Dominant soil bacteria and their ecological attributes across the deserts in northern China

Abstract Soils harbour highly diverse bacterial communities that are essential for nutrient cycling and carbon storage. However, this diversity impedes the efforts to characterize individual taxa and their ecological attributes. In particular, comprehensive assessments of soil bacterial communities in drylands in China are limited. In this study, soil samples were collected across 12 deserts, covering four climatic regions (dry sub‐humid, semi‐arid, arid and hyper‐arid) in northern China to examine the dominant phylotypes, and their environmental preferences and functional traits. Only 3.2% of the bacterial phylotypes (913 phylotypes) were dominant. These dominant phylotypes can be grouped into six major ecological clusters based on high pH, high elevation, low aridity index, high aridity index, low mean annual temperature and low soil water content, each with multiple phyla. Based on the association between diversity indexes for dominant and subdominant phylotypes, these dominant bacteria might be the drivers or indicators of key soil processes across desert soils in northern China. Genes involved in carbon fixation and decomposition and nitrogen metabolism varied across desert soils, suggesting functional differences. These findings provide deeper insights into soil bacterial communities, which are critical for forecasting the ecological consequences of ongoing global environmental change and for a better mechanistic understanding of the biogeochemical cycle. Highlights 3.2% of the bacterial phylotypes were dominant across 12 deserts in northern China. The dominant phylotypes were grouped into six major ecological clusters. Carbon fixation, decomposition and nitrogen metabolism genes varied across desert soils. Some northern China desert soils might undergo nitrogen and carbon loss in the near future.