Adventitious plants of the south-eastern part of the Orel region

The aim of this study was to identify adventitious component of flora of the south-eastern part of the Orel region. The study of flora of the south-eastern part of the Orel region in 2021 was first performed by the grid mapping. During field research, the route method and the method of geobotanical descriptions were used. With the route method, various types of phytocoenosis, both zonal and intrazonal ones, were selected, the species composition of which was recorded in the floral description form. In geobotanical studies in the studied phytocenoses, standard test areas of 100 square meters were laid. The study of the vascular plants flora of the south-eastern part of the Orel region with the mapping grid has revealed 139 adventitious species, which have been analyzed according to the categories of occurrence, time and method of importing, degree of naturalization. Among the adventitious plants, the largest number of species belong to the Compositae family. By the degree of naturalization, half of the adventitious species are occupied by disturbed and semi-disturbed habitats, and about 25% are introduced into natural communities. 29 species are invasive and are included into the Black Book of Russia. 16 species of them are among the most aggressive ones. They intrude into natural communities and convert them: Populus alba L., Lepidium densiflorum Schrad., Amelanchier spicata (Lam.) C. Koch, Lupinus polyphyllus Lindl., Oxalis stricta L., Acer negundo L., Impatiens parviflora DC., Heracleum sosnowskyi Manden., Fraxinus pennsylvanica March., Echinocystis lobata (Michx.) Torr. et Gray, Bidens frоndosa L., Cyclachaena xanthiifolia (Nutt.) Fresen., Erigeron annuus (L.) Pers., E. canadensis L., Galinsoga parviflora Cav., Solidago canadensis L.