Anthropogenic impact on the seasonal dynamics state bark of trees and shrubs on the example of Betula pendula and Rosa acicularis

To find out new spices of plants suitable for bioindication in urban areas a heat-induced change of the ground level chlorophyll fluorescence of phelloderm cells has been used to estimate winter dormancy depth of R. acicularis and B. pendula in the seasonal changes of the state of the photosynthetic apparatus, as well as during the artificial termination of winter dormancy. Fluorescence was induced with photochemically inactive green light at the same time heating the sample of phelloderm from 30 to 80 °C at a rate of 8 °C / min (fluorometer «Foton-11», SFU Russia). Condition of plants was evaluated according to the ratio of low (Fltt) and high (Flht) temperature maxima on the curves of thermally induced fluorescence (R2). Status of the urban environment is determined by physical and chemical parameters of rinse blank from the leaves of plants. The value of R2 of the plant in the state of dormancy is typically less than 0.1; in the period of active vegetation is more than 1 (R2 > 1). During the conversion periods: autumn-winter, winterspring, plants from contaminated sites has higher R2 ratio. This pattern was repeated with the artificial termination of winter dormancy. The differences in physical and chemical characteristics of urban pollution in sample areas were comparable to the differences in relative indicator of the state of plants (RIS = R2 (C) / R2 (R)) in the period of transition from winter dormancy to active vegetation. The results obtained on the wild rose, point to the universal nature of the response of tree and shrub forms to environmental pollution - reduction in the depth of winter dormancy and reduced transition period. High sensitivity of rose hips to the technogenic impact also allows recommending it for bioindication of urban environment.