HR: 16:25h
AN: B24A-01 INVITED     [Abstracts]
TI: Effects of spatial and temporal climatic variability on terrestrial carbon and water fluxes in the Pacific Northwest, US
AU: * Kang, S
EM: kangsk@kangwon.ac.kr
AF: Kangwon National University, Department of Environmental Science, Chunchon, 200-701, Korea, Republic of
AU: Running, S
EM: swr@ntsg.umt.edu
AF: University of Montana, NTSG, School of Forestry, Missoula, MT 59812, United States
AU: Kimball, J
EM: jskimball@ntsg.umt.edu
AF: University of Montana, NTSG, School of Forestry, Missoula, MT 59812, United States
AU: Fagre, D
EM: fagre@usgs.gov
AF: USGS, Science Center Glacier National Park, West Glacier, MT , United States
AU: Michaelis, A
EM: Michaelis@ntsg.umt.edu
AF: University of Montana, NTSG, School of Forestry, Missoula, MT 59812, United States
AU: Peterson, D
EM: Peterson@usgs.gov
AF: USDA, Forest Service, Seattle, WA , United States
AB: The Pacific Northwest (PNW) is characterized with dramatic variations in climate and topography, which provides an ideal geographic region for studying interactions between regional climate and vegetation dynamics. We examined vegetation carbon and water dynamics along the climate and topographic gradients using a process- based biogechemical model, BIOME-BGC. For the purposes, our simulation experiments were designed to have two 18-year (years 1980-1997 and 2088-2105) simulations with two different climatic change scenarios (A2 and B2) identified with each other by differences in temperature and precipitation changes until year 2100: one is characterized with hot and dry climate but the other with warm and humid climate. There were considerable west- to-east spatial variations in carbon and water fluxes and carbon stocks, and these variations are well related with topography and distance from the west coast. Annual variability of NPP and ET were positively correlated with rainfall but inversely proportional to VPD, which indicate that the PNW is predominantly a water-limited ecosystem for NPP and ET. The A2 climate change scenario characterized with hotter (+4.2 oC) and drier (-7 %) climate resulted in 23 % and 10 % increases in NPP and ET but 15 % decrease in outflow. Under the B2 scenario characterized with warmer (+1.6 oC) and wetter (+11 %) climate, NPP and ET resulted in 12 % and 15 % increases but the outflow decreased by 2 % in spite of increased precipitation. Our simulation experiments indicate that the PNW region is overall water-limited ecosystem and water supply to river system would decrease under both drier and wetter climate change scenarios.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0428 Carbon cycling (4806)
DE: 0495 Water/energy interactions (1878)
DE: 1630 Impacts of global change (1225)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
SC: Biogeosciences [B]
MN: 2007 Joint Assembly