SYNTAXONOMICAL COMPOSITION AND COENOTIC STRUCTURE OF THE RIPARIAN-AQUATIC VEGETATION IN DIFFERENT TYPES OF WATER BODIES OF POLTAVA CITY

Abstract

The article deals with the results of studying the syntaxonomical composition and structure of the communities of riparian-aquatic vegetation 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, 16 associations (including 2 variants) of six alliances and four orders of the class PHRAGMITO-MAGNOCARICETEA were identified. Of these, only two associations (Phragmitetum communis and Typhetum latifoliae) are the most typical in urban hydroecotopes.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. Relatively higher species richness of some associations is due to the participation of species of hygro-mesophilic forbs, primarily elements of the synanthropic floral complex, which is associated with a significant disturbance of the natural vegetation cover in the urban area. The nature of the development of the described riparian-aquatic plant communities and the peculiarities of their floristic composition reflect the tendency to shallowing and waterlogging of urban hydroecotopes.In the rank of associations there are 14 communities in urban lentic water bodies and 8 communities on the urban section of the middle river. Most of the identified associations (8) are confined exclusively to urban reservoirs, while only 2 associations are specific to the urban section of the river. Of those 6 associations found both in urban reservoirs and in the middle river’s urban section, the river coenoses 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.