Close‐to‐nature management regulates ecosystem carbon storage through its effects on vegetation community structure in Pinus massoniana plantations

Societal Impact Statement Forest plantations play an increasingly important role in climate change mitigation through carbon sequestration, yet management strategies that enhance long‐term ecosystem carbon storage remain insufficiently understood. We investigated the effects of more than a decade of close‐to‐nature management on community structure and ecosystem carbon storage across different developmental stages of Pinus massoniana plantations. We found that close‐to‐nature management increased ecosystem carbon storage by promoting tree growth, optimizing stand density, and improving understory vegetation conditions. These findings provide practical guidance for carbon‐oriented plantation management and support the development of sustainable forestry policies aimed at strengthening forest‐based climate solutions. Summary Close‐to‐nature management (CTNM) is increasingly promoted as a silvicultural approach for enhancing ecological functions in plantation forests. However, its long‐term effects on ecosystem carbon storage and the mechanisms linking community structure to carbon sequestration remain poorly quantified. This study evaluated the effects of long‐term CTNM (>10 years) on community structure and ecosystem carbon storage in Pinus massoniana plantations across different developmental stages. Comparative field investigations were conducted in young, middle‐aged, and near‐mature P. massoniana plantations under CTNM and control management. Community structural attributes, species diversity, and carbon storage in vegetation and soil pools were measured. Redundancy analysis and hierarchical partitioning were used to identify key structural drivers of ecosystem carbon storage. CTNM significantly altered community structure by increasing tree height, DBH, and species diversity while reducing stand density. Carbon storage increased across multiple ecosystem pools, with the strongest responses observed in near‐mature forests. DBH, stand density, tree height, herb coverage, and shrub coverage were identified as the principal structural indicators associated with ecosystem carbon storage. Long‐term CTNM enhances ecosystem carbon storage in P. massoniana plantations by regulating community structure, particularly through promoting tree growth, optimizing stand density, and improving understory vegetation conditions. These findings provide scientific support for carbon‐oriented forest management and climate change mitigation strategies.