Distribution and Biology of the Invasive Species Erigeron annuus (L.) Pers. in the Republic of Bashkortostan

The distribution and morphometric and population characteristics of invasive species Erigeron annuus (L.) Pers. s.l. in the Republic of Bashkortostan are analyzed. Twenty-five localities of the species were identified and surveyed in nine regions of the republic. It has been shown that the main vector of E. annuus invasion is its spontaneous spread through abandoned fields and along highways. The density of E. annuus plants in coenopopulations ranges from 1.7 to 17.2 ind./m². The aboveground biomass of the species is low—68.5–151.0 g/m². The proportion of the species in a community ranges from 39.3 to 77.9%. When introduced into phytocenoses, it forms a variant of Phalacroloma annuum of the association Agrostio tenuis–Festucetum pratensis Yamalov 2005 or a derivative community of Phalacroloma annuum–Cirsium setosum [Arrhenatheretalia elatioris/Artemisietea vulgaris]. An increase in the number of localities of the species in the Cis-Ural region of Republic of Bashkortostan is predicted for the coming years.