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The extensive boreal biome is little studies relative to its global importance. Its high soil moisture and low temperatures result in large below-ground reservoirs of carbon (C) and nitrogen (N). Presently, such high-latitude ecosystems are undergoing the largest temperature increases in global warming. Change in soil temperature or moisture in the large pools of soil organic matter could fundamentally change ecosystem C and N budgets. Since 1990, we have conducted treeline studies in a small (800 ha) watershed in Noatak National Preserve, northwestern Alaska. Our objectives were to (1) gain an understanding of treeline dynamics, structure, and function; and (2) examine the effects of global climate change, particularly...
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Fire is a particularly important control on the carbon (C) balance of the boreal forest, and fire-return intervals and fire severity appear to have increased since the late 1900s in North America. In addition to the immediate release of stored C to the atmosphere through organic-matter combustion, fire also modifies soil conditions, possibly affecting C exchange between terrestrial and atmospheric pools for decades after the burn. The effects of fire on ecosystem C dynamics vary across the landscape, with topographic position and soil drainage functioning as important controls. The data reported here contributed to a larger U.S. Geological Survey (USGS) study, published in the journal Ecosystems by O’Donnell...
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One objective of the U.S. Geological Survey’s Fate of Carbon in Alaskan Landscapes (FOCAL) project is to study the effects of fire and soil drainage on soil carbon storage in boreal forests. For this purpose, the project has measured the soil carbon content in several chronosequences (time since disturbance) of various soil-drainage types. One such chronosequence near Delta Junction, Alaska was initially studied in 2000 and 2001. Additional sites in the Delta Junction area were sampled in 2006 to expand the number of stand ages represented in the chronosequence. This report describes these additional sites, as well as the procedures used to describe, sample, and analyze the soils. We also present data tables containing,...
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Peatlands in the northern permafrost region store large amounts of organic carbon, most of which is currently stored in frozen peat deposits. Recent warming at high-latitudes has accelerated permafrost thaw in peatlands, which will likely result in the loss of soil organic carbon from previously frozen peat deposits to the atmosphere. Here, we report soil organic carbon inventories, soil physical data, and field descriptions from a collapse-scar bog chronosequence located in a peatland ecosystem at Koyukuk Flats National Wildlife Refuge in Alaska.
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Growing visitor traffic and resource use, as well as natural and anthropogenic land and climatic changes, can place increasing stress on lake ecosystems in Denali National Park and Preserve. Baseline data required to substantiate impact assessment in this sub-arctic region is sparse to non-existent. The U.S. Geological Survey, in cooperation with the National Park Service, conducted a water-quality assessment of several large lakes in and around the Park from June 2006 to August 2008. Discrete water-quality samples, lake profiles of pH, specific conductivity, dissolved-oxygen concentration, water temperature, turbidity, and continuous‑record temperature profile data were collected from Wonder Lake, Chilchukabena...
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Climate change theorists have projected striking changes in local weather on earth due to increases in temperature. These predicted changes may cause melting glaciers and ice caps, rising sea levels, increasing desertification and other environmental changes which seem likely to affect presumed indicator species as harbingers of more significant changes. Wild sheep, even though they are one of the more successful mammalian taxa since Pleistocene times, exhibit a suite of adaptations to glacier driven environments which may be presumed to render them sensitive to environmental changes. The authors began investigation with these assumptions by comparing changes, as determined by satellite imagery, in glacier extent...
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The Chulitna River basin in southwest Alaska drains an area of about 1,160 square miles, with the lower 158 square miles of the basin in Lake Clark National Park and Preserve. Water from this basin influences Lake Clark ecosystems that support salmon that, in part, sustain the Bristol Bay fishery. An area of about 391 square miles in the upper part of the Chulitna River basin has been staked for mining development (1,670 claims), and a proposed large scale copper-gold-molybdenum mine (Pebble Mine) lies adjacent to the Chulitna River drainage. The U.S. Geological Survey in cooperation with the National Park Service conducted a water-quality assessment of the Chulitna River from October 2009 to June 2012. Discrete...
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Growing visitor traffic and resource use, as well as natural and anthropogenic land and climatic changes, can place increasing stress on lake ecosystems in Denali National Park and Preserve. Baseline data required to substantiate impact assessment in this sub-arctic region is sparse to non-existent. The U.S. Geological Survey, in cooperation with the National Park Service, conducted a water-quality assessment of several large lakes in and around the Park from June 2006 to August 2008. Discrete water-quality samples, lake profiles of pH, specific conductivity, dissolved-oxygen concentration, water temperature, turbidity, and continuous‑record temperature profile data were collected from Wonder Lake, Chilchukabena...
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The Chulitna River basin in southwest Alaska drains an area of about 1,160 square miles, with the lower 158 square miles of the basin in Lake Clark National Park and Preserve. Water from this basin influences Lake Clark ecosystems that support salmon that, in part, sustain the Bristol Bay fishery. An area of about 391 square miles in the upper part of the Chulitna River basin has been staked for mining development (1,670 claims), and a proposed large scale copper-gold-molybdenum mine (Pebble Mine) lies adjacent to the Chulitna River drainage. The U.S. Geological Survey in cooperation with the National Park Service conducted a water-quality assessment of the Chulitna River from October 2009 to June 2012. Discrete...
    map background search result map search result map An evaluation of methods for identifying and interpreting buried soils in late Quaternary loess in Alaska Soil data for a collapse-scar bog chronosequence in Koyukuk Flats National Wildlife Refuge, Alaska, 2008 Soil data from different-age Picea mariana stands near Delta Junction, Alaska Initial results from a study of climatic changes and the effect on wild sheep habitat in selected study areas of Alaska Soil physical, chemical, and gas-flux characterization from Picea mariana stands near Erickson Creek, Alaska Treeline biogeochemistry and dynamics, Noatak National Preserve, northwestern Alaska Water-quality and flow data, Chulitna River basin, southwest Alaska, October 2009-June 2012 Environmental and Hydrologic Overview of the Yukon River Basin, Alaska and Canada Limnological and water-quality data from Wonder Lake, Chilchukabena Lake, and Lake Minchumina, Denali National Park and Preserve and surrounding area, Alaska, June 2006-August 2008 Limnological and water-quality data from Wonder Lake, Chilchukabena Lake, and Lake Minchumina, Denali National Park and Preserve and surrounding area, Alaska, June 2006-August 2008 Soil physical, chemical, and gas-flux characterization from Picea mariana stands near Erickson Creek, Alaska Soil data from different-age Picea mariana stands near Delta Junction, Alaska Water-quality and flow data, Chulitna River basin, southwest Alaska, October 2009-June 2012 Initial results from a study of climatic changes and the effect on wild sheep habitat in selected study areas of Alaska Limnological and water-quality data from Wonder Lake, Chilchukabena Lake, and Lake Minchumina, Denali National Park and Preserve and surrounding area, Alaska, June 2006-August 2008 Limnological and water-quality data from Wonder Lake, Chilchukabena Lake, and Lake Minchumina, Denali National Park and Preserve and surrounding area, Alaska, June 2006-August 2008 Soil data for a collapse-scar bog chronosequence in Koyukuk Flats National Wildlife Refuge, Alaska, 2008 Treeline biogeochemistry and dynamics, Noatak National Preserve, northwestern Alaska An evaluation of methods for identifying and interpreting buried soils in late Quaternary loess in Alaska Environmental and Hydrologic Overview of the Yukon River Basin, Alaska and Canada