Soil bacterial and fungal communities beneath different forest types differentially and promptly respond to non-catastrophic typhoon disturbance

Abstract

The immediate responses of soil microbial communities to non-catastrophic typhoon disturbances remain largely unclear, despite soil microorganisms are key contributors to ecosystem functioning and sensitive indicators to forest disturbances. To address this gap, we simultaneously investigated soil microbial communities beneath bamboo forest (BF), Chinese fir forest (CF), secondary broadleaf forest (SF) and mixed forest (MF) in the subtropical mountain area of southeastern China before and after typhoon disturbances. Typhoon disturbances significantly altered the composition of soil microbial communities, decreasing bacterial diversity by 12.3% and network robustness by 22.6% in the topsoil, while increasing fungal diversity by 75.0% and network robustness by 33.2% in the litter layer. Notably, these indices returned to the per-typhoon levels post-disturbance. Meanwhile, typhoon disturbances increased the abundance of functional guild on bacterial cellular processes, fungal dung saprotrophs and plant saprotrophs in the topsoil. Moreover, the immediate responses of microbial community composition and diversity to typhoon disturbances were more pronounced in the CF and SF, and bacterial communities were more responsive in the topsoil, while fungal communities were more responsive in the litter layer. Additionally, soil temperature was the primary driver of microbial communities in the topsoil, while litter cellulose and calcium concentrations were key factors in the litter layer. Besides, carbon and nutrient concentrations were also significantly correlated with the composition of taxa and functional guilds of soil microbial communities. In summary, the immediate responses of microbial communities to typhoon disturbances vary considerably depending on forest types and soil horizon, with rapid recovery following typhoon events.