Diversity of Soil Microbiota Communities in Pinus massonianaSecondary Forests Under Varying Logging Intensities and Years of Vegetation Restoration

This study adopted a space-for-time substitution method to examine the secondary Pinus massoniana forest suffering from Bursaphelenchus xylophilus in the subtropical region. Two cutting methods(moderate logging ML and heavy logging HL) and 3 natural recovery periods(0 a, 5 a, 15 a) were set up. The high-throughput sequencing technology was used to analyze the diversity of soil microbial communities and their relationship with soil nutrients. The results showed that the available nutrients in 0–10 cm soil layer, such as organic matter and alkali hydrolyzed nitrogen, significantly increased with the restoration years. Additionally, both the logging intensity and restoration years jointly influenced the organic matter content in the 10–20 cm soil layer. The richness and diversity of soil bacteria and fungi were significantly affected by the interaction between the logging intensity and the restoration years, and they increased with the extension of the restoration period. The main dominant bacterial phyla included Acidobacteria and Proteobacteria, while the dominant fungal phyla were Ascomycota and Basidiomycota. Rapidly available potassium was a key factor affecting the characteristics of the microbial community, while organic matter, available phosphorus, and rapidly available potassium were positively correlated with bacterial diversity indices. Alkali hydrolyzed nitrogen was the main factor affecting the variation in the 10–20 cm soil layer. In conclusion, moderate logging and natural restoration contribute to increasing soil nutrient content and microbial diversity, promoting positive succession and soil fertility maintenance in forest ecosystems.