COMPARAÇÃO DE MÉTODOS PARA ESTIMAR O VOLUME COMERCIAL EM FLORESTA OMBRÓFILA DENSA NO ESTADO DO AMAZONAS

Abstract

This study compared different methods for the estimation of merchantable volume of standing trees species of Amazonia. We sampled 268 trees at Fazenda Monte Verde, Itacoatiara - AM, distributed in 38 species of 19 families. The volumes of the trees were determined by the Smalian formula and used to test the following procedures to estimate the commercial volumes: form factors of the sample by species and diameter classes; taper functions, volume equations and ratio equations, totalizing, therefore, six treatments, wich were compared with those obtained by volume Smalian (control). The accuracy of the tested models was evaluated using the standard error of estimate (Syx%), coefficient of determination adjusted and corrected for the variable of interest (R?) and by the graphical residual analysis. To complement the analysis of taper functions were also used statistics, deviation, standard deviation of differences, sum of squared relative residuals and relative residuals for the purpose of having a more detailed analysis of the performance of estimates along the stem. To compare the means between treatments was used a completely randomized design and Tukey`s test for the critical level ? ? 0.01. Analysis of variance showed significant differences between the methods, however, the Tukey test identified no difference between treatment means. It was concluded that double entry Meyer volume equation was the best method of performance to estimate the commercial volume. The use of an average form factor by diameter class generates more precise estimates than a single form factor for all sample. The commercial volume estimated from the taper functions tested were less accurate than the estimated by volume equations and the use of ratio equations was not adequate when the diameter used as input variable, but very suitable when the input adopted was commercial heights.