Management Methods and Duration Induces Changes in Soil Microbial Communities of <i>Carya cathayensis</i> var. <i>dabeishansis</i> Forests

Soil microbial communities are involved in and contribute to several processes in soil ecosystems. Nonetheless, how various forest management approaches and their timeframes influence soil microbial community composition and network complexity is poorly understood. Hence, in this study, a time-series method examined how microbial populations in the soil of <i>Carya cathayensis</i> var. <i>dabeishansis</i> forests varied across different management practices (no management, extensive management, and intensive management) and over periods of 0, 3, 8, 15, and 20 years. High-throughput sequencing determined the species composition of soil microbial communities, co-occurrence network analysis assessed interrelationships between communities, and null model theory elucidated deterministic and stochastic processes governing community assembly. The results indicated that under both treatment methods, soil bacterial diversity indices increased compared to the control during short-term management (3 years), but subsequently declined with further prolonged management duration. Moreover, soil acid phosphatase activity and total potassium levels primarily shaped the bacterial species in the soil, with <i>Acidobacteriota</i> (21.96%-31.45%), <i>Proteobacteria</i> (22.82%-31.12%), <i>Actinobacteria</i> (6.81%-13.05%), and <i>Chloroflexi</i> (6.68%-9.67%) representing the most prevalent bacterial taxa. Interactions between soil bacterial and fungal communities were predominantly cooperative across both management strategies (79.88%-100%). However, the degree of cooperation fluctuated throughout the duration. Stochastic processes, particularly diffusion limitation, played a key role in shaping the assembly of these microbial communities. The diffusion limitation of soil microorganisms was smaller in extensively managed forests than in intensively managed forests. These results highlight the need for balanced forest management strategies, where short-term intensive practices could help preserve soil microbial diversity and sustain ecosystem functions. Therefore, we strongly recommend adopting an intermittent forest management approach, particularly in intensively managed forests, where it is necessary to allow the ecosystem adequate time for autonomous recovery.