The spread of alien species of Vallisneria spiral in the waters of Northern Steppe Dnieper

Abstract

Introduction. The Tape grass (Vallisneria spiralis L.) – one of the most famous adventive subtropical species that is widely distributed in the European water bodies. The aim of the study was to trace the distribution characteristics of Tape grass in the steppe Dnieper reservoirs centurie with regard to its findings of this species.Materials and methods. The research was conductedthe general botanical and special hydro botanical collection methods, herbaryzation and species identification. There were analyzed the literature data on this subject for the last hundred years.The distribution of plants in ecosystems of varying degrees of anthropogenic transformation reflect according to the classification of ecosystems, Blume, and Sukopp that based on the concept of “hemeroby” i.e. transformation of ecosystems. It used six degrees of hemeroby in intensity of anthropogenic influence: ahemerobs, olihohemerobs, mezohemerobs, euhemerobs, polihemerobs, metahemerobs.Results and discussion. The Tape grass iswidespread in the waters around the globe, especially in the tropics and subtropics. The area of Vallisneria spiralis in the first half of the twentieth century, covering the Mediterranean, Eastern and Southern Europe, much of Asia, sub-Saharan Africa, North America. Later, its range expanded to almost cosmopolitewith disjunctive character.In Ukraine until1940, in the steppe zone it met sporadically in Poltava, Kharkiv, Dnipropetrovsk, Mykolaiv and Odesa regions. The appearance of Tape grass in the waters of Northern Steppe Dnieper first noticed Akinfiev I. (1889). It is possible to assume that already Ekaterinoslav developed aquaria and Vallisneria could get into the Dnieper from aquaculture.In subsequent years, the area of valisneria within Steppe Dnieper gradually extended, mainly due to construction of reservoirs and the formation of new shallow water.Over the last five years, we have found four location of of Tape grassin the waters of the Steppe Dnieper. In these reservoirs Valisneria grows in places with small depth (0,5–1,5 m) on sandy and silty-sand bottom sediments and forms a monodominat dense phytocoenoses or is dominant in communities of submerged plants.The conclusions. The Tape grass is an indicator of accumulative-erosion weakly-humus zones and freshwater, brackish and little flowing waters.Thus, over the last century Vallisneria spiralis has a tendency to slow but steady distribution in the steppe Dnieper reservoirs. Its spreading farther North caused the creation of reservoirs, including reservoirs-coolers.Vallisneria spiralis in the hemeroby system corresponds to the category mezoeuhemerobs (MsEuHr), ie, it occurs only in areas which is an anthropogenically modified and are under anthropogenic impact.