Tree mycorrhizal association types shape oribatid mite communities in a subtropical forest

Forest management prioritizes sustaining primary productivity and conserving biodiversity, with its processes profoundly influenced by tree mycorrhizal associations and their interactions with soil fauna. However, how mycorrhizal types structure belowground communities is poorly understood. Here, we investigated how arbuscular mycorrhizal (AM), ectomycorrhizal (EM), and mixed (AM × EM) tree species influence oribatid mite communities in a subtropical forest ecosystem. By analyzing environmental factors (canopy cover, litter traits, soil properties) and oribatid mite community metrics (density, species richness, functional traits, and functional diversity) across 21 plots, we identified key drivers of oribatid mite community assemblies among tree mycorrhizal association types. Results revealed that AM tree stands, characterized by rapid litter decomposition and high fungal diversity, supported fungal-feeding oribatid mites with high δ¹³C values, indicating microbial-processed carbon utilization. In contrast, EM tree stands favored parthenogenetic species under thick, recalcitrant litter layers, correlating with higher oribatid mite densities. Mixed mycorrhizal type stands exhibited intermediate traits, suggesting that resource complementarity enhances functional redundancy. Redundancy analysis highlighted canopy cover, litter thickness, soil fungal diversity and soil phosphorus as critical drivers of oribatid mite community structure. These findings demonstrate that mycorrhizal types act as ecological filters, shaping soil fauna through cascading effects on litter chemistry and microbial interactions. Our study underscores the importance of integrating mycorrhizal diversity into forest management to sustain soil biodiversity and ecosystem resilience under global change.