Caracterização dendrométrica e variação da massa específica básica em povoamentos de Azadirachta indica A. Juss, no Município de São José de Espinharas - PB.

Abstract

Dendrometric characterization and basic density variation in Azadirachta indica A. Juss stands, in São José de Espinharas - PB. The Indian Neem (Azadirachta indica A. Juss), originating from Asia and introduced in Brazil in 1986, has great potential, where its leaves, fruits, seeds and wood can be used. The objective of this study is to characterize dendrometrically a population of this species located in São José de Espinharas - PB as to its character and variability of wood, taking as a basis the growth and analysis of specific gravity, respectively. The survey included the following dendrometric direct measurements: circumference at ground level (0.30 m) and chest height (1.30 m), height of the commercial bole, total height and diameter. This step was performed in two populations (14 and 16 years old). Later we selected ten average trees from population I, which were cut to obtain discs in different positions of the trunk (basal, middle and upper), and from them we prepared specimens to determine the variation of specific mass. Indirect measures related to dendrometric data (basal area; cylindrical volume based on the bole and total height; actual volume based on height and stem in total height; stacked volume based on height and stem height in total) were compared by their mean values. The specific mass was initially assessed by multifactorial analysis, verifying the variations between trees, axial position and radial position. Then we calculated the number of trees needed for the sampling of this property considering different levels and confidence interval of the mean. Direct measurements, when compared to three years ago, for population I had a smaller growth in the total height of the commercial bole, the diameter at the base, and crown diameter. In population II, the total height and diameter at the base increased, whereas the opposite happened with the height of the commercial bole and crown diameter. In this work the population II surpassed all indirect measurements when compared to population I. The basic density average showed a significant difference between trees and the axial and radial directions. Where the largest variation were between trees. The specific gravity average for species showed up at 0.60 g/cm3. A variation of this property appeared greater than that between trees inside the trunk, suggesting that sampling must give greater priority to the number of trees. Seven individuals were sufficient to contemplate the confidence level of 95% and a confidence interval of ± 5%.