Non-native species in the vascular flora of the national park «Samarsky Bir»

Results of non-native flora surveys on Samara Dniprovska River valley within the designed National Park «Samarsky Bir» were analyzed in the paper. Scientific justification on first stage creation of the national-level National Park «Samarsky Bir» was prepared in 2012. Its area included the main park area with floodplain, arena and gully landscapes of the rivers Samara and Oril interstream. List of vascular plant species on floodplain, arena and gully habitats of Prisamar'ya counted 887 species. They are classified as 5 divisions, 6 classes, 108 families, 429 genera. This article presents a list of non-native flora fraction with bioecological characteristic of the plant species. The surveys were conducted by conventional methods on vascular flora studying. Analysis of the main plant ecomorphs was carried out by A. L. Belgard ecomorph system (1950). Invasion of plant species in the steppe zone of Ukraine has a long history complicated by significant anthropogenic transformation of the territory. We investigated the status of non-native plants, their ecomorphs, and tendency to invasiveness on the territory of National Park «Samarsky Bir» designed. Presence of 195 adventitious vascular plant species belonging to 48 families was determined. Of them, 7 families with the greatest abundance of non-native species contained 113 taxa (58 % of the total); 20 families were represented with 2–7 advents, and 20 families contained only 1 non-native species. Thus, today the share of non-native species in the vascular flora of the region accounted for nearly 22 %. Most of adventitious species are mesoxerophytes and xeromesophytes. In a cenomorphic relationship, vegetation being ruderal on the territory of Ukraine is dominated in composition of non-native flora. Within the total number of adventitious species, archaeophytes amount up 44 %, whereas neophytes come up to 56 %. The greatest abundance of adventitious species has been found in Brassicaceae, Asterasea and Poaceae families (15 %, 12 %, and 11 % of the total, respectively). 119 non-native vascular plant species were found in the steppe cenoses, 79 species in the gully and watershed forests, 90 species in floodplain forests, and 52 species on the territory of the sandy terrace. Among all the non-native species, 28 species have been identified as invasive, and there was a trend to increased invasiveness of some species in recent years. Among heterogenous species 12 of them were identified as invasive, and there was a tendency to increase theinvasiveness of some species in recent years. The analysis provided on non-native flora in the National Park evidences significant anthropogenic transformation of the territory; that requires establishment of appropriate regime on protection of this important ecological object.