Long-term variations of Оґ13С in tree ring cellulose of the Ob-Tom interfluve
A. N. MARKELOVA, G. V. SIMONOVA, D. A. KALASHNIKOVA, YU. V. VOLKOV
Institute of Monitoring of Climatic and Ecological Systems SB RAN, Tomsk, Russia
Keywords: carbon isotopes, indication of biogeochemical processes, West Siberia
Abstract
Long-term variations of stable carbon isotope rations in tree ring cellulose for two forest sites of the Ob-Tom interfluve territory are analyzed. At the first site, the expected decrease in δ13С values was found, but its rate was higher than the global one by 0.16-0.2 ‰/10 years. At the second site, located 20 m from the peatland, the δ13С value was increased until 1978 and then decreased at the same rate as in the first site - 0.2 ‰/10 years. We assume that the δ13С values variations in tree ring cellulose at the second site reflect changes in δ13С value of СО2 emitted from the peatland. The reason for the changes in dynamics after 1978 is probably the influence of the Tomsk underground water intake, which led to the drying up of the peatland and, accordingly, a decrease in the δ13С value in СО2.
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