Composition of surface water in the Central Forest State Natural Biospheric Reserve

The chemical composition of surface water in the Central Forest State Natural Biospheric Reserve is characterized by well-pronounced seasonal dynamics related to the intensity of biological turnover. Three groups of chemical elements with different types of seasonal dynamics are specified. The impact of soils on the chemical composition of surface water is most pronounced in the summer, when concentrations of dissolved organic carbon and microelements are the highest and correlate with one another. The groundwater is the main source of calcium, sodium, and magnesium for the local Mezha River. Aluminum and water-soluble organic substances are supplied with soil solutions from organic horizons (10–50 cm). Iron and manganese are discharged into the river both with surface soil waters and with the groundwater flow. The migration of aluminum in the Mezha River basin is mainly controlled by the pH conditions, whereas the migration of iron depends on the concentration of dissolved organic carbon.