Changes in spider communities under the influence of anthropogenic environmental pollution

The article considers aspects of the transformation of the spider community under the influence of anthropogenic pressure in the dry-steppe conditions of the Volgograd region. Data on changes in the number and species composition of the Aranei order as they move away from the most typical sources of pollution for the city: an unauthorized landfill (in the Kamyshin-Stalingrad state forest belt), a highway (2nd Longitudinal, near Universitetskijprospekt) and an energy enterprise (Volgograd Thermal Power Plant-3) are presented. Samples were taken near the object of pollution, outside the legally defined zone where the influence of the source of pollution is reduced to acceptable values for farming (for example, in the case of highways, these are the boundaries of the exclusion zone) and in the middle between the object and the boundary of the exclusion zone. In the case of unauthorized landfills, there is no legislative regulation, and therefore a distance of 30 m is taken as the size of the exclusion zone. When collecting spiders, open soil entomological Barber traps with a diameter of 10 cm, with a fixing solution, were used. To assess the qualitative changes in the species composition of spiders (without taking into account the number of individuals of each species), the Chekanovsky-Sørensen index was used, and for qualitative (taking into account the number of individuals), the Bray-Curtis index of quantitative similarity was used. As a result of the carries out research, the qualitative ratio of the species diversity of the Aranei order representatives in the territory near the sources of anthropogenic pollution was established, comparative data on the degree of similarity of the species composition of spiders at key polygons were obtained. The results of the research have shown that the influence of all pollution sources on spider communities is great, but it noticeably weakens with distance from them, and beyond the boundaries of the exclusion zone decreases to acceptable values.