Community Stability Regulated by Different Diversity and Stands Structure Patterns Between Cunninghamia lanceolata and Pinus massoniana Plantations From Natural Forests Insights

Plantations are typically characterized by low biodiversity and fragile community stability. Conversely, natural forests maintain high community stability and sustainability across all developmental stages, thereby serving as a critical reference for sustainable plantation management. However, it remains unclear how biodiversity, interspecific associations, and stand structure shape plantation stability across stand stages, and the maintaining mechanisms of plantation stability, particularly derived from natural forest insights, remain unclear. This study was conducted in Cunninghamia lanceolata and Pinus massoniana plantations, along with mixed natural forests dominated by Liquidambar formosana and Quercus fabri in Qiannan, Guizhou Province, China. A total of 120 plots covering young, intermediate, and mature stands were surveyed to quantify the effect of biodiversity, interspecific associations, and stand spatial structure on community stability. The results demonstrated P. massoniana plantations exhibited similar successional patterns to natural forests. Their diversity and structural complexity increased with stand age, while P. massoniana importance values (IV) decreased. This indicated improving ecosystem stability. However, C. lanceolata plantations suffered competitive degradation. Intense interspecific competition in intermediate‐aged stands reduced biodiversity and structural complexity in mature stands, increasing C. lanceolata IV further worsened ecosystem stability. NMDS ordination confirmed this divergence: P. massoniana plantations aligned with natural forest successional trajectories, while C. lanceolata plantations notably deviated from this pattern. Therefore, P. massoniana plantations had the potential for naturalization as they followed successional trajectories identical to natural forests. However, C. lanceolata plantations deviated from the process of natural succession and therefore did not have the potential for naturalization. This study offers theoretical and practical guidance for sustainable plantation management, highlighting the need for an adaptive management strategy to ensure long‐term ecological stability.