Impacts of stand age on ectomycorrhizal fungal diversity and soil enzyme activities in Pinus massoniana plantations

In forest ecosystems, ectomycorrhizal (ECM) fungi play a crucial role in influencing plant productivity and soil processes. However, the dynamics of ECM fungal diversity during forest development and its relationship with soil enzyme activities remain insufficiently explored. This study focused on ECM fungal communities in Pinus massoniana forests of different ages (15, 25, and 35 years). Our findings revealed that P. massoniana roots harbor diverse ECM fungi, with community composition varying across developmental stages. Notably, the mature 35-year-old forest exhibited lower fungal alpha diversity but higher ECM fungal abundance, along with increased enzyme activities related to carbon, nitrogen, and phosphorus acquisition. Soil pH and C-to-N ratios emerged as key factors influencing ECM fungal community diversity and composition. Redundancy analysis highlighted significant correlations between changes in ECM fungal community composition and soil enzyme activities (S-PPO and S-POD), as well as soil chemical properties (pH and C stoichiometry). Overall, varying stand ages lead to distinct ECM fungal communities, impacting soil functions associated with enzymatic activity.