COMPOSITION AND STRUCTURE OF HYDROPHYTE COMMUNITIES IN DIFFERENT TYPES OF WATER BODIES IN THE CITY OF POLTAVA

Abstract

The article highlights the results of studying the composition and structure of the true aquatic plant communities in different types of water bodies of the city of Poltava (artificial and natural reservoirs, the urban section of the middle River Vorskla), where, according to the ecological and floristic classification, 21 associations (including 8 subassociations) of eight alliances, three orders and two classes were identified. Of these, only association Ceratophylletum demersi is the most typical in urban area. The class POTAMETEA differs in the relatively higher coenotic diversity (13 associations), and the class LEMNETEA differs in the lower diversity (8 associations). 
 The studied plant associations are characterized by a low species richness, the absolute majority of them represents a simplified version of the original natural associations. Communities of class POTAMETEA, observed in urban reservoirs, are especially depleted (1–3 species in the descriptions). There is a general tendency to increase the coenotic activity of the floristic elements that are tolerant to anthropogenic load and eutrophication.
 In the rank of associations there are 18 communities in urban lentic water bodies and 9 communities on the urban section of the middle river. Most of the identified associations (12) are confined exclusively to urban reservoirs, while only 3 associations are specific to the urban section of the river. Of those 6 associations found both in urban reservoirs and in the urban section of the middle river, it is the river coenoses that are more diverse and better developed.
 In the conditions of an urbanized environment, the middle river ecosystems show a higher resistance to anthropogenic influence compared to ecosystems of artificial urban water bodies, which is evidenced, in particular, by a more complex coenotic structure of common associations, as well as the presence of sozologically valuable communities specifically in the river hydroecotopes.