Spatial variability of biogenic elements and organic carbon content in the tributaries of Lake Baikal

The article considers the features of biogenic elements and organic carbon (Corg) content spatial variability in the Lake Baikal tributaries. The role of hydrological conditions and landscape-geochemical features in the chemical elements flow formation is shown. It was found that organic carbon in the river waters is represented mainly by its dissolved form. In the lower reaches of the Selenga, erosion processes and economic activity in the catchment area increase the proportion of suspended forms of organic carbon and mineral phosphorus. In the river delta under the influence of the sedimentation and the intake of organic matter formed during aquatic vegetation decomposition, the content of dissolved Corg increases with a contemporary decrease in its suspended form. As a result of intensification of production and destruction processes in well-heated areas of the delta, a significant decrease in the concentrations of mineral phosphorus and an increase in organic phosphorus occur.