Abstract

Vegetation restoration has emerged as a critical strategy for enhancing soil organic carbon (SOC) sequestration and mitigating climate change impacts. This comprehensive study examines the effects of different vegetation restoration approaches on SOC accumulation and mineralization processes across diverse ecosystems. Through meta-analysis of 156 field studies spanning 25 countries and laboratory incubation experiments involving 45 restored sites, we quantified the temporal dynamics of SOC accumulation and mineralization rates following vegetation restoration. Results demonstrate that forest restoration achieved the highest SOC accumulation rates of 1.8 ± 0.6 Mg C ha⁻¹ year⁻¹, followed by grassland restoration (1.2 ± 0.4 Mg C ha⁻¹ year⁻¹) and shrubland restoration (0.9 ± 0.3 Mg C ha⁻¹ year⁻¹). SOC mineralization rates decreased significantly across all restoration types, with forest restoration showing the greatest reduction (45 ± 12%) compared to degraded baseline conditions. Temporal analysis revealed that SOC accumulation follows a logarithmic pattern, with rapid initial gains during the first 5-10 years post-restoration, followed by gradual stabilization. Soil depth analysis indicated that 65-70% of SOC accumulation occurred in the top 30 cm, while deeper soil layers (30-100 cm) contributed 20-25% of total gains. Climate variables, particularly mean annual precipitation and temperature, significantly influenced both accumulation and mineralization processes, with optimal conditions occurring at 800-1200 mm annual precipitation and 8-15°C mean annual temperature. Microbial community composition shifts were strongly correlated with SOC dynamics, with fungal:bacterial ratios increasing by 2.3-fold in forest restoration sites. Economic valuation revealed that SOC accumulation provides carbon sequestration benefits worth $85-245 ha⁻¹ year⁻¹ at current carbon prices. These findings underscore the substantial potential of vegetation restoration for climate change mitigation while highlighting the importance of restoration type, duration, and environmental context in determining SOC outcomes.