Basic characteristics of different plots among 5 subtypes and 13 genera of saline-alkali soil in arid regions of northwest China. Diversity of bacterium communities in saline-alkali soil in arid regions of Northwest China

The Illumina MiSeq sequencing method was practiced to investigate the bacterial diversity and composition in the 5 subtypes and 13 genera of saline-alkali soil in Gansu Province, China. The results from this study show that the dominant bacterial groups were Euryarchaeota, Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Gemmatimonadetes among the different salinity soil. Euryarchaeota and Proteobacteria were the main indicator species reflecting changes of the main microbial groups. Euryarchaeota was the most abundant in chloride-sulfate-type meadow solonchaks, sulfate-chloride-type meadow solonchaks, chloride-type meadow solonchaks, chloride-sulfate-type orthic solonchaks, sulfate-chloride-type orthic solonchaks, magnesium solonetz, sulfate-type dry solonchaks, chloride-sulfate-type dry solonchaks, and sulfate-chloride-type dry solonchaks, whereas Proteobacteria had the greatest abundance in sulfate-type meadow solonchaks, sulfate-type orthic solonchaks, chloride-type orthic solonchaks, and chloride-type bog solonchaks. Halobacteria was the dominant bacterial class in soil samples except sulfate-type meadow solonchaks, chloride-type orthic solonchaks, sulfate-type orthic solonchaks, and chloride-type bog solonchaks. The richness estimators of Ace and Chao 1 and the diversity indices of Shannon and Simpson revealed a less bacterial community in sulfate-chloride-type orthic solonchaks than that of other soils. The pH value was the most important driving force for bacterial composition (32.1%), and the second most influencing factor was sulfate anion (9.2%) and soil total salt (8.7) contents.