Many studies have been carried‐out on the effects of forest conversion on soil microbial community composition and diversity. However, impacts on soil microbial functions and how diversity changes across scales are poorly understood. To fill the research gap, we used metagenomic sequencing and 16S rRNA and ITS gene sequences to evaluate the microbial composition, diversity, and function of 260 soil samples collected from tropical rainforest and rubber plantation sites across Hainan Island, South China. The results revealed that: (a) Forest conversion resulted in shifts in microbial composition (from the Proteobacteria to Chloroflexi), archaeal composition (from Thaumarchaeota to Bathyarchaeota), and fungal composition (from Basidiomycota to Ascomycota). (b) Bacterial alpha, beta, and gamma diversity were not reduced by forest conversion. However, fungal beta diversity was lower in the plantations, resulting in a decrease in gamma diversity. Archaeal beta diversity was higher in rainforest versus rubber plantation soils, but archaeal gamma diversity showed the opposite pattern. (c) Soil functional composition and diversity did not differ with forest type; however, genes related to metabolism and degradation processes were significantly more abundant in the tropical rainforest. These changes in gene abundance could alter ecosystem processes. (d) Soil pH and environmental heterogeneity were the main drivers of microbial taxonomic composition and functional gene composition. Land use explained 13.28% of the variation in taxonomic composition but did not explain changes in functional gene composition. We concluded that land use changes can alter soil microbial community structure and have profound effects on ecosystem functions and processes.

中文翻译：

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森林转化改变了热带森林土壤微生物群落的结构和功能过程

关于森林转化对土壤微生物群落组成和多样性的影响，已经进行了许多研究。但是，人们对土壤微生物功能的影响以及跨尺度变化的多样性知之甚少。为了填补研究空白​​，我们使用宏基因组测序，16S rRNA和ITS基因序列评估了从华南海南岛热带雨林和橡胶人工林地点采集的260个土壤样品的微生物组成，多样性和功能。结果表明：（a）森林转化导致微生物组成（从变形杆菌到叶绿藻），古细菌组成（从伞形目到Bathyarchaeota）和真菌组成（从担子菌变到子囊目）转移。（b）森林转换未降低细菌的α，β和γ多样性。然而，人工林中的真菌β多样性较低，导致γ多样性下降。雨林中的古细菌β多样性高于橡胶种植土壤，但古细菌的γ多样性表现出相反的格局。（c）土壤功能组成和多样性不因森林类型而异；但是，与代谢和降解过程有关的基因在热带雨林中明显更为丰富。基因丰度的这些变化可能会改变生态系统过程。（d）土壤pH和环境异质性是微生物分类组成和功能基因组成的主要驱动力。土地利用解释了生物分类组成变化的13.28％，但没有解释功能基因组成的变化。