Effects of Slope Aspects on Soil Bacterial and Arbuscular Fungal Communities in a Boreal Forest in China

The effects of slope aspects on soil biogeochemical properties and plant communities in forested environments have been studied extensively; however, slope aspect influence on soil microbial communities remains largely unexamined, despite the central role of soil biota in ecosystem functioning. In this study, the communities of both soil bacteria and arbuscular mycorrhizal fungi （AMF） were investigated using tagged pyrosequencing for three types of slope aspects （south-facing aspect, north-facing aspect and flat area） in a boreal forest of the Greater Khingan Mountains, China. The bacterial and AMF community composition differed with slope aspects. Bacterial diversity was the lowest on the north-facing aspect, and AMF diversity was the lowest on the flat area. Aspects also had a significant impact on soil pH and available phosphorus （P） and shrubby biomass. Soil pH and understory shrub biomass were significantly correlated with bacterial communities, and soil available P and shrub biomass showed significant correlations with AMF communities. Our results suggested that slope aspects affected bacterial and AMF communities, mediated by aspect-induced changes in plant community and soil chemical properties （e.g., pH and available P）, which improved the knowledge on the effects of forest slope aspects on aboveground and belowground communities.

在 forested 环境的土壤 biogeochemical 性质和植物社区上的斜坡方面的效果广泛地被学习了；然而，倾斜对的方面影响大部分玷污微生物引起的社区遗体 unexamined，尽管有在生态系统工作的土壤生物区系的中央角色。在这研究，土壤细菌和 arbuscular mycorrhizal 真菌(AMF ) 的社区在更大的 Khingan 山的一个北方的森林里为斜坡方面(面对南方的方面，面对北方的方面和扁平的区域) 的三种类型用标注 pyrosequencing 被调查，中国。细菌并且 AMF 社区作文与斜坡方面不同。细菌的差异在面对北方的方面上是最低的，并且 AMF 差异在扁平的区域上是最低的。方面也在土壤 pH 和可得到的磷(P) 和灌木状的生物资源上有重要影响。土壤 pH 和 understory 灌木生物资源显著地与细菌的社区被相关，并且玷污可得到的 P 和灌木生物资源与 AMF 社区的显示出的重要关联。我们的结果建议了那个斜坡细菌的影响的方面和 AMF 社区，在植物社区和土壤化学药品性质由导致方面的变化调停了(例如， pH 和可得到的 P ) ，它在森林斜坡方面的效果上改进了知识在上未葬、地下社区。