Large carbon emissions from Amazon forests through drought-induced tree mortality and suppression of wood production
Daniel
Curtis
Nepstad, Woods Hole Research Center & Instituto de Pesquisa Ambiental da Amazonia, dnepstad@whrc.org
(Presenting)
David
Ray, Woods Hole Reseach Center, dray@whrc.org
Paulo
Roberto
Moutinho, Instituto de Pesquisa Ambiental da Amazonia, moutinho@ipam.org.br
Ingrid
Marisa
Tohver, Instituto de Pesquisa Ambiental da Amazonia, marisa@ipam.org.br
Gina
Knust
Cardinot, Instituto de Pesquisa Ambiental da Amazonia, cardinot@ipam.org.br
Several processes may lead to the drying of the Amazon region, including global warming, deforestation-induced rainfall inhibition, and ENSO. We established a partial throughfall exclusion experiment in 1999 to examine the effects of this drying trend on the forest. The most sensitive component of net primary productivity to drying was wood production, with an annual decrease of ~2 Mg ha-1 following three years of drought treatment (50% reduction of rainfall). Tree mortality in response to drought increased five-fold for large canopy trees (>30 cm dbh), shifting 10 Mg C ha-1 yr-1 from live to dead pools. Severe drought episodes can causes net releases of carbon to the atmosphere in excess of deforestation-driven release.
Submetido por Daniel Nepstad em 22-MAR-2004
Tema Científico do LBA: CD (Armazenamento e Trocas de Carbono)