Forest species diversity in river watersheds of the Left-Bank Forest-Steppe of Ukraine
Species diversity of forests in basins of the rivers Sula, Vorskla, Psel, and Seversky Donets and their tributaries (on the territory of Ukraine) are analyzed. The research aimed to identify forest species diversity in 109 watersheds of the rivers Sula, Vorskla, Psel, and Seversky Donets and determine the share of forests in the origin and composition of plantations in the river basins. To delineate the boundaries of 109 catchment areas of the Sula, Psel, Vorskla, and Seversky Donets rivers, the MapInfo Professional 12.5 and a vector map of Ukraine were used. After defining the boundaries of 109 river basins, a vector layer of forest stands (which are subordinated to the State Forest Resources Agency of Ukraine) was applied, and the distribution database of these rivers was formed. It was determined that 63 species of trees were identified in the study region, the most common of which are common oak and Scots pine. The distribution of several tree species on 109 river basins is analyzed. Thus, the most significant number of tributaries (50%) has concentrated from 11 to 20 species of trees, slightly less number of tributaries (24 and 22%) represented 1-10 and 21-30 species, and the smallest number of tributaries (6 and 2%) represented 31-40 and 41-50%, respectively. Mixed plantations dominate (61% of the total forest area) in the river basin; pure plantations are the rest (39%).