Logging Intensity Reshapes Insect Biodiversity in Pine Wilt Disease Forests: A Multi-Trophic Assessment from Jiangxi, China

Yiming Wang^1*Xiaohua Liu¹Mingxia Jin¹Gu-ai Xie¹Longjun Li²Ailin Yu^1*

• ¹Jiangxi Academy of Forestry, Nanchang, China
• ²Jiangxi Institute of natural resources and monitoring, Nanchang, China

Pine wilt disease (PWD), caused by Bursaphelenchus xylophilus, has triggered widespread clearcutting in subtropical China, yet the ecological consequences for insect communities remain poorly quantified. This study evaluates the impacts of clearcutting (CC), selection cutting (SC), and unlogged (UC) treatments on insect diversity, community composition, and functional guild structure across four PWD-affected counties in Jiangxi Province. Stratified sampling of 48 plots revealed significant declines in Shannon (UC: 3.63 ± 0.02 vs. CC: 3.14 ± 0.18; F = 19.17, p = 0.00057) and Simpson indices (UC: 0.960 vs. CC: 0.919) under intensive logging, with PERMANOVA confirming treatment-driven restructuring of nine insect orders (explained variance: 60.7–89.5%, p < 0.05). NMDS ordination demonstrated distinct community clusters, with clearcut sites dominated by disturbance-tolerant taxa (e.g., Cicindelidae, IndVal = 0.94) and unlogged forests supporting specialists like Libellulidae (IndVal = 0.95). Functional guild analysis revealed trophic collapse in predators (-63.7%) and parasitoids (p < 0.001) under CC, contrasting with resilient decomposers. Structural equation modeling identified vegetation cover (β = 0.69, p < 0.001) and litter thickness (β = 0.25, p = 0.041) as critical mediators, with logging intensity indirectly reducing diversity via microhabitat degradation (total R² = 0.81). These findings advocate for retention forestry (≥30% canopy cover, 20–30 m³/ha deadwood) to balance disease control and biodiversity conservation in subtropical pine ecosystems.