Floodplain forest and shrub vegetation of the Dnister river valley

The article is dedicated to the study of floodplain forest and shrub vegetation of the Dniester River valley in Ukraine. The Dniester River is the second largest river in Ukraine, within which its length is 705 km. The analysis was carried out on the basis of personal geobotanical releves collected during field research in 2018–2022. In total, 95 geobotanical releves have been sampled, most of them concentrated in the western regions of Ukraine, and only a small part in the lower part of the Dniester, in the Odessa region. The geographical coverage of the valley along its entire length allowed us to present a relatively complete overview of this type of vegetation. As a result of the work we have identified two classes, five alliances, seven associations and one community of floodplain forest and shrub vegetation in the Dniester River valley. The manuscript presents the characteristics of syntaxons, ecological characteristics of habitats, and results of DCA-ordination analysis based on the obtained values of ecological factors that determine the differentiation and variability of vegetation. It was established that the main ecological factors that influence the ecological and territorial differentiation of the studied vegetation type are soil moisture, nutrients, and light. Our study also allowed us to characterize the distribution of plant associations, determine their diagnostic, constant and dominant species. It was established that the rarest among the studied vegetation types are forests of the class Alno glutinosae-Populetea albae, in particular, the Ficario vernae-Ulmetum campestris association, which are known only from one locality. These forests contain a significant number of ephemeroids and rare plant species, therefore, in places where they are found, it is necessary to create protected areas. The most typical for the Dniester River valley are communities with Salix x rubens. Geographic differentiation of communities is shown. In particular, the coenoses of the Salicetum triandrae and Salicetum purpureae associations are confined to the western regions of Ukraine, and Salicetum albae ˗ to the Black Sea part of the Dniester Valley.