Investigating the Impact of Species Diversity on the Carbon Sequestration Potential of Forest Vegetation Based on Solar-Induced Chlorophyll Fluorescence

Forest species diversity plays a critical role in regulating vegetation carbon sequestration potential. However, the mechanisms by which species diversity influences carbon dynamics under varying forest conditions are not yet fully understood. In this study, we used solar-induced chlorophyll fluorescence (SIF) as a proxy for carbon sequestration potential and integrated nationwide forest plot data collected through standardized protocols. A random forest model was employed to examine the influence of species diversity on carbon sequestration potential across forests differing in origin and succession. The results revealed that: (1) species diversity has a positive effect on vegetation carbon sequestration potential at the national scale (r ≈ 0.15); (2) forest origin significantly modulates this relationship, The importance index of species diversity in natural forests (0.409) was significantly higher than that in planted forests (0.043), with a relative contribution exceeding that of planted forests by approximately 20% and (3) the contribution of species diversity increases with forest succession. These findings highlight forest origin and succession as critical factors shaping the biodiversity–ecosystem functioning relationship. Our study provides a scientific basis for conserving natural forests, promoting the ecological transformation of plantation forests, and managing carbon sinks in alignment with successional dynamics.