Dynamics of Extrazonal Steppes in the Southern Urals over a 20-year Period amid Climatic Changes

Direct multiyear observations were carried out to track changes in the species composition and structure of extrazonal steppes in the boreal zone of the Southern Urals inhabited by many rare plant species. It is shown that the mesophytization of communities has taken place in petrophytic steppes in the period of 1999-2019: the cover of meadow-steppe and steppe species increased by 6.8 times; while the cover of petrophytic-steppe species, by only 2.2 times. A portion of petrophytic steppes has been absorbed by surrounding meadow steppes. It is established that communities less than 40 m(2)in size are most susceptible to the changes. The observed changes are likely caused by an increase in precipitation in the beginning of the growing season.