HR: 0800h
AN: B31B-0331    [Abstracts]
TI: Amazon rainforest regrowth with nutrient stress: A biosphere-atmosphere interaction problem
AU: Senna, M C
EM: monica@vicosa.ufv.br
AF: UFV, Av. P. H. Rolfs, s/n, Vicosa, MG 36570-000, Brazil
AU: * Costa, M H
EM: mhcosta@ufv.br
AF: UFV, Av. P. H. Rolfs, s/n, Vicosa, MG 36570-000, Brazil
AU: Davidson, E A
EM: edavidson@whrc.org
AF: WHRC, 149 Woods Hole Road, Falmouth, MA 02540-1644, United States
AU: Nobre, C A
EM: carlos.nobre@inpe.br
AF: CPTEC-INPE, Rod. Dutra, km 39, Cachoeira Paulista, SP 12630-000, Brazil
AB: Recent literature has demonstrated that precipitation decreases with the increase of tropical deforestation, being proportional to the extent of deforestation. After a tropical deforestation, the regrowth of the secondary forest may be limited by climate and nutrient limitations. In this study we investigate the regrowth of the Amazon rainforest after an hypothetical full deforestation, under nutrient stress. This is a 2-way biosphere-atmosphere interaction problem: The response of the regional climate system to the land cover varies with the forest growth, which, in turn, depends on climate and nutrient stress. Nutrient stress also varies with forest age, being most severe for young forests and declining as forests mature. In this experiment, we ran four simulations (3 ensembles each) with the fully coupled climate-biosphere model CCM3-IBIS. The model was calibrated against LBA tower results, and validated against spatial fields of precipitation, incoming solar radiation, land cover patterns, net primary production, wood NPP, leaf area index, and biomass. The experiment evaluated different initial conditions (forest/pastureland) and different types of nutrient stress. We conclude that the reduction of precipitation caused by a large-scale deforestation is not sufficient to prevent the regrowth of the secondary forest, but the decrease of precipitation combined with nutrient limitations may prevent the regrowth of the secondary forest in southern and eastern Amazonia.
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1622 Earth system modeling (1225)
DE: 4815 Ecosystems, structure, dynamics, and modeling (0439)
SC: Biogeosciences [B]
MN: 2007 Fall Meeting