REGULARITIES OF WOOD STAND DEVELOPMENT COMPOSED OF SCOTS PINE WITH DIFFERENT INITIAL DENSITY

Abstract

Introduction. Wood stand density in one of the core factors defining yield, merchantability, viability, habitatforming properties of plantations and cost effectiveness of forest cultivation. The issue of stand density optimization is of practical importance for the industry; it has been extensively discussed by silviculturists. This may be due to the complexity of the problem and a diversity of approaches to solve it. The research is aimed at elaborating mathematical models of wood stand development dynamics and its stumpage value calculation. These are the two essential components for making a well-grounded decision on the optimum initial density of the wood stand and ensuring the best cost advantage. Materials and methods. The research was carried out on the experimental plot established in 1977 and included 15 sections where the initial density of pure Scots Pine varied from 0.5 to 11 thousand trees per ha. This experiment is unique due to the fact that it covers a wide area including the plots with very low density which didn’t undergo any prior research. Condition tool-assisted assessment of wood stands was carried out in 1988, 1991, 1996, 1999, 2003, 2008 and 2011; in 1996-1999 a complex research into the structure of subordinate vegetation, mushroom productivity and population of soil mesofauna was carried out. Statistical material was processed by mathematical statistics using the packages of standard application programmes Excel and Statistica. Conclusions. In the conditions of dry and fresh pine wood of the Mari El Republic it is deemed reasonable to establish plantations of Scots Pine with initial thickness below 1.5-2 thousand trees per ha. It allows significant reduction of production costs, ensures long intensive increment and helps avoid thinning to waste. The final decision in terms of selection of optimum initial density of the stand can be made based on econometric calculations, which assess the stumpage value dynamics, as well as on forest pa-thology situation, which requires additional specific research and monitoring coverage.