Beard-grass steppes of Stavropol territory
Beard-grass steppes are the result of change of zone virgin land by a pasturable stressor. They are various in flora composition. But depending on former pasturable loading, indicators of their biological diversity differ. The floristic saturation of plants in these associations is on average 39 types on the registration area 100 sq. m (10 m x 10 m). In herbage perennials prevail, on average they amount 86.1 %. The steppe-precursor on average is richer by 19 species than evolved from it beard-grass steppes. In the zone steppe sod-forming grasses Agropyron pectinatum, Carex humilis, Festuca valesiaca, Koeleria cristata, Stipa lessingiana, etc. act as dominants. Among communities Bothriochloa ischaemum, these sod-forming grasses are the accompanying species. Another feature of beard-grass steppes is the usage only as a pasture for different types of animals, only in the short of time of the active vegetation. Alienation of herbage of such grounds in the region with grazing use begins in the first decade of June. The nutritiousness of forage reduces within the later periods. Beard-grass steppes are not suitable as hay fields as their main leaf mass concentrates in 10.15 cm above the soil surface, which leads to a considerable shortage of forage at haying. However the steppe with Bothriochloa ischaemum in a role of the dominant remains the important source of soiling food on pastures during the autumn and winter period. In other words today the insurance importance of forage of beard-grass steppes is sufficiently high. However the needs for the gradual transformation of their extensive area in more productive and qualitative herbages will arise in the pasture economy of the south of Russia. One of the possible ways of this modification of beard-grass communities to initial virgin phytocenosis is the method of agrosteppes.