Analysis of the flora species distribution along the altitudinal zones of the Argun river basin

The Argun River is the largest river in the Sunzha basin. It originates on the Main Caucasian Ridge near the Chokismta-Matura peak (3189.7 m) in Georgia (historical region of Khevsureti). Before crossing the Lateral Ridge, it receives a large right tributary of the Andaki River (31 km long), whose sources are also on the Main Ridge near the Mal. Barbalo peak (3136 m). The length of the Argun River is 148 km, the total area of the basin is 3390 km2, it flows into the Sunzha River, a right tributary of the Terek River. In the upper reaches before the confluence with the right tributary, the Sharo-Argun River is historically called Chanty-Argun. Materials and methods. Materials and methods of research. Flora species and floristic complexes with different habitats within the Argun River basin were selected as the object of study. The material for the study was obtained during expeditionary trips for observations and herbarium collections in the period 2020–2023 in various altitudinal zones of the Argun River basin. Results and discussion. As a result of the research carried out in the Argun. Results. River basin, we recorded three groups of floras in the study area: plain-foothill, mid-mountain and high-mountain, the uneven distribution of floristic complexes in which made it possible to distinguish 6 floristic regions; More than half of the flora territory is located in the protected area system (2 reserves of republican significance, one of federal significance), 116 species are listed in the Red Books of the federal and regional levels, and another 16 species are proposed for protection. Discussion. The presence of narrow-local endemics in the flora also emphasizes its originality. It is advisable to include the entire Itum-Kalinsky floristic region in the territory of the Sovetsky biological reserve. Thus, many “Red Book” species, most of which are found only in this area, will be taken under real protection. These are Astracantha denudata, Berberis vulgaris, Сeltis glabrata, Cerasus incana, Cladochaeta candidissima Clenmatis integrifolia, Colutea orientalis, Cotynus coggygria, Crambe grandiflora, Dianthus daghestanicus, Ephedra procera, Fumana procumbens, Galanthus caucasicus, Gentiana grossheimii, Hippophaer hamnoides, Iris pumila, Gladiolus tenuis, Juniperus oblonga, Mandenovia komarovii, Medicago daghestanica, Notholaena maranthae, Omphalodes rupestris, Scabiosa rotata, Stipa caucasica, S. pennata, S. pulcherrima, Xanthobrychys majorovii. Conclusions. The total number of flora elements is significantly greater than the number of species in this area, since many of them are ecologically flexible and can be found in two or three vegetation zones, less often in four. Most species are confined to the steppe and forest zones, where the highest percentage of ruderal-segetal and alien species is observed, i.e. the quantitative composition is associated with anthropogenic impact on natural phytocenoses. The least number of species is in the subnival zone, where only petrophytes live, mostly endemics and subendemics.