Distribution Characteristics and Driving Factors of the Bacterial Community Structure in the Soil Profile of a Discontinuous Permafrost Region

• Published in: Forests
• Main Authors: Qilong Liu, Liquan Song, Siyuan Zou, Xiaodong Wu, Shuying Zang
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2024
• Subjects: soil profile; bacterial community; bacterial diversity; soil properties; prediction of gene functions; permafrost; Plant ecology; QK900-989
• Online Access: https://doi.org/10.3390/f15081456; https://doaj.org/article/b6a253a5b3cd4235863e2e2acaf6bde7

Global warming leads to the melting of permafrost, affects changes in soil microbial community structures and related functions, and contributes to the soil carbon cycle in permafrost areas. Located at the southern edge of Eurasia’s permafrost region, the Greater Khingan Mountains are very sensitive to climate change. Therefore, by analyzing the bacterial community structure, diversity characteristics, and driving factors of soil profiles (active surface layer, active deep layer, transition layer, and permafrost layer) in this discontinuous permafrost region, this research provides support for the study of the carbon cycling process in permafrost regions. The results show that the microbial diversity (Shannon index (4.81)) was the highest at 0–20 cm, and the Shannon index of the surface soil of the active layer was significantly higher than that of the other soil layers. Acidobacteria and Proteobacteria were the dominant bacteria in the active layer soil of the permafrost area, and Chloroflexi , Actinobacteria , and Firmicutes were the dominant bacteria in the permafrost layer. Chloroflexi made the greatest contribution to the bacterial community in the permafrost soil, and Bacteroidota made the greatest contribution to the bacterial community in the active surface soil. The structure, richness, and diversity of the soil bacterial community significantly differed between the active layer and the permafrost layer. The number of bacterial species was the highest in the active layer surface soil and the active layer bottom soil. The difference in the structure of the bacterial community in the permafrost soil was mainly caused by changes in electrical conductivity and soil–water content, while that in the active layer soil was mainly affected by pH and soil nutrient indices. Soil temperature, NO 3 − -N, and pH had significant effects on the structure of the bacterial community. The active layer and permafrost soils were susceptible to environmental information processing and genetic information processing. ...