Abstract
<jats:p>Relevance. Removal of dissolved organic carbon from bogs to rivers is an important component of the carbon balance. Aim. To assess the patterns of organic carbon dynamics in the mire–river system in a small catchment area. Objects. The north-eastern part of the Great Vasyugan Mire (Bakchar bog), within the catchment area of the small Klyuch River (Polynyanka village, Bakcharsky district, Tomsk region). Methods. Temperature, potentiometric, conductometric measurements, determination of the dissolved O2 content in the field, sampling of bog and river waters to determine the content of organic carbon, CO2, hydrological monitoring and calculation of carbon removal from the catchment area of the Klyuch River flowing down from the Bakchar Bog. Statistical analysis of the data was performed using the nonparametric Mann–Whitney U-test, discriminant analysis and the principal component method. Results. The average organic carbon content in water samples collected in different areas of the Bakchar Bog varies significantly: it increases from the central parts to the marginal part of the bog and decreases along the length of the Klyuch River. The increase in the concentration of organic carbon in waters along the bog profile is in good agreement with the increase in the carbon content in the active layer of the peat deposit from the sedge-Sphagnum lagg area to the pine dwarf-shrub Sphagnum community close to the boarder area, which is determined by the change in the botanical composition of peats and the degree of decomposition. Studies shown that the type of vegetation, the physicochemical characteristics and the hydrothermal regime of the peat deposit have a significant effect on the content of organic carbon in the waters, and the forest–bog contact zone and swamp forest make a significant contribution to the total volume of organic carbon removal from the study area. For citation: Kharanzhevskaya Yu.A., Raudina T.V., Istigechev G.I., Kurashev D.G., Bebishev A.I. Spatial and temporal patterns of organic carbon fluxes in mire–river system within a small river basin in Western Siberia. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2026, vol. 337, no. 3, pp. 178–191. https://doi.org/10.18799/24131830/2026/3/5171</jats:p>