CARBON DIOXIDE RELEASE FROM MELTED GROUND ICE SAMPLES UNDER CONDITIONS OF AN INCUBATION EXPERIMENT
P.B. Semenov1, A.O. Kil1, E.V. Shatrova1,2, N.G. Belova3,4, O.V. Levochkina4, M.O. Leibman4, G.E. Oblogov4, A.V. Khomutov4,5, I.D. Streletskaya3
1Federal State Budgetary Institution "Academician I. S. GRAMBERG All-Russia Scientific Research Institute for Geology and Mineral Resources of the Ocean", Saint-Petersburg, Russia
2St. Petersburg State University, Institute of Earth Sciences, St. Petersburg, Russia
3Lomonosov Moscow State University, Department of Geography, Moscow, Russia
4Tyumen Research Centre, Siberian branch of the Russian Academy of Sciences, Earth Cryosphere Institute, Tyumen, Russia
5Industrial University of Tyumen, Tyumen, Russia
Keywords: ground ice, dissolved organic matter, carbon dioxide, incubation experiments, biodegradable dissolved organic carbon
Abstract
This work aims to study the quantitative transformation of dissolved organic matter into CO2 in ground ice samples collected from typical exposures of the Russian Arctic under conditions of an incubation experiment. The CO2 emission during incubation has two peaks, the first being associated with the utilization of organic carbon dissolved in ground ice; and the second, with the mobilization of organic matter from the solid fraction of melted ground ice. Melted ice samples are characterized by high values of biodegradable dissolved organic carbon (> 65 %) and a significant positive correlation (R2 = 0.82) between the values of cumulative CO2 emission and biodegradable dissolved organic carbon. Our data indicate a high potential for ground ice to be a source of labile carbon in the ecosystem under thermodenudation.
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