HR: 09:30h
AN: B51E-07    [Abstracts]
TI: Vulnerability of soil organic matter to temperature changes: Exploring constraints due to substrate decomposability and microbial community structure
AU: * Conant, R T
EM: conant@nrel.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Plante, A F
EM: plante@nrel.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Paul, E A
EM: eldor@nrel.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Haddix, M L
EM: mlhaddix@nrel.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Steinweg, M
EM: steinweg@nrel.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Drijber, R J
EM: rdrijber@unlnotes.unl.edu
AF: University of Nebraska, 254 Keim Hall Department of Agronomy and Horticulture University of Nebraska-Lincoln P. O. Box 830915, Lincoln, NE 68583-0915 United States
AU: Six, J
EM: josix@bronze.ucdavis.edu
AF: University of California, Davis, Department of Agronomy and Range Science One Shields Avenue, Davis, CA 95616 United States
AU: Carlson, J
EM: jennysarac@yahoo.com
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AU: Greenwood, R
EM: beckwood@holly.colostate.edu
AF: Colorado State University, NREL Campus Delivery 1499, Fort Collins, CO 80523-1499 United States
AB: Even modest temperature increases could cause large releases of CO2 from the soil; a one-degree temperature increase could prompt soil carbon losses (as CO2) equivalent to five times the annual CO2 release from all fossil fuel burning. But, such forecasts are based on short-term data that implicitly assume all of the carbon in the soil is uniformly temperature sensitive. Much of the applicable research suggests that older, more resistant carbon fractions may be less temperature sensitive. We hypothesize that the physical, chemical, and biochemical mechanisms that protect soil carbon from decomposition act to reduce the temperature sensitivity of soil carbon. An important corollary is that soil carbon stocks are less vulnerable to changes in temperature than previously supposed. We are testing this hypothesis by comparing temperature sensitivities of soils with more labile material versus soils with less. We present results from studies examining temperature responses of biochemically protected soil C, responses of whole soil C, and responses of soil C derived from native plant species versus introduced plant species (i.e., old versus young soil C).
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0486 Soils/pedology (1865)
SC: Biogeosciences [B]
MN: Fall Meeting 2005