Dynamics of ectomycorrhizal fungal communities and soil enzyme activities in <i>Pinus massoniana</i> forests across developmental stages

Ectomycorrhizal (ECM) fungi are essential in regulating nutrient cycling and plant–soil interactions in forest ecosystems, yet their dynamics and functional roles across developmental stages remain underexplored. We characterized the ECM fungal community composition, diversity, and soil enzyme activities in Pinus massoniana forests of three developmental stages (15, 25, and 35 years) to uncover their relationships and ecological implications. The results revealed distinct shifts in ECM fungal communities, with young forests exhibiting higher diversity and dominance of short-distance exploration types, while mature forests showed reduced diversity but increased abundance of long-distance exploration types. Soil enzyme activities associated with carbon, nitrogen, and phosphorus cycling varied significantly with forest development. Mature forests exhibited the highest soil urease and soil β-glucosidase activities, aligning with the dominance of long-distance exploration types. Soil pH and nutrient stoichiometry emerged as key drivers shaping ECM fungal communities and enzyme activities, with lower pH in mature forests favoring acidophilic fungal taxa. Redundancy analysis further highlighted the strong influence of soil chemical properties and enzyme activities on ECM fungal community structure. These findings underscore the critical role of ECM fungi in modulating soil nutrient dynamics and plant growth during forest development, providing insights into sustainable forest management and the ecological functioning of subtropical pine plantations.