HR: 0830h
AN: GC41A-04    [Abstracts]
TI: Climate Change Effects on North American Ecosystems: Contribution to the 2007 IPCC Assessment
AU: * Lenihan, J
EM: lenihan@fsl.orst.edu
AF: USDA Forest Service Pacific Northwest Research Station, 3500 SW Jefferson Way, Corvallis, OR 97331 United States
AU: Bachelet, D
EM: bachelet@fsl.orst.edu
AF: Oregon State University, 3500 SW Jefferson Way, Corvallis, OR 97331 United States
AU: Drapek, R
EM: drapek@fsl.orst.edu
AF: USDA Forest Service Pacific Northwest Research Station, 3500 SW Jefferson Way, Corvallis, OR 97331 United States
AU: Neilson, R
EM: neilson@fsl.orst.edu
AF: USDA Forest Service Pacific Northwest Research Station, 3500 SW Jefferson Way, Corvallis, OR 97331 United States
AB: The MAPSS team has generated model simulations of future climate impacts on ecosystems in the United States for several national and international assessments, including those of the Intergovernmental Panel on Climate Change (IPCC). The IPCC is currently drafting its next assessment using a new suite of future climate scenarios. We have generated new ecosystem simulations using our MC1 dynamic general vegetation model (DGVM) that depict potential changes in vegetation distribution, fire dynamics, and carbon sequestration in response to six of these new climate scenarios. The six climate scenarios were constructed for North America using General Circulation Model (GCM) output from three different models (Canadian CGCM2, UK HadCM3, and Australian CSIRO Mk2) forced by two different emission scenarios (IPCC SRES A2 and B2). By 2100, the climate scenarios show a projected temperature increase of about 6o C in summer and 8oC in winter for the A2 emissions scenario, compared to 4oC and 6oC for B2, respectively. The scenarios also show winter precipitation increasing by as much as 20% under the A2 emissions scenario, and 10% under the B2. We were able to compare the results of our MC1 ecosystem simulations under these new climate scenarios to those under older climate scenarios generated by two of the GCMs (Canadian and UK) in the conterminous United States. Differences in the response of vegetation, fire, and carbon were most pronounced in the Pacific Northwest and southwestern United States where one or more of the newer scenarios were significantly drier.
DE: 1615 Biogeochemical processes (4805)
DE: 1630 Impact phenomena
DE: 1699 General or miscellaneous
SC: Global Climate Change [GC]
MN: 2005 Joint Assembly