Soil characteristics and microbial community structure on along elevation gradient in a Pinus armandii forest of the Qinling Mountains, China

Lots of studies have shown that elevation, plant species, and soil characteristics and their relationships significantly affect microbial community in forest soils. However, how do elevation, soil characteristics, and their relationship affect microbial community in the same plant community in different latitudes, such as warm temperature zone and subtropical zone, remains unclear. Here, microbial community structure, soil characteristics, and their relationship were analyzed in Pinus armandii forests in subtropical zone at an altitude of 1700–2300 m in the Huoditang Forest of the Qinling Mountains, China. Bacterial and fungal communities were analyzed by Illumina sequencing. Elevation showed a significant effect on soil organic matter (SOM) and pH. Proteobacteria, Acidobacteria, Ascomycota, and Basidiomycota were higher abundant phyla across elevations. Ectomycorrhizal fungi abundance decreased with increasing elevation. The fungi richness decreased with increasing elevation and was negatively and significantly correlated with SOM and elevation. The relative abundance of Acidobacteria, Verrucomicrobia, Sordariomycetes, and Eurotiomycetes and Ectomycorrhizal fungi abundance was significantly correlated with soil pH. Additionally, Agaricomycetes abundance was positively correlated (p < 0.05) with available potassium (AK) in soils. Elevation, pH, soil temperature, SOM, and AK were significant factors affecting microbial communities according to the data on Pearson and redundancy analyses. Overall, responses of soil characteristics to elevation significantly affected microbial community structure in P. armandii forests of the Qinling Mountains. The results will make us better understand the roles of microbial communities in providing ecosystem services in subtropical forests.