Kozhevnikova N.K., Lutsenko T.N., Boldeskul A.G., Yurchenko S.G.
V.Ya.Levanidov memorial lectures 2025; (11): 77-89
The results of field study of the release dynamics of the dissolved species of organic carbon and biogenic elements from river catchments with di erent landscape structures are presented. The potential influence of various types of forest communities and the hydrological factor on the retention or output of biogenic elements within the catchment area has been revealed. It is shown that the tendency of concentrations increase and output is observed during the summer months. This is due to the activation of biochemical processes within forest communities and an increase in the water discharge. It has been established that the most contrasting changes between streams are manifested in the migration of various species of dissolved nitrogen and dissolved organic carbon. In the both streams, the dissolved organic carbon dominates and its export amounts to 1070-2250 kg/km2 per season (64-68 % of the total dissolved). The concentration of the total dissolved nitrogen is 3-4 times higher in the waters of the stream draining slopes with primary cedar-broadleaf forests. Such di erences are associated with high concentrations (1,2-1,4 mgN/l) of nitrate in the stream. In the waters of the stream draining the slopes with secondary oak forests, ammonium nitrogen (0,2-0,4 mgN/l) dominates in May-June, and organic nitrogen (0,3-0,4 mgN/l) prevails in the July-September. For a more complete understanding of the biocycles in catchments with di erent landscape-forming factors, continuous monitoring is needed, which will be useful for identifying the peculiarities of biogeochemical cycles within basins.
