Bacteria are widely distributed and play an important role in soil carbon (C) cycling. The impact of soil bacterial diversity on soil C storage has been well established, yet little is known about the underlying mechanisms and the interactions among them. Here, we examined the association between soil bacterial diversity and soil C storage in relation to vegetation restoration on the Loess Plateau. The dominant phyla among land use types (artificial forest, Af; natural shrubland, Ns; artificial grassland, Ag; natural grassland, Ng; slope cropland, Sc) were Acidobacteria, Actinobacteria, Alphaproteobacteria, and Betaproteobacteria, which transited from Acidobacteria-dominant to Actinobacteria-dominant community due to vegetation restoration. Soil C storage and the Shannon diversity index of soil bacterial community (H_Bacteria) showed the order Ns > Ng > Af > Ag > Sc, whereas no significant difference was found in Good's coverage (p > .05). Further, a strong relationship was observed between the relative abundance of dominant bacterial groups and soil C storage (p < .05). Additionally, soil bacterial diversity was closely related to soil C storage based on the structural equation model (SEM) and generalized additive models (GAMs). Specifically, soil C storage had the largest deterministic effects, explaining >70% of the variation and suggesting a strong association between soil C storage and soil bacterial diversity. Overall, we propose that further studies are necessary with a focus on the soil bacterial groups with specific functions in relation to soil C storage on the Loess Plateau.

细菌广泛分布，并在土壤碳（C）循环中起重要作用。土壤细菌多样性对土壤碳存储的影响已得到充分证实，但对其潜在机理及其​​之间的相互作用知之甚少。在这里，我们研究了黄土高原土壤细菌多样性与土壤碳储量与植被恢复之间的关系。在土地利用类型中（人工林，Af；天然灌木林，Ns；人工草地，Ag；天然草地，Ng；坡耕地，Sc），主要的菌群是酸性细菌，放线菌，α-变形杆菌和β-变形杆菌，它们从酸性细菌过渡到了酸性细菌。放线菌-由于植被恢复而成为主要社区。土壤碳储量和土壤细菌群落（H的香农多样性指数_细菌）显示的顺序Ns个>伍> AF> AG> SC，而没有显著差异，在良好的覆盖（发现p  > 0.05）。此外，观察到优势菌群的相对丰度与土壤碳储量之间存在很强的相关性（p <.05）。此外，基于结构方程模型（SEM）和广义加性模型（GAM），土壤细菌多样性与土壤碳储量密切相关。具体而言，土壤C的储存具有最大的确定性影响，解释了> 70％的变化，并表明土壤C的储存与土壤细菌多样性之间有很强的联系。总的来说，我们建议有必要进一步研究，重点是与黄土高原土壤碳存储有关的具有特定功能的土壤细菌群。