The Effects of Different Management Methods on the Stand Growth and Structural Characteristics of Schima superba Forest of Dense Diplopterygium glaucum Layer

The Schima superba foerst community featuring a dense Diplopterygium glaucum shrub layer in Tiantong Forest Farm was selected as the research object. Three management approaches were implemented: target tree management, integrated tending management, and extensive management. For each approach, three 20 m × 20 m permanent plots were established to investigate the effects of different management practices on community growth and structure over six years. The results indicate that: After six years of management, the dominance of Schima superba in target tree management plots was lower than in integrated tending and extensive management plots. In contrast, the dominance of Castanopsis fargesii significantly increased under target tree management, becoming the dominant species and facilitating the regeneration of rare species such as Cinnamomum subavenium. Under integrated tending management, the dominance of C. fargesii and Castanopsis carlesii declined, being replaced by S. superba, Lithocarpus glaber, and Sassafras tzumu. In extensive management, the dominance of C. fargesii slightly decreased, while that of S. superba and L. glaber increased. Among the three management approaches, the stand basal area ranked as follows: target tree management (38.03 m²·hm⁻²) > integrated tending (36.06 m²·hm⁻²) > extensive management (29.31 m²·hm⁻²). No significant differences were observed in stand density, mean diameter at breast height (DBH), or tree height across the S. superba plots under different management regimes. With intensified management practices, the stock volume followed the order: target tree management (326.5 ± 20.8 m³·hm⁻²) > integrated tending (300.8 ± 18.4 m³·hm⁻²) > extensive management (223.5 ± 23.1 m³·hm⁻²), with significant differences (P<0.05) between the former two and extensive management. Increased management intensity reduced the number of understory shrubs and saplings, but target tree management promoted a higher number of saplings for arbor species compared to the other approaches.