Наукові праці Лісівничої академії наук України (Dec 2022)
Dynamics of dimensional structure and merchantability of aspen stands in the Slobozhansky forest typological district
Abstract
The paper provides an analysis of Populus tremula L. stands distribution by types of forest site conditions in the forest fund of the study region, mensurational indicators of stands of this species were determined and the dimensional structure of aspen stands was considered. The article also analyzes the distribution of the trees by diameter. As a result of correlation analysis, a close relationship was established between indicators such as average age (A), average diameter (D), average height (H). The corresponding correlation coefficients range from 0.76 to 0.95. No significant relationships were found for relative density of stocking (P). Models of diameter variability, the ratio of variability of the merchantable part to the total variability of the stand diameter are calculated, taking into account the minimum and maximum diameters of modal stands. The diameter distribution of trees is characterized mainly by a blunt-top curve with right-handed asymmetry. The average values of the skewness of the distributions are 0.553; kurtosis – -1,286. Calculations of diameter distribution models of aspen trunks have shown that the β-distribution is optimal for this object of study. The relationship between the share of merchantable trunks and the age of modal aspen stands has been established. Tables of merchantable structure dynamics of modal coppice aspen stands are drawn up taking into account the distribution of volumes of merchantable trunks by diameter classes and subclasses of round timber. According to the developed standards of marketability dynamics, the yield of commercial timber is lower (on average by 5%) in the case of its assessing not by diameter at top but by mid-diameter, and the greatest impact is observed at the younger age of stands (30-40 years). The standards of trees distribution by diameters and dynamics of merchantable structure of modal aspen stands taking into account distribution of commercial wood by diameter classes allow increasing accuracy of parameters assessment of aspen stands in the Slobozhansky forest typological district.
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