Abstract
Invasion of organisms pose a potential threat to the existence of natural habitats and lead to impoverishment of biological diversity. Particularly pronounced is the negative impact within the boundaries of the Middle Dnieper region, where approximately a quarter of vascular plant species are of alien origin. The purpose of the study was to identify the current species composition of alien vascular plant species, the specific features of their distribution outside the culture, naturalisation, and involvement in plant communities of Moshnohirsky Ridge biotopes. The species composition of plants was recorded by transects and releves in the habitats of representatives of alien plant species were conducted to achieve this goal. It was determined that the vegetation cover of forest and related biotopes in the research area is significantly contaminated with alien vascular plant species, amounting to 48 species from 45 genera and 29 families. Substantial involvement of alien species is noted in Forest biotopes of hornbeam-oak forests – 35.4%, and oak and pine-oak forests – 29.2%. Among the alien species that have a substantial impact on the structure of plant communities of these broad-leaved forest biotopes are Impatiens parviflora DC., Robinia pseudoacacia L., Acer negundo L. Over time, the majority of introduced species are considered neophytes (81.3%), with a significant portion originating from North America (43.8%), the Mediterranean region (16.7%), and East Asia (8.3%). In terms of their penetration into natural ecosystems, species that are capable of actively integrating into natural communities, namely agriophytes and agriocoenophytes, hold high positions (a total of 30.2%). In contrast to these groups, limited alien species without active distribution – ephemerophytes and colonophytes are substantially represented in the groupings of the research area (30.6%). The identified patterns of distribution and cenotic distribution of alien species are the primary basis for the formation of optimal measures to counteract new invasions in forest communities and restrain the process of population compaction for species that already have a wide distribution within the research area