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The growing season greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia
M. K. van der Molen1, J. van Huissteden1, F. J. W. Parmentier1, A. M. R. Petrescu1, A. J. Dolman1, T. C. Maximov2, A. V. Kononov2, S. V. Karsanaev2, and D. A. Suzdalov2
1Department of Hydrology and Geo-Environmental Sciences, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
2Institute of Biological Problems of the Cryolithozone, Russian Academy of Sciences, Siberian Division, 41, Lenin Prospekt, Yakutsk, The Republic of Sakha (Yakutia), 677980, Russian Federation
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Abstract. Carbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia.
This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite
of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and
leaf cuvettes. Net carbon dioxide fluxes were high compared with other tundra sites, with NEE=−92 g C m−2 yr−1, which is
composed of an Reco=+141 g C m−2 yr−1 and GPP=−232 g C m−2 yr−1. This large carbon dioxide sink
may be explained by the continental climate, that is reflected in low winter soil temperatures (−14°C), reducing the respiration rates,
and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the
frequency of light limitation (Rg<200 W m−2), whereas Reco depends most directly on soil temperature and time in the
growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate
availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m−2 yr−1, so that the greenhouse gas
balance was −64 g C-CO2e m−2 yr−1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to
hydrological conditions and vegetation composition.
Final Revised Paper (PDF, 2141 KB) Discussion Paper (BGD)
Citation: van der Molen, M. K., van Huissteden, J., Parmentier, F. J. W., Petrescu, A. M. R., Dolman, A. J., Maximov, T. C., Kononov, A. V., Karsanaev, S. V., and Suzdalov, D. A.: The growing season greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia, Biogeosciences, 4, 985-1003, 2007. Bibtex EndNote Reference Manager
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