Coarse Woody Debris Remineralization Rates in an Undisturbed Forest and Selective-Logged Areas at the FLONA Tapajos, Santarem
Hudson
Silva, University of New Hampshire, Complex Systems Research Center, hsilvaus@yahoo.com
(Presenting)
Patrick
Michael
Crill, University of New Hampshire, Complex Systems Research Center and Stockholm University, Department of Geology and Geochemistry, patrick.crill@unh.edu
Michael
M.
Keller, University of New Hampshire, Complex Systems Research Center and USDA Forest Service, International Institute of Tropical Forestry,Rio Piedras, Puerto Rico, michael.keller@unh.edu
Coarse woody debris pool (CWD) has a major role on tropical forest carbon fluxes because of high rates of tree mortality and decomposition processes observed in tropical forest. Despite its importance, the dynamics of this pool is poorly understood. The present study aims to capture the efflux rates of carbon dioxide (CO2) from CWD and the main parameters on controlling that CO2 flux. An undisturbed area at the FLONA Tapajos is being studied together with a nearby site in the same forest that was selectively logged from 1999 through 2003. In an undisturbed forest located at the km 67 at BR-163, efflux rates from CWD pool averaged 1.95 ± 1.95 µmol CO2 m2 wood.s-1, n = 51 and for selective logged areas at km 83, the fluxes reached 2.61 ± 1.44 µmol CO2 m2 wood.s-1, n = 537. A chronosequence of Five years of selective logging have been studied and flux variation among species was observed as a result of decay processes. Three species of commercial timber with different densities were studied to capture differences in decay rates. Respiration rates from CWD were strongly correlated to wood water content showing a decrease in CO2 flux with increasing of moisture content and increasing wood densities (0.63, 0.74 and 0.9 g.cm-3) seem to have an effect on retarding decay processes.
Submetido por Hudson Cleber Pereira Silva em 24-MAR-2004