The black-list of alien species in the flora of vascular plants of Omsk region

The proposed «black»-list is based on the preliminary analysis of the literature sources of XIX-XXI centuries, herbarium collections and authors' private collections. In the region, there are 90 invasive and potentially invasive species. The 1st category (the ‘transformer' species) includes North American Acer negundo, Elodea canadensis and Hordeum jubatum. The 2nd category includes 13 species, actively dispersed and naturalized in disturbed, semi-natural and natural habitats. The 3rd category (adventive species that are settling and naturalizing in disturbed habitats) consists of 43 species. There are 31 species of potentially invasive species that are capable of renewal at the sites of drift (the 4th category). A number of species spread through the territory of the region due to wildlife consumption ( Echinocystis lobata, Solidago canadensis, Galega orientalis, Elymus trachycaulus, Hippophae rhamnoides, Aquilegia vulgaris, Convallaria majalis, Alcea rosea, Fragaria moschata, etc.), and other species from foci of deliberate introductions ( Amelanchier spicata, Acer negundo, Malus baccata, Elodea canadensis, Ribes aureum ). The greatest number of alien species appeared on the territory of the region at the beginning of the 20th century that could have been a result of the resettlement of peasants from the European part of Russia and the active agricultural development of the region. In recent years, new adventitious species have been identified for the region: Rudbeckia hirta, Medicago × varia, Lepidium densiflorum, Eremopyrum triticeum, Juncus tenuis. The most aggressive alien species originate mainly from North America. Further monitoring studies are needed to assess the economic damage caused by the most aggressive species and to develop control measures.