European Geosciences Union, Biogeosciences, 12(9), p. 5323-5340, 2012
European Geosciences Union, Biogeosciences Discussions, 6(9), p. 6579-6626
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We determine the net land to atmosphere flux of carbon in Russia, including Ukraine, Belarus and Kaza-khstan, using inventory-based, eddy covariance, and inver-sion methods. Our high boundary estimate is −342 Tg C yr −1 from the eddy covariance method, and this is close to the upper bounds of the inventory-based Land Ecosys-tem Assessment and inverse models estimates. A lower boundary estimate is provided at −1350 Tg C yr −1 from the inversion models. The average of the three methods is −613.5 Tg C yr −1 . The methane emission is estimated sepa-rately at 41.4 Tg C yr −1 . These three methods agree well within their respective er-ror bounds. There is thus good consistency between bottom-up and top-down methods. The forests of Russia primar-ily cause the net atmosphere to land flux (−692 Tg C yr −1 from the LEA. It remains however remarkable that the three methods provide such close estimates (−615, −662, −554 Tg C yr −1) for net biome production (NBP), given the inherent uncertainties in all of the approaches. The lack of recent forest inventories, the few eddy covariance sites and associated uncertainty with upscaling and undersampling of concentrations for the inversions are among the prime causes of the uncertainty. The dynamic global vegetation models (DGVMs) suggest a much lower uptake at −91 Tg C yr −1 , and we argue that this is caused by a high estimate of het-erotrophic respiration compared to other methods.