An estimate of the terrestrial carbon budget of Russia using inventory-based, eddy covariance and inversion methods

[摘要] We determine the net land to atmosphere flux of carbon in Russia, includingUkraine, Belarus and Kazakhstan, using inventory-based, eddy covariance, andinversion methods. Our high boundary estimate is −342 Tg C yr⁻¹ fromthe eddy covariance method, and this is close to the upper bounds of theinventory-based Land Ecosystem Assessment and inverse models estimates. Alower boundary estimate is provided at −1350 Tg C yr⁻¹ fromthe inversion models. The average of the three methods is −613.5 Tg C yr⁻¹.The methane emission is estimated separately at 41.4 Tg C yr⁻¹.

These three methods agree well within their respective error bounds. Thereis thus good consistency between bottom-up and top-down methods. The forestsof Russia primarily cause the net atmosphere to land flux (−692 Tg C yr⁻¹from the LEA. It remains however remarkable that the threemethods 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 ofrecent forest inventories, the few eddy covariance sites and associateduncertainty with upscaling and undersampling of concentrations for theinversions are among the prime causes of the uncertainty. The dynamic globalvegetation models (DGVMs) suggesta much lower uptake at −91 Tg C yr⁻¹, and we argue that this is caused bya high estimate of heterotrophic respiration compared to other methods.

[学科分类] 地球化学与岩石