ECOLOGICAL AND FLORISTIC ANALYSIS OF THE GENUS STIPA L. IN THE STEPPE ECOSYSTEMS OF STAVROPOL KRAI

The object of this study was the genus Stipa L. representatives (feather grass) from the Stavropol territory flora. The relevance of the work is due to their high phytocenotic significance and the status of key components of the steppe phytocenoses in the region. The purpose of the study is to inventory and assess the current state of Stipa L. species on the territory under study. Comparative morphological, anatomical, and ecological-geographical analyses were used as the main methods. The ranges of the species were mapped using the point method based on original field data using herbarium collections and literary sources. The distribution analysis was carried out in the context of the florogenetic zoning of the North Caucasus and Northwestern Transcaucasia. The nomenclature of taxa was checked against the “Synopsis of the flora of Stavropol.” Anatomical analysis included making sections of vegetative organs followed by light microscopy. Micrographs obtained on a JSM-6390LA scanning electron microscope were used to study micromorphology (stomatal apparatus, cuticle). The presence of 13 species of the genus Stipa, systematized in five ecological sections, was confirmed in the North Caucasus. A detailed analysis of their macro- and micromorphological, as well as anatomical characteristics was carried out, revealing stable correlations with environmental conditions. The geographical distribution of species across the territory of the region is heterogeneous. Two relict taxa were identified among species with a limited range: S. caucasica Schmalh. and S. sareptana A. Beck. Representatives of the genus Stipa L. perform an environment-forming function and are edifiers of steppe communities. Most of the species have high economic value, being important pasture plants and components of hayfields.