Assessing Forest Carbon Sequestration in China Under Multiple Climate Change Mitigation Scenarios

Understanding how climate policies impact forest carbon sequestration is crucial for optimizing mitigation strategies. This study evaluated forest carbon sequestration in China from 2020 to 2060 under three climate scenarios: SSP1-2.6 (high mitigation), SSP3-7.0 (limited mitigation), and SSP5-8.5 (no mitigation). We integrated the land-use harmonization (LUH2) and patch-generating land-use simulation (PLUS) models to project forest cover change, and the Lund–Potsdam–Jena managed land (LPJmL) model to simulate carbon dynamics. The results showed stronger mitigation efforts led to higher sequestration, with annual rates of 0.49, 0.48, and 0.20 Pg yr−1 across the scenarios. SSP1-2.6 achieved the highest carbon density (17.75 kg m−2) and sequestration (56.95 Pg), driven by the greatest increases in the carbon density of existing forests (+41.56%) and soil carbon (+39.94%). SSP3-7.0, despite the highest forest cover (34.74%), had a lower carbon density (17.19 kg m−2) and sequestration (56.84 Pg). SSP5-8.5 recorded the lowest forest cover (27.12%) and sequestration (45.62 Pg). Increasing carbon density, rather than expanding forest area, could be more effective for carbon sequestration in China. The carbon density and annual sequestration in existing forests were 2.36 and 2.89 times higher than in new forests. We recommend prioritizing SSP1-2.6 to maximize sequestration, focusing on protecting southwest forests and soil carbon.