Materials for the Black Book of Voronezh oblast

Establishment of “blacklists” is one of the attempts to focus on the issue of biological invasions of alien species that pose the most significant threat to regional biodiversity of a certain region. Blacklists contain biological and environmental characteristics and information on invasive species distribution. In Russia, regional blacklists of invasive species are often based on expert opinions or various criteria. For the standardization of alien species information, we propose (1) to use a quantitative assessment of the participation of invasive species in regional floras and plant communities, which makes it possible to evaluate objectively the invasive status of a species and the degree of its impact; (2) to include all invasive species of the region in the regional “Black Books”; and (3) to present potentially invasive species as separate lists. We offer 65 invasive alien plant species for inclusion in the regional Black Book of Voronezh oblast: 9 species are transformers, 20 are actively inhabiting and naturalizing in disturbed seminatural and natural habitats, and 32 are spreading in disturbed habitats. The status of four species is still not defined. Twenty-two species are potentially invasive, because they do not have large spread in the area, but showed themselves as invasive in adjacent regions (in deciduous forests and forest-steppe zones).