HR: 0800h
AN: A21B-0850    [Abstracts]
TI: Terrestrial Vegetation Response to Climate Change Over North America from Increased Atmospheric CO2
AU: * Ming, M
EM: mchen@gust.sr.unh.edu
AF: University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824
AU: Mao, H
EM: hmao@typhoon.sr.unh.edu
AF: University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824
AU: Talbot, R
EM: robert.talbot@unh.edu
AF: University of New Hampshire, Morse Hall, 39 College Road, Durham, NH 03824
AB: We used a regional climate version of the MM5 mesoscale atmospheric modeling system that was asynchronically and simultaneously coupled with the biogeographical model BIOME to explore vegetation-climate interactions over North America. The impact of climate change due to increased greenhouse gases on potential ecosystem evolution was assessed, and a future scenario of vegetation distribution was explored. Doubled CO2 conditions induced strong high-latitude warming, while the southern U.S. became cooler in winter. Across almost all of the model domain precipitation tended to increase in all seasons with the highest intensification found over the Northeast, Southeast, and the Great Plains. In response to this future climate scenario, vegetation migrated northward systematically in the eastern United States. In particular, the sparsely vegetated area around Hudson Bay was predicted to be covered by cool conifer forests. Over the Great Plains and parts of the Midwest, the supply of water from precipitation was found to be a crucial factor affecting the natural evolution of vegetation; more precipitation under doubled CO2 led to temperate deciduous forests extending northward and to the northwest. Grasslands in the northern half of the Great Plains are expected to be replaced by cool conifer and mixed forests due to increased precipitation. Over the Cascade and Rocky Mountain ranges in the western U.S., no systematic changes in vegetation are predicted, due to the complex terrain and unsystematic changes in temperature and precipitation. Averaged over the whole model domain, 39% of areas are projected to have vegetation type changes under doubled CO2. The above results were obtained with model simulations using 108 km resolution, and they will be compared with runs using 50 km resolution to study the potential impact of model resolution on regional ecosystem response to climate change.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 1610 Atmosphere (0315, 0325)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005