Population organization of rare species of the genus Jurinea as an indicator of conservation of steppe ecosystems of the Volga Region (Russian Federation)

Abstract

Abstract The article presents the results of the study of the population structure of rare species of the genus Jurinea (Jurinea polyclonos (L.) DC. s. l. (incl. Ju. tenuiloba Bunge), J. ewersmannii Bunge, J. ledebourii Bunge and J. multiflora (L.) B. Fedtsch.) in the steppe Volga region (European part of the Russian Federation). The species is characterized by rarity and its population characteristics change under the influence of anthropogenic factors. The works were carried out in 2000-2021 using population-ontogenetic methods. The species has insufficient potential for self-regeneration of their natural populations. Demographic indices (Replacement index, Recovery index, Aging index) are low. Ontogenetic spectra of populations are similar in their parameters, the predominant group of individuals are mature generative. Anthropogenic pressure leads to a decrease in the number of individuals, their density, low reproductive activity, and gradual aging of populations.