HR: 0800h
AN: B51C-0223    [Abstracts]
TI: Spatial Patterns of Soil Organic Carbon in the United States
AU: * Bliss, N B
EM: bliss@usgs.gov
AF: SAIC, USGS/EROS, 47914 252nd St., Sioux Falls, SD 57198 United States
AB: The Department of the Interior (DOI) has jurisdiction influencing approximately 22 percent of the land area of the United States. The poster presents estimates of the current stocks of soil organic carbon (SOC) on all lands and Federal lands. The DOI lands have about 22 percent of the nation's SOC, so the average carbon intensity (8.66 kg C m^-2) about matches the average for all lands (8.81 kg C m^-2). However the carbon on DOI lands is not evenly distributed. Of the 17.76 Petagrams (1 Pg = 10¹⁵ grams) of SOC on DOI lands, 13.07 Pg (74 percent) are in Alaska, and 4.69 Pg (26 percent) are in the Conterminous U.S. The Alaska soils are wetter and colder than the national average, and the DOI lands in the conterminous U.S. are warmer and drier than the average. A set of SOC maps is shown, developed by intersecting the State Soil Geographic (STATSGO) database with data on federal lands from the National Atlas. With 22 percent of the nation's soil carbon, the DOI lands are important in a national accounting of greenhouse gas emission and sequestration. Future behavior of these lands is uncertain, but in scenarios of warming or drying, carbon released by respiration may exceed carbon captured by photosynthesis, resulting in a net release of carbon to the atmosphere. If warming stimulates a net release of greenhouse gases, this represents a positive feedback contributing to future global warming, a very unstable condition for the global climate system.
DE: 0428 Carbon cycling (4806)
DE: 0486 Soils/pedology (1865)
DE: 9350 North America
SC: Biogeosciences [B]
MN: Fall Meeting 2005