Biogeographical Patterns and Assembly of Bacterial Communities in Saline Soils of Northeast China

Xiaolong Liang; Xiaoyu Wang; Ning Zhang; Bingxue Li

doi:10.3390/microorganisms10091787

Biogeographical Patterns and Assembly of Bacterial Communities in Saline Soils of Northeast China

Microorganisms. 2022 Sep 5;10(9):1787. doi: 10.3390/microorganisms10091787.

Authors

Xiaolong Liang¹, Xiaoyu Wang², Ning Zhang³, Bingxue Li²

Affiliations

¹ Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
² College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
³ College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang 110866, China.

Abstract

Increasing salinity undermines soil fertility and imposes great threats to soil ecosystem productivity and ecological sustainability. Microbes with the ability to adapt to environmental adversity have gained increasing attention for maintenance and restoration of the salt-affected soil ecosystem structure and functioning; however, the characterization of microbial communities in saline-sodic soils remains limited. This study characterized the bacterial community composition and diversity in saline-sodic soils along a latitude gradient across Northeast China, aiming to reveal the mechanism of physicochemical and geographic characteristics shaping the soil bacterial communities. Our results showed that the bacterial community composition and diversity were significantly impacted by soil pH, electrical conductivity, Na⁺, K⁺, Cl^-, and CO₃^2-. Significant differences in bacterial diversity were revealed along the latitude gradient, and the soil factors accounted for 58.58% of the total variations in bacterial community composition. Proteobacteria, Actinobacteria, Gemmatimonadetes, Chloroflexi, and Bacteroidetes were dominant across all samples. Actinobacteria and Gemmatimonadetes were significantly enriched in high soil sodicity and salinity, while Acidobacteria and Proteobacteria were suppressed by high pH and salt stress in the saline-sodic soils. Increase in soil pH and salinity significantly decreased bacterial species richness and diversity. Community composition analysis indicated that bacterial taxonomic groups (e.g., Bacillus, Egicoccus, Truepera, Halomonas, and Nitrolancea) that may adapt well to high salinity were greatly enriched in the examined soils. The findings collectively evidenced that bacterial community composition and diversity in a broad biographic scale were determined by niche-based environmental characteristics and biotic interactions. The profiling of the soil bacterial communities along the latitude gradient will also provide a basis for a better understanding of the salt-affected soil ecosystem functioning and restoration of these soil ecosystems.

Keywords: bacterial community; biogeographical pattern; latitude gradient; salinity–sodicity; soil degradation; soil pH.

Abstract

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