Estrutura diamétrica da comunidade de plantas na floresta de terra firme na Flona de Caxiuanã, Pará, Brasil.

Abstract

The terra firme forests in the Amazon are characterized by a high diversity of tree species with a low number of individuals, which arouses scientific interest due to ecological, environmental and business standards and processes regarding the timber potential. This research aimed to analyze the diametric distribution of the tree community in a stretch of terra firme forest in the National Forest (FLONA) of Caxiuanã. Six plots of 1 hectare (100m x 100m) were installed divided into 25 subplots of 20 m x 20 m where all tree species with DBH≥ 10 cm were identified and characterized at the level of family, genus and species. The diametric study was performed for the entire community in general and for the species that obtained the number of individuals ≥ 100, using classes CI (10-20cm), CII (20.1-30), CIII (30.1-40), CIV (40.1-50), CV (50.1-60) and CVI (≥ 60.1) and analyzed using the De Liocourt “q” quotient. In the community, 2,903 individuals distributed in all diameter classes were recorded and it behaved as expected for tropical forests, with an inverted J-diametric distribution curve. The populations of Eschweilera coriacea, Lecythis idatimon, Licania octandra, Licania membranacea and Rinorea guianensis followed the typical pattern of inverted-J diametric distribution, being representative for the total community. The diameter structure of the Caxiuanã National Forest showed j-inverted behavior.