ИСТИНА

The floodplain meadows on the territory of the Zvenigorod Biological Station (Russia, Moscow region) in the second half of the 20 century were subjected to grazing, mowing, recreation and plowing. At present the main usages of these communities are recreation and moderate grazing. The aim of the investigation is to reveal a community diversity and analysis of the factors defining structure of meadow communities by using syntaxonomical and ordinations approaches. We use 17 relevés of meadows made in central part of the floodplain. Syntaxonomical analysis was carried out by the Braun-Blanquet approach. For ordination we used Detrended Correspondence Analysis (DCA). Identification of ordination axis conducted using Ellenberg’s ecological scales: light, soil moisture, soil reaction and nitrogen supply. As result of the syntaxonomical analysis classification scheme is given. 3 association and 3 communities were classified into three alliances: Festucion pratensis, Cynosurion, Aegopodion podagrariae representing two classes: Molinio-Arrhenatheretea and Galio-Urticetea. First two axes of DCA explain about 30,3 % of variance in communities’ species compositions. Ordination of relevés along the first two axes of DCA showed strong gradient of abiotic factors (light, moisture and nitrogen supply) along the first axis and anthropogenic disturbance along the second. The abiotic factors define species compositions of the meadows are more than factor of anthropogenic disturbance. Along the first axis vegetation changes from most dry and low nitrogen representatives of alliance Cynosurion through alliance Festucion pratensis to the alliance Aegopodion podagrariae corresponds to moist, rich and shaded sites. Along the second axis vegetation change from most disturbed communities of alliance Cynosurion (grazing, recreation, effects of plowing in the past) to least disturbed community of alliance Festucion pratensis.