| Soil microorganisms constitute a major portion of the biodiversity in soils, and play an essential role in maintaining soil processes. Which ultimately affect the functioning of terrestrial ecosystems. Meanwhile, physicochemical property of the soil and the geographic distance influence microbial community composition and distribution.The Tibetan Plateau is the Earth’s largest (2×106km2) and highest (-4000m on average) plateau. The higher throughput permitted by pyrosequencing allows us to characterize the diversity and distribution of differ depth of soil in Alidiqu of Tibetan Plateau. We collected soil sample from13sites (Upper-layer:0-15cm; Sublayer:16-30cm, all26samples) across the Alidiqu of Tibetan Plateau. The major result are as following:1. We collected a total of34phyla of soil bacteria in Alidiqu of Tibetan Plateau. The dominant phyla were Actinobacteria(41.3%), Alphaproteobacteria(9.3%), Acidobacteria(7%), Chloroflexi(5.9%), Gemmatimonadetes(7.2%), Firmicutes(3.3%), Betaproteobacteria(3.1%), Deltaproteobacteria(2.2%), Gammaproteobacteria(2.9%), Planctomycetes(2.1%), Bacteroidetes(2%), accounting for more than85%of the bacterial sequences. The relative abundance of Acidobacteria, Deltaproteobacteria and Firmicutes of upper-layer soil were significantly higher than sublayer. The relative abundance of Betaproteobacteria and Gemmatimonadetes were significantly lower than sublayer.2. The relative abundance of Alphaproteobacteria, Betaproteobacteria, Acidobacteria and Firmicutes were decreased as total carbon (TC) increased, but Gammaproteobacteria and Planctomycetes were increased. The relative abundance of Alphaproteobacteria were positive correlate with ammoniacal nitrogen. The relative abundance of Betaproteobacteria and Gemmatimonadetes were negative correlate with nitrate nitrogen and dissolved organic nitrogen. Elevation showed positive correlations with the relative abundance of Actinobacteria, but Planctomycetes were the opposite.3. The bacterial phylotype richness and phylogenetic diversity of upper layer soil were significant higher than sublayer. Pearson correlation analysis found that nitrate nitrogen and dissolved organic nitrogen were the dominant factors influening the bacterial phylotype richness and phylogenetic diversity.4. Bacterial communities were distinct from differ depth soil in Alidiqu of Tibetan Plateau. We found that Total carbon drive the bacterial communities distribution by mantel test and CCA analysis. |
