ON FOREST CULTIVATION IN DRY SOIL LANDS: THEORETICAL APPROACH

Abstract

Forest restoration at the dry soils is one of the crucial problems for modern forestry. The goal of the research is to develop a logical model stand growth in dry sandy soil with the purpose to predict stand growth (up to mature age) based on the analysis of the model of plantations growth (plantations have specific initial density and soil moisture conditions). Methods. A comparative analysis of data,  obtained by the authors, was used in the research. The authors obtained data in the gradients of soil moistening and in the gradients of initial density of the cenosis of artificial origin. The following characteristics were analyzed: the reverse reaction to competitiveness by way of frequency and productivity change of the right and left types (according to А.V.Khokhrin) of pine and fir; heritable adaptation of these species either to dry or moist soils; differences in genotypic structure (population of different density); heritable “memory” of new generation to competitive conditions, which parent trees were growing in; stands growth depending on initial density strongly within the definite growth models. Results. The analysis showed that all these factors lead to the critical period occurrence in stands development. Later it will be almost impossible to change  development od stands. Thus, it is vital to control density of plantations and natural young stands well before trees have maximum density, closure stands, canopy closure and increment.  The earlier this work is done, the more productive the stand will be and   the longer the period of intensive growth will be.