MODELLING THE DIAMETER DISTRIBUTION OF EUCALYPTUS STANDS USING THE GAMMA FUNCTION

Abstract

This study evaluated the behavior of the Gamma probability density function to describe the diameter distribution of eucalyptus stand at different ages. A projection model of the distribution of diameters was constructed and fitted to data from permanent plots. The settings of the Gamma function were assessed by Kolmogorov-Smirnov (KS) test and the diametric distribution model was assessed by the determination coefficients and residual graphs of the estimates generated by the equations that compose the model. The diameter distributions estimated by the system of equations were compared with the distributions observed by the KS test. Most of the adjustments made by the KS test presented adherence. The model was able to design the diameter distributions satisfactorily, following the trend of flattening of the curve of distribution in a sequence of ages. Thus, the Gamma function can be used with statistical efficiency in a projection model of the diameter distribution in eucalyptus stands.