Taxonomic composition of dry and floodplain meadows of the Bolshaya Kokshaga nature reserve

The paper deals with the study of the taxonomic structure of floodplain and dry meadow communities of the Bolshaya Kokshaga State Nature Reserve of the Republic of Mari El. The dependence between the meso- and microrelief of the territory and the conditions of plant growth is revealed. It has turned out that the flora of the studied 12 meadow phytocoenoses (6 floodplain and 6 dryland) includes 174 species of vascular plants belonging to 110 genera from 36 families. The leading families with the greatest species diversity include 6: Compositae (23 species), Poaceae (19), Fabaceae (15), Rosaceae (15), Scrophulariaceae (12), Caryophyllaceae (11), which include 55,17% of the total flora of the meadows studied. The Jacquard coefficient revealed the similarity of the species composition of dry and floodplain meadows. Both types of meadows are dominated by species of the family Compositae and Poaceae. The studies have shown that in the absence of anthropogenic load, processes of transformation of meadow communities into forest communities are observed. The most intensive processes of overgrowth are in forest hayfields, due to the proximity of forest phytocoenoses, the possibility of invasion of seed and vegetative diasporas. One of the common variants of overgrowth observed on the territories after the cessation of economic activity is a gradual reduction in the area of meadow communities along the edges from bordering forest communities. In this case, explerent species of trees and shrubs growing in forest coenoses are introduced. After a certain period of time, meadow communities are replaced by aspen, birch, and pine forests. As long as the meadows are regularly mowed down, the restoration of woody vegetation is not possible.