HR: 0800h
AN: B41D-0220    [Abstracts]
TI: Variations in fire severity and frequency as a driver of changes in succession and long-term patterns of carbon storage in Alaskan boreal forests
AU: Johnstone, J
EM: jjohnsto@yukoncollege.yk.ca
AF: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 United States
AU: * Kasischke, E S
EM: ekasisch@geog.umd.edu
AF: Department of Geography, University of Maryland, College Park, MD 20742 United States
AU: Bourgeau-Chavez, L
EM: laura.chavez@gd-ais.com
AF: Ocean and Terrestrial Applications Group General Dynamics Advanced Information Systems, P.O. Box 900, Ypsilanti, MI 48197
AU: Chapin, F S
EM: fffsc@uaf.edu
AF: Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775 United States
AB: Black spruce is the dominant forest cover type in the North American boreal region (they represent some 57 percent of all forests in this region). These spruce forests are a major North American terrestrial carbon reservoir because cold ground temperatures lead to low decomposition rates and the building up of carbon-rich layers of dead organic matter over century and longer time scales. The surface organic layers and living vegetation of these forests contain an estimated 22.6 Gt of carbon, with nearly two-thirds of this amount stored in the surface organic layer lying on top of mineral soil. There has been a significant increase in fire activity the boreal forest region of North America, with annual area burned doubling between the 1960s and 1990s in association with warming climates. This rise in temperature and disturbance from fire brings into question the fate of the large carbon reservoir present in the black spruce forests of this region. Here we present a conceptual framework based on a state-factors model that can be used to examine how variations in the fire regime alter successional pathways and carbon storage in the black spruce forests of Alaska. In particular, we focus on the factors and site conditions that will allow black spruce forests to switch to successional trajectories containing a significant deciduous component. To illustrate the concepts presented in this framework, results from recent research will be presented.
DE: 0400 BIOGEOSCIENCES
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0439 Ecosystems, structure and dynamics (4815)
SC: Biogeosciences [B]
MN: Fall Meeting 2005