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David McGuire

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Projecting the Future Distribution and Flow of Water in Alaskan Coastal Forest Watersheds
Water is a key ecosystem service that provides life to vegetation, animals, and human communities. The distribution and flow of water on a landscape influences many ecological functions, such as the distribution and health of vegetation and soil development and function. However, the future of many important water resources remains uncertain. Reduced snowfall and snowpack, earlier spring runoff, increased winter streamflow and flooding, and decreased summer streamflow have all been identified as potential impacts to water resources due to climate change. These factors all influence the water balance in the Pacific Coastal Temperate Rainforest (PCTR). Ensuring healthy flow and availability of water resources is...
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Development of the Alaska Integrated Ecosystem Model to Illustrate Future Landscape Change
Ongoing and future climate change throughout Alaska has the potential to affect terrestrial ecosystems and the services that they provide to the people of Alaska and the nation. These services include the gathering of food and fiber by Alaskan communities, the importance of ecosystems to recreation, cultural, and spiritual activities of people in Alaska, and the way that land cover and vegetation in ecosystems affect temperature and water flow (runoff, flooding etc.) throughout the state. Assessments of the effects of climate change on these “ecosystem services” have been hindered by a lack of tools (e.g. computer models) capable of forecasting future landscapes in a changing climate while taking into account numerous...
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This assessment was conducted to fulfill the requirements of section 712 of the Energy Independence and Security Act of 2007 and to contribute to knowledge of the storage, fluxes, and balance of carbon and methane gas in ecosystems of Alaska. The carbon and methane variables were examined for major terrestrial ecosystems (uplands and wetlands) and inland aquatic ecosystems in Alaska in two time periods: baseline (from 1950 through 2009) and future (projections from 2010 through 2099). The assessment used measured and observed data and remote sensing, statistical methods, and simulation models. The national assessment, conducted using the methodology described in SIR 2010-5233, has been completed for the conterminous...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12757/abstract): The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate,...
Abstract (from http://www.nature.com/nature/journal/v520/n7546/full/nature14338.html): Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to...
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