ACT A AMAZONICA Efeitos de area e de borda sobre a estrutura florestal em fragmentos de floresta de terra-firme apos 13-17 anos de isolamento

Density and biomass of live trees >10 cm DBHandsaplings 1-9.9 cm DBH, coarse woody debris (LCG—diameter > 10 cm), fine woody debris (LCF — diameter 2.5-9.9 cm), and standing dead trees (>10 cm DBH) were quantified in 56permanent, 1-ha sample plots. These plots are located in four 1(4plots), three 10(12 plots) and two 100(14plots) forestfagments in size and nearby continuous forests (19 plots) as well as in two classes of distancefom the edges<300m (29plots) and > 300 m (21 plots). Density and biomass of primary species did not differ significantly among the four size categories and the two edge distance classes. However, forest fagments and distance < 300 m fom the edges had more biomass and density of pioneer trees and saplings than did continuous forest and distance > 300 mfom the edge, respectively. Therewereno significantdifferences among the size categories for standing deadtrees. Forest fagments, however, had more quantity of LCG and LCF than did continuous forests. Moreover, distances < 300 mfom the edges had higher quantity of LCG and LCF and total necromass than did distances > 300 m. We performed an ANCOVA to assess whether differences in LCG and LCF in fagments were due to proximity of forest borders. An ANCOVA showed that there was no significant effect offagment size on necromass, but a significant effect of edge distance on both LCG and LCF. The quantity of LCG and LCF was correlated negatively with edge distance—sites close to the edge presented over 40-60% more LCG than sites far fom the edges in both forest fagments and continuous forests.