HR: 1340h
AN: B33E-1095    [Abstracts]
TI: Impacts of global warming on boreal larch forest in East Siberia: simulations with a coupled carbon cycle and fire regime model
AU: * Ito, A
EM: itoh@jamstec.go.jp
AF: FRCGC-JAMSTEC, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 236-0001 Japan
AB: Boreal forest is one of the focal areas in the study of global warming and carbon cycle. In this study, a coupled carbon cycle and fire regime model was developed and applied to a larch forest in East Siberia, near Yakutsk. Fire regime is simulated with a cellular automaton (20 km x 20 km), in which fire ignition, propagation, and extinction are parameterized in a stochastic manner, including the effects of fuel accumulation and weather condition. For each grid, carbon cycle is simulated with a 10-box scheme, in which net biome production by photosynthesis, respiration, decomposition, and biomass burning are calculated explicitly. Model parameters were calibrated with field data of biomass, litter stock, and fire statistics; the carbon cycle scheme was examined with flux measurement data. As a result, the model successfully captured average carbon stocks, productivity, fire frequency, and biomass burning. To assess the effects of global warming, a series of simulations were performed using climatic projections based on the IPCC-SRES emission scenarios from 1990 to 2100. The range of uncertainty among the different climate models and emission scenarios was assessed by using multi-model projection data by CCCma, CCSR/NIES, GFDL, and HCCPR corresponding to the SRES A2 and B2 scenarios. The model simulations showed that global warming in the 21st century would considerably enhance the fire regime (e.g., cumulative burnt area increased by 80 to 120 percent), leading to larger carbon emission by biomass burning. The effect was so strong that growth enhancement by elevated atmospheric CO2 concentration and elongated growing period was cancelled out at landscape scale. In many cases, the larch forest was estimated to act as net carbon sources of 2 to 5 kg C m_|2 by the end of the 21st century, underscoring the importance of forest fire monitoring and management in this region.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 0476 Plant ecology (1851)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
SC: Biogeosciences [B]
MN: Fall Meeting 2005