HR: 16:00h
AN: B14C-01    [Abstracts]
TI: The vulnerability of carbon storage in boreal North America during the 21st Century to increases in wildfire activity
AU: * Balshi, M
EM: ftmsb@uaf.edu
AF: Department of Biology & Wildlife University of Alaska Fairbanks, 211 Irving I Building, Fairbanks, AK 99775, United States
AU: McGuire, A D
EM: ffadm@uaf.edu
AF: USGS Alaska Cooperative Fish & Wildlife Research Unit, University of Alaska Fairbanks 216 Irving I Building, Fairbanks, AK 99775, United States
AU: Duffy, P
EM: paul.duffy@neptuneinc.org
AF: Neptune & Company, 8550 W. 14th Ave., Suite 100, Lakewood, CO 80215, United States
AU: Flannigan, M
EM: mflannig@nrcan-rncan.gc.ca
AF: Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste. Marie, ON P6A 2E5, Canada
AU: Walsh, J
EM: jwalsh@iarc.uaf.edu
AF: International Arctic Research Center, 930 Koyukuk Drive P.O. Box 757340, Fairbanks, AK 99775, United States
AU: Kicklighter, D
EM: dkick@mbl.edu
AF: The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, United States
AU: Melillo, J
EM: jmelillo@mbl.edu
AF: The Ecosystems Center, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543, United States
AB: The boreal forest contains large reserves of carbon. Across this region, wildfires influence the temporal and spatial dynamics of carbon storage, which has the potential to be altered under a changing climate. The temporal and spatial dynamics of fire are also likely to be altered as the climate continues to change. In this study, we develop temporally and spatially explicit relationships between air temperature and fuel moisture codes derived from the Canadian Fire Weather Index System to estimate annual area burned at 2.5° resolution using a Multivariate Adaptive Regression Splines (MARS) approach across boreal North America. At the boreal North American scale, the empirical fire models explain on the order of 80 % of the variation in annual area burned for the period 1960-2002. To understand how the temporal and spatial dynamics of fire might be altered by future climate change, the empirical fire models were driven by output from the A2 and B2 scenarios from the Canadian Climate Center CGCM2 global climate model to predict annual area burned through year 2100. Historical and future area burned estimates are then coupled to the process-based Terrestrial Ecosystem Model (TEM) to simulate fire emissions and changes in carbon storage for boreal North America in the context of changing atmospheric CO2 concentration and climate from the start of the historically recorded fire records in the 20th century through the end of the 21st century. Relative to the last decade of the 20th century, decadal total carbon emissions from fire increase on the order of 2.5 to 4.4 times by 2091-2100, depending on the climate scenario and assumptions about CO2 fertilization. The effect of CO2 fertilization is a major uncertainty in this analysis. For the 21st century, our simulations indicate that boreal North America is a carbon sink in response to CO2 fertilization, climate variability, and fire, but an increase in fire results in a decrease in the sink strength. While this study highlights the importance of future atmospheric CO2, climate, and fire on the carbon dynamics of boreal North America, several limitations and uncertainties exist and should be addressed in future process- based analyses. Future studies should incorporate the role of dynamic vegetation to more accurately represent post-fire successional processes, incorporate fire severity parameters that change in time and space, and integrate the role of other disturbances and their interactions with future fire regime.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0430 Computational methods and data processing
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0466 Modeling
SC: Biogeosciences [B]
MN: 2007 Fall Meeting