The edificator role of species from the genus Stipa L. (Poaceae) in phytocenoses of petrophytic and shrub steppe in the Donetsk upland and Northern Azov region

A study of the syntaxonomic diversity and distribution in the Donetsk upland and Northern Azov region of phytocenoses of meadow and shrub steppes allowed us to determine the composition of plant communities with dominance and subdomination of feather grass: 50 associations from 14 formations of the meadow steppe (Steppa pratensis), 42 associations from 14 formations of the shrub steppe (Steppa fruticosa). Of these, 35 and 26 plant communities, respectively, can be recommended for special protection. Respectively, 15 and 16 plant communities are regionally rare. As many as 29 rarity communities of meadow steppe and 37 of shrub steppe have been recorded in specially protected natural areas. The widest environmental and phytocenotic range is associated with Stipa capillata L., S. grafiana Steven, S. lessingiana Trin. & Rupr., S. tirsa Steven, which enables these species to participate in forming of various classes of steppe vegetation formations. The most associatively represented formations are Stipeta capillatae, Stipeta grafianae, Stipeta tirsae.