Modelagem do crescimento e produção em classes de diâmetro para plantios de Eucalyptus grandis

Abstract

This study aimed to develop growth and yield models by diameter classes for Eucalyptus grandis plantation with thinnings. The data used for modeling came from Eucalyptus grandis plantation made available by the company Klabin S.A., located in Telêmaco Borba, Parana State. This data came from permanent plots, temporary plots and pre-harvesting inventory, with ages ranging from 2.5 to 26.5 years. The Weibull probability density function was chosen to generate the diameter distribution. The stand attributes modeling process was divided into stages, considering the development stages of stands. Thus, two prognosis systems were produced: the first was used for the prediction of the attributes in the age of thinning and the second for the projection of the attributes in the age of the second thinning or final cut. The modeled attributes were those required for recovery the Weibull function parameters at the ages of intervention by the Moments Method. Two alternative methods of thinning simulation were tested. To evaluate the prognoses the Kolmogorov-Smirnov adherence test and the L&O identity test proposed by Leite and Oliveira (2002) were used. The two prognosis systems presented, in general, good estimates of adjustment and accuracy. The thinning equation used by Scolforo (1990) was chosen for the simulation of the two thinnings, however, it was necessary to use a correction factor to improve control of the number of trees removed, generated adequately results compared to simulations without this control. The methodology used allowed to simulate the growth and yield in Eucalyptus grandis stands along the rotation, generating adequate results, especially for the final cut where the best trees are harvested with higher aggregate values.