HR: 1340h
AN: B23A-0941    [Abstracts]
TI: Selecting Locations for Medium Intensity Sampling of Soil Organic Carbon in Alaska
AU: * Bliss, N B
EM: bliss@usgs.gov
AF: USGS EROS Data Center, SAIC, 47914 252nd Street, Sioux Falls, SD 57198 United States
AU: Maursetter, J
EM: johnmaursetter@msn.com
AF: University of South Dakota, Agricultural and Biosystems Engineering, Brookings, SD 57007 United States
AB: A warming climate may lead to the release of the greenhouse gases carbon dioxide and methane from Arctic soils, resulting in a positive feedback. Quantifying soil carbon stocks is necessary for calibrating models of carbon flux. The total stocks of soil carbon in high latitudes are poorly quantified because there are few soil samples. As a guide to additional sampling, such as the new 3rd Tier Medium-Intensity Sampling planned in the North American Carbon Program, we have investigated methods of using existing soil databases to map the intensities and calculate the total quantities of soil carbon in Alaska. We have related the laboratory data on soil physical and chemical properties for specific locations (the pedon data) to the soil components of the digital maps in the State Soil Geographic (STATSGO) database. Both data sources are from the U.S. Department of Agriculture's Natural Resources Conservation Service. We evaluated 523 pedons for Alaska, selected those for which soil organic carbon could be calculated, and investigated several methods of matching them to the digital soil maps. The soil taxonomic classification (usually at the suborder, great group, or subgroup level), slope, and location were used in multiple combinations for linking the detailed profile descriptions to the general soil maps. We illustrate the uncertainty of estimations of carbon stocks by using alternative methods of performing the data selection and matching. Each matching method allows a many-to-many relation between the pedon point observations and the components of the soil maps. Once extrapolated to the map, a large measure of carbon stock attributed to a given sample point indicates an area in which additional sampling would efficiently reduce the uncertainty of the soil organic carbon estimates.
DE: 9350 North America
DE: 1823 Frozen ground
DE: 1615 Biogeochemical processes (4805)
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting