Biological Systems: Theory and Innovation

National Nature Park “Pyryatynsky” is a valuable reserve of flora and vegetation of the Le-Bank Dnipro. The extensive hydrological network of the Udai River and the wide representation within this nature reserve of floodplain reservoirs are the reason for the high diversity of plant communities of higher aquatic vegetation. In this article we classified the communities of order Callitricho-Batrachietalia in the National Nature Park “Pyryatynskyi” and identify the features of their syntaxonomic and ecological differentiation. Fragmentary and non-complete information about this type of vegetation on are existed in literature, however, without geobotanical releves and detailed characteristics of the structure of phytoceonoses, synecology and synchorology. All obtained results based on original field data. In total, 22 geobotanical releves were performed during the period 2010–2017. The description of communities was carried out within their natural boundaries. Treatment of fitosociological data was performed with the JUICE software package. The nomenclature of syntaxons was consistent with the International Code of Phytosociological Nomenclature (ICFN). The order of Callitricho-Batrachietalia on the territory of NPP “Pyriatynsky” is represented by alliance Batrachion aqua lis Gehu 1961 and 4 associations (Batrachietum aqua lis Gehu 1961, Potameto perfolia–Batrachietum circina Sauer 1937, Ho onietum palustris Sauer 1947, Veronico beccabungae–Callitrichetum stagnalis (Oberdorfer 1957) Th. Müller 1962). This is first prodrome of order Callitricho-Batrachietalia for territory of National Nature Park “Pyryatynskyi”. The communities of this syntaxon occupy small areas and have a limited distribution in the region. Most of them are rare and vulnerable to changes in environmental conditions. Monitoring of their structure, chorology and dynamics is an important task to maintain and preserve the species and cogenetic diversity of NPP “Pyryatynsky”

aquatic vegetation; Potametea; syntaxonomy; NPP “Pyriatynsky”; phytocenoses