Comparative analysis of the effectiveness of bioindication methods in monitoring environmental studies in St Petersburg

The purpose of the research is to evaluate the effectiveness of bioindication methods in determining the state of the environment in St. Petersburg on the example of Vasileostrovsky and Pushkinsky districts. The content of chemical elements in soils, poplar bark Populus balsamifera, Tilia cordata and Betula pendula leaves, moss (Sphagnum angustifolium) and lichen (Cladonia stellaris) traps was studied, the integral index of fluctuating asymmetry of linden leaves T. cordata and birch B. pendula was calculated, soil biotesting using Daphnia magna and Chlorella vulgaris was carried out. It is established that the main sources of pollution of the urban environment are motor transport, the Baltic plant in Vasileostrovsky district and the industrial zones "Shushary" and "Pushkinskaya" in Pushkin district. The territory of the park zone of the Pushkin district can be considered as a conditional background for environmental monitoring. The use of fluctuating asymmetry of tree species leaves in bioindication studies is recommended only in conjunction with the results of chemical analysis. Poplar bark seems to be the most convenient bioindicator for assessing environmental pollution over a long period, the chemical composition of the leaves of tree species (linden T. cordata and birch B. pendula) reflects information about the intake of pollutants during one growing season, analysis of the chemical composition of moss and lichen traps allows you to determine the intake of pollutants in a relatively short period of time and identify sources of pollution. To assess the ecological state of the urban environment on the basis of the Harrington desirability function, an integral bioindication parameter BIP has been developed, taking into account the degree of transformation of individual environmental components under the influence of anthropogenic load: a change in the chemical composition of plants relative to clark (background) values; the manifestation of fluctuating asymmetry of tree species leaves compared to the norm. The effectiveness of BIP application for geoecological assessment of the state of the environment in cities is shown.