Estoque e Dinâmica de Biomassa Arbórea em Floresta Ombrófila Densa na FLONA Tapajós: Amazônia Oriental

Abstract

The analysis of the oscillations of biomass stocks in tropical forests allows us to describe the behavior of these ecosystems in the face of natural or anthropogenic changes. The objective of this study was to evaluate the inventory and dynamics of biomass in the period (2007-2010) in dense rain forest in two areas of research in the National Forest -Tapajós, eastern Amazonia, called AREA 1 and AREA 2, 45 Km distant from each other. The biomass was estimated using allometric equation and DAP, from 12 permanent plots, with six in each area. The results showed a significant difference in annual average stock biomass between AREA 1 (293.19 ± 27.74, 298.21 ± 31.73, 299.60 ± 29.46, 298.11 ± 29.40 Mg. ha-1) and Area 2 (254.35 ± 69.61, 259.10 ± 70.05, 261.00 ± 69.43, 248.92 ± 61.78 Mg.ha-1). Besides that, it was noted annual change in stock biomass measurements at intervals of greater than one year due to fluctuations in mortality, recruitment and growth, besides the basal area and abundance of individuals in each area. Although the highest concentrations of individuals are in diametric classes DAP 10 ≤ DAP ≤ 30 cm, it was found that individuals with DAP ≥ 60 cm in minor amounts equivalent to stockpile biomass classes DAP 10 ≤ DAP ≤ 30 cm. Ten groups of specimens contributed 53.28% and 44.23% respectively in AREA 1 and AREA 2 in stock average annual biomass. We conclude that fluctuations in mortality, recruitment and growth, and abundance and basal area of these sites affected the stock biomass.