Abstract:

Tree mortality model is an important part of tree growth model system. Logistic regression was used to model tree mortality of Larix based on the data from l31 diameter-class groups of l2 forest management inventory remeasured plots in Wangqing Forestry Bureau of Jilin Province. Independent variables are diameter class, relative diameter (RD), number of stems per hectare, basal area per hectare, quadratic mean diameter (DG), degree of closeness (P) and sum of squared diameter of larger trees than the predicting diameter class. An empirical equation including RD, P and DG was proposed by means of square correlation coefficient and coefficient of variation for all parameters. The equation is characterized by simple form, convenient measurement and calculation, without requiring stand age and site quality index, and good stability of the parameters. It may be used to predict mortality ratio of diameter class and mortality probability of individual tree for Larix.

Key words: Larix, Tree mortality model, Forest management inventory