrial, marine, freshwater...... and coastal environments. The CBMP Terrestrial Plan is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect......, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity, and to identify knowledge gaps and priorities. This poster will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based monitoring...

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

    Science.gov (United States)

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

    2014-01-01

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

  5. Variations and trends of terrestrial NPP and its relation to climate ...

    Indian Academy of Sciences (India)

    Considering global climate change, near surface temperature is the major factor affecting the terrestrial ecosystem, followed by the precipitation. This means terrestrial ecosystem NPP is more closely related to near surface temperature than precipitation. Between 1976 and 2005, NPP shows an obvious increasing temporal ...

  6. Landscape-level terrestrial methane flux observed from a very tall tower

    Science.gov (United States)

    Ankur R. Desai; Ke Xu; Hanqin Tian; Peter Weishampel; Jonathan Thom; Dan Baumann; Arlyn E. Andrews; Druce D. Cook; Jennifer Y. King; Randall. Kolka

    2015-01-01

    Simulating the magnitude and variability of terrestrial methane sources and sinks poses a challenge to ecosystem models because the biophysical and biogeochemical processes that lead to methane emissions from terrestrial and freshwater ecosystems are, by their nature, episodic and spatially disjunct. As a consequence, model predictions of regional methane emissions...

  7. Variations and trends of terrestrial NPP and its relation to climate ...

    Indian Academy of Sciences (India)

    ing the terrestrial ecosystem has had a positive response to climate change. MME NPP has increased. 3.647PgC during historical period, which shows an increasing temporal trend of 3.9 gCm ..... In reality, the terrestrial ecosystem is a complex variable, which can be effected by many factors, such as climate, CO2, human ...

  8. Climate control of terrestrial carbon exchange across biomes and continents

    DEFF Research Database (Denmark)

    Yi, Chuixiang; Ricciuto, Daniel; Li, Runze

    2010-01-01

    climate and terrestrial CO2 exchange with the atmosphere across biomes and continents are lacking. Here we present data describing the relationships between net ecosystem exchange of carbon (NEE) and climate factors as measured using the eddy covariance method at 125 unique sites in various ecosystems...

  9. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    NARCIS (Netherlands)

    Ciais, P.; Wang, T.; Piao, S.L.; Ottlé, C.; Brender, P.; Moors, E.J.

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the

  10. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Science.gov (United States)

    T. Wang; P. Ciais; S.L. Piao; C. Ottle; P. Brender; F. Maignan; A. Arain; A. Cescatti; D. Gianelle; C. Gough; L Gu; P. Lafleur; T. Laurila; B. Marcolla; H. Margolis; L. Montagnani; E. Moors; N. Saigusa; T. Vesala; G. Wohlfahrt; C. Koven; A. Black; E. Dellwik; A. Don; D. Hollinger; A. Knohl; R. Monson; J. Munger; A. Suyker; A. Varlagin; S. Verma

    2011-01-01

    Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal...

  11. Riparian vegetation in the alpine connectome: Terrestrial-aquatic and terrestrial-terrestrial interactions.

    Science.gov (United States)

    Zaharescu, Dragos G; Palanca-Soler, Antonio; Hooda, Peter S; Tanase, Catalin; Burghelea, Carmen I; Lester, Richard N

    2017-12-01

    Alpine regions are under increased attention worldwide for their critical role in early biogeochemical cycles, their high sensitivity to environmental change, and as repositories of natural resources of high quality. Their riparian ecosystems, at the interface between aquatic and terrestrial environments, play important geochemical functions in the watershed and are biodiversity hotspots, despite a harsh climate and topographic setting. With climate change rapidly affecting the alpine biome, we still lack a comprehensive understanding of the extent of interactions between riparian surface, lake and catchment environments. A total of 189 glacial - origin lakes were surveyed in the Central Pyrenees to test how key elements of the lake and terrestrial environments interact at different scales to shape riparian plant composition. Secondly, we evaluated how underlying ecotope features drive the formation of natural communities potentially sensitive to environmental change and assessed their habitat distribution. At the macroscale, vegetation composition responded to pan-climatic gradients altitude and latitude, which captured in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with major water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local influences from mafic bedrock and soil water saturation. Community analysis identified four keystone ecosystems: (i) damp ecotone, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) calcareous substrate. These communities and their connections with ecotope elements could be at risk from a number of environmental change factors including warmer seasons, snow line and lowland species advancement, increased nutrient/metal input and water level fluctuations. The results imply important natural terrestrial-aquatic linkages in the riparian environment

  12. Reconciling estimates of the contemporary North American carbon balance among terrestrial biosphere models, atmospheric inversions, and a new approach for estimating net ecosystem exchange from inventory-based data

    Science.gov (United States)

    Daniel J. Hayes; David P. Turner; Graham Stinson; A. David Mcguire; Yaxing Wei; Tristram O. West; Linda S. Heath; Bernardus Dejong; Brian G. McConkey; Richard A. Birdsey; Werner A. Kurz; Andrew R. Jacobson; Deborah N. Huntzinger; Yude Pan; W. Mac Post; Robert B. Cook

    2012-01-01

    We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000-2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO2,...

  13. Belowground biodiversity and ecosystem functioning

    NARCIS (Netherlands)

    Bardgett, R.D.; van der Putten, W.H.

    2014-01-01

    Belowground biodiversity is largely out of sight and mind, but there is mounting evidence to show that the vast diversity of subterranean microorganisms and animals that live belowground contribute significantly to shaping the overall biodiversity and and terrestrial ecosystem function. In this

  14. Microtopography recreation benefits ecosystem restoration

    Science.gov (United States)

    Wei Wei; Liding Chen; Lei Yang; F. Fred Samadani; Ge Sun

    2012-01-01

    Within the context of global warming and accelerated human activities, the surrounding environments of many terrestrial ecosystems worldwide have become increasingly deteriorated, such that finding suitable methods and effective environmental technology to confront climate change and prevent land degradation is critical to the health and sustainability of the earth. In...

  15. Ecosystem services

    Science.gov (United States)

    Trista Patterson

    2014-01-01

    Since its inception, the ecosystem service approach has stimulated interest from numerous planning, management, and partnership perspectives. To date, however, research that quantifies ecosystem services in the study area (in the form of explicit ecosystem service studies) has been limited. This chapter reviews and synthesizes the concept of ecosystem services,...

  16. Terrestrial forest management plan for Palmyra Atoll

    Science.gov (United States)

    Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

    2011-01-01

    This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

  17. Inside Ecosystems.

    Science.gov (United States)

    Moll, Gary; And Others

    1995-01-01

    The third in a series of articles featuring the urban ecosystem. Discusses the inner workings of an ecosystem and the links that connect its elements, including the link between people and the environment. Graphics illustrate "layers" of the landscape. (LZ)

  18. Application of 34S analysis for elucidating terrestrial, marine and freshwater ecosystems: Evidence of animal movement/husbandry practices in an early Viking community around Lake Mývatn, Iceland

    Science.gov (United States)

    Sayle, Kerry L.; Cook, Gordon T.; Ascough, Philippa L.; Hastie, Helen R.; Einarsson, Árni; McGovern, Thomas H.; Hicks, Megan T.; Edwald, Ágústa; Friðriksson, Adolf

    2013-11-01

    Carbon and nitrogen stable isotope ratios (δ13C and δ15N) have been used widely in archaeology to investigate palaeodiet. Sulphur stable isotope ratios (δ34S) have shown great promise in this regard but the potential of this technique within archaeological science has yet to be fully explored. Here we report δ34S, δ13C and δ15N values for 129 samples of animal bone collagen from Skútustaðir, an early Viking age (landnám) settlement in north-east Iceland. This dataset represents the most comprehensive study to date of its kind on archaeological material and the results show a clear offset in δ34S values between animals deriving their dietary resources from terrestrial (mean = +5.6 ± 2.8‰), freshwater (mean = -2.7 ± 1.4‰) or marine (mean = +15.9 ± 1.5‰) reservoirs (with the three food groups being significantly different at 2σ). This offset allows reconstruction of the dietary history of domesticated herbivores and demonstrates differences in husbandry practices and animal movement/trade, which would be otherwise impossible using only δ13C and δ15N values. For example, several terrestrial herbivores displayed enriched bone collagen δ34S values compared to the geology of the Lake Mývatn region, indicating they may have been affected by sea-spray whilst being pastured closer to the coast, before being traded inland. Additionally, the combination of heavy δ15N values coupled with light δ34S values within pig bone collagen suggests that these omnivores were consuming freshwater fish as a significant portion of their diet. Arctic foxes were also found to be consuming large quantities of freshwater resources and radiocarbon dating of both the pigs and foxes confirmed previous studies showing that a large freshwater radiocarbon (14C) reservoir effect exists within the lake. Overall, these stable isotope and 14C data have important implications for obtaining a fuller reconstruction of the diets of the early Viking settlers in Iceland, and may allow

  19. Alpine ecosystems

    Science.gov (United States)

    P.W. Rundel; C.I. Millar

    2016-01-01

    Alpine ecosystems are typically defined as those areas occurring above treeline, while recognizing that alpine ecosystems at a local scale may be found below this boundary for reasons including geology, geomorphology, and microclimate. The lower limit of the alpine ecosystems, the climatic treeline, varies with latitude across California, ranging from about 3500 m in...

  20. Terrestrial short-term ecotoxicity of a green formicide.

    Science.gov (United States)

    Tiepo, Erasmo N; Corrêa, Albertina X R; Resgalla, Charrid; Cotelle, Sylvie; Férard, Jean-François; Radetski, Claudemir M

    2010-07-01

    When ants become annoying, large quantities of formicide are applied to terrestrial ecosystems in tropical regions, but awareness of the health and environmental impacts related to the use of synthetic pesticides has been increasing. The use of green pesticides to combat target organisms could reduce these impacts. In this regard, terrestrial ecotoxicity tests with higher plants (Brassica olaracea, Lactuca sativa and Mucuna aterrima), annelids (Eisenia foetida), Collembola (Folsomia candida) and soil enzyme activity analysis (diacetate fluorescein hydrolysis) were used to evaluate short-term terrestrial ecotoxicity of a green pesticide prepared from naturally-occurring organic compounds. At the highest formicide concentration tested in these experiments (i.e., 50 g kg(-1) soil) no toxicity toward terrestrial organisms was observed. The lack of short-term terrestrial ecotoxicity suggest that this green formicide can be classed as an environmentally friendly product as compared to the ecotoxicity of the most commonly used commercialized formicides. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  1. Introduced Terrestrial Species (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are...

  2. Terrestrial ecology in South Africa - project abstracts for 1980-1981

    CSIR Research Space (South Africa)

    Huntley, BJ

    1982-12-01

    Full Text Available Abstracts are provided for research projects conducted during 1980-1981 in South African terrestrial ecosystems. The abstracts are arranged alphabetically according to author name and a keyword index is provided....

  3. Terrestrial ecology in South Africa and South West Africa – project abstracts for 1979

    CSIR Research Space (South Africa)

    Ecosystems Programmes, Cooperative Scientific Programmes

    1981-05-01

    Full Text Available Brief descriptions of over 200 research projects undertaken during 1979 in South African and South West African terrestrial ecosystems are presented. The abstracts are arranged alphabetically according to author name and a keyword index is provided...

  4. Towards an ecosystem-based approach of Guam's coral reefs

    NARCIS (Netherlands)

    Weijerman, M.; Grace-McCaskey, Cynthia; Grafeld, Shanna L.; Kotowicz, Dawn M.; Oleson, Kirsten L.L.; Putten, van Ingrid E.

    2016-01-01

    Management of tropical reef ecosystems under pressure from terrestrial and extractive marine activities is not straightforward, especially when the interests of extractive and non-extractive marine resource sectors compete. Before implementing management actions, potential outcomes of alternative

  5. Forestry, ecosystems, and wildlife: The differences are in the details

    Science.gov (United States)

    Linda Joyce

    2008-01-01

    Climate affects all terrestrial and aquatic ecosystems in Colorado, and over the long term, plants and animals adapt. In the short term, fires, increased attacks by insects and invasive plant species, and higher temperatures are changing familiar landscapes.

  6. Bayreuth Institute of Terrestrial Ecosystem Research (BITOEK). Research report 1994. Predicting and explaining the response and critical threshold of ecosystems to changing environment; Bayreuter Institut fuer Terrestrische Oekosystemforschung (BITOeK). Forschungsbericht 1994. Vorhersage und Erklaerung des Verhaltens und der Belastbarkeit von Oekosystemen unter veraenderten Umweltbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Matzner, E.; Gollan, T.; Hauhs, M.; Huwe, B.

    1995-05-01

    Understanding the function and critical thresholds of ecosystems is a supposition for their appropriate management. Thus the aim of BITOEK is to understand and predict the impact of changing environmental conditions on forest ecosystems. Focus is given to the effects of decreasing S inputs, chronically high N inputs and to the regulation of transpiration. Investigations are conducted on various temporal and spatial scales reaching from short term laboratory to several year field studies. Generalization of the results is the aim of modelling and ecosystem-theroy. BITOe?`K has shown, - that the N load of forest ecosystems is higher than assumed, - that N-deposition causes several destabilizing changes in forest ecosystems, - that N deposition influences water quality from forested catchments, - that the N emissions needs a drastic decrease in order to match critical loads, - that decreasing S deposition does not immediately result in recovery of soils and groundwater, - that soil and water acidification will continue to be high - that the ground vegetation adds significantly to the total transpiration of forests, - that the transpiration can be quantitatively modelled on various scales. The results demonstrate the strong implication of atmospheric pollutants on the functioning of forest ecosystems and will find their application in forest- and water management, nature conservation, and air pollution strategies. (orig.) [Deutsch] Der oekologisch vertraegliche Umgang mit Oekosystemen setzt die Kenntnis ihrer Funktionsweise und Belastbarkeit vorraus. Ziel der Arbeiten von BITOeK ist daher die Erklaerung und Vorhersage der Effekte von Umweltveraenderungen in Waldoekosystemen. Im Mittelpunkt stehen dabei die Auswirkungen verminderter S-Eintraege, chronisch ueberhoehter N-Eintraege und die Regulation der Verdunstung durch Umweltfaktoren. Die Untersuchungen finden auf verschiedenen Ebenen der raeumlichen und zeitlichen Aufloesung statt und reichen von relativ kurzfristigen

  7. Terrestrial freshwater lenses: Unexplored subterranean oases

    Science.gov (United States)

    Laattoe, Tariq; Werner, Adrian D.; Woods, Juliette A.; Cartwright, Ian

    2017-10-01

    Freshwater lenses are lenticular bodies of fresh (TDS lenses in coastal aquifers, the formation, location and persistence of freshwater lenses in terrestrial settings are poorly understood. This is despite inland aquifers commonly containing saline groundwater, particularly in arid and semi-arid climates, and the local occurrences of freshwater being critical for ecosystems and human endeavour. We identify and classify known terrestrial freshwater lenses (TFLs) using four formation categories, namely topography, geology, groundwater-surface water interaction and recharge mechanisms. The resulting typology highlights the importance of buoyancy in the formation of TFLs in otherwise unlikely situations, implying that TFLs may be more prevalent than previously thought. TFLs represent some of the most vulnerable and precious freshwater resources on Earth that require considerably more research into mechanisms of formation and threats to their existence.

  8. Status and potential of terrestrial carbon sequestration in West Virginia

    Science.gov (United States)

    Benktesh D. Sharma; Jingxin. Wang

    2011-01-01

    Terrestrial ecosystem management offers cost-effective ways to enhance carbon (C) sequestration. This study utilized C stock and C sequestration in forest and agricultural lands, abandoned mine lands, and harvested wood products to estimate the net current annual C sequestration in West Virginia. Several management options within these components were simulated using a...

  9. Conservation and monitoring of invertebrates in terrestrial protected areas

    OpenAIRE

    Melodie A. McGeoch; Hendrik Sithole; Samways, Michael J.; Simaika, John P; Pryke, James S.; Mike Picker; Charmaine Uys; Armstrong, Adrian J.; Ansie S. Dippenaar-Schoeman; Ian A. Engelbrecht; Brigitte Braschler; Michelle Hamer

    2011-01-01

    Invertebrates constitute a substantial proportion of terrestrial and freshwater biodiversity and are critical to ecosystem function. However, their inclusion in biodiversity monitoring and conservation planning and management has lagged behind better-known, more widely appreciated taxa. Significant progress in invertebrate surveys, systematics and bioindication, both globally and locally, means that their use in biodiversity monitoring and conservation is becoming increasingly feasible. Here ...

  10. Inventory of Some Environmental Components in the Terrestrial and ...

    African Journals Online (AJOL)

    A survey of some environmental components in the terrestrial and aquatic ecosystems in the Integrated Waste Treatment Facility in Makurdi was carried out to obtain baseline information on the area. Inventory, semi-structured interviews and field observations/walks were carried out to obtain information on useful plants, ...

  11. Terrestrial species viability assessments for national forests in northeastern Washington

    Science.gov (United States)

    William L. Gaines; Barbara C. Wales; Lowell H. Suring; James S. Begley; Kim Mellen-McLean; Shawne. Mohoric

    2017-01-01

    We developed a process to address terrestrial wildlife species for which management for ecosystem diversity may be inadequate for providing ecological conditions capable of sustaining viable populations. The process includes (1) identifying species of conservation concern, (2) describing source habitats, and other important ecological factors, (3) organizing species...

  12. Isotopic tracers for net primary productivity for a terrestrial esocystem ...

    African Journals Online (AJOL)

    The coupling effect of vapour release and CO2 uptake during photosynthesis plays an important role in the carbon and hydrologic cycles. The water use efficiency (WUE) for transpiration was used in calculating the net primary productivity (NPP) for terrestrial ecosystem. Three parameters were used in calculating the water ...

  13. 171 inventory of some environmental components in the terrestrial ...

    African Journals Online (AJOL)

    2010-09-02

    Sep 2, 2010 ... ABSTRACT. A survey of some environmental components in the terrestrial and aquatic ecosystems in the. Integrated Waste Treatment Facility in Makurdi was carried out to obtain baseline information on the area. Inventory, semi-structured interviews and field observations/walks were carried out to obtain ...

  14. Wetlands as early warning (eco)systems for water resource ...

    African Journals Online (AJOL)

    2005-10-04

    Oct 4, 2005 ... saturation is permanent or semi-permanent (Table 1). As transitional ecosystems, wetlands represent the aquatic edge for many terrestrial biota and the terrestrial edge for many aquatic biota (Mitsch and Gosselink, 1993). Thus, land-use practices that alter the balance between inputs and outputs of water to ...

  15. Imaging spectroscopy for ecological analysis in forest and grassland ecosystems

    NARCIS (Netherlands)

    Homolova, L.

    2014-01-01

    Terrestrial vegetation is an important component of the Earth’s biosphere and therefore playing an essential role in climate regulation, carbon sequestration, and it provides large variety of services to humans. For a sustainable management of terrestrial ecosystems it is essential to

  16. Variations of Terrestrial Net Primary Productivity in East Asia

    Directory of Open Access Journals (Sweden)

    Fangmin Zhang

    2012-01-01

    Full Text Available Due to the heterogeneity and complexity of terrestrial ecosystems of East Asia, a better understanding of relationships between climate change and net primary productivity (NPP distribution is important to predict future carbon dynamics. The objective of this study is to analyze the temporal-spatial patterns of NPP in East Asia (10°S - 55°N, 60 - 155°E from 1982 to 2006 using the process-based Boreal Ecosystem Productivity Simulator (BEPS model. Prior to the regional simulation, the annual simulated NPP was validated using field observed NPP demonstrating the ability of BEPS to simulate NPP in different ecosystems of East Asia.

  17. Terrestrial and extraterrestrial fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, D.; Jenneskens, L.W.; Jehlicka, J; Koper, C.; Vlietstra, E. [Rice Univ, Houston, TX (United States). Dept. of Earth Science

    2003-07-01

    This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous-Tertiary-Boundary and Pennian-Triassic-Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated processes of fullerene formation, including the suggestion that some natural fullerenes might have formed from biological (algal) remains.

  18. Batteries for terrestrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Kulin, T.M.

    1998-07-01

    Extensive research has been conducted in the design and manufacture of very long life vented and sealed maintenance free nickel-cadmium aircraft batteries. These batteries have also been used in a number of terrestrial applications with good success. This study presents an overview of the Ni-Cd chemistry and technology as well as detailed analysis of the advantages and disadvantages of the Ni-Cd couple for terrestrial applications. The performance characteristics of both sealed and vented Ni-Cd's are presented. Various charge algorithms are examined and evaluated for effectiveness and ease of implementation. Hardware requirements for charging are also presented and evaluated. The discharge characteristics of vented and sealed Ni-Cd's are presented and compared to other battery chemistries. The performance of Ni-Cd's under extreme environmental conditions is also compared to other battery chemistries. The history of various terrestrial applications is reviewed and some of the lessons learned are presented. Applications discussed include the NASA Middeck Payload Battery, Raytheon Aegis Missile System Battery, THAAD Launcher battery, and the Titan IV battery. The suitability of the Ni-Cd chemistry for other terrestrial applications such as electric vehicles and Uninterruptible Power Supply is discussed.

  19. Terrestrial planet formation.

    Science.gov (United States)

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

  20. Terrestrial nitrogen cycles: Some unanswered questions

    Science.gov (United States)

    Vitousek, P.

    1984-01-01

    Nitrogen is generally considered to be the element which most often limits the growth of plants in both natural and agricultural ecosystems. It regulates plant growth because photosynthetic rates are strongly dependent on the concentration of nitrogen in leaves, and because relatively large mounts of protein are required for cell division and growth. Yet nitrogen is abundant in the biosphere - the well-mixed pool in the atmosphere is considered inexhaustible compared to biotic demand, and the amount of already fixed organic nitrogen in soils far exceeds annual plant uptake in terrestrial ecosystems. In regions where natural vegetation is not nitrogen limited, continuous cultivation induces nitrogen deficiency. Nitrogen loss from cultivated lands is more rapid than that of other elements, and nitrogen fertilization is generally required to maintain crop yield under any continuous system. The pervasiveness of nitrogen deficiency in many natural and most managed sites is discussed.

  1. Ecosystem functioning

    National Research Council Canada - National Science Library

    Jax, Kurt

    2010-01-01

    "In the face of decreasing biodiversity and ongoing global changes, maintaining ecosystem functioning is seen both as a means to preserve biological diversity as well as for safeguarding human well...

  2. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    Science.gov (United States)

    E. M. Stacy; S. C. Hart; C. T. Hunsaker; D. W. Johnson; A. A. Berhe

    2015-01-01

    Lateral movement of organic matter (OM) due to erosion is now considered an important flux term in terrestrial carbon (C) and nitrogen (N) budgets, yet most published studies on the role of erosion focus on agricultural or grassland ecosystems. To date, little information is available on the rate and nature of OM eroded from forest ecosystems. We present annual...

  3. Mapping and Quantifying Terrestrial Vertebrate Biodiversity at ...

    Science.gov (United States)

    The ability to assess, report, map, and forecast functions of ecosystems is critical to our capacity to make informed decisions to maintain the sustainable nature of our environment. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales. In answer to this challenge, the U.S. Environmental Protection Agency has created a partnership with other Federal agencies, academic institutions, and Non-Governmental Organizations to develop the EnviroAtlas (https://www.epa.gov/enviroatlas), an online national Decision Support Tool that allows users to view and analyze the geographical description of the supply and demand for ecosystem services, as well as the drivers of change. As part of the EnviroAtlas, an approach has been developed that uses deductive habitat models for all terrestrial vertebrates of the conterminous United States and clusters them into biodiversity metrics that relate to ecosystem service-relevant categories. Metrics, such as species and taxon richness, have been developed and integrated with other measures of biodiversity. Collectively, these metrics provide a consistent scalable process from which to make geographic comparisons, provide thematic assessments, and to monitor status and trends in biodiversity. The national biodiversity component operates across approximatel

  4. The vulnerability of ecosystem services to land use change

    NARCIS (Netherlands)

    Metzger, M.J.; Rounsevell, M.D.A.; Acosta-Michlik, L.; Leemans, R.; Schroter, D.

    2006-01-01

    Terrestrial ecosystems provide a number of vital services for people and society, such as biodiversity, food, fibre, water resources, carbon sequestration, and recreation. The future capability of ecosystems to provide these services is determined by changes in socio-economic characteristics, land

  5. Toward understanding the effect of top predators on ecosystems

    Science.gov (United States)

    Lecomte, Nicolas; Ehrich, Dorothée; Ims, Rolf A

    2009-01-01

    To what extent top predators - carnivores at the top of food chains - drive or just respond to ecosystem dynamics is a central, but partially unresolved, question in ecology. In this report, we highlight how different research approaches employed in aquatic and terrestrial ecology may have a bearing on how the role of top predators in ecosystems is perceived. PMID:20948660

  6. Ecological history vs. social expectations: managing aquatic ecosystems.

    Science.gov (United States)

    Gordon H. Reeves; Sally L. Duncan

    2009-01-01

    The emerging perspective of ecosystems as both non-equilibrium and dynamic fits aquatic ecosystems as well as terrestrial systems. It is increasingly recognized that watersheds historically passed through different conditions over time. Habitat conditions varied in quantity and quality, primarily as a function of the time since the last major disturbance and the legacy...

  7. The Niger Delta wetland ecosystem: What threatens it and why ...

    African Journals Online (AJOL)

    The Niger Delta wetland ecosystem is of high economic importance to the local dwellers and the nation in general. The region is rich in both aquatic and terrestrial biodiversity and serves as a main source of livelihood for rural dwellers as well as stabilizing the ecosystem. Tremendous changes have occurred recently in the ...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  9. Solar-Terrestrial Interactions

    Science.gov (United States)

    2008-01-01

    satellite for polar cap passes during large SEP events to determine the experimental geographic cutoff latitudes for the two energy ranges. 9 These...E. Lamanna, Societa Italiana di Fisica , Bologna, Italy, 1997.) Shea, M.A., and D.F. Smart, Overview of the Effects of Solar Terrestrial Phenomena...Conference, Invited, Rapporteurs, & Highlight Papers, edited by N. Iucci and E. Lamanna, Societa Italiana di Fisica , Bologna, Italy, 1997.) 27

  10. Influence of multiple global change drivers on terrestrial carbon storage

    DEFF Research Database (Denmark)

    Yue, Kai; Fornara, Dario A; Yang, Wanqin

    2017-01-01

    The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum...... of their individual effects) rather than synergistic or antagonistic. We further show that (1) elevated CO2 , warming, N addition, P addition and increased rainfall, all exerted positive individual effects on plant C pools at both single-plant and plant-community levels; (2) plant C pool responses to individual...... additive effects of multiple global change drivers into future assessments of the C storage ability of terrestrial ecosystems....

  11. Environmental radionuclides tracers and timers of terrestrial processes

    CERN Document Server

    Froehlich, Klaus

    2009-01-01

    The book presents a state-of-the-art summary of knowledge on the use of radionuclides to study processes and systems in the continental part of the Earth's environment. It is conceived as a companion to the two volumes of this series, which deal with isotopes as tracers in the marine environment (Livingston, Marine Radioactivity) and with the radioecology of natural and man-made terrestrial systems (Shaw, Radioactivity in Terrestrial Ecosystems). Although the book focuses on natural and anthropogenic radionuclides (radioactive isotopes), it also refers to stable environmental isotopes, which i

  12. Towards 250 m mapping of terrestrial primary productivity over Canada

    Science.gov (United States)

    Gonsamo, A.; Chen, J. M.

    2011-12-01

    Terrestrial ecosystems are an important part of the climate and global change systems. Their role in climate change and in the global carbon cycle is yet to be well understood. Dataset from satellite earth observation, coupled with numerical models provide the unique tools for monitoring the spatial and temporal dynamics of territorial carbon cycle. The Boreal Ecosystems Productivity Simulator (BEPS) is a remote sensing based approach to quantifying the terrestrial carbon cycle by that gross and net primary productivity (GPP and NPP) and terrestrial carbon sinks and sources expressed as net ecosystem productivity (NEP). We have currently implemented a scheme to map the GPP, NPP and NEP at 250 m for first time over Canada using BEPS model. This is supplemented by improved mapping of land cover and leaf area index (LAI) at 250 m over Canada from MODIS satellite dataset. The results from BEPS are compared with MODIS GPP product and further evaluated with estimated LAI from various sources to evaluate if the results capture the trend in amount of photosynthetic biomass distributions. Final evaluation will be to validate both BEPS and MODIS primary productivity estimates over the Fluxnet sites over Canada. The primary evaluation indicate that BEPS GPP estimates capture the over storey LAI variations over Canada very well compared to MODIS GPP estimates. There is a large offset of MODIS GPP, over-estimating the lower GPP value compared to BEPS GPP estimates. These variations will further be validated based on the measured values from the Fluxnet tower measurements over Canadian. The high resolution GPP (NPP) products at 250 m will further be used to scale the outputs between different ecosystem productivity models, in our case the Canadian carbon budget model of Canadian forest sector CBM-CFS) and the Integrated Terrestrial Ecosystem Carbon model (InTEC).

  13. Terrestrial Ecosystems - Surficial Lithology of the Conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey (USGS) has generated a new classification and map of the lithology of surficial materials for the contiguous United States. This was...

  14. The pace of shifting climate in marine and terrestrial ecosystems.

    Science.gov (United States)

    Burrows, Michael T; Schoeman, David S; Buckley, Lauren B; Moore, Pippa; Poloczanska, Elvira S; Brander, Keith M; Brown, Chris; Bruno, John F; Duarte, Carlos M; Halpern, Benjamin S; Holding, Johnna; Kappel, Carrie V; Kiessling, Wolfgang; O'Connor, Mary I; Pandolfi, John M; Parmesan, Camille; Schwing, Franklin B; Sydeman, William J; Richardson, Anthony J

    2011-11-04

    Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate change (geographic shifts of isotherms over time) and the shift in seasonal timing of temperatures. Both measures are higher in the ocean than on land at some latitudes, despite slower ocean warming. These indices give a complex mosaic of predicted range shifts and phenology changes that deviate from simple poleward migration and earlier springs or later falls. They also emphasize potential conservation concerns, because areas of high marine biodiversity often have greater velocities of climate change and seasonal shifts.

  15. Terrestrial Ecosystems - Land Surface Forms of the Conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey (USGS) has generated land surface form classes for the contiguous United States. These land surface form classes were created as part of...

  16. Terrestrial Ecosystems - Isobioclimates of the Conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey (USGS) has generated and mapped isobioclimate classes for the contiguous United States. These isobioclimate classes were created as part...

  17. Global Distribution of Fine Root Biomass in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: A global data set of root biomass, rooting profiles, and concentrations nutrients in roots was compiled from the primary literature and used to study...

  18. Global Distribution of Root Profiles in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — Rooting depths were estimated from a global database of root profiles assembled from the primary literature to study relationships of abiotic and biotic factors...

  19. Global Distribution of Root Turnover in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Estimates of root turnover rates were calculated from measurements of live root standing crop and belowground net primary production (BNPP) compiled from...

  20. The pace of shifting climate in marine and terrestrial ecosystems

    DEFF Research Database (Denmark)

    Burrows, Michael T.; Schoeman, David S.; Buckley, Lauren B.

    2011-01-01

    Climate change challenges organisms to adapt or move to track changes in environments in space and time. We used two measures of thermal shifts from analyses of global temperatures over the past 50 years to describe the pace of climate change that species should track: the velocity of climate cha...

  1. Extremophiles: from abyssal to terrestrial ecosystems and possibly beyond

    Science.gov (United States)

    Canganella, Francesco; Wiegel, Juergen

    2011-04-01

    The anthropocentric term "extremophile" was introduced more than 30 years ago to describe any organism capable of living and growing under extreme conditions—i.e., particularly hostile to human and to the majority of the known microorganisms as far as temperature, pH, and salinity parameters are concerned. With the further development of studies on microbial ecology and taxonomy, more "extreme" environments were found and more extremophiles were described. Today, many different extremophiles have been isolated from habitats characterized by hydrostatic pressure, aridity, radiations, elevated temperatures, extreme pH values, high salt concentrations, and high solvent/metal concentrations, and it is well documented that these microorganisms are capable of thriving under extreme conditions better than any other organism living on Earth. Extremophiles have also been investigated as far as the search for life in other planets is concerned and even to evaluate the hypothesis that life on Earth came originally from space. Extremophiles are interesting for basic and applied sciences. Particularly fascinating are their structural and physiological features allowing them to stand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA polymerase, thermostable enzymes), the search was successful and the final application was achieved, but certainly further exploitations are next to come.

  2. Terrestrial Ecosystems - Topographic Moisture Potential of the Conterminous United States

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The U.S. Geological Survey (USGS) has generated topographic moisture potential classes for the contiguous United States. These topographic moisture potential classes...

  3. Terrestrial Ecology Guide.

    Science.gov (United States)

    Morrison, James W., Ed.; Hall, James A., Ed.

    This collection of study units focuses on the study of the ecology of land habitats. Considered are such topics as map reading, field techniques, forest ecosystem, birds, insects, small mammals, soils, plant ecology, preparation of terrariums, air pollution, photography, and essentials of an environmental studies program. Each unit contains…

  4. Terrestrial Steering Group. 2014. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Aastrup, Peter; Aronsson, Mora; Barry, Tom

    implementation of the Arctic Terrestrial Biodiversity Monitoring Plan for the next two years. Identify expert networks required for successful implementation of the plan. Identify key gaps and opportunities for the TSG related to plan implementation and identify near-term next steps to address gaps.......The Terrestrial Steering Group (TSG), has initiated the implementation phase of the CBMP Terrestrial Plan. The CBMP Terrestrial Steering Group, along with a set of invited experts (see Appendix A for a participants list), met in Iceland from February 25-27th to develop a three year work plan...... to guide implementation of the CBMP-Terrestrial Plan. This report describes the outcome of that workshop. The aim of the workshop was to develop a three year work plan to guide implementation of the CBMP-Terrestrial Plan. The participants were tasked with devising an approach to both (a) determine what...

  5. Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands.

    NARCIS (Netherlands)

    Bokhorst, S.F.; Huiskes, A.; Convey, P.; Aerts, R.

    2007-01-01

    Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in

  6. Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands

    NARCIS (Netherlands)

    Bokhorst, S.F.; Huiskes, A.H.L.; Convey, P.; Aerts, R.A.M.

    2007-01-01

    Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in

  7. Priming effect: bridging the gap between terrestrial and aquatic ecology.

    Science.gov (United States)

    Guenet, Bertrand; Danger, Michael; Abbadie, Luc; Lacroix, Gérard

    2010-10-01

    Understanding how ecosystems store or release carbon is one of ecology's greatest challenges in the 21st century. Organic matter covers a large range of chemical structures and qualities, and it is classically represented by pools of different recalcitrance to degradation. The interaction effects of these pools on carbon cycling are still poorly understood and are most often ignored in global-change models. Soil scientists have shown that inputs of labile organic matter frequently tend to increase, and often double, the mineralization of the more recalcitrant organic matter. The recent revival of interest for this phenomenon, named the priming effect, did not cross the frontiers of the disciplines. In particular, the priming effect phenomenon has been almost totally ignored by the scientific communities studying marine and continental aquatic ecosystems. Here we gather several arguments, experimental results, and field observations that strongly support the hypothesis that the priming effect is a general phenomenon that occurs in various terrestrial, freshwater, and marine ecosystems. For example, the increase in recalcitrant organic matter mineralization rate in the presence of labile organic matter ranged from 10% to 500% in six studies on organic matter degradation in aquatid ecosystems. Consequently, the recalcitrant organic matter mineralization rate may largely depend on labile organic matter availability, influencing the CO2 emissions of both aquatic and terrestrial ecosystems. We suggest that (1) recalcitrant organic matter may largely contribute to the CO2 emissions of aquatic ecosystems through the priming effect, and (2) priming effect intensity may be modified by global changes, interacting with eutrophication processes and atmospheric CO2 increases. Finally, we argue that the priming effect acts substantially in the carbon and nutrient cycles in all ecosystems. We outline exciting avenues for research, which could provide new insights on the responses

  8. Microstructure of terrestrial catastrophism

    Energy Technology Data Exchange (ETDEWEB)

    Clube, S.V.M. (Oxford Univ. (UK). Dept. of Astrophysics); Napier, W.M. (Royal Observatory, Edinburgh (UK))

    1984-12-15

    The theory of evolution involving episodic terrestrial catastrophism predicts that the Oort cloud is disturbed by close encounters with massive nebulae. Each disturbance generates bombardment pulses of a few million years duration, the pulse frequencies being determined by the Sun's passage through the spiral arms and central plane of the Galaxy where nebulae concentrate. The structure within a pulse is shown here to be dominated by a series of 'spikes' of approx. 0.01-0.1 Myr duration separated by approx. 0.1-1.0 Myr, each caused by the arrival in circumterrestrial space of the largest comets followed by their disintegration into short-lived Apollo asteroids. Evidence is presented that a bombardment pulse was induced 3-5 Myr ago and that a 'spike' in the form of debris from a Chiron-like progenitor of Encke's comet has dominated the terrestrial environment for the last 0.02 Myr.

  9. Modeling and Monitoring Terrestrial Primary Production in a Changing Global Environment: Toward a Multiscale Synthesis of Observation and Simulation

    Directory of Open Access Journals (Sweden)

    Shufen Pan

    2014-01-01

    Full Text Available There is a critical need to monitor and predict terrestrial primary production, the key indicator of ecosystem functioning, in a changing global environment. Here we provide a brief review of three major approaches to monitoring and predicting terrestrial primary production: (1 ground-based field measurements, (2 satellite-based observations, and (3 process-based ecosystem modelling. Much uncertainty exists in the multi-approach estimations of terrestrial gross primary production (GPP and net primary production (NPP. To improve the capacity of model simulation and prediction, it is essential to evaluate ecosystem models against ground and satellite-based measurements and observations. As a case, we have shown the performance of the dynamic land ecosystem model (DLEM at various scales from site to region to global. We also discuss how terrestrial primary production might respond to climate change and increasing atmospheric CO2 and uncertainties associated with model and data. Further progress in monitoring and predicting terrestrial primary production requires a multiscale synthesis of observations and model simulations. In the Anthropocene era in which human activity has indeed changed the Earth’s biosphere, therefore, it is essential to incorporate the socioeconomic component into terrestrial ecosystem models for accurately estimating and predicting terrestrial primary production in a changing global environment.

  10. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

    Science.gov (United States)

    Adams, Byron J.; Wall, Diana H.; Virginia, Ross A.; Broos, Emma; Knox, Matthew A.

    2014-01-01

    Abstract The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

  11. Climate-mediated spatiotemporal variability in terrestrial productivity across Europe

    Science.gov (United States)

    Wu, X.; Babst, F.; Ciais, P.; Frank, D.; Reichstein, M.; Wattenbach, M.; Zang, C.; Mahecha, M. D.

    2014-06-01

    Quantifying the interannual variability (IAV) of the terrestrial ecosystem productivity and its sensitivity to climate is crucial for improving carbon budget predictions. In this context it is necessary to disentangle the influence of climate from impacts of other mechanisms underlying the spatiotemporal patterns of IAV of the ecosystem productivity. In this study we investigated the spatiotemporal patterns of IAV of historical observations of European crop yields in tandem with a set of climate variables. We further evaluated if relevant remote-sensing retrievals of NDVI (normalized difference vegetation index) and FAPAR (fraction of absorbed photosynthetically active radiation) depict a similar behaviour. Our results reveal distinct spatial patterns in the IAV of the analysed proxies linked to terrestrial productivity. In particular, we find higher IAV in water-limited regions of Europe (Mediterranean and temperate continental Europe) compared to other regions in both crop yield and remote-sensing observations. Our results further indicate that variations in the water balance during the active growing season exert a more pronounced and direct effect than variations of temperature on explaining the spatial patterns in IAV of productivity-related variables in temperate Europe. Overall, we observe a temporally increasing trend in the IAV of terrestrial productivity and an increasing sensitivity of productivity to water availability in dry regions of Europe during the 1975-2009 period. In the same regions, a simultaneous increase in the IAV of water availability was detected. These findings suggest intricate responses of carbon fluxes to climate variability in Europe and that the IAV of terrestrial productivity has become potentially more sensitive to changes in water availability in the dry regions in Europe. The changing sensitivity of terrestrial productivity accompanied by the changing IAV of climate is expected to impact carbon stocks and the net carbon balance

  12. Terrestrial Plume Impingement Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Masten Space Systems proposes to create a terrestrial plume impingement testbed for generating novel datasets for extraterrestrial robotic missions. This testbed...

  13. Dissolved Organic Carbon Fluxes in Rivers of the Conterminous United States: Influence of Terrestrial - Aquatic Linkages

    Science.gov (United States)

    Stackpoole, S. M.; Butman, D. E.; Stets, E.; Striegl, R. G.; Bachelet, D. M.; Zhu, Z.; Liu, S.

    2015-12-01

    Management of terrestrial carbon stocks in natural ecosystems has been proposed as a sustainable approach to counteracting the anthropogenic contribution of carbon dioxide to the atmosphere. One factor of uncertainty in carbon accounting is that a portion of carbon assumed to be sequestered in soils may in fact be transported to river networks. The primary objectives of this study are to: 1) determine if the magnitude of empirical estimates of dissolved organic carbon (DOC) export in rivers correlates with simulated soil DOC leachate values from terrestrial carbon models, and 2) quantify terrestrial loading of DOC to river networks across the conterminous US. We evaluated the magnitude of riverine DOC fluxes relative to carbon storage in terrestrial biomass and soils using the aggregated results from the terrestrial carbon models included in the LandCarbon and Multi-scale Synthesis and Terrestrial Model Intercomparison Projects. We also compared gridded terrestrial DOC leaching values to downstream DOC fluxes in rivers estimated by the USGS LOADEST model. Quantification of terrestrial-aquatic linkages is necessary to better evaluate ecosystem carbon sequestration as a potential tool for mitigating anthropogenic perturbance to the global carbon cycle.

  14. Effects of red-backed salamanders on ecosystem functions.

    Directory of Open Access Journals (Sweden)

    Daniel J Hocking

    Full Text Available Ecosystems provide a vast array of services for human societies, but understanding how various organisms contribute to the functions that maintain these services remains an important ecological challenge. Predators can affect ecosystem functions through a combination of top-down trophic cascades and bottom-up effects on nutrient dynamics. As the most abundant vertebrate predator in many eastern US forests, woodland salamanders (Plethodon spp. likely affect ecosystems functions. We examined the effects of red-backed salamanders (Plethodon cinereus on a variety of forest ecosystem functions using a combined approach of large-scale salamander removals (314-m(2 plots and small-scale enclosures (2 m(2 where we explicitly manipulated salamander density (0, 0.5, 1, 2, 4 m(-2. In these experiments, we measured the rates of litter and wood decomposition, potential nitrogen mineralization and nitrification rates, acorn germination, and foliar insect damage on red oak seedlings. Across both experimental venues, we found no significant effect of red-backed salamanders on any of the ecosystem functions. We also found no effect of salamanders on intraguild predator abundance (carabid beetles, centipedes, spiders. Our study adds to the already conflicting evidence on effects of red-backed salamander and other amphibians on terrestrial ecosystem functions. It appears likely that the impact of terrestrial amphibians on ecosystem functions is context dependent. Future research would benefit from explicitly examining terrestrial amphibian effects on ecosystem functions under a variety of environmental conditions and in different forest types.

  15. Origins of the terrestrial flora: A symbiosis with fungi?

    Directory of Open Access Journals (Sweden)

    Selosse Marc-André

    2015-01-01

    Full Text Available Land phototrophs need to exploit both atmosphere (providing gas and light and substrate (furnishing water and minerals. Yet, their algal ancestors were poorly pre-adapted to such a life at the interface. We review the paleontological evidence that fungal symbioses which can exploit substrate resources, helped adaptation to land constraints. Diverse structures dating back to the Devonian present convincing evidence for lichens, (symbioses between fungi and microscopic algae but fossils remain scarce, so that early lichen abundance and ecological relevance remain questionable. Several enigmatic but abundant fossils from the Siluro-Devonian, such as Spongiophytonor the giant Prototaxites (Nematophytes, likely represent fungus-algal symbioses, which shaped early terrestrial ecosystems. Yet, these taxa are fully extinct, and do not have clear affinities with extant groups. Finally, terrestrialization of Embryophyta (land plants, which currently dominate land ecosystems, is linked to a symbiosis with Glomeromycetes. Today, these fungi form arbuscular mycorrhizae, which help most Embryophyta to exploit soil, and molecular data combined with paleontological evidence support the idea that this type of association is ancestral. The role of symbiotic Mucoromycetes during terrestrialization is not fully understood and mycorrhizal association diversified later in the evolution of Embryophyta. Fungal-algal symbioses thus recurrently contributed to terrestrialization of phototrophs.

  16. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature......, ultraviolet radiation and reactive oxygen species. Further, we analyze rates of measured emission of aerobically produced CH4 in pectin and in plant tissues from different studies and argue that pectin is very far from the sole contributing precursor. Hence, scaling up of aerobic CH4 emission needs to take...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  17. Space Weather: Terrestrial Perspective

    Directory of Open Access Journals (Sweden)

    Pulkkinen Tuija

    2007-05-01

    Full Text Available Space weather effects arise from the dynamic conditions in the Earth’s space environment driven by processes on the Sun. While some effects are influenced neither by the properties of nor the processes within the Earth’s magnetosphere, others are critically dependent on the interaction of the impinging solar wind with the terrestrial magnetic field and plasma environment. As the utilization of space has become part of our everyday lives, and as our lives have become increasingly dependent on technological systems vulnerable to space weather influences, understanding and predicting hazards posed by the active solar events has grown in importance. This review introduces key dynamic processes within the magnetosphere and discusses their relationship to space weather hazards.

  18. Future directions of ecosystem science

    Science.gov (United States)

    Baron, Jill; Galvin, Kathleen A.

    1990-01-01

    Scientific knowledge about ecosystem structure and function has expanded greatly during the past few decades. Terrestrial and aquatic nutrient cycling, ecosystem energetics, population dynamics, belowground processes, and food webs have been studied at the plot, stand, watershed, and landscape levels at many locations around the globe. Ideas about terrestrial-atmospheric interactions and human interference in these processes have changed dramatically. There is new appreciation of the need to incorporate into ecosystem studies the interactions between human populations and the ecosystem, not only because humans affect ecosystem processes, but because these systems support human populations (Glantz 1988, Holden 1988, Parry et al. 1988, WCED 1987). Recent advances in ecosystem science are due, in part, to technological improvements in computing power, new laboratory and field physical and chemical analytical techniques, and satellite imagery for remote sensing of Earth's structure and dynamics. Modeling and geographic information systems have provided the capability for integrating multiple data sets with process simulations to generate hypotheses about regional ecosystem function. Concurrent with these scientific developments has been a growing concern about the links between the health of the environment and world-wide industrial, land, and resource-management practices. Environmental damage at the local level was widely recognized in the 1960s, prompting the environmental movement of that decade. Regional environmental problems with multiple effects and politically difficult solutions have been perceived more recently; the issue of acidic deposition provides an example of such a second-generation concern (Clark and Holling 1985). Today there is a growing awareness of global-scale environmental degradation brought about by the combined actions of all peoples on Earth (Clark 1989, Woodmansee et al. 1988). The three levels of environmental concern--local, regional

  19. From individuals to ecosystem function: toward an integration of evolutionary and ecosystem ecology.

    Science.gov (United States)

    Schmitz, Oswald J; Grabowski, Jonathan H; Peckarsky, Barbara L; Preisser, Evan L; Trussell, Geoffrey C; Vonesh, James R

    2008-09-01

    An important goal in ecology is developing general theory on how the species composition of ecosystems is related to ecosystem properties and functions. Progress on this front is limited partly because of the need to identify mechanisms controlling functions that are common to a wide range of ecosystem types. We propose that one general mechanism, rooted in the evolutionary ecology of all species, is adaptive foraging behavior in response to predation risk. To support our claim, we present two kinds of empirical evidence from plant-based and detritus-based food chains of terrestrial and aquatic ecosystems. The first kind comes from experiments that explicitly trace how adaptive foraging influences ecosystem properties and functions. The second kind comes from a synthesis of studies that individually examine complementary components of particular ecosystems that together provide an integrated perspective on the link between adaptive foraging and ecosystem function. We show that the indirect effects of predators on plant diversity, plant productivity, nutrient cycling, trophic transfer efficiencies, and energy flux caused by consumer foraging shifts in response to risk are qualitatively different from effects caused by reductions in prey density due to direct predation. We argue that a perspective of ecosystem function that considers effects of consumer behavior in response to predation risk will broaden our capacity to explain the range of outcomes and contingencies in trophic control of ecosystems. This perspective also provides an operational way to integrate evolutionary and ecosystem ecology, which is an important challenge in ecology.

  20. Taiwan's industrial heavy metal pollution threatens terrestrial biota

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, M.J. [Department of Biological Sciences, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Selvaraj, K. [Institute of Marine Geology and Chemistry, National Sun Yat-sen University, Kaohsiung 804, Taiwan (China); Agoramoorthy, G. [Department of Pharmacy, Tajen University, Yanpu, Pingtung 907, Taiwan (China)]. E-mail: agoram@mail.tajen.edu.tw

    2006-09-15

    The bioconcentration levels of essential (Cu, Fe, Mg, Mn, and Zn) and non-essential (As, Cd, Hg, Pb, and Sn) elements have been investigated in different terrestrial biota such as fungi, plant, earthworm, snail, crab, insect, amphibian, lizard, snake, and bat including the associated soil, to investigate the ecosystem health status in Kenting National Park, Taiwan. High bioconcentrations of Cd, Hg, and Sn in snail, earthworm, crab, lizard, snake, and bat indicated a contaminated terrestrial ecosystem. High concentrations of Cd, Hg, and Sn in plant species, effective bioaccumulation of Cd by earthworm, snail, crab and bat, as well as very high levels of Hg found in invertebrates, amphibians, and reptiles revealed a strong influence from industrial pollution on the biotic community. This study for the first time presents data on the impact of heavy metal pollution on various terrestrial organisms in Taiwan. - Metal effects occur at any terrestrial levels in Taiwan.

  1. Predictors of Drought Recovery across Forest Ecosystems

    Science.gov (United States)

    Anderegg, W.

    2016-12-01

    The impacts of climate extremes on terrestrial ecosystems are poorly understood but central for predicting carbon cycle feedbacks to climate change. Coupled climate-carbon cycle models typically assume that vegetation recovery from extreme drought is immediate and complete, which conflicts with basic plant physiological understanding. Here, we discuss what we have learned about forest ecosystem recovery from extreme drought across spatial and temporal scales, drawing on inference from tree rings, eddy covariance data, large scale gross primary productivity products, and ecosystem models. In tree rings, we find pervasive and substantial "legacy effects" of reduced growth and incomplete recovery for 1-4 years after severe drought, and that legacy effects are most prevalent in dry ecosystems, Pinaceae, and species with low hydraulic safety margins. At larger scales, we see relatively rapid recovery of ecosystem fluxes, with strong influences of ecosystem productivity and diversity and longer recovery periods in high latidue forests. In contrast, no or limited legacy effects are simulated in current climate-vegetation models after drought, and we highlight some of the key missing mechanisms in dynamic vegetation models. Our results reveal hysteresis in forest ecosystem carbon cycling and delayed recovery from climate extremes and help advance a predictive understanding of ecosystem recovery.

  2. Sulfide intrusion and detoxification in seagrasses ecosystems

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Holmer, Marianne

    Sulfide intrusion in seagrasses represents a global threat to seagrasses and thereby an important parameter in resilience of seagrass ecosystems. In contrast seegrasses colonize and grow in hostile sediments, where they are constantly exposed to invasion of toxic gaseous sulfide. Remarkably little...... strategies of seagrasses to sustain sulfide intrusion. Using stable isotope tracing, scanning electron microscopy with x-ray analysis, tracing sulfur compounds combined with ecosystem parameters we found different spatial, intraspecific and interspecific strategies to cope with sulfidic sediments. 1...... not present in terrestrial plants at that level. Sulfide is not necessarily toxic but used as sulfur nutrition, presupposing healthy seagrass ecosystems that can support detoxification mechanisms. Presence or absence of those mechanisms determines susceptibility of seagrass ecosystems to sediment sulfide...

  3. Grazers: biocatalysts of terrestrial silica cycling.

    Science.gov (United States)

    Vandevenne, Floor Ina; Barão, Ana Lúcia; Schoelynck, Jonas; Smis, Adriaan; Ryken, Nick; Van Damme, Stefan; Meire, Patrick; Struyf, Eric

    2013-12-07

    Silica is well known for its role as inducible defence mechanism countering herbivore attack, mainly through precipitation of opaline, biogenic silica (BSi) bodies (phytoliths) in plant epidermal tissues. Even though grazing strongly interacts with other element cycles, its impact on terrestrial silica cycling has never been thoroughly considered. Here, BSi content of ingested grass, hay and faeces of large herbivores was quantified by performing multiple chemical extraction procedures for BSi, allowing the assessment of chemical reactivity. Dissolution experiments with grass and faeces were carried out to measure direct availability of BSi for dissolution. Average BSi and readily soluble silica numbers were higher in faeces as compared with grass or hay, and differences between herbivores could be related to distinct digestive strategies. Reactivity and dissolvability of BSi increases after digestion, mainly due to degradation of organic matrices, resulting in higher silica turnover rates and mobilization potential from terrestrial to aquatic ecosystems in non-grazed versus grazed pasture systems (2 versus 20 kg Si ha(-1) y(-1)). Our results suggest a crucial yet currently unexplored role of herbivores in determining silica export from land to ocean, where its availability is linked to eutrophication events and carbon sequestration through C-Si diatom interactions.

  4. Top-down constraints on disturbance dynamics in the terrestrial carbon cycle: effects at global and regional scales

    NARCIS (Netherlands)

    Bloom, A. A.; Exbrayat, J. F.; van der Velde, I.; Peters, W.; Williams, M.

    2014-01-01

    Large uncertainties preside over terrestrial carbon flux estimates on a global scale. In particular, the strongly coupled dynamics between net ecosystem productivity and disturbance C losses are poorly constrained. To gain an improved understanding of ecosystem C dynamics from regional to global

  5. Heterotrophic activity, bacterial types and abundance in different ecosystems of the Queen Maud Land

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Kodagali, J.; Nair, S.; Sheelu, G.; Chandramohan, D.

    Microbiological studies from the marine, limnetic, terrestrial and glacial ecosystems were carried out during the Ninth Indian Expedition (1989-90) to estimate the bacterial numbers, to characterise the generic types and also to estimate the uptake...

  6. Terrestrial locomotion in arachnids.

    Science.gov (United States)

    Spagna, Joseph C; Peattie, Anne M

    2012-05-01

    In this review, we assess the current state of knowledge on terrestrial locomotion in Arachnida. Arachnids represent a single diverse (>100,000 species) clade containing well-defined subgroups (at both the order and subordinal levels) that vary morphologically around a basic body plan, yet exhibit highly disparate limb usage, running performance, and tarsal attachment mechanisms. Spiders (Araneae), scorpions (Scorpiones), and harvestmen (Opiliones) have received the most attention in the literature, while some orders have never been subject to rigorous mechanical characterization. Most well-characterized taxa move with gaits analogous to the alternating tripod gaits that characterize fast-moving Insecta - alternating tetrapods or alternating tripods (when one pair of legs is lifted from the ground for some other function). However, between taxa, there is considerable variation in the regularity of phasing between legs. Both large and small spiders appear to show a large amount of variation in the distribution of foot-ground contact, even between consecutive step-cycles of a single run. Mechanisms for attachment to vertical surfaces also vary, and may depend on tufts of adhesive hairs, fluid adhesives, silks, or a combination of these. We conclude that Arachnida, particularly with improvements in microelectronic force sensing technology, can serve as a powerful study system for understanding the kinematics, dynamics, and ecological correlates of sprawled-posture locomotion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Use of terrestrial field studies in the derivation of bioaccumulation potential of chemicals.

    Science.gov (United States)

    van den Brink, Nico W; Arblaster, Jennifer A; Bowman, Sarah R; Conder, Jason M; Elliott, John E; Johnson, Mark S; Muir, Derek C G; Natal-da-Luz, Tiago; Rattner, Barnett A; Sample, Bradley E; Shore, Richard F

    2016-01-01

    Field-based studies are an essential component of research addressing the behavior of organic chemicals, and a unique line of evidence that can be used to assess bioaccumulation potential in chemical registration programs and aid in development of associated laboratory and modeling efforts. To aid scientific and regulatory discourse on the application of terrestrial field data in this manner, this article provides practical recommendations regarding the generation and interpretation of terrestrial field data. Currently, biota-to-soil-accumulation factors (BSAFs), biomagnification factors (BMFs), and bioaccumulation factors (BAFs) are the most suitable bioaccumulation metrics that are applicable to bioaccumulation assessment evaluations and able to be generated from terrestrial field studies with relatively low uncertainty. Biomagnification factors calculated from field-collected samples of terrestrial carnivores and their prey appear to be particularly robust indicators of bioaccumulation potential. The use of stable isotope ratios for quantification of trophic relationships in terrestrial ecosystems needs to be further developed to resolve uncertainties associated with the calculation of terrestrial trophic magnification factors (TMFs). Sampling efforts for terrestrial field studies should strive for efficiency, and advice on optimization of study sample sizes, practical considerations for obtaining samples, selection of tissues for analysis, and data interpretation is provided. Although there is still much to be learned regarding terrestrial bioaccumulation, these recommendations provide some initial guidance to the present application of terrestrial field data as a line of evidence in the assessment of chemical bioaccumulation potential and a resource to inform laboratory and modeling efforts. © 2015 SETAC.

  8. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    This report presents the 2004 results of the Danish National Monitoring and Assess-ment Programme for the Aquatic and Terrestrial Environments (NOVANA). 2004 was the first year in which terrestrial nature was included in the monitoring pro-gramme. The report reviews the state of the groundwater......, watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  9. Effects of Timber Harvests and Silvicultural Edges on Terrestrial Salamanders

    Science.gov (United States)

    MacNeil, Jami E.; Williams, Rod N.

    2014-01-01

    Balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. However, the effects of timber harvests on salamanders, though often researched, are still not well understood. To further this understanding, we used artificial cover objects to monitor the relative abundance of terrestrial salamanders for two seasons (fall and spring) pre-harvest and five seasons post-harvest in six forest management treatments, and for three seasons post-harvest across the edge gradients of six recent clearcuts. In total, we recorded 19,048 encounters representing nine species of salamanders. We observed declines in mean encounters of eastern red-backed salamanders (Plethodon cinereus) and northern slimy salamanders (P. glutinosus) from pre- to post-harvest in group selection cuts and in clearcuts. However, we found no evidence of salamander declines at shelterwoods and forested sites adjacent to harvests. Edge effects induced by recent clearcuts influenced salamanders for approximately 20 m into the forest, but edge influence varied by slope orientation. Temperature, soil moisture, and canopy cover were all correlated with salamander counts. Our results suggest silvicultural techniques that remove the forest canopy negatively affect salamander relative abundance on the local scale during the years immediately following harvest, and that the depth of edge influence of clearcuts on terrestrial salamanders is relatively shallow (harvests (<4 ha) and techniques that leave the forest canopy intact may be compatible with maintaining terrestrial salamander populations across a forested landscape. Our results demonstrate the importance of examining species-specific responses and monitoring salamanders across multiple seasons and years. Long

  10. Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth Efeitos de fauna de solo e qualidade de liteira sobre o consumo, biomassa microbiana e crescimento de plantas em modelo de ecossistemas terrestres tropicais

    Directory of Open Access Journals (Sweden)

    Bernhard Förster

    2009-08-01

    Full Text Available The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree, Flemingia macrophylla (a shrubby legume or Brachiaria decumbens (a pasture grass was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms, Porcellionides pruinosus or Circoniscus ornatus (woodlice, and Trigoniulus corallinus (millipedes were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.O objetivo deste trabalho foi avaliar o modelo de ecossistema terrestre (TME como ferramenta para o estudo dos efeitos da qualidade da liteira, de invertebrados do solo e da fertilização mineral na decomposição da liteira e no crescimento das plantas em condições controladas. Foram coletados quarenta e oito cilindros de solo intacto (Latossolo Amarelo de 17,5 cm de diâmetro e 30 cm de comprimento em um seringal abandonado na Amazônia Central brasileira e mantidos a 28ºC em laboratório, por quatro meses. Folhas da liteira de Hevea pauciflora (seringueira, ou de Flemingia

  11. Biological control of the terrestrial carbon sink

    Directory of Open Access Journals (Sweden)

    E.-D. Schulze

    2006-01-01

    Full Text Available This lecture reviews the past (since 1964 when the International Biological Program began and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in

  12. Biological control of the terrestrial carbon sink

    Science.gov (United States)

    Schulze, E.-D.

    2006-03-01

    This lecture reviews the past (since 1964 when the International Biological Program began) and the future of our understanding of terrestrial carbon fluxes with focus on photosynthesis, respiration, primary-, ecosystem-, and biome-productivity. Photosynthetic capacity is related to the nitrogen concentration of leaves, but the capacity is only rarely reached under field conditions. Average rates of photosynthesis and stomatal conductance are closely correlated and operate near 50% of their maximal rate, with light being the limiting factor in humid regions and air humidity and soil water the limiting factor in arid climates. Leaf area is the main factor to extrapolate from leaves to canopies, with maximum surface conductance being dependent on leaf level stomatal conductance. Additionally, gas exchange depends also on rooting depth which determines the water and nutrient availability and on mycorrhizae which regulate the nutrient status. An important anthropogenic disturbance is the nitrogen uptake from air pollutants, which is not balanced by cation uptake from roots and this may lead to damage and breakdown of the plant cover. Photosynthesis is the main carbon input into ecosystems, but it alone does not represent the ecosystem carbon balance, which is determined by respiration of various kinds. Plant respiration and photosynthesis determine growth (net primary production) and microbial respiration balances the net ecosystem flux. In a spruce forest, 30% of the assimilatory carbon gain is used for respiration of needles, 20% is used for respiration in stems. Soil respiration is about 50% the carbon gain, half of which is root respiration, half is microbial respiration. In addition, disturbances lead to carbon losses, where fire, harvest and grazing bypass the chain of respiration. In total, the carbon balance at the biome level is only about 1% of the photosynthetic carbon input, or may indeed become negative. The recent observed increase in plant growth has

  13. Banking carbon: A review of organic carbon storage and physical factors influencing retention in floodplains and riparian ecosystems

    Science.gov (United States)

    Nicholas A. Sutfin; Ellen E. Wohl; Kathleen A. Dwire

    2016-01-01

    Rivers are dynamic components of the terrestrial carbon cycle and provide important functions in ecosystem processes. Although rivers act as conveyers of carbon to the oceans, rivers also retain carbon within riparian ecosystems along floodplains, with potential for long-term (> 102 years) storage. Research in ecosystem processing emphasizes the...

  14. Ontogenetic shifts in terrestrial reliance of stream-dwelling brown trout

    Directory of Open Access Journals (Sweden)

    Javier Sánchez-Hernández

    2016-07-01

    Full Text Available This study focuses on terrestrial reliance of brown trout (Salmo trutta and compared it to the potential prey available (macrozoobenthos and drifting invertebrates in three temperate rivers (Galicia, NW Spain, with special emphasis on variations in terrestrial energy intake through the ontogeny of brown trout. Additionally, we paid particular attention to individual variation of terrestrial resource use within and between age classes. Prey items were grouped in four categories: i aquatic invertebrates; ii imagoes of aquatic invertebrates; iii terrestrial invertebrates; and iv fish prey. Next, energy composition was measured according to dry weight-energy equations for each individual in line with above-mentioned prey categories. Our findings illustrate that terrestrial invertebrates appeared to be scarce in the environment, whereas aquatic food resources were rather abundant and accessible. The use of terrestrial invertebrates tended to increase with age, but with a high degree of inter-individual variation in resource use. In fact, the individual reliance of brown trout on terrestrial invertebrates may vary considerably (between 0% and 76.9%. Besides, the frequency of terrestrial foragers, i.e., individuals with terrestrial invertebrates in their stomachs, increased with age, except in one population which had the maximum value in the age-2 class. The acquisition of terrestrial invertebrates thus appears to be a process strongly dependent upon the actual food availability in the environment, but with a high degree of individual variance in resource use within the same age class. Finally, we discuss that terrestrial invertebrates may largely contribute to cover the energy intake of the species, highlighting the interface between terrestrial and aquatic ecosystems, and thereby the importance of riparian canopy cover as a key factor for food supply of stream-dwelling salmonids species.

  15. Introduction to watershed ecosystem services: Chapter 1

    Science.gov (United States)

    Hall, Jefferson S.; Stallard, Robert F.; Kirn, Vanessa

    2015-01-01

    Humans derive a great number of goods and services from terrestrial ecosystems (Millennium Ecosystem Assessment, 2003, 2005). Some, like timber, fruits, bush meat, and other forest based food stuffs, are evident but others are not so obvious. Increasingly policy makers have realized the importance of forests and other ecosystems in sequestering carbon, as clearing of once vibrant vegetation or draining of swamps releases carbon dioxide (U.S. DOE, 2012) and where planting trees – particularly in the tropics - takes carbon dioxide out of the atmosphere (Bala et al., 2007). Scientists and conservationists have long called our attention to the value of Neotropical landscapes for biodiversity conservation as forests and other ecosystems harbor vast numbers of species. In recent decades conservationists and policy makers have also highlighted the potential of forests and other ecosystems to regulate stream flows (Ibáñez et al., 2002, Laurance, 2007 but also see Calder et al., 2007) and play a role in assuring clean water (Uriarte et al., 2011). All of these goods and services are part of what is collectively referred to as ecosystem services or goods and services that are provided to humanity through the unimpeded natural function of the ecosystem.

  16. Changing Arctic ecosystems - measuring and forecasting the response of Alaska's terrestrial ecosystem to a warming climate

    Science.gov (United States)

    Pearce, John; DeGange, Anthony R.; Flint, Paul; Fondell, Tom F.; Gustine, David; Holland-Bartels, Leslie; Hope, Andrew G.; Hupp, Jerry; Koch, Josh; Schmutz, Joel; Talbot, Sandra L.; Ward, David; Whalen, Mary

    2012-01-01

    The Arctic Coastal Plain of northern Alaska is a complex landscape of lakes, streams, and wetlands scattered across low relief tundra that is underlain by permafrost. This region of the Arctic has experienced a warming trend over the past three decades, leading to thawing of on-shore permafrost and the disappearance of sea ice at an unprecedented rate. The loss of sea ice has increased ocean wave action, leading to higher rates of erosion and salt water inundation of coastal habitats. Warming temperatures also have advanced the overall phenology of the region, including earlier snowmelt, lake ice thaw, and plant growth. As a result, many migratory species now arrive in the Arctic several days earlier in spring than in the 1970s. Predicted warming trends for the future will continue to alter plant growth, ice thaw, and other basic landscape processes. These changes will undoubtedly result in different responses by wildlife (fish, birds, and mammals) and the food they rely upon (plants, invertebrates, and fish). However, the type of response by different wildlife populations and their habitats-either positively or negatively-remains largely unknown.

  17. Forest ecosystems and environments scaling up from shoot module to watershed

    CERN Document Server

    Kohyama, Takashi; Ojima, Dennis S

    2005-01-01

    Coastal East and Southeast Asia are characterized by wet growing seasons, and species-rich forest ecosystems develop throughout the latitudinal and altitudinal gradients. In this region, the Global Change Impacts on Terrestrial Ecosystems in Monsoon Asia (TEMA) project was carried out as a unique contribution to the international project Global Change and Terrestrial Ecosystems. TEMA aimed to integrate forest ecosystem processes, from leaf physiology to meteorological budget and prediction of long-term change of vegetation composition and architecture through demographic processes. Special attention was given to watershed processes, where forest ecosystem metabolism affects the properties and biogeochemical budgets of freshwater ecosystems, and where rivers, wetlands, and lakes are subject to direct and indirect effects of environmental change. This volume presents the scaling-up concept for better understanding of ecosystem functioning.

  18. Anthropogenic litter in urban freshwater ecosystems: distribution and microbial interactions.

    Directory of Open Access Journals (Sweden)

    Timothy Hoellein

    Full Text Available Accumulation of anthropogenic litter (i.e. garbage; AL and its ecosystem effects in marine environments are well documented. Rivers receive AL from terrestrial habitats and represent a major source of AL to marine environments, but AL is rarely studied within freshwater ecosystems. Our objectives were to 1 quantify AL density in urban freshwaters, 2 compare AL abundance among freshwater, terrestrial, and marine ecosystems, and 3 characterize the activity and composition of AL biofilms in freshwater habitats. We quantified AL from the Chicago River and Chicago's Lake Michigan shoreline, and found that AL abundance in Chicago freshwater ecosystems was comparable to previously reported data for marine and terrestrial ecosystems, although AL density and composition differed among habitats. To assess microbial interactions with AL, we incubated AL and natural substrates in 3 freshwater ecosystems, quantified biofilm metabolism as gross primary production (GPP and community respiration (CR, and characterized biofilm bacterial community composition via high-throughput sequencing of 16S rRNA genes. The main driver of biofilm community composition was incubation location (e.g., river vs pond, but there were some significant differences in biofilm composition and metabolism among substrates. For example, biofilms on organic substrates (cardboard and leaves had lower GPP than hard substrates (glass, plastic, aluminum and tiles. In addition, bacterial communities on organic substrates were distinct in composition from those on hard substrates, with higher relative abundances of bacteria associated with cellulose decomposition. Finally, we used our results to develop a conceptual diagram designed to unite the study of AL in terrestrial and freshwater environments with the well-established field of marine debris research. We suggest this broad perspective will be useful for future studies which synthesize AL sources, ecosystem effects, and fate across

  19. Light use efficiency of terrestrial vegetation from remote sensing of chlorophyll fluorescence

    Science.gov (United States)

    Badgley, G. M.; Guan, K.; Berry, J. A.; Lobell, D. B.; Ryu, Y.

    2014-12-01

    Light use efficiency, the rate with which plants use absorbed photons to fix carbon dioxide, is a crucial parameter for estimating terrestrial carbon fluxes. Estimates of light use efficiency lie at the heart of how we model and understand ecosystem productivity. Here, we make use of the recent availability of high-resolution, multi-year records of remotely sensed measurements of chlorophyll fluorescence to refine estimates of light use efficiency in terrestrial ecosystems at the global scale. Directly estimating light use efficiency from remote sensing can help guide the current approach of constraining a theoretical maximum light use efficiency using meteorological data. We explore the usefulness of a derived light use efficiency at the global scale from remotely sensed records of chlorophyll fluorescence, photosynthetically active radiation, and canopy leaf area. Our estimates of light use efficiency show good agreement with light use efficiency calculated using Fluxtower data spanning several continents and a wide variety of ecosystems. We further benchmark our approach against the light use efficiency estimated from a variety of ecosystem models, such as BESS. Further refinement of our proposed technique promises to advance our ability to detect ecosystem stresses and further constrain our estimates of carbon fluxes within terrestrial ecosystems.

  20. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  1. Microbial Ecosystems, Protection of

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Nelson, K.E.

    2014-01-01

    Synonyms Conservation of microbial diversity and ecosystem functions provided by microbes; Preservation of microbial diversity and ecosystem functions provided by microbes Definition The use, management, and conservation of ecosystems in order to preserve microbial diversity and functioning.

  2. Astronomical Ecosystems

    Science.gov (United States)

    Neuenschwander, D. E.; Finkenbinder, L. R.

    2004-05-01

    Just as quetzals and jaguars require specific ecological habitats to survive, so too must planets occupy a tightly constrained astronomical habitat to support life as we know it. With this theme in mind we relate the transferable features of our elementary astronomy course, "The Astronomical Basis of Life on Earth." Over the last five years, in a team-taught course that features a spring break field trip to Costa Rica, we have introduced astronomy through "astronomical ecosystems," emphasizing astronomical constraints on the prospects for life on Earth. Life requires energy, chemical elements, and long timescales, and we emphasize how cosmological, astrophysical, and geological realities, through stabilities and catastrophes, create and eliminate niches for biological life. The linkage between astronomy and biology gets immediate and personal: for example, studies in solar energy production are followed by hikes in the forest to examine the light-gathering strategies of photosynthetic organisms; a lesson on tides is conducted while standing up to our necks in one on a Pacific beach. Further linkages between astronomy and the human timescale concerns of biological diversity, cultural diversity, and environmental sustainability are natural and direct. Our experience of teaching "astronomy as habitat" strongly influences our "Astronomy 101" course in Oklahoma as well. This "inverted astrobiology" seems to transform our student's outlook, from the universe being something "out there" into something "we're in!" We thank the SNU Science Alumni support group "The Catalysts," and the SNU Quetzal Education and Research Center, San Gerardo de Dota, Costa Rica, for their support.

  3. Changes in rainfall patterns in Mediterranean ecosystems: the MIND project

    Directory of Open Access Journals (Sweden)

    Papale D

    2007-12-01

    Full Text Available Will Mediterranean terrestrial ecosystems be affected by the expected changes in precipitation regimes? If so, by how much and in which direction? These questions are at the basis of the research performed in context of the EU MIND project, whose key objectives were: i to investigate the potential effects of increasing drought on Mediterranean terrestrial ecosystems at the process, ecosystem and regional scales and ii to assess ecosystem vulnerability to changes in rainfall patterns. A network of experimental study sites has been created in Portugal, Spain, France and Italy, where field manipulations alter the amount of water available to the ecosystem. The most up-to-date methods of ecophysiology, micrometeorology, soil ecology and remote sensing have been used to elucidate the mechanisms that regulate the response of vegetation and soil to changes in water availability. This information is providing the basis for the implementation and validation of simulation models capable of predicting the drought response of Mediterranean terrestrial ecosystems, and their vulnerability to future climate change, on a larger scale. The out-coming results are elucidating how water availability affects plant ecophysiological processes, the dynamics of soil carbon and the overall exchange of mass and energy between the land and the atmosphere. This paper focuses on some of the important, yet preliminary, results on C and energy fluxes that have been obtained at the large scale troughfall manipulation experiment (Tolfa, Italy, in a forest dominated by Arbutus unedo L.

  4. Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model.

    Directory of Open Access Journals (Sweden)

    Michael B J Harfoot

    2014-04-01

    Full Text Available Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude across the globe led to emergent properties at individual (e.g., growth rate, community (e.g., biomass turnover rates, ecosystem (e.g., trophic pyramids, and macroecological scales (e.g., global patterns of trophic structure that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures.

  5. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah M.; Stets, Edward G.; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

  6. Effects of predatory ants within and across ecosystems in bromeliad food webs.

    Science.gov (United States)

    Gonçalves, Ana Z; Srivastava, Diane S; Oliveira, Paulo S; Romero, Gustavo Q

    2017-07-01

    Predation is one of the most fundamental ecological processes affecting biotic communities. Terrestrial predators that live at ecosystem boundaries may alter the diversity of terrestrial organisms, but they may also have cross-ecosystem cascading effects when they feed on organisms with complex life cycles (i.e. organisms that shift from aquatic juvenile stages to terrestrial adult stages) or inhibit female oviposition in the aquatic environment. The predatory ant Odontomachus hastatus establishes its colonies among roots of Vriesea procera, an epiphytic bromeliad species with water-filled tanks that shelters many terrestrial and aquatic organisms. Ants may impact terrestrial communities and deter adult insects from ovipositing in the water of bromeliads via consumptive and non-consumptive effects. Ants do not forage within the aquatic environment; thus, they may be more efficient predators on terrestrial organisms. Therefore, we predict that ants will have stronger effects on terrestrial than aquatic food webs. However, such effects may also be site contingent and depend on the local composition of food webs. To test our hypothesis, we surveyed bromeliads with and without O. hastatus colonies from three different coastal field sites in the Atlantic Forest of southeast Brazil, and quantified the effect of this predatory ant on the composition, density and richness of aquatic and terrestrial metazoans found in these bromeliads. We found that ants changed the composition and reduced the overall density of aquatic and terrestrial metazoans in bromeliad ecosystems. However, effects of ants on species diversity were contingent on site. In general terms, the effects of the ant on aquatic and terrestrial metazoan communities were similar in strength and magnitude. Ants reduced the density of virtually all aquatic functional groups, especially detritivore insects as well as metazoans that reach bromeliads through phoresy on the skin of terrestrial animals (i.e. Ostracoda

  7. Arctic ecosystem responses to a warming climate

    DEFF Research Database (Denmark)

    Mortensen, Lars O.

    The Arctic embraces one of the simplest terrestrial ecosystems in the world and yet it covers roughly 11% of the world’s surface. Summer temperatures rarely exceed 10°C and most of the limited precipitation falls as snow. The landmasses are predominantly polar tundra, while the Arctic Ocean...... is frozen solid for the main part of the year. However, in recent decades, arctic temperatures have in-creased between two and three times that of the global averages, which have had a substantial impact on the physical environment of the arctic ecosystem, such as deglaciation of the Greenland inland ice......-trophic interaction patterns. However, while studies have documented the climatic effects on the arctic biotic ecosys-tem, detailed studies have been constrained by short time series or the lack of comprehensive multivariate tools, which enables the disentanglement of direct effects and effects mediated through...

  8. A National System to Map and Quantify Terrestrial Vertebrate ...

    Science.gov (United States)

    Biodiversity is crucial for the functioning of ecosystems and the products and services from which we transform natural assets of the Earth for human survival, security, and well-being. The ability to assess, report, map, and forecast the life support functions of ecosystems is absolutely critical to our capacity to make informed decisions to maintain the sustainable nature of our environment now and into the future. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales.Nevertheless, the need to measure and assess occurrence of biodiversity, changes over time and space, agents of change, and consequences for the provision of ecosystem services for human livelihood remains important. In answer to this challenge, the U.S. Environmental Protection Agency has created a partnership with other Federal agencies, academic institutions, and Non-Governmental Organizations to develop the EnviroAtlas (https://www.epa.gov/enviroatlas), an online national Decision Support Tool that allows users to view and analyze the geographical description of the supply and demand for ecosystem services, as well as the drivers of change. As part of the EnviroAtlas, an approach has been developed that uses deductive habitat models for all the terrestrial vertebrates of the conterminous United States and cluste

  9. Trends and Future Challenges in Sampling the Deep Terrestrial Biosphere

    Directory of Open Access Journals (Sweden)

    Michael J Wilkins

    2014-09-01

    Full Text Available Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on Trends and Future Challenges in Sampling The Deep Subsurface was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty, and sponsored by The Ohio State University and the Sloan Foundation’s Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.

  10. Trends and Future Challenges in Sampling the Deep Terrestrial Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; Daly, Rebecca; Mouser, Paula J.; Trexler, Ryan; Sharma, Shihka; Cole, David R.; Wrighton, Kelly C.; Biddle , Jennifer F.; Denis, Elizabeth; Fredrickson, Jim K.; Kieft, Thomas L.; Onstott, T. C.; Peterson, Lee; Pfiffner, Susan M.; Phelps, Tommy J.; Schrenk, Matthew O.

    2014-09-12

    Research in the deep terrestrial biosphere is driven by interest in novel biodiversity and metabolisms, biogeochemical cycling, and the impact of human activities on this ecosystem. As this interest continues to grow, it is important to ensure that when subsurface investigations are proposed, materials recovered from the subsurface are sampled and preserved in an appropriate manner to limit contamination and ensure preservation of accurate microbial, geochemical, and mineralogical signatures. On February 20th, 2014, a workshop on “Trends and Future Challenges in Sampling The Deep Subsurface” was coordinated in Columbus, Ohio by The Ohio State University and West Virginia University faculty, and sponsored by The Ohio State University and the Sloan Foundation’s Deep Carbon Observatory. The workshop aims were to identify and develop best practices for the collection, preservation, and analysis of terrestrial deep rock samples. This document summarizes the information shared during this workshop.

  11. Estimated nation wide effects of pesticide spray drift on terrestrial habitats in the Netherlands

    NARCIS (Netherlands)

    Jong, de F.M.W.; Snoo, de G.R.; Zande, van de J.C.

    2008-01-01

    This study estimated the potential effects of pesticide drift on terrestrial ecosystems outside target areas, for the Dutch situation. A series of field trials was conducted to estimate the effects of drift on different species groups at different distances from a treated plot for different

  12. Terrestrial gross carbon dioxide uptake : Global distribution and covariation with climate

    NARCIS (Netherlands)

    Beer, Christian; Reichstein, Markus; Tomelleri, Enrico; Ciais, Philippe; Jung, Martin; Carvalhais, Nuno; Rödenbeck, Christian; Arain, M. Altaf; Baldocchi, Dennis D.; Bonan, Gordon B.; Bondeau, Alberte; Cescatti, Alessandro; Lasslop, Gitta; Lindroth, Anders; Lomas, Mark; Luyssaert, Sebastiaan; Margolis, Hank; Oleson, Keith W.; Roupsard, Olivier; Veenendaal, Elmar; Viovy, Nicolas; Williams, Christopher M.; Woodward, F. Ian; Papale, Dario

    2010-01-01

    Terrestrial gross primary production (GPP) is the largest global CO 2 flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123 ± 8 petagrams of carbon per year (Pg C year-1) using eddy covariance flux data and various diagnostic models. Tropical forests

  13. Terrestrial gross carbon dioxide uptake: Global distribution and covariation with climate

    NARCIS (Netherlands)

    Beer, C.; Veenendaal, E.M.

    2010-01-01

    Terrestrial gross primary production (GPP) is the largest global CO2 flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123 ± 8 petagrams of carbon per year (Pg C year-1) using eddy covariance flux data and various diagnostic models. Tropical forests

  14. Global assessment of nitrogen deposition effects on terrestrial plant diversity: a synthesis

    Science.gov (United States)

    R. Bobbink; K. Hicks; J. Galloway; T. Spranger; R. Alkemade; M. Ashmore; M. Bustamante; S. Cinderby; E. Davidson; F. Dentener; B. Emmett; J.-W. Erisman; M. Fenn; F. Gilliam; A. Nordin; L. Pardo; W. De Vries

    2010-01-01

    Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to...

  15. Exotic aquatic and terrestrial animals in the Hoosier-Shawnee ecological assessment area

    Science.gov (United States)

    Brooks M. Burr; Cynthia M. Basile; Ginny L. Adams; Matthew C. Nicholson

    2004-01-01

    We reviewed the impact of exotic aquatic and terrestrial wildlife on ecosystems within the Hoosier-Shawnee Ecological Assessment Area. Recent collections within the assessment area have demonstrated that faunal diversity is expanding rapidly from the intentional and unintentional release of nonindigenous species. We report on the origin, status, trends, habitat...

  16. Baltic Sea Maritime Spatial Planning for Sustainable Ecosystem Services

    DEFF Research Database (Denmark)

    Hansen, Henning Sten; Schrøder, Anne Lise

    2017-01-01

    in the marine and maritime sectors with great potential for innovation and economic growth. Holistic spatial planning systems supporting sustainable development have proved themselves in terrestrial planning and are also needed at sea. Due to this reason, the BONUS BASMATI project is based on the ecosystem...... services approach to assist in assessing sustainable solutions corresponding to policy goals....

  17. Focus on CSIR research in water resource: Aquifer dependent ecosystems.

    CSIR Research Space (South Africa)

    Colvin, C

    2007-08-01

    Full Text Available of rivers. In terrestrial and riparian ecosystems, groundwater is not seen at the surface but is tapped by plants and used as ‘cryptic’ discharge. ADEs are important indicators of aquifer health and flow regimes. An oasis is a classic ADE, and like many...

  18. Regime shifts, resilience, and biodiversity in ecosystem management

    NARCIS (Netherlands)

    Folke, C.; Carpenter, S.; Walker, B.; Scheffer, M.; Elmqvist, T.; Gunderson, L.; Holling, C.S.

    2004-01-01

    We review the evidence of regime shifts in terrestrial and aquatic environments in relation to resilience of complex adaptive ecosystems and the functional roles of biological diversity in this context. The evidence reveals that the likelihood of regime shifts may increase when humans reduce

  19. Ecosystem resilience despite large-scale altered hydroclimatic conditions

    Science.gov (United States)

    G. E. Ponce Campos; M. S. Moran; A. Huete; Y. Zhang; C. Bresloff; T.E. Huxman; D. Eamus; D. D. Bosch; A. R. Buda; S. A. Gunter; T. Heartsill Scalley; S. G. Kitchen; M. P. McClaran; W. H. McNab; D. S. Montoya; J. A. Morgan; D. P. C. Peters; E. J. Sadler; M. S. Seyfried; P. J. Starks

    2013-01-01

    Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological model for many regions1. Largescale, warm droughts have recently occurred in North America, Africa, Europe, Amazonia and Australia, resulting in major effects on terrestrial ecosystems, carbon balance and food...

  20. Invasion of exotic earthworms into ecosystems inhabited by native earthworms

    Science.gov (United States)

    P. F. Hendrix; G. H. Baker; M. A. Callaham Jr; G. A. Damoff; Fragoso C.; G. Gonzalez; S. W. James; S. L. Lachnicht; T. Winsome; X. Zou

    2006-01-01

    The most conspicuous biological invasions in terrestrial ecosystems have been by exotic plants, insects and vertebrates. Invasions by exotic earthworms, although not as well studied, may be increasing with global commerce in agriculture, waste management and bioremediation. A number of cases has documented where invasive earthworms have caused significant changes in...

  1. Partitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological components

    NARCIS (Netherlands)

    Rey, A.; Belelli Marchesini, L.; Etiope, G.; Papale, D.; Canfora, E.; Valentini, R.; Pegoraro, E.

    2014-01-01

    Recent studies have highlighted the need to consider geological carbon sources when estimating the net ecosystem carbon balance (NECB) of terrestrial ecosystems located in areas potentially affected by geofluid circulation. We propose a new methodology using physical parameters of the atmospheric

  2. Strengthening governance for intertidal ecosystems requires a consistent definition of boundaries between land and sea.

    Science.gov (United States)

    Rog, Stefanie M; Cook, Carly N

    2017-07-15

    The protection of intertidal ecosystems is complex because they straddle both marine and terrestrial realms. This leads to inconsistent characterisation as marine and/or terrestrial systems, or neither. Vegetated intertidal ecosystems are especially complex to classify because they can have an unclear border with terrestrial vegetation, causing confusion around taxonomy (e.g., mangrove-like plants). This confusion and inconsistency in classification can impact these systems through poor governance and incomplete protection. Using Australian mangrove ecosystems as a case study, we explore the complexity of how land and sea boundaries are defined among jurisdictions and different types of legislation, and how these correspond to ecosystem boundaries. We demonstrate that capturing vegetated intertidal ecosystems under native vegetation laws and prioritizing the mitigation of threats with a terrestrial origin offers the greatest protection to these systems. We also show the impact of inconsistent boundaries on the inclusion of intertidal ecosystems within protected areas. The evidence presented here highlights problems within the Australian context, but most of these issues are also challenges for the management of intertidal ecosystems around the world. Our study demonstrates the urgent need for a global review of legislation governing the boundaries of land and sea to determine whether the suggestions we offer may provide global solutions to ensuring these critical systems do not fall through the cracks in ecosystem protection and management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Temporal and among-site variability of inherent water use efficiency at the ecosystem level

    NARCIS (Netherlands)

    Beer, C.; Ciais, P.; Reichstein, M.; Baldocchi, D.; Law, B.E.; Papale, D.; Soussana, J.F.; Ammann, C.; Buchmann, N.; Frank, D.; Gianelle, D.; Janssens, I.A.; Knohl, A.; Kostner, B.; Moors, E.J.; Roupsard, O.; Verbeeck, H.; Vesala, T.; Williams, C.A.; Wohlfahrt, G.

    2009-01-01

    Half-hourly measurements of the net exchanges of carbon dioxide and water vapor between terrestrial ecosystems and the atmosphere provide estimates of gross primary production (GPP) and evapotranspiration (ET) at the ecosystem level and on daily to annual timescales. The ratio of these quantities

  4. The terrestrial biosphere in the SFR region

    Energy Technology Data Exchange (ETDEWEB)

    Jerling, L.; Isaeus, M. [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J. [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T.; Schueldt, R. [Danish Nature Council, Copenhagen (Denmark)

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results

  5. Decadal trends in the seasonal-cycle amplitude of terrestrial CO2 exchange resulting from the ensemble of terrestrial biosphere models

    Directory of Open Access Journals (Sweden)

    Akihiko Ito

    2016-05-01

    Full Text Available The seasonal-cycle amplitude (SCA of the atmosphere–ecosystem carbon dioxide (CO2 exchange rate is a useful metric of the responsiveness of the terrestrial biosphere to environmental variations. It is unclear, however, what underlying mechanisms are responsible for the observed increasing trend of SCA in atmospheric CO2 concentration. Using output data from the Multi-scale Terrestrial Model Intercomparison Project (MsTMIP, we investigated how well the SCA of atmosphere–ecosystem CO2 exchange was simulated with 15 contemporary terrestrial ecosystem models during the period 1901–2010. Also, we made attempt to evaluate the contributions of potential mechanisms such as atmospheric CO2, climate, land-use, and nitrogen deposition, through factorial experiments using different combinations of forcing data. Under contemporary conditions, the simulated global-scale SCA of the cumulative net ecosystem carbon flux of most models was comparable in magnitude with the SCA of atmospheric CO2 concentrations. Results from factorial simulation experiments showed that elevated atmospheric CO2 exerted a strong influence on the seasonality amplification. When the model considered not only climate change but also land-use and atmospheric CO2 changes, the majority of the models showed amplification trends of the SCAs of photosynthesis, respiration, and net ecosystem production (+0.19 % to +0.50 % yr−1. In the case of land-use change, it was difficult to separate the contribution of agricultural management to SCA because of inadequacies in both the data and models. The simulated amplification of SCA was approximately consistent with the observational evidence of the SCA in atmospheric CO2 concentrations. Large inter-model differences remained, however, in the simulated global tendencies and spatial patterns of CO2 exchanges. Further studies are required to identify a consistent explanation for the simulated and observed amplification trends, including their

  6. Ecosystem extent and fragmentation

    Science.gov (United States)

    Sayre, Roger; Hansen, Matt

    2017-01-01

    One of the candidate essential biodiversity variable (EBV) groups described in the seminal paper by Pereira et al. (2014) concerns Ecosystem Structure. This EBV group is distinguished from another EBV group which encompasses aspects of Ecosystem Function. While the Ecosystem Function EBV treats ecosystem processes like nutrient cycling, primary production, trophic interactions, etc., the Ecosystem Structure EBV relates to the set of biophysical properties of ecosystems that create biophysical environmental context, confer biophysical structure, and occur geographically. The Ecosystem Extent and Fragmentation EBV is one of the EBVs in the Ecosystem Structure EBV group.Ecosystems are understood to exist at multiple scales, from very large areas (macro-ecosystems) like the Arctic tundra, for example, to something as small as a tree in an Amazonian rain forest. As such, ecosystems occupy space and therefore can be mapped across any geography of interest, whether that area of interest be a site, a nation, a region, a continent, or the planet. One of the most obvious and seemingly straightforward EBVs is Ecosystem Extent and Fragmentation. Ecosystem extent refers to the location and geographic distribution of ecosystems across landscapes or in the oceans, while ecosystem fragmentation refers to the spatial pattern and connectivity of ecosystem occurrences on the landscape.

  7. Azospirillum genomes reveal transition of bacteria from aquatic to terrestrial environments.

    Directory of Open Access Journals (Sweden)

    Florence Wisniewski-Dyé

    2011-12-01

    Full Text Available Fossil records indicate that life appeared in marine environments ∼3.5 billion years ago (Gyr and transitioned to terrestrial ecosystems nearly 2.5 Gyr. Sequence analysis suggests that "hydrobacteria" and "terrabacteria" might have diverged as early as 3 Gyr. Bacteria of the genus Azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. We obtained genome sequences of two Azospirillum species and analyzed their gene origins. While most Azospirillum house-keeping genes have orthologs in its close aquatic relatives, this lineage has obtained nearly half of its genome from terrestrial organisms. The majority of genes encoding functions critical for association with plants are among horizontally transferred genes. Our results show that transition of some aquatic bacteria to terrestrial habitats occurred much later than the suggested initial divergence of hydro- and terrabacterial clades. The birth of the genus Azospirillum approximately coincided with the emergence of vascular plants on land.

  8. Azospirillum genomes reveal transition of bacteria from aquatic to terrestrial environments.

    Science.gov (United States)

    Wisniewski-Dyé, Florence; Borziak, Kirill; Khalsa-Moyers, Gurusahai; Alexandre, Gladys; Sukharnikov, Leonid O; Wuichet, Kristin; Hurst, Gregory B; McDonald, W Hayes; Robertson, Jon S; Barbe, Valérie; Calteau, Alexandra; Rouy, Zoé; Mangenot, Sophie; Prigent-Combaret, Claire; Normand, Philippe; Boyer, Mickaël; Siguier, Patricia; Dessaux, Yves; Elmerich, Claudine; Condemine, Guy; Krishnen, Ganisan; Kennedy, Ivan; Paterson, Andrew H; González, Victor; Mavingui, Patrick; Zhulin, Igor B

    2011-12-01

    Fossil records indicate that life appeared in marine environments ∼3.5 billion years ago (Gyr) and transitioned to terrestrial ecosystems nearly 2.5 Gyr. Sequence analysis suggests that "hydrobacteria" and "terrabacteria" might have diverged as early as 3 Gyr. Bacteria of the genus Azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. We obtained genome sequences of two Azospirillum species and analyzed their gene origins. While most Azospirillum house-keeping genes have orthologs in its close aquatic relatives, this lineage has obtained nearly half of its genome from terrestrial organisms. The majority of genes encoding functions critical for association with plants are among horizontally transferred genes. Our results show that transition of some aquatic bacteria to terrestrial habitats occurred much later than the suggested initial divergence of hydro- and terrabacterial clades. The birth of the genus Azospirillum approximately coincided with the emergence of vascular plants on land.

  9. Quantifying the Climate Regulation Values of Ecosystems Globally

    Science.gov (United States)

    Anderson-Teixeira, K. J.; DeLucia, E. H.; Snyder, P. K.; LeBauer, D.; Long, S.

    2014-12-01

    Terrestrial ecosystems play an important role in the climate system, regulating climate through both biogeochemical (greenhouse-gas regulation) and biophysical (regulation of water and energy) mechanisms. However, initiatives aimed at climate protection through land management account only for biogeochemical mechanisms. By ignoring biophysical processes, these initiatives risk promoting suboptimal solutions. Our recently proposed metric for the climate regulation value (CRV) of ecosystems provides one potential approach to quantifying how biogeochemical and biophysical effects combine to determine the climate services of terrestrial ecosystems. In order to provide broadly accessible estimates of CRV for ecosystems worldwide, we have created an online ecosystem climate regulation services calculator with global coverage. The CRV calculator incorporates global maps of climatically significant ecosystem properties (for example, biomass, soil carbon, and evapotranspiration) to provide location-specific CRV estimates. We use this calculator to derive values for forests globally, revealing that CRV commonly differs meaningfully from values derived based purely on carbon storage. In the face of increasing land-use pressures and the increasingly urgent need for climate change mitigation, the CRV calculator has the potential to facilitate improved quantification of ecosystem climate regulation services by scientists, conservationists, policy makers, and the private sector.

  10. The imprint of plants on ecosystem functioning: A data-driven approach

    Science.gov (United States)

    Musavi, Talie; Mahecha, Miguel D.; Migliavacca, Mirco; Reichstein, Markus; van de Weg, Martine Janet; van Bodegom, Peter M.; Bahn, Michael; Wirth, Christian; Reich, Peter B.; Schrodt, Franziska; Kattge, Jens

    2015-12-01

    Terrestrial ecosystems strongly determine the exchange of carbon, water and energy between the biosphere and atmosphere. These exchanges are influenced by environmental conditions (e.g., local meteorology, soils), but generally mediated by organisms. Often, mathematical descriptions of these processes are implemented in terrestrial biosphere models. Model implementations of this kind should be evaluated by empirical analyses of relationships between observed patterns of ecosystem functioning, vegetation structure, plant traits, and environmental conditions. However, the question of how to describe the imprint of plants on ecosystem functioning based on observations has not yet been systematically investigated. One approach might be to identify and quantify functional attributes or responsiveness of ecosystems (often very short-term in nature) that contribute to the long-term (i.e., annual but also seasonal or daily) metrics commonly in use. Here we define these patterns as "ecosystem functional properties", or EFPs. Such as the ecosystem capacity of carbon assimilation or the maximum light use efficiency of an ecosystem. While EFPs should be directly derivable from flux measurements at the ecosystem level, we posit that these inherently include the influence of specific plant traits and their local heterogeneity. We present different options of upscaling in situ measured plant traits to the ecosystem level (ecosystem vegetation properties - EVPs) and provide examples of empirical analyses on plants' imprint on ecosystem functioning by combining in situ measured plant traits and ecosystem flux measurements. Finally, we discuss how recent advances in remote sensing contribute to this framework.

  11. Global Taxonomic Diversity of Anomodonts (Tetrapoda, Therapsida) and the Terrestrial Rock Record Across the Permian-Triassic Boundary

    OpenAIRE

    Fröbisch, Jörg

    2008-01-01

    The end-Permian biotic crisis (~252.5 Ma) represents the most severe extinction event in Earth's history. This paper investigates diversity patterns in Anomodontia, an extinct group of therapsid synapsids ('mammal-like reptiles'), through time and in particular across this event. As herbivores and the dominant terrestrial tetrapods of their time, anomodonts play a central role in assessing the impact of the end-Permian extinction on terrestrial ecosystems. Taxonomic diversity analysis reveals...

  12. Impact of non-native terrestrial mammals on the structure of the terrestrial mammal food web of Newfoundland, Canada.

    Directory of Open Access Journals (Sweden)

    Justin S Strong

    Full Text Available The island of Newfoundland is unique because it has as many non-native terrestrial mammals as native ones. The impacts of non-native species on native flora and fauna can be profound and invasive species have been identified as one of the primary drivers of species extinction. Few studies, however, have investigated the effects of a non-native species assemblage on community and ecosystem properties. We reviewed the literature to build the first terrestrial mammal food web for the island of Newfoundland and then used network analyses to investigate how the timing of introductions and trophic position of non-native species has affected the structure of the terrestrial mammal food web in Newfoundland. The first non-native mammals (house mouse and brown rat became established in Newfoundland with human settlement in the late 15th and early 16th centuries. Coyotes and southern red-backed voles are the most recent mammals to establish themselves on the island in 1985 and 1998, respectively. The fraction of intermediate species increased with the addition of non-native mammals over time whereas the fraction of basal and top species declined over time. This increase in intermediate species mediated by non-native species arrivals led to an overall increase in the terrestrial mammal food web connectance and generality (i.e. mean number of prey per predator. This diverse prey base and sources of carrion may have facilitated the natural establishment of coyotes on the island. Also, there is some evidence that the introduction of non-native prey species such as the southern red-backed vole has contributed to the recovery of the threatened American marten. Long-term monitoring of the food web is required to understand and predict the impacts of the diverse novel interactions that are developing in the terrestrial mammal food web of Newfoundland.

  13. Transformation of Digital Ecosystems

    DEFF Research Database (Denmark)

    Henningsson, Stefan; Hedman, Jonas

    2014-01-01

    the Digital Ecosystem Technology Transformation (DETT) framework for explaining technology-based transformation of digital ecosystems by integrating theories of business and technology ecosystems. The framework depicts ecosystem transformation as distributed and emergent from micro-, meso-, and macro- level...... coopetition. The DETT framework consists an alternative to the existing explanations of digital ecosystem transformation as the rational management of one central actor balancing ecosystem tensions. We illustrate the use of the framework by a case study of transformation in the digital payment ecosystem......In digital ecosystems, the fusion relation between business and technology means that the decision of technical compatibility of the offering is also the decision of how to position the firm relative to the coopetive relations that characterize business ecosystems. In this article we develop...

  14. Longer Food Chains in Pelagic Ecosystems: Trophic Energetics of Animal Body Size and Metabolic Efficiency.

    Science.gov (United States)

    McGarvey, Richard; Dowling, Natalie; Cohen, Joel E

    2016-07-01

    Factors constraining the structure of food webs can be investigated by comparing classes of ecosystems. We find that pelagic ecosystems, those based on one-celled primary producers, have longer food chains than terrestrial ecosystems. Yet pelagic ecosystems have lower primary productivity, contrary to the hypothesis that greater energy flows permit higher trophic levels. We hypothesize that longer food chain length in pelagic ecosystems, compared with terrestrial ecosystems, is associated with smaller pelagic animal body size permitting more rapid trophic energy transfer. Assuming negative allometric dependence of biomass production rate on body mass at each trophic level, the lowest three pelagic animal trophic levels are estimated to add biomass more rapidly than their terrestrial counterparts by factors of 12, 4.8, and 2.6. Pelagic animals consequently transport primary production to a fifth trophic level 50-190 times more rapidly than animals in terrestrial webs. This difference overcomes the approximately fivefold slower pelagic basal productivity, energetically explaining longer pelagic food chains. In addition, ectotherms, dominant at lower pelagic animal trophic levels, have high metabolic efficiency, also favoring higher rates of trophic energy transfer in pelagic ecosystems. These two animal trophic flow mechanisms imply longer pelagic food chains, reestablishing an important role for energetics in food web structure.

  15. A new framework to evaluate ecosystem health: a case study in the Wei River basin, China.

    Science.gov (United States)

    Wu, Wei; Xu, Zongxue; Zhan, Chesheng; Yin, Xuwang; Yu, Songyan

    2015-07-01

    Due to the rapid growth of the population and the development of economies in the Guanzhong district, central China, the river ecosystem is gradually deteriorating, which makes it important to assess the aquatic ecosystem health and take measures to restore the damaged ecosystem. An index of catchment ecosystem health has been developed to assist large-scale management of watersheds by providing an integrated measure of ecosystem health, including aquatic and terrestrial ecosystem. Most researches focus on aquatic ecosystem or terrestrial ecosystem, but little research integrates both of them to assess the catchment ecosystem health. In this paper, we combine these two aspects into catchment ecosystem health. Ecosystem indicators derived from field samples and modeling are identified to integrate into ecosystem health. These included indicators of ecological landscape pattern (based on normalized difference vegetation index (NDVI), vegetation cover, dominance index, Shannon's diversity index, Shannon's evenness index, and fragmentation index), hydrology regime (based on 33 hydrological parameters), physical form condition (based on substrate, habitat complexity, velocity/depth regimes, bank stability, channel alteration), water quality (based on electrical conductivity (Cond), dissolved oxygen (DO), NH3_N, total nitrogen (TN), total phosphorus (TP), chemical oxygen demand-permanganate (CODMn)), and biological quality (based on fish abundance). The index of ecosystem health is applied in the Guanzhong district, and the ecosystem health was fair. The ecosystem health in the upstream to Linjiacun (U-L) and Linjiacun to Weijiabao (L-W) reaches was in good situation, while that in Weijiabao to Xianyang (W-X), Xianyang-Weijiabao (X-W), and Weijiabao to Tongguan (W-T) reaches was in fair situation. There is a trend that the ecosystem health in the upstream was better than that in the downstream. The ecosystem health assessment is expected to play a key role in future

  16. Freshwater processing of terrestrial dissolved organic matter: What governs lability?

    Science.gov (United States)

    D'Andrilli, J.; Smith, H. J.; Junker, J. R.; Scholl, E. A.; Foreman, C. M.

    2016-12-01

    Aquatic and terrestrial ecosystems are linked through the transfer of energy and materials. Allochthonous organic matter (OM) is central to freshwater ecosystem function, influencing local food webs, trophic state, and nutrient availability. In order to understand the nature and fate of OM from inland headwaters to the open ocean, it is imperative to understand the links between OM lability and ecosystem function. Thus, biological, chemical, and physical factors need to be evaluated together to inform our understanding of environmental lability. We performed a laboratory processing experiment on naturally occurring OM leachates from riparian leaves, grasses, and pine needles. Measures of water chemistry, OM optical and molecular characterization, bacterial abundances, microbial assemblage composition, respiration, and C:N:P were integrated to discern the nature and fate of labile and recalcitrant OM in a freshwater stream. Peak processing of all OM sources in the stream water occurred after two days, with spikes in bacterial cell abundances, respiration rates, microbial assemblage shifts, and maximum C utilization. Respiration rates and microbial assemblages were dependent on the degree of lability of the OM molecular composition. Within the first few days, no differences in respiration rates were observed between leachate sources, however, beyond day five, the rates diverged with C processing efficiency correlated with OM lability. Originally comprised of amino acid-like, labile fluorescent species, the inoculated stream water OM became more recalcitrant after 16 days, indicating humification processing over time. Our study highlights the importance of interdisciplinary approaches for understanding the processing and fate of OM in aquatic ecosystems.

  17. Terrestrial hyperspectral image shadow restoration through fusion with terrestrial lidar

    Science.gov (United States)

    Hartzell, Preston J.; Glennie, Craig L.; Finnegan, David C.; Hauser, Darren L.

    2017-05-01

    Recent advances in remote sensing technology have expanded the acquisition and fusion of active lidar and passive hyperspectral imagery (HSI) from exclusively airborne observations to include terrestrial modalities. In contrast to airborne collection geometry, hyperspectral imagery captured from terrestrial cameras is prone to extensive solar shadowing on vertical surfaces leading to reductions in pixel classification accuracies or outright removal of shadowed areas from subsequent analysis tasks. We demonstrate the use of lidar spatial information for sub-pixel HSI shadow detection and the restoration of shadowed pixel spectra via empirical methods that utilize sunlit and shadowed pixels of similar material composition. We examine the effectiveness of radiometrically calibrated lidar intensity in identifying these similar materials in sun and shade conditions and further evaluate a restoration technique that leverages ratios derived from the overlapping lidar laser and HSI wavelengths. Simulations of multiple lidar wavelengths, i.e., multispectral lidar, indicate the potential for HSI spectral restoration that is independent of the complexity and costs associated with rigorous radiometric transfer models, which have yet to be developed for horizontal-viewing terrestrial HSI sensors. The spectral restoration performance of shadowed HSI pixels is quantified for imagery of a geologic outcrop through improvements in spectral shape, spectral scale, and HSI band correlation.

  18. Use It or Lose It: Advances in Our Understanding of Terrestrial Nitrogen Retention and Loss (Invited)

    Science.gov (United States)

    Silver, W. L.; Yang, W. H.

    2013-12-01

    Understanding of the terrestrial nitrogen (N) cycle has grown over the last decade to include a variety of pathways that have the potential to either retain N in the ecosystem or result in losses to the atmosphere or groundwater. Early work has described the mechanics of these N transformations, but the relevance of these processes to ecosystem, regional, or global scale N cycling has not been well quantified. In this study, we review advances in our understanding of the terrestrial N cycle, and focus on three pathways with particular relevance to N retention and loss: dissimilatory nitrate and nitrite reduction to ammonium (DNRA), anaerobic ammonium oxidation (annamox), and anaerobic ammonium oxidation coupled to iron reduction (Feammox). We discuss the role of these processes in the microbial N economy (sensu Burgin et al. 2011) of the terrestrial N cycle, the environmental and ecological constraints, and relationships with other key biogeochemical cycles. We also discuss recent advances in analytical approaches that have improved our ability to detect these and related N fluxes in terrestrial ecosystems. Finally, we present a scaling exercise that identifies the potential importance of these pathways for N retention and loss across a range of spatial and temporal scales, and discuss their significance in terms of N limitation to net primary productivity, N leaching to groundwater, and the release of reactive N gases to the atmosphere.

  19. Contrasting effects of aquatic subsidies on a terrestrial trophic cascade.

    Science.gov (United States)

    Graf, Nadin; Bucher, Roman; Schäfer, Ralf B; Entling, Martin H

    2017-05-01

    Subsidies from adjacent ecosystems can alter recipient food webs and ecosystem functions, such as herbivory. Emerging aquatic insects from streams can be an important prey in the riparian zone. Such aquatic subsidies can enhance predator abundances or cause predators to switch prey, depending on the herbivores. This can lead to an increase or decrease of in situ herbivores and herbivory. We examined the effects of aquatic subsidies on a simplified terrestrial food web consisting of two types of herbivores, plants and predators (spiders). In our six-week experiment, we focused on the prey choice of the spiders by excluding predator immigration and reproduction. In accordance with predator switching, survival of leafhoppers increased in the presence of aquatic subsidies. By contrast, the presence of aquatic subsidies indirectly reduced weevils and herbivory. Our study shows that effects of aquatic subsidies on terrestrial predators can propagate through the food web in contrasting ways. Thereby, the outcome of the trophic cascade is determined by the prey choice of predators. © 2017 The Author(s).

  20. Estimating Tropical Forest Structure Using a Terrestrial Lidar.

    Science.gov (United States)

    Palace, Michael; Sullivan, Franklin B; Ducey, Mark; Herrick, Christina

    2016-01-01

    Forest structure comprises numerous quantifiable biometric components and characteristics, which include tree geometry and stand architecture. These structural components are important in the understanding of the past and future trajectories of these biomes. Tropical forests are often considered the most structurally complex and yet least understood of forested ecosystems. New technologies have provided novel avenues for quantifying biometric properties of forested ecosystems, one of which is LIght Detection And Ranging (lidar). This sensor can be deployed on satellite, aircraft, unmanned aerial vehicles, and terrestrial platforms. In this study we examined the efficacy of a terrestrial lidar scanner (TLS) system in a tropical forest to estimate forest structure. Our study was conducted in January 2012 at La Selva, Costa Rica at twenty locations in a predominantly undisturbed forest. At these locations we collected field measured biometric attributes using a variable plot design. We also collected TLS data from the center of each plot. Using this data we developed relative vegetation profiles (RVPs) and calculated a series of parameters including entropy, Fast Fourier Transform (FFT), number of layers and plant area index to develop statistical relationships with field data. We developed statistical models using a series of multiple linear regressions, all of which converged on significant relationships with the strongest relationship being for mean crown depth (r2 = 0.88, p forest structure.

  1. Mars : a small terrestrial planet

    OpenAIRE

    Mangold, N.; Baratoux, David; Witasse, O.; Encrenaz, T.; Sotin, C.

    2016-01-01

    Mars is characterized by geological landforms familiar to terrestrial geologists. It has a tenuous atmosphere that evolved differently from that of Earth and Venus and a differentiated inner structure. Our knowledge of the structure and evolution of Mars has strongly improved thanks to a huge amount of data of various types (visible and infrared imagery, altimetry, radar, chemistry, etc) acquired by a dozen of missions over the last two decades. In situ data have provided ground truth for rem...

  2. Measuring Entrepreneurial Ecosystems

    NARCIS (Netherlands)

    Stam, F.C.

    How can entrepreneurial ecosystems and productive entrepreneurship can be traced empirically and how is entrepreneurship related to entrepreneurial ecosystems. The analyses in this chapter show the value of taking a systems view on the context of entrepreneurship. We measure entrepreneurial

  3. Coral reefs - Specialized ecosystems

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.

    This paper discusses briefly some aspects that characterize and differentiate coral reef ecosystems from other tropical marine ecosystems. A brief account on the resources that are extractable from coral reefs, their susceptibility to natural...

  4. Mapping cultural ecosystem services:

    DEFF Research Database (Denmark)

    Paracchini, Maria Luisa; Zulian, Grazia; Kopperoinen, Leena

    2014-01-01

    Research on ecosystem services mapping and valuing has increased significantly in recent years. However, compared to provisioning and regulating services, cultural ecosystem services have not yet been fully integrated into operational frameworks. One reason for this is that transdisciplinarity...

  5. FWS Ecosystem Regions

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Digital ecosystem information portraying the location and boundaries of the ecosystems. The Service originally chose the U.S. Geological Survey's Hydrologic Unit Map...

  6. Quantifying Forest Carbon and Structure with Terrestrial LiDAR

    Science.gov (United States)

    Stovall, A. E.; Shugart, H. H., Jr.

    2014-12-01

    Current rising atmospheric CO2 concentrations are a major concern with significant global ramifications, however, of the carbon (C) fluxes that are known to occur on Earth, the terrestrial sink has the greatest amount of uncertainty. Improved monitoring of forest cover and change is required for reducing emissions from deforestation and forest degradation (REDD). We determine C storage from volume measurements with a high-precision Terrestrial Laser Scanner (TLS), substantially improving current standard ground validation techniques. This technology is utilized on several 30 m x 30 m plots in a Virginia temperate forest. Aboveground C is calculated on each of the study sites with commonly used allometric equations to offer a realistic comparison of field-based estimations to TLS-derived methods. The TLS and aerial LiDAR point cloud data are compared via the development of canopy height models at the plot scale. The novel method of point cloud voxelization is applied to our TLS data in order to produce detailed volumetric calculations in these complex forest ecosystems. Statistical output from the TLS data allows us to resolve and compare forest structure on scales from the individual plot to the entire forest landscape. The estimates produced from this research will be used to inform more widely available remote sensing datasets provided by NASA's Landsat satellites, significantly reducing the uncertainty of the terrestrial C cycle in temperate forests. Preliminary findings corroborate previous research, suggesting the potential for highly detailed monitoring of forest C storage as defined by the REDD initiative and analysis of complex ecosystem structure.

  7. Global Ecosystem Restoration Index

    DEFF Research Database (Denmark)

    Fernandez, Miguel; Garcia, Monica; Fernandez, Nestor

    2015-01-01

    The Global ecosystem restoration index (GERI) is a composite index that integrates structural and functional aspects of the ecosystem restoration process. These elements are evaluated through a window that looks into a baseline for degraded ecosystems with the objective to assess restoration...

  8. Ecosystem classification, Chapter 2

    Science.gov (United States)

    M.J. Robin-Abbott; L.H. Pardo

    2011-01-01

    The ecosystem classification in this report is based on the ecoregions developed through the Commission for Environmental Cooperation (CEC) for North America (CEC 1997). Only ecosystems that occur in the United States are included. CEC ecoregions are described, with slight modifications, below (CEC 1997) and shown in Figures 2.1 and 2.2. We chose this ecosystem...

  9. Towards ecosystem accounting

    NARCIS (Netherlands)

    Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

    2015-01-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

  10. Rights to ecosystem services

    NARCIS (Netherlands)

    Davidson, M.

    2014-01-01

    Ecosystem services are the benefits people obtain from ecosystems. Many of these services are provided outside the borders of the land where they are produced; this article investigates who is entitled to these non-excludable ecosystem services from two libertarian perspectives. Taking a

  11. Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

    Science.gov (United States)

    Luvall, J. C.; Rickman, D.; Fraser, R.

    2013-12-01

    Thermal remote sensing can provide environmental measuring tools with capabilities for measuring ecosystem development and integrity. Recent advances in applying principles of nonequilibrium thermodynamics to ecology provide fundamental insights into energy partitioning in ecosystems. Ecosystems are nonequilibrium systems, open to material and energy flows, which grow and develop structures and processes to increase energy degradation. More developed terrestrial ecosystems will be more effective at dissipating the solar gradient (degrading its exergy content) and can be measured by the effective surface temperature of the ecosystem on a landscape scale. Ecosystems are viewed as open thermodynamic systems with a large gradient impressed on them by the exergy flux from the sun. Ecosystems, according to the restated second law, develop in ways that systematically increases their ability to degrade the incoming solar exergy, hence negating it's ability to set up even larger gradients. Thus it should be expected that more mature ecosystems degrade the exergy they capture more completely than a less developed ecosystem. The degree to which incoming solar exergy is degraded is a function of the surface temperature of the ecosystem. If a group of ecosystems receives the same amount of incoming radiation, we would expect that the most mature ecosystem would reradiate its energy at the lowest quality level and thus would have the lowest surface temperature (coldest black body temperature). Initial development work was done using NASA's airborne Thermal Infrared Multispectral Scanner (TIMS) followed by the use of a multispectral visible and thermal scanner- Airborne Thermal and Land Applications Sensor (ATLAS). Luvall and his co-workers have documented ecosystem energy budgets, including tropical forests, mid-latitude varied ecosystems, and semiarid ecosystems. These data show that under similar environmental conditions (air temperature, relative humidity, winds, and solar

  12. Thermal Remote Sensing and the Thermodynamics of Ecosystem Development

    Science.gov (United States)

    Luvall, Jeffrey C.; Rickman, Doug.; Fraser, Roydon F.

    2013-01-01

    Thermal remote sensing can provide environmental measuring tools with capabilities for measuring ecosystem development and integrity. Recent advances in applying principles of nonequilibrium thermodynamics to ecology provide fundamental insights into energy partitioning in ecosystems. Ecosystems are nonequilibrium systems, open to material and energy flows, which grow and develop structures and processes to increase energy degradation. More developed terrestrial ecosystems will be more effective at dissipating the solar gradient (degrading its exergy content) and can be measured by the effective surface temperature of the ecosystem on a landscape scale. Ecosystems are viewed as open thermodynamic systems with a large gradient impressed on them by the exergy flux from the sun. Ecosystems, according to the restated second law, develop in ways that systematically increases their ability to degrade the incoming solar exergy, hence negating it's ability to set up even larger gradients. Thus it should be expected that more mature ecosystems degrade the exergy they capture more completely than a less developed ecosystem. The degree to which incoming solar exergy is degraded is a function of the surface temperature of the ecosystem. If a group of ecosystems receives the same amount of incoming radiation, we would expect that the most mature ecosystem would reradiate its energy at the lowest quality level and thus would have the lowest surface temperature (coldest black body temperature). Initial development work was done using NASA's airborne Thermal Infrared Multispectral Scanner (TIMS) followed by the use of a multispectral visible and thermal scanner- Airborne Thermal and Land Applications Sensor (ATLAS). Luvall and his coworkers have documented ecosystem energy budgets, including tropical forests, midlatitude varied ecosystems, and semiarid ecosystems. These data show that under similar environmental conditions (air temperature, relative humidity, winds, and solar

  13. Committed ecosystem changes and contributions to climate recovery

    Science.gov (United States)

    Jones, C. D.; Lowe, J. A.; Liddicoat, S. K.; Betts, R. A.

    2009-04-01

    Future climate change and the carbon cycle are tightly coupled. Many studies have now shown positive feedbacks which amplify climate change, reduce the natural uptake of carbon and influence global emissions pathways to stabilisation. On the timescale of 1 or 2 centuries, this feedback is mainly due to the terrestrial biosphere. Here we assess to what extent the biosphere contributes to recovery of CO2 levels after a cessation of carbon emissions. We find that when significant climate change has weakened natural terrestrial carbon sinks, these sinks do not recover after a stop of emissions and thus recovery of CO2 (and hence climate) is slow. Further, we find that the terrestrial biosphere exhibits significant inertia and can continue to respond to climate changes decades after stabilisation of climate. This has serious implications for definitions of dangerous climate change based simply on stabilisation temperature as the absence of significant biome changes at the time of stabilisation does not preclude significant and potentially detrimental changes in subsequent decades. Assessments of targets for stabilising climate change often consider the impacts of different levels of global warming. These assessments usually consider impacts that would occur at the time of reaching a particular level of warming. However, global terrestrial ecosystems continue to respond over longer timescales. Here we introduce the concept of "committed ecosystem changes" analogous to climate warming commitments and committed sea-level rise due to thermal inertia. The true impact of climate change on ecosystems will not be revealed for many decades after stabilising temperatures. Further, we suggest that ecosystems may become committed to substantial damage long before any is observable. For example, significant loss of forest cover in Amazonia may become inevitable significantly below a global warming of 2K. When defining dangerous climate change, and forming policy to avoid it, such

  14. Global terrestrial N2O budget for present and future

    Science.gov (United States)

    Olin, Stefan; Xing, Xu-Ri; Wårlind, David; Eliasson, Peter; Smith, Ben; Arneth, Almut

    2017-04-01

    Nitrogen (N) plays an important role in plant productivity and physiology and is the main limiting nutrient in a majority of the terrestrial ecosystems. The enhanced input of anthropogenic reactive nitrogen (Nr) in agriculture have enhanced global food production, but with adverse effects on biodiversity and water quality, and substantially increased emissions of N trace gases that affect air quality and climate. Emissions of N gases affects the climate, either through cloud forming nitrogen oxides (NOx) gases or as greenhouse gases, where nitrous oxide (N2O) is the most important being approximately 300 times more potent than carbon dioxide (CO2). In this study we use the process-based global vegetation model Lund-Potsdam-Jena General Ecosystem Simulator (LPJ-GUESS) (Olin et al. 2015) that recently have incorporated a new soil N transformation scheme, adopted from Xu-Ri and Prentice (2008), which makes it possible to study the N2O emission respond to changes in climate and CO2 concentration as well as anthropogenic N enhancements on a global scale. We present here results from the validation of the new model against site-scale N2O measurements from agricultural and non-agricultural ecosystems. We will also present results from a study to examine how land use, land use change and anthropogenic N fertilisation influence historical and future global N2O emissions. This new development represents a key component within future projects in CMIP6 (LUMIP) and in EC-Earth for the EU Horizon 2020 project CRESCENDO. Olin, S., Lindeskog, M., Pugh, T., Schurgers, G., Mischurow, M., Wårlind, D., Zaehle, S., Stocker, B., Smith, B. and Arneth, A. 2015. Soil carbon management in large-scale Earth system modelling: implications for crop yields and nitrogen leaching. Earth System Dynamics, 6, 745-768. Xu-Ri and Prentice IC. 2008. Terrestrial nitrogen cycle simulation with a dynamic global vegetation model. Global Change Biology, 14, 1745-1764.

  15. Mapping groundwater dependent ecosystems in California.

    Directory of Open Access Journals (Sweden)

    Jeanette Howard

    Full Text Available BACKGROUND: Most groundwater conservation and management efforts focus on protecting groundwater for drinking water and for other human uses with little understanding or focus on the ecosystems that depend on groundwater. However, groundwater plays an integral role in sustaining certain types of aquatic, terrestrial and coastal ecosystems, and their associated landscapes. Our aim was to illuminate the connection between groundwater and surface ecosystems by identifying and mapping the distribution of groundwater dependent ecosystems (GDEs in California. METHODOLOGY/PRINCIPAL FINDINGS: To locate where groundwater flow sustains ecosystems we identified and mapped groundwater dependent ecosystems using a GIS. We developed an index of groundwater dependency by analyzing geospatial data for three ecosystem types that depend on groundwater: (1 springs and seeps; (2 wetlands and associated vegetation alliances; and (3 stream discharge from groundwater sources (baseflow index. Each variable was summarized at the scale of a small watershed (Hydrologic Unit Code-12; mean size = 9,570 ha; n = 4,621, and then stratified and summarized to 10 regions of relative homogeneity in terms of hydrologic, ecologic and climatic conditions. We found that groundwater dependent ecosystems are widely, although unevenly, distributed across California. Although different types of GDEs are clustered more densely in certain areas of the state, watersheds with multiple types of GDEs are found in both humid (e.g. coastal and more arid regions. Springs are most densely concentrated in the North Coast and North Lahontan, whereas groundwater dependent wetlands and associated vegetation alliances are concentrated in the North and South Lahontan and Sacramento River hydrologic regions. The percentage of land area where stream discharge is most dependent on groundwater is found in the North Coast, Sacramento River and Tulare Lake regions. GDE clusters are located at the highest

  16. Mapping Groundwater Dependent Ecosystems in California

    Science.gov (United States)

    Howard, Jeanette; Merrifield, Matt

    2010-01-01

    Background Most groundwater conservation and management efforts focus on protecting groundwater for drinking water and for other human uses with little understanding or focus on the ecosystems that depend on groundwater. However, groundwater plays an integral role in sustaining certain types of aquatic, terrestrial and coastal ecosystems, and their associated landscapes. Our aim was to illuminate the connection between groundwater and surface ecosystems by identifying and mapping the distribution of groundwater dependent ecosystems (GDEs) in California. Methodology/Principal Findings To locate where groundwater flow sustains ecosystems we identified and mapped groundwater dependent ecosystems using a GIS. We developed an index of groundwater dependency by analyzing geospatial data for three ecosystem types that depend on groundwater: (1) springs and seeps; (2) wetlands and associated vegetation alliances; and (3) stream discharge from groundwater sources (baseflow index). Each variable was summarized at the scale of a small watershed (Hydrologic Unit Code-12; mean size = 9,570 ha; n = 4,621), and then stratified and summarized to 10 regions of relative homogeneity in terms of hydrologic, ecologic and climatic conditions. We found that groundwater dependent ecosystems are widely, although unevenly, distributed across California. Although different types of GDEs are clustered more densely in certain areas of the state, watersheds with multiple types of GDEs are found in both humid (e.g. coastal) and more arid regions. Springs are most densely concentrated in the North Coast and North Lahontan, whereas groundwater dependent wetlands and associated vegetation alliances are concentrated in the North and South Lahontan and Sacramento River hydrologic regions. The percentage of land area where stream discharge is most dependent on groundwater is found in the North Coast, Sacramento River and Tulare Lake regions. GDE clusters are located at the highest percentage

  17. Fishing for ecosystem services

    Science.gov (United States)

    Pope, Kevin L.; Pegg, Mark A.; Cole, Nicholas W.; Siddons, Stephen F.; Fedele, Alexis D.; Harmon, Brian S.; Ruskamp, Ryan L.; Turner, Dylan R.; Uerling, Caleb C.

    2016-01-01

    Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystem-based management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, and taking a more proactive approach, we expect sustainable, quality fisheries that are resilient to future disturbances. To that end, we contend that: (1) management always involves tradeoffs; (2) explicit management of fisheries for ecosystem services could facilitate a transition from reactive to proactive management; and (3) adaptive co-management is a process that could enhance management for ecosystem services. We propose adaptive co-management with an ecosystem service framework where actions are implemented within ecosystem boundaries, rather than political boundaries, through strong interjurisdictional relationships.

  18. Fishing for ecosystem services.

    Science.gov (United States)

    Pope, Kevin L; Pegg, Mark A; Cole, Nicholas W; Siddons, Stephen F; Fedele, Alexis D; Harmon, Brian S; Ruskamp, Ryan L; Turner, Dylan R; Uerling, Caleb C

    2016-12-01

    Ecosystems are commonly exploited and manipulated to maximize certain human benefits. Such changes can degrade systems, leading to cascading negative effects that may be initially undetected, yet ultimately result in a reduction, or complete loss, of certain valuable ecosystem services. Ecosystem-based management is intended to maintain ecosystem quality and minimize the risk of irreversible change to natural assemblages of species and to ecosystem processes while obtaining and maintaining long-term socioeconomic benefits. We discuss policy decisions in fishery management related to commonly manipulated environments with a focus on influences to ecosystem services. By focusing on broader scales, managing for ecosystem services, and taking a more proactive approach, we expect sustainable, quality fisheries that are resilient to future disturbances. To that end, we contend that: (1) management always involves tradeoffs; (2) explicit management of fisheries for ecosystem services could facilitate a transition from reactive to proactive management; and (3) adaptive co-management is a process that could enhance management for ecosystem services. We propose adaptive co-management with an ecosystem service framework where actions are implemented within ecosystem boundaries, rather than political boundaries, through strong interjurisdictional relationships. Published by Elsevier Ltd.

  19. Columbia River Estuary Ecosystem Classification Ecosystem Complex

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Estuarine ecosystems are controlled by a variety of processes that operate at multiple spatial and temporal scales. Understanding the hierarchical nature of these...

  20. Terrestrial chemical cues help coral reef fish larvae locate settlement habitat surrounding islands.

    Science.gov (United States)

    Dixson, Danielle L; Jones, Geoffrey P; Munday, Philip L; Pratchett, Morgan S; Srinivasan, Maya; Planes, Serge; Thorrold, Simon R

    2011-12-01

    Understanding the degree of connectivity between coastal and island landscapes and nearby coral reefs is vital to the integrated management of terrestrial and marine environments in the tropics. Coral reef fish are capable of navigating appropriate settlement habitats following their pelagic larval phase, but the mechanisms by which they do this are unclear. The importance of olfactory cues in settlement site selection has been demonstrated, and there is increasing evidence that chemical cues from terrestrial sources may be important for some species. Here, we test the olfactory preferences of eight island-associated coral reef fish recruits and one generalist species to discern the capacity for terrestrial cue recognition that may aid in settlement site selection. A series of pairwise choice experiments were used to evaluate the potential role that terrestrial, water-borne olfactory cues play in island-reef recognition. Olfactory stimuli tested included near-shore water, terrestrial rainforest leaf litter, and olfactory cues collected from different reef types (reefs surrounding vegetated islands, and reefs with no islands present). All eight island-associated species demonstrated high levels of olfactory discrimination and responded positively toward olfactory cues indicating the presence of a vegetated island. We hypothesize that although these fish use a suite of cues for settlement site recognition, one mechanism in locating their island/reef habitat is through the olfactory cues produced by vegetated islands. This research highlights the role terrestrial olfactory cues play in large-scale settlement site selection and suggests a high degree of ecosystem connectivity.

  1. Can polar bears use terrestrial foods to offset lost ice-based hunting opportunities?

    Science.gov (United States)

    Rode, Karyn D.; Robbins, Charles T.; Nelson, Lynne; Amstrup, Steven C.

    2015-01-01

    Increased land use by polar bears (Ursus maritimus) due to climate-change-induced reduction of their sea-ice habitat illustrates the impact of climate change on species distributions and the difficulty of conserving a large, highly specialized carnivore in the face of this global threat. Some authors have suggested that terrestrial food consumption by polar bears will help them withstand sea-ice loss as they are forced to spend increasing amounts of time on land. Here, we evaluate the nutritional needs of polar bears as well as the physiological and environmental constraints that shape their use of terrestrial ecosystems. Only small numbers of polar bears have been documented consuming terrestrial foods even in modest quantities. Over much of the polar bear's range, limited terrestrial food availability supports only low densities of much smaller, resident brown bears (Ursus arctos), which use low-quality resources more efficiently and may compete with polar bears in these areas. Where consumption of terrestrial foods has been documented, polar bear body condition and survival rates have declined even as land use has increased. Thus far, observed consumption of terrestrial food by polar bears has been insufficient to offset lost ice-based hunting opportunities but can have ecological consequences for other species. Warming-induced loss of sea ice remains the primary threat faced by polar bears.

  2. Ecosystem engineering effects on species diversity across ecosystems: a meta-analysis.

    Science.gov (United States)

    Romero, Gustavo Q; Gonçalves-Souza, Thiago; Vieira, Camila; Koricheva, Julia

    2015-08-01

    Ecosystem engineering is increasingly recognized as a relevant ecological driver of diversity and community composition. Although engineering impacts on the biota can vary from negative to positive, and from trivial to enormous, patterns and causes of variation in the magnitude of engineering effects across ecosystems and engineer types remain largely unknown. To elucidate the above patterns, we conducted a meta-analysis of 122 studies which explored effects of animal ecosystem engineers on species richness of other organisms in the community. The analysis revealed that the overall effect of ecosystem engineers on diversity is positive and corresponds to a 25% increase in species richness, indicating that ecosystem engineering is a facilitative process globally. Engineering effects were stronger in the tropics than at higher latitudes, likely because new or modified habitats provided by engineers in the tropics may help minimize competition and predation pressures on resident species. Within aquatic environments, engineering impacts were stronger in marine ecosystems (rocky shores) than in streams. In terrestrial ecosystems, engineers displayed stronger positive effects in arid environments (e.g. deserts). Ecosystem engineers that create new habitats or microhabitats had stronger effects than those that modify habitats or cause bioturbation. Invertebrate engineers and those with lower engineering persistence (1 year. Invertebrate species richness was particularly responsive to engineering impacts. This study is the first attempt to build an integrative framework of engineering effects on species diversity; it highlights the importance of considering latitude, habitat, engineering functional group, taxon and persistence of their effects in future theoretical and empirical studies. © 2014 The Authors. Biological Reviews © 2014 Cambridge Philosophical Society.

  3. Century-Scale Responses of Ecosystem Carbon Storage and Flux to Multiple Environmental Changes in the Southern United States

    Science.gov (United States)

    Hanqin Tian; Guangsheng Chen; Chi Zhang; Mingliang Liu; Ge Sun; Arthur Chappelka; Wei Ren; Xiaofeng Xu; Chaoqun Lu; Shufen Pan; Hua Chen; Dafeng Hui; Steven McNulty; Graeme Lockaby; Eric Vance

    2012-01-01

    Terrestrial ecosystems in the southern United States (SUS) have experienced a complex set of changes in climate, atmospheric CO2 concentration, tropospheric ozone (O3), nitrogen (N) deposition, and land-use and land-cover change (LULCC) during the past century. Although each of these factors has received attention for its alterations on ecosystem carbon (C) dynamics,...

  4. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2014-01-01

    Terrestrial water storage (TWS) comprises groundwater, soil moisture, surface water, snow,and ice. Groundwater typically varies more slowly than the other TWS components because itis not in direct contact with the atmosphere, but often it has a larger range of variability onmultiannual timescales (Rodell and Famiglietti, 2001; Alley et al., 2002). In situ groundwaterdata are only archived and made available by a few countries. However, monthly TWSvariations observed by the Gravity Recovery and Climate Experiment (GRACE; Tapley et al.,2004) satellite mission, which launched in 2002, are a reasonable proxy for unconfinedgroundwater at climatic scales.

  5. Assessment of ecosystem resilience to hydroclimatic disturbances in India.

    Science.gov (United States)

    Sharma, Ashutosh; Goyal, Manish Kumar

    2017-09-14

    Recent studies have shown an increasing trend in hydroclimatic disturbances like droughts, which are anticipated to become more frequent and intense under global warming and climate change. Droughts adversely affect the vegetation growth and crop yield, which enhances the risks to food security for a country like India with over 1.2 billion people to feed. Here, we compared the response of terrestrial net primary productivity (NPP) to hydroclimatic disturbances in India at different scales (i.e., at river basins, land covers, and climate types) to examine the ecosystems' resilience to such adverse conditions. The ecosystem water use efficiency (WUEe : NPP/Evapotranspiration) is an effective indicator of ecosystem productivity, linking carbon (C) and water cycles. We found a significant difference (p biome incapability to withstand such conditions. The ecosystem resilience at land cover and climate type scale did not completely relate to the basin-scale ecosystem resilience, which indicated that ecosystem resilience at basin scale is controlled by some other ecohydrological processes. Our results facilitate the identification of the most sensitive regions in the country for ecosystem management and climate policy making, and highlight the need for taking sufficient adaptation measures to ensure sustainability of ecosystems. © 2017 John Wiley & Sons Ltd.

  6. Animals as indicators of ecosystem responses to air emissions

    Science.gov (United States)

    Newman, James R.; Schreiber, R. Kent

    1984-07-01

    With existing and proposed air-quality regulations, ecological disasters resulting from air emissions such as those observed at Copperhill, Tennessee, and Sudbury, Ontario, are unlikely. Current air-quality standards, however, may not protect ecosystems from subacute and chronic exposure to air emissions. The encouragement of the use of coal for energy production and the development of the fossil-fuel industries, including oil shales, tar sands, and coal liquification, point to an increase and spread of fossil-fuel emissions and the potential to influence a number of natural ecosystems. This paper reviews the reported responses of ecosystems to air-borne pollutants and discusses the use of animals as indicators of ecosystem responses to these pollutants. Animal species and populations can act as important indicators of biotic and abiotic responses of aquatic and terrestrial ecosystems. These responses can indicate long-term trends in ecosystem health and productivity, chemical cycling, genetics, and regulation. For short-term trends, fish and wildlife also serve as monitors of changes in community structure, signaling food-web contamination, as well as providing a measure of ecosystem vitality. Information is presented to show not only the importance of animals as indicators of ecosystem responses to air-quality degradation, but also their value as air-pollution indices, that is, as air-quality-related values (AQRV), required in current air-pollution regulation.

  7. Invasive European bird cherry disrupts stream-riparian linkages: effects on terrestrial invertebrate prey subsidies for juvenile coho salmon

    Science.gov (United States)

    Roon, David A.; Wipfli, Mark S.; Wurtz, Tricia L.; Blanchard, Arny L.

    2016-01-01

    The spread of invasive species in riparian forests has the potential to affect both terrestrial and aquatic organisms linked through cross-ecosystem resource subsidies. However, this potential had not been explored in regards to terrestrial prey subsidies for stream fishes. To address this, we examined the effects of an invasive riparian tree, European bird cherry (EBC, Prunus padus), spreading along urban Alaskan salmon streams, by collecting terrestrial invertebrates present on the foliage of riparian trees, their subsidies to streams, and their consumption by juvenile coho salmon (Oncorhynchus kisutch). Riparian EBC supported four to six times less terrestrial invertebrate biomass on its foliage and contributed two to three times lower subsidies relative to native deciduous trees. This reduction in terrestrial invertebrate biomass was consistent between two watersheds over 2 years. In spite of this reduction in terrestrial prey resource input, juvenile coho salmon consumed similar levels of terrestrial invertebrates in stream reaches bordered by EBC. Although we did not see ecological effects extending to stream salmonids, reduced terrestrial prey subsidies to streams are likely to have negative consequences as EBC continues to spread.

  8. Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current.

    Science.gov (United States)

    Reimer, Janet J; Vargas, Rodrigo; Rivas, David; Gaxiola-Castro, Gilberto; Hernandez-Ayon, J Martin; Lara-Lara, Ruben

    2015-01-01

    Some land and ocean processes are related through connections (and synoptic-scale teleconnections) to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO]) decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature) may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST) in regions with strong coastal upwelling and terrestrial gross primary production (GPP) across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP) with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation), while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns). Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that could

  9. Sea Surface Temperature Influence on Terrestrial Gross Primary Production along the Southern California Current.

    Directory of Open Access Journals (Sweden)

    Janet J Reimer

    Full Text Available Some land and ocean processes are related through connections (and synoptic-scale teleconnections to the atmosphere. Synoptic-scale atmospheric (El Niño/Southern Oscillation [ENSO], Pacific Decadal Oscillation [PDO], and North Atlantic Oscillation [NAO] decadal cycles are known to influence the global terrestrial carbon cycle. Potentially, smaller scale land-ocean connections influenced by coastal upwelling (changes in sea surface temperature may be important for local-to-regional water-limited ecosystems where plants may benefit from air moisture transported from the ocean to terrestrial ecosystems. Here we use satellite-derived observations to test potential connections between changes in sea surface temperature (SST in regions with strong coastal upwelling and terrestrial gross primary production (GPP across the Baja California Peninsula. This region is characterized by an arid/semiarid climate along the southern California Current. We found that SST was correlated with the fraction of photosynthetic active radiation (fPAR; as a proxy for GPP with lags ranging from 0 to 5 months. In contrast ENSO was not as strongly related with fPAR as SST in these coastal ecosystems. Our results show the importance of local-scale changes in SST during upwelling events, to explain the variability in GPP in coastal, water-limited ecosystems. The response of GPP to SST was spatially-dependent: colder SST in the northern areas increased GPP (likely by influencing fog formation, while warmer SST at the southern areas was associated to higher GPP (as SST is in phase with precipitation patterns. Interannual trends in fPAR are also spatially variable along the Baja California Peninsula with increasing secular trends in subtropical regions, decreasing trends in the most arid region, and no trend in the semi-arid regions. These findings suggest that studies and ecosystem process based models should consider the lateral influence of local-scale ocean processes that