HR: 0800h
AN: B11D-0770    [Abstracts]
TI: Spatial variability in organic layer characteristics following wildfire in interior Alaskan black spruce forests
AU: * Kane, E S
EM: ftesk@uaf.edu
AF: Michigan State University, Dept. of Plant Biology; Plant Biology Bldg. 122-S, East Lansing, MI 48824,
AU: Turetsky, M R
EM: mrt@msu.edu
AF: Michigan State University, Dept. of Plant Biology; Plant Biology Bldg. 122-S, East Lansing, MI 48824,
AU: Kasischke, E S
EM: ekasisch@umd.edu
AF: University of Maryland, Department of Geography; 2181 LeFrak Hall, College Park, MD 20742,
AU: Harden, J W
EM: jharden@usgs.gov
AF: US Geological Survey, 345 Middlefield Rd ms 962, Menlo Park, CA 94025,
AU: Manies, K L
EM: kmanies@usgs.gov
AF: US Geological Survey, 345 Middlefield Rd ms 962, Menlo Park, CA 94025,
AB: We measured residual organic layer characteristics at 194 test sites following 13 wildfire events in 2002 - 2005 in interior Alaska to further understanding of changes in post-fire variability in different landscape positions. North- facing and toe-slope forest organic layers were the least variable following wildfires (mean coefficient of variation = 64%). Flatter toe-slope forests had the highest mean cover of unburned and singed moss and Sphagnum moss species (33% of all sites surveyed) remaining after fire, and unburned organic matter patches were almost always associated with Sphagnum moss. We suggest that patchiness of moss dominated hummocks, which retain moisture effectively, largely determined variability in organic layer consumption in flat toe-slope forests. Across all sites, variation in post-fire organic layer depths increased as the fire season progressed, likely owing to the continued drying of surface fuels. Post-fire variability in organic layer depths was highest in wildfires occurring in the drier more severe fire years (2004-2005 vs. 2002-2003). These data suggest that variability in post-fire organic layer characteristics is not only mediated by biophysical properties at local scales, but is also largely influenced by climate variations within a fire season. We can therefore expect variability in post-fire organic layer depths to increase with increases in the duration of the fire season or with continued drying trends in a changing climate, especially in forests lacking significant cover of highly moisture-retentive Sphagnum mosses.
DE: 0475 Permafrost, cryosphere, and high-latitude processes (0702, 0716)
DE: 1605 Abrupt/rapid climate change (4901, 8408)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1621 Cryospheric change (0776)
DE: 4806 Carbon cycling (0428)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting