Modeling of forest dynamics

• Main Authors: F. S. Berezovskaya, G. P. Karev
• Format: Article
• Language: English
• Published: Russian Academy of Sciences, Siberian Branch Publishing House 2015-06-01
• Series: Сибирский лесной журнал
• Subjects: self-thinning; heterogeneous population; Malthusian model of death; ergodicity
• Online Access: http://xn--80abmehbaibgnewcmzjeef0c.xn--p1ai/upload/iblock/936/9365d9273320fd670756752433895c15.pdf
• ISSN: 2311-1410; 2312-2099

The concept of describing the process of self-thinning stands is considered from the standpoint of the general theory and methods of modeling the dynamics of biological populations and communities. Heterogeneity is one of the fundamental factors that determine the population dynamics of both the evolutionary time, and at the level of the lifetime of one generation. The study of various well-known formulas of one-species stands self-thinning in the frameworks of theory of non-homogeneous population models showed that these formulas are the solutions of the simplest Malthusian model of heterogeneous population death with different initial distributions of Malthusian parameter (intensity of death). It is shown that all the above formulas describe the self-thinning of stands as essentially the same Malthusian process of death, but under different conditions, which in summary form are taken into account in the initial distribution. Applied research methods of Malthusian dynamics of inhomogeneous models study allow us to refine the known formulas of self-thinning and build a number of new, choosing a suitable initial intensity distribution death. The proposed methods allow testing of various hypotheses on the initial distribution of the amount of tree loss for various stands. It is shown that an alternative approach to addressing the diversity of crops may be based on a multi-stage model of Leslie and use to simulate a modified version of the Poletaev’ model. A simple model constructed that operates with only three stages of stand development, but it is sufficient for reliable real and calculated data. We found that the inclusion of stand’s heterogeneity even in a very simplified form is not only necessary, but also to a certain extent is sufficient for constructing adequate models of self-thinning stands.