Equações volumétricas para andiroba e mogno em sistema silvipastoril na Amazônia
Abstract
The aim of this study is to adjust mathematical models and select equations for commercial volume estimation with bark of species of andiroba (Carapa guianensis Aubl.) and mahogany (Swietenia macrophylla King). Data were collected in a silvopasture plantation of seven years with spacing of 7 m x 7 m, located on the plateau area of Santarém, state of Pará. One hundred andiroba and mahogany trees were cubed for obtaining commercial volume using the Smalian method. Seven mathematical models were adjusted for volume estimation. The criteria for choosing the best equation were: adjusted coefficient of determination, standard error of the estimation, significance of the parameters, normality of waste, and graphical analysis of waste. Chi squared test was used to validate the best equations. From Schumacher Hall model, in logarithmic form, resulted the best equations for andiroba and mahogany.