Aims Soil bacterial communities play vital roles in subtropical broad-leaved forests (SBFs), however, the mechanisms regulating their formation remain poorly understood. The present work aimed to address this question. Methods We used dIVI (Important Value Index of deciduous canopy trees) to quantitively classify three SBFs. Soil bacterial traits such as community composition, diversity and potential interactions (via network analyses) were studied. The relationship between bacterial community composition and environmental factors was analyzed. Results SBFs were determined as a deciduous forest (DBF, dIVI = 0.99), a mixed forest (MBF, dIVI = 0.52) and an evergreen forest (EBF, dIVI = 0.19). Soil bacterial communities were different considerably among vegetation types, which was largely attributed to soil pH, dIVI and plant diversity, in which soil pH exerted stronger impacts than the others (coefficients of partial Mantel tests: 0.87 for soil pH versus 0.35 for dIVI, 0.26 for plant diversity). Compared to the MBF and the EBF, the DBF exhibited significantly higher bacterial diversity and more intensive potential interactions. Conclusions This study implies that soil pH, vegetation type and plant diversity are key driving forces of soil bacterial community composition in SBFs, which improves our understanding of mechanisms regulating soil bacterial community composition.

中文翻译：

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土壤pH值对亚热带阔叶林土壤细菌群落组成的影响大于植被类型和植物多样性

土壤细菌群落在亚热带阔叶林 (SBF) 中起着至关重要的作用，然而，调节其形成的机制仍然知之甚少。目前的工作旨在解决这个问题。方法 我们使用 dIVI（落叶树冠重要价值指数）对三个 SBF 进行定量分类。研究了土壤细菌性状，例如群落组成、多样性和潜在的相互作用（通过网络分析）。分析了细菌群落组成与环境因素的关系。结果 SBF 被确定为落叶林（DBF，dIVI = 0.99）、混交林（MBF，dIVI = 0.52）和常绿林（EBF，dIVI = 0.19）。不同植被类型的土壤细菌群落差异很大，这主要归因于土壤 pH 值、dIVI 和植物多样性，其中土壤 pH 值的影响比其他因素更大（部分 Mantel 测试的系数：土壤 pH 值为 0.87，dIVI 为 0.35，植物多样性为 0.26）。与 MBF 和 EBF 相比，DBF 表现出显着更高的细菌多样性和更密集的潜在相互作用。结论 本研究表明土壤 pH 值、植被类型和植物多样性是 SBF 中土壤细菌群落组成的关键驱动力，这提高了我们对调节土壤细菌群落组成机制的理解。