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The seasonal cycle of the greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia
M. K. van der Molen1, J. C. van Huissteden1, F. J. 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 unusually 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.
Discussion Paper (PDF, 2550 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (BG)
Citation: van der Molen, M. K., van Huissteden, J. C., Parmentier, F. J., Petrescu, A. M. R., Dolman, A. J., Maximov, T. C., Kononov, A. V., Karsanaev, S. V., and Suzdalov, D. A.: The seasonal cycle of the greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia, Biogeosciences Discuss., 4, 2329-2384, 2007. Bibtex EndNote Reference Manager
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