HR: 13:45h
AN: B22B-01 INVITED     [PDF]
TI: Progress and Challenges in Modeling Soil Carbon Dynamics of High Latitude Ecosystems: Temporal and Spatial Perspectives
AU: * McGuire, A D
EM: ffadm@uaf.edu
AF: U.S. Geological Survey University of Alaska Fairbanks, 214 Irving I Building Institute of Arctic Biology University of Alaska Fairbanks, Fairbanks, AK 99775 United States
AB: Much progress has been made in modeling the role of soil carbon dynamics in high latitude ecosystems in response to temporal and spatial variation in climate and disturbance. Temporal variation in climate affects soil carbon dynamics at seasonal to millennial temporal scales. At seasonal time scales, progress has been achieved by representing soil thermal dynamics of high latitude ecosystems including the insulating effects of snow in the cold season and the freeze-thaw dynamics of permafrost soils. At inter-annual time scales, some studies indicate that cooling of the Northern Hemisphere after the Pinatubo Eruption affected the atmospheric growth rate of carbon dioxide through the effects of cooling on decomposition. At decadal and longer time scales, responses of decomposition to climate variability largely depend on how fast vs. slow pools are represented in models. Modeling studies and emerging data from field studies of temporal variation in decomposition after disturbance indicate that decomposition is largely controlled by the amount of remaining substrate and inputs to the soil rather than changes in soil environmental conditions after disturbance. Across high latitude ecosystems, both climate and disturbance appear to interact to influence latitudinal patterns of soil carbon storage. Also, glaciation and soil drainage substantially influence soil carbon storage through interactions with permafrost. While there has been much recent progress in representing how soil thermal dynamics influence soil carbon dynamics, the representation of disturbance regimes, glacial history, and soil drainage in a spatial context presents substantial challenges to modeling spatial variation in soil carbon storage. Modeling the lateral transport and processing of carbon in high latitude soils and surface waters has only recently received attention.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
DE: 1615 Biogeochemical processes (4805)
DE: 3210 Modeling
SC: Biogeosciences [B]
MN: 2003 Fall Meeting