Seasonal changes in the biodiversity of bird communities of small towns in the forest-steppe zone of Western Siberia (on the example of the city of Ishim in the Tyumen region)

The article discusses the problems of human adaptation and sustainability of urban ornithological communities. The gradient of anthropogenic stress revealed a reduction in the number of bird species, simplifying the taxonomic structure of communities, modifying their ecological structure in favor of increasing the proportion of synanthropic species in both residential zones. In the direction from the forest zone to the zone of high-rise buildings showed a decrease in the indices of species biodiversity and sustainability of communities. Method a qualitative cluster analysis indicated that area high-rise buildings are well differentiated from the forested areas. This can be explained by loss of contact with natural habitats; increase of complex influence of factors of urbanization, reduction of resource capacity of the habitat due to degradation of vegetation and reduction of areas occupied by green spaces. Analysis of seasonal and interannual dynamics of bird fauna in different functional zones of the city showed that the seasonal differences are more pronounced than interannual. This indicates that ornithofauna different areas of the city represent a single dynamic, but relatively stable system with duplicate processes in each of the seasons. In addition, each of the functional areas in different seasons of the year performing different roles in the life of the avifauna of the city. Comparison of functional zones of the city as a whole as part of the overall system and the control plot shows that the urban area in winter has a greater resource capacity than natural habitats.