POTENTILLA BIFURCA L. ON THE URALS' ASH DUMPS IN DIFFERENT ZONAL CLIMATIC CONDITIONS
The aim of this work was to study the spatial structure and age characteristics of the plat in focus. We also identified morphological and physiological parameters and mycotrophic indicators of Potentilla bifurca L. coenopopulations (the family of Rosaceae Juss.), which grows on the reclaimed Urals' ash dumps: Yuzhnouralskaya (YUGRES, forest-steppe zone) and Verkhnetagilskaya (VTGRES, taiga zone) state district power stations. Potentilla bifurca - hamephyte, kseromezophyte, and drought-resistant species grow in steppe areas on dry, open clay soils and stony slopes. The plant in focus is rather rare for the forest taiga zone; it is considered to be an adventitious type of species for the Middle Urals. It is shown that coenopopulations of Potentilla bifurca, growing on the reclaimed ash dumps, are characterized by high density, are normal, not complete, dominant in species of pregenerative age. Maintenance of Potentilla bifurca population is conducted predominantly by vegetative means. The structural and functional leaf parameters (thickness, number of cells and the number of chloroplasts per unit area, the total index assimilating surface of cells and chloroplasts, flavonoids, nitrogen and phosphorus) were analyzed. Our research of Potentilla bifurca photosynthetic apparatus structure has shown that plants from YUUGRES ash dump differ from plants of VTGRES ash dump by the fairly large size of the leaf blades, and by their thickness caused by the larger size of the palisade mesophyll cells. A significant (33 %) increase in the number of palisade parenchyma cells per unit leaf area of plants on the YUUGRES ash dump was registered. The results were obtained in the process of comparison with the plants from VTGRES ash dump. It is shown that the amount of flavonoids, total nitrogen and total phosphorus in the leaves of Potentilla bifurca is significantly higher in the forest-steppe zone. The arbuscular mycorrhiza was found in the roots of Potentilla bifurca. It was presented by hyphae, vesicles and single arbuscular mycorrhiza. Mycorrhizal indexes were higher in the taiga zone. The zonal climatic conditions, related mainly to the amount of precipitation and insolation, influenced Potentilla bifurca biometric, morphological and physiological parameters and indicators of mycorrhizae.