Optimizing anthropogenic management practices can effectively enhance the vegetation carbon sequestration in China

Terrestrial ecosystems play a crucial role in absorbing carbon dioxide from atmosphere and mitigating climate change. However, few studies assessed whether the vegetation carbon sequestration can be bolstered by optimizing anthropogenic management practices (AMP). In this study, we proposed a method based on neighborhood substitution of environmental similarity for assessing net primary productivity (NPP) potential and whether vegetation carbon sequestration can be effectively enhanced without changing the vegetation types and its spatial patterns in China. Specifically, environmentally similar areas with higher productivity were identified as reference conditions, and their management practices were regarded as attainable pathways for improving NPP in lower-productivity areas, including improved water and nutrient management, reduced grazing pressure, and optimized forest management. The results indicated that the vegetation NPP can be increased by 23% compared to the NPP in 2023, reaching 568.2 gC/m²/year (5.0 PgC in total). Vegetation NPP potential of different ecosystems varied considerably, with the greatest NPP potential in forests (957.6 gC/m²/year) and the greatest increase in grasslands (25%). Vegetation NPP potential derived from the increase of net ecosystem productivity (NEP) and the decrease of heterotrophic respiration (R_H). The vegetation NEP can be increased by 149.3 gC/m²/year (1.3 PgC in total) and R_H can be decreased by 41.4 gC/m²/year (0.4 PgC in total), indicating that optimizing AMP of vegetation can substantially augment carbon uptake. Moreover, we found that areas with high NPP potential showed significant spatial aggregation and scale effects with developed carbon sequestration potential indices.