WILDFIRE-RELATED CHANGES OF MIRE WATER CHEMISTRY IN FOREST-TUNDRA AND TAIGA ZONES OF WESTERN SIBERIA

Abstract

Link for citation: Kharanzhevskaya Yu.A., Sinyutkina A.A. Wildfire-related changes of mire water chemistry in forest-tundra and taiga zones of Western Siberia. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 6, рр.193-203. In Rus. The relevance of the study is caused by the need to assess changes in waters chemical composition of mires under the influence of the pyrogenic factor. The aim: to study mire water chemistry of post-fire areas in the forest-tundra and taiga zones of Western Siberia, to analyze the conditions for its formation and patterns of spatial variation depending on the degree of surface burnout. Objects: Great Vasyugan Mire, Ust-Bakchar bog, palsa mire near Pangody village. Methods. Laboratory analysis of the water chemical composition was carried out by titrimetry, spectrophotometry, and flame photometry at the Laboratory and Analytical Center of the Siberian Research Institute of Agriculture and Peat. Analysis of Cu, Pb, Cd, Zn, P, Mn content in water samples was carried out by inductively coupled plasma mass spectrometry (ICP-MS) at the Plasma Chemical Analytical Center. Statistical data processing was carried out using the nonparametric Wilcoxon test, cluster analysis, and principal component analysis. Results. Studies have shown that an indicator of the influence of the pyrogenic factor on the water chemistry is an increase in pH, total dissolved solids and concentrations of K+, SO42–, as well as Са2+, Mg2+, HCO3–, NO3–, Fetotal, P, Mn, Zn, Cd, Cu, Pb. During the self-restоratiоn of mires after the fire, a gradual increase in the concentrations of NH+4, DOC and COD is noted in the waters. Analysis of the data showed 4–16 times higher concentrations of Са2+, Mg2+, K+, Na+, NH+4, NO3–, Fetotal, HCO3–, DOC and COD, P, Mn, Cu, Zn, Cd, Pb in the waters of palsa mire in the forest-tundra zone in comparison with water samples taken in the burnt areas in the taiga zone of Western Siberia. Factor analysis showed that the leading factor in the formation of water chemistry is the degree of surface burnout, water temperature, and water table levels. Thus, studies have shown that the water chemistry of post-fire mires largely depends on the degree of surface burnout, the initial genetic characteristics of the mire, and the time elapsed after the fire.

Keywords

• Waters
• chemical composition
• pyrogenic factor
• influence
• Western Siberia