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Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12875/abstract): Permafrost thaw can alter the soil environment through changes in soil moisture, frequently resulting in soil saturation, a shift to anaerobic decomposition, and changes in the plant community. These changes, along with thawing of previously frozen organic material, can alter the form and magnitude of greenhouse gas production from permafrost ecosystems. We synthesized existing methane (CH 4) and carbon dioxide (CO 2) production measurements from anaerobic incubations of boreal and tundra soils from the geographic permafrost region to evaluate large-scale controls of anaerobic CO 2 and CH 4 production and compare the relative importance...
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Permafrost (perennially frozen) and active-layer (seasonally thawed) soils varying in soil carbon (C) and nitrogen (N) content and radiocarbon age were collected from three sites in interior Alaska to determine potential release of dissolved organic carbon (DOC), total dissolved N (TDN), dissolved organic nitrogen (DON), and dissolved inorganic nitrogen (DIN) upon thaw. Soil cores were cut into 15 cm thick sections, and deep active-layer (15-30 cm above the permafrost boundary) and shallow permafrost (15-30 cm below the permafrost boundary) sections were thawed and leached with deionized water. Soil leachates were analyzed for DOC, TDN, nitrate (NO3-), and ammonium (NH4+) concentrations, dissolved organic matter...
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The Northwest Boreal Landscape Conservation Cooperative is a collaborative, multi-jurisdictional partnership that works to enhance the ability of organizations and communities to understand, manage, and adapt to our changing landscape. Our vision is a dynamic landscape that maintains functioning, resilient boreal ecosystems and associated cultural resources.
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Changing climate conditions (e.g. changes to air temperature, surface temperature, snowpack duration, and soil temperature) are affecting where trees are able to successfully grow and are bringing changes to the structure of forests throughout many parts of Alaska. In order to understand and project future vegetation changes, scientists use computer models to establish the relationships between climate variables, such as those mentioned above, and ecological responses such as the presence or absence of a tree species, tree growth and establishment, changes in sap flow, and other demographic and physiological responses. These computer models, however, frequently do not account for Alaska’s extreme topography and...
Abstract (from http://www.ncbi.nlm.nih.gov/pubmed/26463267): Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse-scar bogs, low shrub/scrub, and forests growing on elevated ice-rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5 °C of thawing. Increased permafrost thaw in lowland boreal forests in response to warming may have consequences for...


    map background search result map search result map Northwest Boreal Landscape Conservation Cooperative Observing and Understanding the Impacts of Climate on Alaskan Forests Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska Northwest Boreal Landscape Conservation Cooperative Observing and Understanding the Impacts of Climate on Alaskan Forests