Data from: Pathogens and Soil Nutrients Contrastingly Drive Arbuscular and Ectomycorrhizal Tree Species Abundance in a Subtropical Forest

Understanding the factors that determine tree species abundance in forest ecosystems has garnered considerable scientific attention. However, the mechanisms underlying species abundance patterns among trees with different mycorrhizal types in tropical and subtropical forests remain poorly understood. Current evidence suggests that natural enemy dynamics and niche differentiation are two key mechanisms driving tree species abundance. Yet, how these factors separately influence the abundances of arbuscular (AM) and ectomycorrhizal (ECM) tree species remains critically lacking. In this study, we employed high-throughput sequencing of fungal communities in rhizosphere soils from 312 individuals representing 65 tree species within a 25-ha subtropical forest. Our findings revealed a negative relationship between tree species abundance and rhizosphere pathogen load in AM tree species but not in ECM species. Notably, rare AM species exhibited significantly higher pathogen accumulation rates than common AM ones. To complement these findings, we conducted a field survey to examine the relationship between soil nutrients and the abundances of AM and ECM tree species. Soil organic phosphorus (OP) content was positively correlated with the abundance of AM tree species but negatively correlated with that of ECM tree species. Notably, ECM species exhibit the opposite pattern. Together, these findings suggest that distinct ecological processes drive the abundance of AM and ECM trees: pathogen accumulation limits the abundance of AM trees, while organic nutrient preference primarily governs the abundance of ECM trees species. This study provides novel insights into the mechanisms underlying tree species abundance and coexistence from both biotic and abiotic perspectives.