Taxonomic indicators and vital status of Quercus robur L. in different forest conditions of the mouth and middle part of the ravine Yatsevo (Dnipropetrovsk region)

Abstract

The influence of forest and vegetation conditions on the taxonomic characteristics and vital state of the common oak (Quercus robur L.) was analyzed. The research was conducted on four experimental plots in the Yatsevo tract: in the thalweg (CL3) and on the lower third of the slope (CL2) of the southern exposure of the mouth part and in the thalweg (CL3) and the upper third of the slope (CL1-2) of the same exposure in the middle part of the gully. In the thalweg of the middle part of the gully, a linden-pack oak forest with elm grows, the density of this stand (1700 pcs./ha) is the largest among the studied phytocoenoses. On the rest of the experimental plots, elm-pack oak forests grow with a density of 917 to 1150 pcs./ha. The average values of the main taxonomic parameters (height, diameter, cross-sectional area, and reserve) practically do not differ in Q. robur plants growing in the thalweg (CL3) and the lower third of the slope (CL2) of the mouth part of the tract. These indicators in thalweg plants (CL3) of the middle part of the gully are the highest among all experimental variants, and in individuals of the upper third of the slope (CL1-2) - are the lowest. In all studied hygrotopes, healthy trees prevail, with weakened individuals taking the second place by the number of individuals. The vital status index (Ln) shows that the thalweg stands in both the mouth and middle parts of the gully are healthy (Ln 86.3 and 84.3, respectively). The stands of the lower third of the slope (CL2) of the mouth part of the tract and the upper third of the slope (CL1-2) of the middle part are somewhat weakened (Ln 76.9 and 76.7). The pathologies of the crown and trunk of Q. robur trees in the experimental plots were analyzed. It was found that hygromesophilic conditions (CL3) are preferable for the formation of healthy stands.