THE RATIO OF THE FREQUENCY OF OCCURRENCE OF MONO- AND POLYDOMINANT COMMUNITIES IN SYNANTHROPIC VEGETATION WITH DIFFERENT PARTICIPATION OF ALIEN SPECIES

If the invasion of alien species into the vegetation cover leads to an increase in the area of monodominant communities, then this may have negative consequences for native plant species in the long term. We compared the frequency of occurrence of communities with the dominance of alien species, with the dominance of native species, as well as polydominant communities, in 71 sites of synanthropic vegetation in the vicinity of the settlements of the Republic of Adygea and the Krasnodar Territory (Russia). The results showed that sites with a higher frequency of alien species dominance are characterized by a predominantly lower frequency of native species dominance, as well as a lower occurrence of polydominant communities, and, accordingly, a higher occurrence of monodominant communities in general. At the same time, the peculiarities of the biology of alien plant species reaching a high coverage in the studied areas suggest that this is due, rather, to the ability of alien species to quickly populate disturbed (open) habitats than to displace native species from closed grass stands. Therefore, the influence of the factor assessed by us on the floristic richness of synanthropic vegetation in the study area can be considered as limited. However, in other regions of the world, as follows from the publications known to us, it can be significant.