Carbon sequestration in biomass and soil following reforestation: a case study of the Yangtze River Basin

The effect of reforestation on carbon sequestration has been extensively studied but there is less understanding of the changes that stand age and vegetation types have on changes in biomass carbon and soil organic carbon (SOC) after reforestation. In this study, 150 reforested plots were sampled across six provinces and one municipality in the Yangtze River Basin (YRB) during 2017 and 2018 to estimate carbon storage in biomass and soil. The results illustrate that site-averaged SOC was greater than site-averaged biomass carbon. There was more carbon sequestered in the biomass than in the soil. Biomass carbon accumulated rapidly in the initial 20 years after planting. In contrast, SOC sequestration increased rapidly after 20 years. In addition, evergreen species had higher carbon density in both biomass and soil than deciduous species and economic species (fruit trees). Carbon sequestration in evergreen and deciduous species is greater than in economic species. Our findings provide new evidence on the divergent responses of biomass and soil to carbon sequestration after reforestation with respect to stand ages and vegetation types. This study provides relevant information for ecosystem management as well as for carbon sequestration and global climate change policies.