The influence of atmospheric pollution in Novosibirsk on soil microorganisms of the nitrogen cycle

Abstract

The research was carried out in Novosibirsk, a large metropolis with a population of more than 1.6 million people. The city has a well-developed transportation and logistics infrastructure, and an industrial complex that contribute to an increased environmental burden due to pollutants with a synergistic effect The study assessed the microbiological characteristics of soil as an indicator of the environmental status in areas with reduced traffic, motor vehicle, and industrial pollution. These findings were compared with data from instrumental analysis of atmospheric air conducted by West Siberian Administration for Hydrometeorological and Environmental Monitoring at stationary sites adjacent to the soil sampling points. It was revealed that the microbiological processes of the nitrogen cycle are disrupted in the urban-gray forest soil of Novosibirsk, especially in the area affected by transport and industrial pollution. This leads to a decrease in the number of nitrogen-fixing and protein-mineralizing microorganisms. The trend of development of microorganisms that utilize organic and mineral nitrogen correlates with air pollution from dust, nitrogen dioxide, formaldehyde, and carbon monoxide in the surveyed areas. The abundance of autotrophic nitrogen fixers in the soils of different zones of the city is similar, which may be attributed to the intensity of fuel combustion processes. Despite the relatively high nitrogen content, the potential for the development of denitrifies in the densely populated Central district of the city, with its high traffic load, is not realized in the soil due to the salt content. Changes in the nitrogen cycle indicate degradation of the ecological functions of the soil in polluted urban areas.