Ekaterina Yurievna Tsyutsura

The paper presents the results of a study of the impact of rail transport on the forest ecosystems of the Valdai National Park. Previously, comprehensive scientific studies of the impact of railways on specially protected natural areas were not conducted. The location of the park in an important transport corridor affects the ecological state of natural systems. Unlike most territories through which railway communication is carried out, the site chosen for research allows assessing the environmental impact of railway transport in the absence of other anthropogenic sources of impact. The gross content of heavy metals and metalloids in the soils of the section adjacent to the railway and the background territories of the park has been determined. Analysis of the gross content of heavy metals in soil samples taken in 5 m increments from the railway embankment showed an excess of the maximum permissible concentrations (MPC) of some elements at a distance of 30 meters from the track. The maximum permissible concentration is observed in manganese, nickel, copper, zinc, arsenic, cadmium and lead. The embankment has a high content of elements such as strontium, barium, copper, and iron. The calculation of quantitative indicators of soil contamination showed that a strong level of contamination is observed at the embankment and at a distance of 25 and 30 m from it. A correlation analysis was conducted, and a model for the distribution of heavy metals and metalloids was presented. An important result of the study was the identification of the role of natural plant communities in the migration and accumulation of pollutants. It was found that the gray alder, located 30 meters away from the embankment, acts as the first mechanical barrier that limits the spread of heavy metals. The second barrier is formed by the sour spruce, which grows 43 meters away from the railway track. These natural filters help to reduce the intensity of the migration of pollutants into the depths of the forest. Exceeding the permissible limits for manganese, nickel, copper, zinc, and cadmium in soils is associated with the wear and tear of railway transport facilities (wheels, rails, and wagons). Arsenic is a component of diesel particulate matter. The increased copper content is associated with railway lubrication, and barium and strontium indicate the use of carbonate crushed stone on railway embankments. The results obtained contribute to understanding the mechanisms of the spread of pollutants from linear transport facilities, are of practical importance for the development of environmental protection measures, and can be used to normalize the impact of rail transport within specially protected natural areas affected by railway.