EFFECT OF TREE DENSITY ON THE DBH DISTRIBUTION IN CRYPTOMERIA JAPONICA PLANTATIONS : FREQUENCY DISTRIBUTION OF INDIVIDUAL WEIGHT, STEM DIAMETER AND HEIGHT IN PLANT STANDS. VII

Abstract

The effect of tree density upon the frequency distribution of diameter at breast height (DBH) in plantation forests of Cryptomeria japonica was examined by applying PEARSON'S type VII distribution to observed data. The DBH data followed REINEKE'S model concerning the effect of tree density on the mean DBH in a stand. Limited by REINEKE'S model, all coefficients of PEARSON'S type VII distribution were formulated by empirical equations of tree density. From these empirical equations, a mathematical model was developed for the frequency distribution of individual DBH in forest stands limited by REINEKE'S model. Furthermore, the dependence of individual DBH upon tree density was formulated from a function of tree density. In conclusion, a normalized density function of DBH yielded a statistical basis to REINEKE'S model.