Structure and assembly mechanism of soil bacterial community under different soil salt intensities in arid and semiarid regions

• Published in: Ecological indicators Vol. 158; p. 111631
• Main Authors: Wei, Yuxi, Chen, Lijuan, Feng, Qi, Xi, Haiyang, Zhang, Chengqi, Gan, Kaiyuan, Yong, Tian
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2024; Elsevier
• Subjects: Bacterial diversity; Co-occurrence network; Community assembly; Community structure; Salt intensity; Community structure; Salt intensity; Community assembly; Bacterial diversity; Co-occurrence network
• ISSN: 1470-160X; 1872-7034
• DOI: 10.1016/j.ecolind.2024.111631

•Soil salinity negatively affected soil bacterial diversity.•The community structure in solonchak was simpler and more prone to damage.•Rare taxa were as important as abundant taxa for co-occurrence network stability.•Community assembly was gradually dominated by stochasticity as salinity increased. Soil salinization has become the most expansive form of soil degradation in arid and semiarid regions, and the management of soil salinization is imperative for achieving sustainable development. Soil microorganisms are supposed to play an integral role in controlling soil salinization, and the effects of high-salt environments on microbial community have been widely investigated, but there is currently limited comprehensive study on taxon co-occurrence patterns and assembly processes under different salt intensities. Here, based on high-throughput sequencing technologies, we analysed bacterial community structure and assembly mechanism under salt intensity in arid and semiarid regions. The results demonstrated that bacterial diversity was negatively correlated with soil salinity, and community structure also varied with changes in salt intensity. Solonchaks (soils with high soluble salt accumulation) had the lowest average degree of bacterial co-occurrence network, and there was a lower level of connectivity and correlation among bacteria in solonchaks compared to other salt-affected soils. The highest competitive connections among soil bacteria were detected in light-intensity saline soils, whereas overall collaborative connections increased with soil salinity. For co-occurrence network stability, the rare taxa (with each taxon’s relative abundance < 0.1%) were more essential than the abundant taxa (> 1%). As soil salinity increased, stochastic processes gradually dominated the community assembly, and the dispersal limitation contributed from 45.18% to 58.73%. These findings offered valuable information about how soil salt intensity affected soil bacterial community and would be useful in controlling soil salinization.