HR: 0800h
AN: B31A-0055    [Abstracts]
TI: Carbon-Nitrogen Cycle Model of Terrestrial Ecosystem for Plot Scale: Application to Cool Temperate Deciduous Broad-leaved Forest and Cool Temperate Evergreen Coniferous Forest in Central Japan
AU: Ito, A
EM: itoh@nies.go.jp
AF: NIES, Onogawa 16-2, Tsukuba, 3058506, Japan
AU: Ito, A
EM: itoh@nies.go.jp
AF: FRCGC, JAMSTEC, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 2360001, Japan
AU: * Inatomi, M
EM: inatomi@jamstec.go.jp
AF: FRCGC, JAMSTEC, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 2360001, Japan
AB: By developing a biogeochemical model that fully includes carbon cycle and nitrogen cycle in a single framework, we can consider nitrogen nutrition as a limiting elements in the model and evaluate atmosphere-ecosystem exchange of trace greenhouse gases in addition to carbon dioxide (i.e. methane and nitrous oxide). In this study, a process-based model simulating carbon-nitrogen cycle was developed and applied to a cool-temperate deciduous broad-leaved forest in Takayama (36N, 137E, 1420m ASL) and a cool-temperate evergreen coniferous forest in Fujiyoshida (35N, 138E, 1030m ASL), central Japan. Models of nitrogen cycle were introduced into a revised terrestrial ecosystem model Sim-CYCLE, which is a simple box-type carbon cycle model simulating net ecosystem CO2 exchange on the basis of ecophysiological relationships. Using the model, photosynthetic and respiratory CO2 fluxes were simulated during the periods from 1948 to 2004 at daily step using time-series climate data. On average during the last 10 years, the model estimated that the temperate forest absorbed net CO2 and CH4 at rates of 804.53 g CO2 m-2 yr-1 and 0.34 g CH4 m-2 yr-1, and net released N2O at a rate of 0.02 g N2O m-2 yr-1, respectively. Based on the 100-year GWP of greenhouse gases in IPCC (2001), the forest was estimated to have a negative (i.e. ameliorating) effect of GWP by 807.74 g CO2 (equivalent) m-2 yr-1. Because the results seem reasonable, we are working on scaling-up of the model to regional scale, in our forthcoming studies.
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 0469 Nitrogen cycling
DE: 0490 Trace gases
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting