Phytocenotic confinement and ecological features of habitats of Eremogone saxatilis (L.) Ikonn. in different parts of its range

Ecological features of Eremogone saxatilis (L.) Ikonn. habitats in the national parks of “Mariy Chodra” (Mariy El Republic), “Khvalynsky” (Saratov Region) and in the Voronezh Region were identified using D.N. Tsyganov's amplitude scales. Field studies were conducted from 2017 to 2024. The analysis of 12 geobotanical descriptions of plant communities with E. saxatilis (6 in the center and 6 at the boundary of the range), obtained through applying the route method, suggests that the core of the flora of plant communities in the center of the range in Voronezh and Saratov regions consists of meadow and true steppe (23% and 29%, respectively), as well as wet meadow (21.3% and 9%) species. In the “Mariy Chodra” National Park, pine forest-edge species of pine forests (51.3%) and fresh meadows (15.4%) predominate at the northeastern boundary of the range. The distribution of E. saxatilis is limited by the ombroclimatic, soil moistening and fertility, including moisture variability and illumination factors. In the Saratov Region, a reducing effect of the factor was noted on the cryoclimatic (up to 4.00 grades), ombroclimatic (up to 3.75), thermoclimatic (up to 4.00), and climate continentality scales (up to 4.25). The ecological position of the species on the soil nitrogen supply scale was within 1.00–4.92 (from nitrogenfree soils to soils sufficiently supplied with nitrogen) and on the soil acidity scale from 2.38 to 7.48. Plant communities with E. saxatilis most fully realized their ecological potential in the center of the range.