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Advancing our mechanistic understanding of ecosystem responses to climate change is critical to improve ecological theories, develop predictive models to simulate ecosystem processes, and inform sound policies to manage ecosystems and human activities. Manipulation of temperature in the field, or the “ecosystem warming experiment,” has proved to be a powerful tool to understand ecosystem responses to changes in temperature. No comprehensive synthesis has been conducted since the last one more than 10 years ago. A new synthetic analysis is critically needed to advance our understanding of ecosystem responses to warming, to highlight experimental artifacts and appropriate interpretations, and to guide development...
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Tropical forests contain > 50% of the world’s known species (Heywood 1995), 55% of global forest biomass (Pan et al. 2011), and exchange more carbon (C), water and energy with the atmosphere than any other ecosystem type (e.g., Saugier et al. 2001). Despite their importance, there is more uncertainty associated with predictions of how tropical forests will respond to warming than for any other biome (Randerson et al. 2009). This uncertainty is of global concern due to the large quantity of C cycled by these forests and the high potential for biodiversity loss. Given the importance of tropical forests, decision makers and land managers around the globe need increased predictive capacity regarding how tropical forests...
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These data can be used in a geographic information system (GIS) for any number of purposes such as assessing wildlife habitat, water quality, pesticide runoff, land use change, etc. The State data sets are provided with a 300 meter buffer beyond the State border to faciliate combining the State files into larger regions. The user must have a firm understanding of how the datasets were compiled and the resulting limitations of these data. The National Land Cover Dataset was compiled from Landsat satellite TM imagery (circa 1992) with a spatial resolution of 30 meters and supplemented by various ancillary data (where available). The analysis and interpretation of the satellite imagery was conducted using very large,...
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Amphibian populations are declining globally at unprecedented rates but statistically rigorous identification of mechanisms is lacking. Identification of reasons underlying large-scale declines is imperative to plan and implement effective conservation efforts. Most research on amphibian population decline has focused on local populations and local factors. However, the ubiquity of declines across species and landscapes suggests that causal factors at a broader scale are also important. Elucidation of the mechanisms driving population change has lagged, mainly because data have been unavailable at continental scales. We propose to address this need by assembling data to answer questions about broad-scale drivers...
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Global hydroclimatic conditions have been significantly altered, over the past century, by anthropogenic influences that arise from warming global climate and also from local/regional anthropogenic disturbances. There has been never been an effort that has systematically analyzed how the spatio-temporal variability of land-surface fluxes vary in natural and human-altered watersheds globally. This synthesis study will adapt and extend the classical Budyko framework to quantify the role of drivers - changing climate and local human disturbances - in altering flow regimes and in creating urban heat island episodes over the globe. An allied goal is to develop parsimonious hydroclimatic models that explain the spatio-temporal...
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Migratory species may provide more ecosystem goods and services to humans in certain parts of their range than others. These areas may or may not coincide with the locations of habitat on which the species is most dependent for its continued population viability. This situation can present significant policy challenges, as locations that most support a given species may be in effect subsidizing the provision of services in other locations, often in different political jurisdictions. The ability to quantify these spatial subsidies could be used to develop economic incentives that internalize the costs and benefits of protecting migratory species, enhancing cross-jurisdictional cooperative management. Targeted payments...
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Plants convert carbon dioxide into sugars for food during photosynthesis, and this provides food for all animal life. However, photosynthesis is inhibited when a plant’s enzymes use oxygen instead of carbon dioxide. To avoid this use of oxygen, some plants developed a photosynthetic adaptation – called C4 photosynthesis – to concentrate carbon dioxide around the enzymes. While less than 5% of plants use the C4 photosynthetic pathway, they make up ~20% of global terrestrial gross primary productivity. Due to their high productivity, C4 plants have a profound impact on ecosystems, economies, the carbon cycle, and our climate. Corn and sugarcane are both C4 plants, as are foundational western livestock and wildlife...
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Nitrogen deposition is altering forest dynamics, terrestrial carbon storage, and biodiversity. However, our ability to forecast how different tree species will respond to N deposition, especially key response thresholds, is limited by a lack of synthesis across spatial scales and research approaches. To develop our best understanding of N deposition impact on tree growth and survival, we will integrate plot-­‐ level studies describing plant growth and survival responses to N inputs and plant-­‐ available soil nutrients with a continental scale analysis across a N deposition gradient. Our primary outcome will be estimates of tree response to N deposition with explicit representation of uncertainty and the identification...
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Wetlands provide many important ecosystem services, including wildlife habitat, water purification, flood protection, and carbon metabolism. Our ability to manage these services and predict the long-term health of wetlands is strongly linked to their carbon fluxes, of which methane (CH4) is a key component. Natural wetlands emit approximately 30% of global CH4 emissions, as their waterlogged soils create ideal conditions for CH4 production. They are also the largest, and potentially most uncertain, natural source of CH4 to the atmosphere. To understand and predict CH4 fluxes across wetlands globally, we propose the first synthesis of CH4 flux tower data accompanying a global database of CH4 emissions. By taking...
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Soils are a vast reservoir of organic carbon (C), rendering the fate of soil C an important control on the global climate system. Widespread changes in soil C storage capacity present a potentially strong feedback to global change. Yet, a comprehensive understanding of how soil C will respond to climate and/or land use disturbance remains illusive, resulting in major uncertainties in global climate models. Our working group will synthesize information on the processes controlling soil C storage across different spatial scales and develop new procedures to translate local measurements to the regional and global scale datasets used by models. These activities will improve our ability to map the vulnerability of soil...
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Water cycling and availability exert dominant control over ecological processes and the sustainability of ecosystem services in water - limited ecosystems. Consequently, dryland ecosystems have the potential to be dramatically impacted by hydrologic alterations emerging from global change, notably increasing temperature and altered precipitation patterns. In addition, the possibility of directly manipulating global solar radiation by augmenting stratospheric SO2 is receiving increasing attention as CO2 emissions continue to increase - these manipulations are anticipated to decrease precipitation, a change that may be as influential as temperature increases in dryland ecosystems. We propose to integrate a proven...
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Groundwater withdrawals in the western US are a critical component of the water resources strategy for the region. Climate change already may be substantially altering recharge into groundwater systems; however, the quantity and direction (increase or decrease) of changes are relatively unknown as most climate change assessments have focused on surface water systems. We propose to conduct a broad scale literature review followed by a synthesis of available data, analysis and simulations with available downscaled climate scenarios to understand how recharge in the western US might respond to plausible climatic shifts during the rest of the 21st Century. We will produce an estimated range of impacts on groundwater...
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Biological nitrogen fixation (BNF) is a critical biogeochemical process that converts inert atmospheric N2 gas into biologically usable forms of the essential nutrient nitrogen. A variety of free-living and symbiotic organisms carry out BNF, and in most regions worldwide, BNF is the largest source of nitrogen that fuels terrestrial ecosystems. As a result, BNF has far reaching effects on ecosystem properties (water quality, carbon storage), sustainability (plant growth, soil fertility), and the global climate system. Despite this cross-cutting importance, existing syntheses of BNF have major gaps, with particular challenges in upscaling local measurements across large areas. These gaps, and a corresponding lack...


map background search result map search result map National Land Cover Data Set 1992 for Wyoming 30 meter Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets Animal Migration and Spatial Subsidies: Establishing a Framework for Conservation Markets National Land Cover Data Set 1992 for Wyoming 30 meter