Carbon and nutrients in the Yenisei River tributaries draining the Western Siberia Peatlands

Abstract

The study is focused on carbon and nutrient behaviour in tributaries of the Yenisei River draining the Western Siberian Plain. The previous studies showed that dissolved organic carbon (DOC) concentrations in riverine systems are influenced by wetland cover within a watershed and modulating effect of permafrost. Our data point out more complex interactions within the south-north transect of the Yenisei River basin including a partitioning of sources at different seasons and in-river metabolic processing of DOC involving utilization of nutrients and production of DIC. On the other hand, DOC concentration in rivers is driven by available stock of labile carbon and, thus, is a function of total organic matter stored in soils. Terrigenic C and nutrient fluxes to rivers are enhanced in colder environments of northern Western Siberia, contradicting the earlier observations and respective future projections of permafrost degradation effects on riverine C release.