Ecological and Cenotic Analysis of the Coenopopulations of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk. (Apiaceae) in the Republic of Buryatia

Natural populations of Saposhnikovia divaricata (Turcz. ex Ledeb.) Schischk. have recently been subjected to strong anthropogenic impact due to biologically active substances with a wide spectrum of action detected in plants. The purpose of this study is to determine the state of natural populations of S. divaricata and identify biological features of the species that contribute to the stability of the populations. Seven coenopopulations have been studied in the Republic of Buryatia. Phytocenoses and ontogenetic states of S. divaricata are described, demographic indicators of coenopopulations are given, and environmental and biological factors affecting the existence of this species have been identified. S. divaricata has a wide ecological amplitude and occurs from tree communities to steppes and fallow areas. Its proportion in communities does not exceed 2% of the general projective cover. Most populations are characterized by a low density of individuals (5–48 individuals/100 m²) due to the destruction of plants (root extraction). One stable population without damage (density of 209 individuals/100 m²) and one recovering population (113 individuals/100 m²) have been revealed. The height of generative plants varies significantly from 35 to 100 cm, depending on the growing conditions. Environmental factors that negatively affect the stability of natural populations of S. divaricata include biotic (massive damage to seeds by invertebrates) and anthropogenic (root harvesting and grazing) ones. A number of biological features determine the strategy of the species in nature: a probable low stock of seeds in soil and a sharp rise in the amount of seedlings during seed dispersal; biological longevity of seeds for more than 5 years; early contractility of roots; dormant buds and renewal buds in the leaf axils of previous years are protected by remnants of leaf sheaths; when the apical bud is damaged, monopodial growth is changed to sympodial (more often at the beginning of the virginal ontogenetic state); duration of the pregenerative period of 10–12 years; and monocarpicity, up to 50% of generative individuals in the population form false whorls, the percentage of fruit formation in a simple umbel is 50–100%.