Assessment of effects of the anthropogenic disturbance on plant communities and soils in urbanized territories

Abstract

The research was conducted in forest and forest park zones of industrial cities of Irkutsk, Angarsk, Usolie-Sibirskoye, and Shelekhov (Irkutsk region, Eastern Siberia, Russia). The disturbance of biogeocenoses in the urban environment was assessed by a set of visual and morphostructural parameters of trees, the state of the grass cover, morphological and physical properties of soils. The study showed to what extent the structural and functional parameters of trees, grass cover, and soils of urbanized areas have changed in comparison with the background, what is the main trend of their transformation. It has been established that in urban forest parks, under conditions of high recreational load, the morphological and physical parameters of the topsoils are informative, as evidenced by their high correlations with the morphostructural parameters of trees. The results indicate that the most weakened trees grow on soils with a high density of the soil's upper horizons and unfavorable water-air conditions. For recreational areas, an increased level of degradation of organic matter, as well as a reduced content of plant nutrients were found. The selected set of parameters of plants and soils allows to estimate reliably the degree of their disturbance and can be used when substantiating the levels of anthropogenic loads on forest ecosystems within urbanized territories.