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SOC in northern high latitudes is highly vulnerable to disturbances Disturbances are an important component of the northern soil C cycle Soils in northern high latitudes could loose their long-term C sink character This synthesis addresses the vulnerability of the North American high-latitude soil organic carbon (SOC) pool to climate change. Disturbances caused by climate warming in arctic, subarctic, and boreal environments can result in significant redistribution of C among major reservoirs with potential global impacts. We divide the current northern high-latitude SOC pools into (1) near-surface soils where SOC is affected by seasonal freeze-thaw processes and changes in moisture status, and (2) deeper permafrost...
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Permafrost soils are large reservoirs of potentially labile carbon (C). Understanding the dynamics of C release from these soils requires us to account for the impact of wildfires, which are increasing in frequency as the climate changes. Boreal wildfires contribute to global emission of greenhouse gases (GHG[mdash]CO2, CH4 and N2O) and indirectly result in the thawing of near-surface permafrost. In this study, we aimed to define the impact of fire on soil microbial communities and metabolic potential for GHG fluxes in samples collected up to 1[thinsp]m depth from an upland black spruce forest near Nome Creek, Alaska. We measured geochemistry, GHG fluxes, potential soil enzyme activities and microbial community...
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Stratigraphic observations from sites in eastern Beringia - Ch'ijee's Bluff and nearby exposures in northern Yukon, the Palisades on the Yukon River in Alaska, and placer mining exposures at Thistle Creek in west-central Yukon - provide insight into the chronostratigraphic significance of Old Crow tephra (124 ± 10 ka) and permafrost response to warming during the last interglaciation. Pollen and insect, bryophyte, and vascular plant macrofossils from a vegetated surface buried by Old Crow tephra suggest the local presence of mesic tundra, wet meadow, and aquatic habitat when the tephra was deposited. A revised glass fission-track age for Old Crow tephra places its deposition closer to the time of the last interglaciation...
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Many northern lake-rich regions are undergoing pronounced hydrological change, yet inadequate knowledge of the drivers of these landscape-scale responses hampers our ability to predict future conditions. We address this challenge in the thermokarst landscape of Old Crow Flats (OCF) using a combination of remote sensing imagery and monitoring of stable isotope compositions of lake waters over three thaw seasons (2007?2009). Quantitative analysis confirmed that the hydrological behavior of lakes is strongly influenced by catchment vegetation and physiography. Catchments of snowmelt-dominated lakes, typically located in southern peripheral areas of OCF, encompass high proportions of woodland/forest and tall shrub vegetation...
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1] Increasing surface air temperatures from anthropogenic forcing are melting permafrost at high latitudes and intensifying the hydrological cycle. Long-term streamflow records (≥30 yrs) from 23 stream gauges in the Canadian Northwest Territories (NWT) indicate a general significant upward trend in winter baseflow of 0.5–271.6 %/yr and the beginning of significant increasing mean annual flow (seen at 39% of studied gauge records), as assessed by the Kendall-τ test. The NWT exports an average discharge of ≥308.6 km3/yr to the Beaufort Sea, of which ≥120.9 km3/yr is baseflow. We propose that the increases in winter baseflow and mean annual streamflow in the NWT were caused predominately by climate warming via permafrost...


    map background search result map search result map Permafrost degradation and ecological changes associated with a warming climate in central Alaska Permafrost in Canada, a challenge to northern development Landslide processes in discontinuous permafrost, Little Salmon Lake (NTS 105L/1 and 2), south-central Yukon The recent warming of permafrost in Alaska Climate and permafrost dynamics of the Alaskan boreal forest A reconnaissance inventory of permafrost-related landslides in the Pelly River watershed, central Yukon Increasing winter baseflow and mean annual streamflow from possible permafrost thawing in the Northwest Territories, Canada Spatially simulating changes of soil water content and their effects on carbon sequestration in Canada's forests and wetlands Stratigraphy, chronology and paleoenvironmental significance of perennially frozen interglacial sediments in eastern Beringia What glaciers are telling us about Earth's changing climate Debris flow susceptibility mapping using a qualitative heuristic method and Flow-R along the Yukon Alaska Highway Corridor, Canada Controls on water balance of shallow thermokarst lakes and their relations with catchment characteristics: a multi-year, landscape-scale assessment based on water isotope tracers and remote sensing in Old Crow Flats, Yukon (Canada) Vulnerability of high-latitude soil organic carbon in North America to disturbance Ice layers as an indicator of summer warmth and atmospheric blocking in Alaska Impact of fire on active layer and permafrost microbial communities and metagenomes in an upland Alaskan boreal forest Impact of fire on active layer and permafrost microbial communities and metagenomes in an upland Alaskan boreal forest Controls on water balance of shallow thermokarst lakes and their relations with catchment characteristics: a multi-year, landscape-scale assessment based on water isotope tracers and remote sensing in Old Crow Flats, Yukon (Canada) Permafrost degradation and ecological changes associated with a warming climate in central Alaska Ice layers as an indicator of summer warmth and atmospheric blocking in Alaska A reconnaissance inventory of permafrost-related landslides in the Pelly River watershed, central Yukon The recent warming of permafrost in Alaska Climate and permafrost dynamics of the Alaskan boreal forest Debris flow susceptibility mapping using a qualitative heuristic method and Flow-R along the Yukon Alaska Highway Corridor, Canada Increasing winter baseflow and mean annual streamflow from possible permafrost thawing in the Northwest Territories, Canada Stratigraphy, chronology and paleoenvironmental significance of perennially frozen interglacial sediments in eastern Beringia What glaciers are telling us about Earth's changing climate Vulnerability of high-latitude soil organic carbon in North America to disturbance Permafrost in Canada, a challenge to northern development Spatially simulating changes of soil water content and their effects on carbon sequestration in Canada's forests and wetlands