Evaluation of the condition and productivity of some medicinal plants in the Nerchinsk steppe of the Transbaikalia territory

The article aims to evaluate the condition of the coenopopulation, productivity and quality of medicinal plants in the northern steppe region of the Transbaikalia Territory under conditions of mass illegal harvesting of medicinal raw materials. The studied plants were Saposhnikovia divaricata (Turcz.) Schischk., Phlojodicarpus sibiricus (Stephan ex Spreng.) Koso-Pol), Paeonia lactiflora Pall. and Euphorbia fischeriana Steudel. These plants are included in the Red Book of the Transbaikalia Territory, while Paeonia lactiflora is included in the Red Book of Russia. The research was conducted using the key-site method. The article provides an agrochemical characteristic of soils retrieved from the sample plots, including the content of toxic elements such as As, Pb, Hg and Cd in the soil. The features of the plants' habitats are considered, including morphological characteristics and productivity, yield of medicinal raw materials and anthropogenic impact on the plants. Data on the concentration of As, Pb, Hg and Cd in the raw material mass were obtained. It is shown that the accumulation of As in the plant roots exceeds the permissible concentration level established for the medicinal plants. At end of the growing seasons the bright color of the leaves allows for an assessment of plant density using an aircraft. The studies on the medicinal plant coenopopulation allowed us to conclude that there has been a significant reduction in the density of Saposhnikovia divaricata on most sample plots due to increased demand for the raw materials from China and weak law enforcement by the environmental authorities in the region. The vital condition of other plants on the sample plots was relatively good, but their existence will be threatened by the possible increased demand for the medicinal raw materials. To reduce the level of danger, it is important to stimulate research, experimental and production works on the cultivation of these plants in the region.