Syntaxonomical diversity of vegetation of the Dnieper River mouth region. VI. Classes Salicetea purpureae, Alnetea glutinosae
Authors: Dubyna D. V. , Dziuba T. P. 
Published: February 2020

The work presents a sequel of publication series on vegetation of the Dnieper River mouth region. The characteristic of syntaxonomical diversity of forest and shrub vegetation of the Dnieper River mouth area belonging to the Salicetea purpureae and Alnetea glutinosae classes are presented. There have been picked out 12 associations and 1 community attributed to 3 orders and 4 alliances. Salicetea purpureae class in the Dnieper River mouth is represented by communities formed under long time inundation conditions, along the sides of islands, arms of the main river-bed, lakes, and also along the sides of secondary arms with salty marsh or soddy sandy soils. These communities are more typical for river mouth habitats. The class includes the Salicetum albae, Saliceto-Populetum, Populetum nigro-albae, Fraxino-Populetum, Populetum marylandicae, Elaeagnetum angustifoliae, Amorpha fruticosa com., Salicetum triandrae aassociations. Mass expansion of com. Amorpha fruticosa was recorded in the Dnieper River Delta. Due to the high coenotic activities of this species the community spreads over the flood territories. To prevent Amorpha fruticosa invasions there have been induction of a long time and powerful spring water discharge from the reservoirs of the Dnieper’s cascade. Alnetea glutinosae class includes Salicetum cinereae, Thelypteridi-Salicetum cinereae, Urtico dioicae–Alnetum glutinosae, Carici acutiformis–Alnetum, Carici elatae–Alnetum glutinosae associations. The plant communities occur in the nature complexes of the river mouth at the offshore parts of islands under a long time inundation. Syntaxonomical analysis of phytocoenotic tables confirms the integration of Alnetea glutinosae and Franguletea classes as long as these communities occupy similar habitats (mire ecotopes with peaty-mire and mire soils) and they have a number of common diagnostic species. The coenotaxonomical and coenotical particularities of forest and shrub vegetation communities were revealed. In comparison with similar plant communities of the northern regions they do not take a big part in specific composition of boreal flora, but the role of species of the ancient Mediterranean origin is more remarkable. Considerable part of alnetal florocoenotic complex species is absent (Kuzmichev, 1992) or so-called alder forest historical suite (Zozulin, 1973), in particular, genus Sphagnum species. Other representatives of mire flora that are typical for mezotrophic and eutrophic mires of the forest zone are missing also. The forest stand structure is characterized by slight or absent understory, and in grass layer there are typical steppe and salt habitat species. As a result of significant human impact for the last ten years an expansion of mesophytes and xeromesophytes in the grass layer as well as adventitious and ruderal plant species was noticed. A change of coenoses of flood-forest vegetation under recreation by the communities of forest-park type takes place, and in depressions they are replaced by mire or salt meadows (Chinkina, 2003). It is necessary to underline the needs of ecology-sozological monitoring of their conditions and conservation of coenoses as well as the rare species population.