Salinity and soil pH both drive distribution of bacterial communities in saline soils: Scientists

Saline soils account for 6.5% of the total land area globally, covering about 800 million hectares of land. Nearly 70% of the area in northwestern China comprises saline soil. Although soil microbes play an unequivocal role in maintaining biogeochemical cycles and delivering integral ecosystem services, little is known about the microbial diversity and community composition in saline soils.
Recently, scientists from China have defined two key factors shaping the bacterial communities in saline soils: soil pH and salinity.
Through analysis on samples collected from the hypersaline Ebinur Lake vegetated shoreline in northwestern China, TIAN Changyan and his team at the Xinjiang Institute of Ecology and Geography found that bacterial communities in this area were diverse, with Gammaproteobacteria, Actinobacteria, Firmicutes, Alphaproteobacteria, Bacteroidetes and Betaproteobacteria as the dominant phyla.
“These dominant phyla made a significant contribution to community structure variations between soils.” said TIAN.
Scientists also identified the indicator taxa across salinity gradient, which are Halomonas, Smithella, Pseudomonas and Comamonas.
“Bacterial communities were determined by both salt content and pH, and the effect of salt content was similar to that of the soil pH,” TIAN said. Interestingly, their study showed that bacterial phylotype richness and phylogenetic diversity were higher in soils with middle-level salt rates.
Results of the study were published recently in Scientific Reports, entitled “Soil pH is equally important as salinity in shaping bacterial communities in saline soils under halophytic vegetation”.