Carbon sequestration in vegetation and its change in the Three-North Shelter Forest region of China in 2000-2021

Abstract Carbon sequestration in vegetation can offset a large proportion of carbon emissions, and plays an important role in mitigation climate change. Based on satellite data and ground observation data, we examined carbon sequestration rate and its long-term change in the Three-North Shelter Forest Program (TNSFP) region, where a series of large-scale ecological projects have been implemented. The results indicated that carbon sequestration rate in vegetation was 458.3 ± 45 g C m − 2 yr − 1 in the TNSFP region during the period 2000–2021. Obvious increase trend of carbon sequestration rate was observed covering approximately 90% of the TNSFP region, with an average increase rate of 5.06 ± 4.3 g C m − 2 yr − 1 . There was a larger increase rate of 7.78 ± 2.07 g C m − 2 yr − 1 in forest than that of 3.27 ± 0.55 g C m − 2 yr − 1 in grassland. Total carbon sequestration into vegetation was 26.1054 P g C (1 P g = 10 15 g) in the TNSFP region, with annual carbon sequestration of 1186.6 ± 122.6 T g C (1 T g = 10 12 g) during the period 2000–2021. Our results revealed that both human activities and climate change have positive effect on carbon sequestration rate. Human activities contribute to carbon sequestration increment of 1.7905 Pg C approximately under assumptions that the existing forest transformed from original natural grass land due to afforestation and reforestation. Climate change has promoted carbon sequestration rate due to increase in annual precipitation, but the increase in annual air temperature is harmful in enhancing carbon sequestration rate.