Soil contribution to carbon budget of Russian forests

•We developed a modeling system for assessing soil C and heterotrophic respiration.•The total heterotrophic soil respiration flux for the Russian forest is estimated.•Interannual variability of heterotrophic soil respiration is high for zones and regions.•It was shown that the Russian forest ecosystems serve as a carbon sink.•The allocation of sequestered carbon in European and Asian forests is different.