Spatial-temporal variation of the carbon sequestration rate of afforestation in China: Implications for carbon trade and planning

Afforestation and reforestation (A&R) are nature-based and cost-effective solutions for enhancing terrestrial carbon sinks and facilitating faster carbon neutrality. However, the lack of hierarchical spatial-temporal maps for the carbon sequestration rate (CSR) from A&R at the national scale impedes the scientific implementation of forest management planning to a large extent. Here, we assessed the spatial-temporal CSR per area for A&R at the provincial, prefectural, and county levels in China using a forest carbon sequestration model under three climate scenarios. Results showed that the CSR of vegetation (CSRVeg), soil (CSRSoil), and the ecosystem (CSREco) significantly varied across space and time. In China, the CSRVeg, CSRSoil, and CSREco were primarily regulated by the spatial variations in temperature and precipitation. Additionally, CSRVeg was found to be positively influenced by precipitation and temperature, whereas temperature had a negative influence on CSRSoil. Therefore, the differences between the CSRVeg and CSRSoil should be emphasized in the future. These information on the spatiotemporal variation of CSR of A&R (vegetation, soil, and ecosystem) on unit area basis and at levels of province, prefecture, and county in China, can be used as a comparable protocol to estimate the carbon sinks of A&R at different scales. Overall, these hierarchical spatiotemporal maps for CSR on A&R may help to identify priority areas of forest management planning and carbon trade policy to achieve faster carbon neutrality for China in the future.