Plant invasions in Ukraine

We present a comprehensive review of the plant invasions of 42 alien species and their impact on vegetation cover in Ukraine. Among these species, those currently posing the greatest threat to the environment have been identified. The structural features of this group were analyzed. In the life form spectrum the phanerophytes and therophytes are dominant, in the ecological spectrum the mesophytes are dominant, and kenophytes predominate at the time of immigration. Among the examined species, plants of North American origin predominate, agriophytes prevail by their degree of naturalization, and ergasiophytes are predominant by their way of entry. The participation of invasive species in natural and anthropogenic plant communities and biotopes was analyzed. These species are a stable component of grasses, scrub and forest habitats. Most of these invasive plants (33 species) are observed in anthropogenic habitats (I). Slightly fewer species of the studied group prefer habitat types E (25), F and G (22 each), although the largest invasions are observed exactly in these biotopes. Invasive species are characterized by eurytopicity. Four species have the greatest ecological plasticity, each of these is found in six types of habitats: Ailanthus altissima (B, F, G, I, J, H), Amaranthus retroflexus (C, E, F, G, I, J), Opuntia humifusa (B, E, F, G, H, I) and Xanthium albinum (B, C, E, F, G, I). Erigeron canadensis is found in five habitat types (C, E, F, G, I). The studied group is characterized by an insignificant regional specificity of the species composition, high invasive potential and stability of population reproduction.