HR: 11:50h
AN: B22C-07    [Abstracts]
TI: Carbon accumulation in bogs and fens after permafrost degradation in central Alaska
AU: * Jorgenson, M T
EM: tjorgenson@abrinc.com
AF: ABR, Inc., PO Box 80410, Fairbanks, AK 99708, United States
AU: Cater, T
EM: tcater@abrinc.com
AF: ABR, Inc., PO Box 80410, Fairbanks, AK 99708, United States
AU: Roth, J
EM: jroth@abrinc.com
AF: ABR, Inc., PO Box 80410, Fairbanks, AK 99708, United States
AU: Pullman, E
EM: epullman@abrinc.com
AF: ABR, Inc., PO Box 80410, Fairbanks, AK 99708, United States
AU: Racine, C
EM: cracine@crrel.usace.army.mil
AF: Cold Regions Research and Engineering Laboratory, 72 Lyme Road, Hanover, NH 03755, United States
AU: Harden, J
EM: jharden@usgs.gov
AF: U.S. Geological Survey, 345 Middlefield Road ms 962, Menlo Park, CA 94025,
AB: In the discontinuous zone in Alaska about 60% of the land area has permafrost and 5% has thermokarst terrain, which is comprised mostly of thermokarst lakes, bogs and fens. The collapse of lowland forests on seasonally saturated soils on ice-rich terrain into permanently saturated ombrotrophic bogs, dominated by Sphagnum and ericaceous shrubs, and into minerotrophic fens, dominated by herbaceous vegetation, can radically alter the carbon balance of boreal ecosystems. To assess the consequences of permafrost degradation on carbon storage in boreal ecosystems, we investigated accumulation rates of soil organic carbon at various stages of vegetation succession in five bogs and six fens on the Tanana Flats in central Alaska. Bogs ranged from 109 to 637 yrs in age based on calibrated radiocarbon dates. The mean carbon stock of bog peat at the oldest successional stage was 42 kg/m2. Fens ranged in age from 50 to 102 conventional radiocarbon years that could not be calibrated to calendar years. The mean carbon stock of fen peat was 20 kg/m2 at the oldest successional stage. Carbon accumulation rates slowed at later successional stages.
DE: 0428 Carbon cycling (4806)
DE: 0702 Permafrost (0475)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting