Análise das variações temporais na florísitica e estruturada comunidade arbórea de uma floresta explorada com plano de manejo

Abstract

This research was accomplished in a survey of the arboreal compartment in an area subjected to a sustained management of an open ombrófila forest located in Lábrea County, Amazon. The objective was to characterize the floristic and physiognomic composition and, the diversity of the area, the species distribution pattern and to verify possible variations of the distribution patterns of these arboreal species as a function of the management. To realize this work, the area has been divided in 18 primaries unities with 30ha each one and from the selected ones, three unities at which has been allocated ten secondary unities (plot) of 100 x 100m (one hectare), in a total of 30ha. Each plot has been subdivided in sub plots of 10 x 10m (100m2), totalizing 100 subplots in each secondary unity. In 20 fromthese unities, all the individuals withDBH(Diameter at breast height) 3cmwere measured, while in the 80 lefts, all the individuals ones with DBH 6 cm have been measured. The results showed a total of 16.487 individuals inventoried before the exploitation and a total of 15.328 individuals after the exploitation. The 10 families that occur more frequently represent 53% of the sampled trees. The diametric distribution didn t present significant variation among the events. The values of Shannon s Index (H = 4.738 and H = 4.735), of Pielou s equability index (J = 0.803 and J = 0.804) and of Simpson s Index (0.01803 and 0.01805), before and after the exploitation, respectively, indicate high diversity in the area. Most of the species (53.6%) presented a random distribution pattern.