Typology of Ukrainian Roztochia Aquatic Vegetation: Class Potametea Klika in Klika et Novak 1941

Abstract

The habitats typology of aquatic vegetation from the class Potametea Klika in Klika et Novak 1941 in Ukrainian Roztochia is covered in this article. Communities of this class play an important role in the processes of eutrophication and overgrown of fresh water basins, serving as an intermediate link in a series of successional transition of aquatic vegetation to coastal water one. Typization of the water vegetation location of the Potametea class allows one to predict the course of successions caused by natural and anthropogenic factors. Typology of habitats was studied by methods of obtaining data from phytoindicational score assessment of the environmental habitats’ regimes on seven parameters: L – light, T – thermal mode, K – continentality, F –
moisture mode, R – acidity, N – nitrogen, S – salt content. The research included three main stages: studying the structure of plant communities in the relative position of multidimensional space of environmental parameters, mathematical modeling of the structure and verification of mathematical model. For the vegetation ecosystems of the Potametea class of Ukrainian Roztochia, a relatively narrow range of variations in the values of environmental parameters is determined. The parameters of water regime (depth of reservoirs) and nitrogen content are the most important for the differentiation of places. In a simplified form, the typological scheme of aquatic vegetation of the Potametea class may be represented as a triangle in the center of which is the association Hydrocharitetum morsus-ranae, and the associations Ceratophylletum demersi, Potametum natantis and Hottonietum palustris are on the vertices. In a three-dimensional space, the typological scheme has the form of a triangular pyramid, the apex of which is the association Ranunculo-Sietum erecto-submersi. The less common associations such as Ranunculetum circinati and Nupharo-Nymphaeetum albae occupy the periphery of the ecological space of aquatic vegetation.