Meta-analysis and field experiments reveal the global impact of management practices on Forest soil organic carbon

Forest soil organic carbon (SOC) plays a vital role in regulating the global carbon cycle. Forest management practices significantly impact SOC stocks, yet most existing studies remain plot-scale. We conducted a global meta-analysis of harvesting, fertilization, and reforestation using controlled experimental data. Management effects were analyzed by time scale (short-term ≤5 years; long-term >5 years). Harvesting in tropical forests showed a 15.77 % decline (effect size:-0.23, p < 0.01). Short-term harvesting (≤5 years) increased SOC by 7.96 % (effect size: 0.10, p < 0.05), particularly in temperate forests (9.45 %, effect size: 0.08, p < 0.05), while long-term harvesting (>5 years) reduced SOC by 7.76 % (effect size:-0.19, p < 0.01), with tropical forests experiencing a 20.95 % decline (effect size: −0.30, p < 0.01). Fertilization in tropical forests resulted in a 6.30 % increase (effect size: 0.05 p < 0.01). Long-term fertilization in tropical forests showed an 11.24 % increase (effect size:0.11, p < 0.05), but subtropical forests experienced a 10.16 % reduction ( p < 0.01). Reforestation had a weak effect on SOC, with long-term reforestation (>5 years) also showing a non-significant impact. We investigated the effects of forest management practices on SOC in subtropical Moso bamboo forests. Harvesting exhibited variable impacts: moderate harvesting significantly reduced SOC by 10.30 %, while light and heavy harvesting increased SOC by 43.24 % and 17.39 %, respectively. Fertilization consistently enhanced SOC, with light and heavy biochar applications increasing SOC by 32.91 % and 42.18 %. Our research highlights that forest management measures exert varying effects on SOC when assessed across different climate zones, underscoring the value of a cross-biome comparative perspective. Therefore, future studies on adaptive climate management should prioritize scientifically differentiated strategies to enhance forest SOC stocks effectively. • Harvesting intensity exhibits significant temporal divergence in its effects on SOC. • Fertilization and harvesting have significantly different effects on SOC in tropical forests. • The research revealed the significant climatic variability in the effects of fertilization measures on SOC.