Ivanov V. V., Borisov A. N., Petrenko A. E., Semenyakin D. A., Sobachkin D. S., Sobachkin R. S. The Density of Pine Stands under Intensive Forest Growing

On permanent sample plots in young, middle-aged and mature, pure pine stands of the same age, the effectiveness of cuttings of different intensities was studied, to ensure intensive forest growing. Existing standards on the intensity of cutting and relative density do not fully provide the optimal parameters of stands after cutting. Meanwhile, the remaining part of the stand determines growth and productivity of the stand formed by the felling. The sample plots have been established in the «Pogorelsky Bor» experimental forest of V. N. Sukachev Institute of Forest SB RAS, territorially entering the Krasnoyarsk island forest-steppe. In the studied stands, the felling led to an increase in current radial increment, which depends on the area of ​​the dominance square (S_OD), which determines the amount of available resources for the tree after felling. Based on the analysis of the dynamics of radial growth and its relationship with the values ​​of S_OD for pine forest stands at different age stages and with different density, the optimum value of S_OD is determined, which provides forming of trees of the 2–3^rd Kraft classes of growth. Optimum values ​​of the OD area were calculated depending on the values ​​of the stem DBH and taking into account the habitat conditions. With a density that is lower than optimal, higher tree growth values ​​can be obtained, but this does not mean achieving the maximum productivity of the stand as a whole. The studies allow, within the framework of the proposed approach, to provide intensive forest growing and formation of the stand structure that ensure the fulfillment of both economic and environmental functions of forests. The obtained data can be used in the development of recommendations for carrying out thinning in pine stands at different age stages of their formation.