Phytomass of the crown component of robinite forests in the northern steppe of Ukraine

The main factors influencing the formation of phytomass of forest plantations are the genetics and origin of the tree species, the conditions of natural habitat, the way of planting, the forest vegetation, weather and climatic conditions of treestanding and the biometric characteristics. The purpose of the study was to develop the norms for assessing the components of the above-ground phytomass of the structural components of the crown of robinite treestands in the Northern Steppe of Ukraine. The classical forest-tactical method of material collecting and processing is used in the research. Correlation analysis was used for the statistical processing of data and the regression dependence of the phytosanitary components of the crown plantings of the unrealized plantings from the taxonomic and forestry indices of the treestand was established. A working data set has been formed, which characterizes the phytosanitary components of the krona for assessing the biotic productivity of artificial pine forests. Three-factor mathematical models for estimating phytomass of the crown - branches in the cortex, woody greens and leaves are developed and presented. The informative, statistically significant predictors during the development of mathematical models determined the average data of the diameter and height of the stands and relative completeness. Phytomass of wood greens and leaves will be larger in the planting, where the smaller is the average diameter in trees with the same average height and relative completeness. Indicators of the average height of the tree stand and its relative completeness in mathematical models have a positive value, which causes an increase in the phytomass of the components of the crown (branches, woody greens and leaves) with the increase of the indicated biometric and forestry parameters. On the basis of regression models, normative informational tables for the Northern steppe zone of Ukraine were constructed. The proposed alometric equations for calculating the phytomass of branches, woody greens and leaves can be used for practical forest management purposes during forest inventory works, determination of forest use volumes with an orientation towards comprehensive development of resources of robin forest stands