HR: 0800h
AN: B41B-0185    [Abstracts]
TI: Carbon Fluxes Parameterization and Modeling at Regional Scale Thanks to Dendrochronological Time Series
AU: * Gaucherel, C
EM: gaucherel@cerege.fr
AF: CNRS, CEREGE BP 80, Europole Mediterraneen de l'Arbois, Aix-en-Provence, 13545 France
AU: Misson, L
EM: lmisson@nature.berkeley.edu
AF: University of California, ESPM Department, 151 Hilgard Hall Berkeley, Berkeley, CA 94720-3 United States
AU: Guiot, J
EM: Guiot@cerege.fr
AF: CNRS, CEREGE BP 80, Europole Mediterraneen de l'Arbois, Aix-en-Provence, 13545 France
AB: Global change scientific community is today facing an interesting challenge by understanding the impact of greenhouse gases increase on ecosystems at regional scale. One of the ways to contribute to this question is to use dendrochronological series, which record for centuries annual biomass and to analyze them in relation with climate and other environmental and anthropogenic factors. Process-based models are of considerable help to simulate changes in carbon stocks in different tree compartments, but needs to be finely parameterized to reproduce ecophysiological processes driving tree-growth. Using site and species parameters, in addition to the climatic driving variables at a daily time step, the MAIDEN model computes the water balance at ecosystem level and daily increment of carbon storage in the stem through photosynthesis processes to reproduce the structure of the tree-ring series. We calibrated finely this model for Pinus Halepensis species sampled in the South of France under a Mediterranean climate, using Monte Carlo Markov Chains and Particle Filtering methods. The principle of both methods is to move in the parameter-space according to different statistical rules to compute each parameter distribution leading to a relatively high simulations-observations fit. The resulting parameters and their uncertainties can then be directly used to simulate annual increment series of tree-growth under different climates. Past data are used for calibrating and validating the model and simulations using a general circulation model are used to predict the effect of future climatic changes on the tree-growth.
UR: http://www.cerege.fr
DE: 0429 Climate dynamics (1620)
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0466 Modeling
DE: 0476 Plant ecology (1851)
DE: 4920 Dendrochronology
SC: Biogeosciences [B]
MN: Fall Meeting 2005