Avaliação dos impactos da redução da pluviometria na biomassa aérea florestal.

Abstract

This study was conducted out in Caxiuanã National Forest, Pará, Brazil, to analyze the effects of decrease in rainfall on biomass, tree height, tree mortality and basal area of tropical rainforest within of ESECAFLOR Project (LBA). The experimental design was two experimental sector with one hectare each of natural forest as following: sector A under normal conditions of climate and sector B with rainfall exclusion of about 90%. The growth parameters presented in this study refers the monthly data during the experimental period from 2005 to 2009 for the two experimental sector. Results showed that a decrease in rainfall affects significantly all tree growth parameters over forest. The main evidence for this is that rainfall exclusion provides a reduction in basal area especially with DAP higher than 10 cm. Also, an increase in tree mortality rate and consequently a loss in plant biomass are larger in forest area with rainfall exclusion than under natural conditions of climate.