Institute for Complex Analysis of Regional Problems Far Eastern Branch Russian Academy of Sciences, Birobidzhan, Russia 

Abstract. This paper presents the results of modeling and study of the processes of self-thinning of even-aged spruce stands, depending on the initial spatial location of trees and heterogeneity of the population. The main research tool is developed previously individual-based model of spatiotemporal dynamics of the stand. It is shown that for a quantitative description of the self-thinning process must be considered as a heterogeneous composition of the population as well as the initial spatial structure of the stand. Computational experiments for spruce stands second site class showed that a satisfactory correspondence between the real and model data are obtained by random and cluster the initial location of the trees. At the same time to describe the initial heterogeneity of the population structure was sufficient to seven groups of trees of different ages with different probability of dying out as a result of competition for light.

Key words: self-thinning of the stand, even-aged forest stand, spatial structure, heterogeneity of the population composition, simulation.