Formation of vegetation on 40-year-old overburden dumps in arid regions of Khakassia

\nThe article presents the results of observations on the peculiarities of vegetation formation on 40-year old dumps in arid regions of Khakassia. The dumps of Chernogorsky open-cut mine were created as a result of open-cut coal mining. Five-year studies were carried out on different elements of the dumps mesorelief. It was established that primary succession is characterised by grass type of overgrowing 43 species of vascular plants were identified, among which 91% are native. Endemics group is represented by one species - Thesium repens Ledeb. The leading families are Asteraceae and Poaceae. The plant communities are dominated by grass species Artemisia sieversiana, A. tanacetifolia, Chenopodium aristatum and others, as well as grasses Calamagrostis epigeios, Setaria viridis and others. Among ecological groups, mesophytes are most widely represented (49%), and among geographical groups, species with Eurasian range predominate (39.6%). The analysis of species significance curves showed that during succession the structure becomes more complex with increasing number of species and equalisation of their abundance. The studied communities are at one of the intermediate stages of recovery and differ in composition and structure from zonal communities.\n