Liu Shiliang, Sun Yongxiu, Shi Fangning, Liu Yixuan, Wang Fangfang, Dong Shikui, Li Mingqi
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing, China.
School of Grassland Science, Beijing Forestry University, Beijing, China.
Front Plant Sci. 2022 Apr 25;13:819661. doi: 10.3389/fpls.2022.819661. eCollection 2022.
The microorganisms of soil are sensitive to their living microenvironment, and their community structure and function will change with the environmental conditions. In the agro-pastoral area on the Qinghai-Tibet Plateau, revealing the diversity of the soil microbial communities and its response to different soil physicochemical properties and environmental factors are important for ecosystem management. The microbial (bacteria and archaea) community composition and diversity under different land use types (cultivated land, grazing grassland and planted forest) were analyzed by 16S rRNA (V4 region) method in a typical agro-pastoral region in the upper Yellow River basin. Also, the soil nutrients were studied and correlated with the microbial community. The results showed that the soil nutrient contents in grassland were low, but the available nutrients were relatively high. There was a great spatial variability under different distances to the river. The microbial community diversity was lower in the grassland than the cultivated land and forest land closer to the river. For all land uses, the dominant phyla of soil microorganisms included Proteobacteria, Actinobacteria, and Bacteroidetes, while the abundance of Clostridia was significantly higher than that of the other groups, indicating that Clostridia dominated the Firmicutes and affected soil microbial community composition. The linear discriminant analysis (LDA) effect size (LefSe) analysis showed different biomarkers were more abundant in grassland than other land use types, suggesting that the structure and diversity of soil microorganisms in grassland were significantly different compared with cultivated land and forest land. The distance-based redundancy analysis (db-RDA) results showed that the total phosphorus (TP) and calcium (Ca) were the key environmental factors affecting the diversity and abundance of the soil microbial community in cultivated land and forestland, respectively. However, the microbial diversity in grassland was more related to spatial distance of the river. These results provided a theoretical basis for the changes in the composition, structure, and function of soil microbial communities in agro-pastoral areas.
土壤中的微生物对其生存的微环境敏感，其群落结构和功能会随环境条件而变化。在青藏高原农牧区，揭示土壤微生物群落的多样性及其对不同土壤理化性质和环境因子的响应，对生态系统管理具有重要意义。采用16S rRNA（V4区）方法，对黄河上游典型农牧区不同土地利用类型（耕地、放牧草地和人工林）下的微生物（细菌和古菌）群落组成和多样性进行了分析。同时，对土壤养分进行了研究，并将其与微生物群落进行了关联分析。结果表明，草地土壤养分含量较低，但有效养分相对较高。在距河流不同距离处存在很大的空间变异性。草地的微生物群落多样性低于靠近河流的耕地和林地。对于所有土地利用类型，土壤微生物的优势门类包括变形菌门、放线菌门和拟杆菌门，而梭菌纲的丰度显著高于其他类群，表明梭菌纲在厚壁菌门中占主导地位并影响土壤微生物群落组成。线性判别分析效应大小（LefSe）分析表明，草地中不同生物标志物的丰度高于其他土地利用类型，这表明草地土壤微生物的结构和多样性与耕地和林地相比存在显著差异。基于距离的冗余分析（db-RDA）结果表明，总磷（TP）和钙（Ca）分别是影响耕地和林地土壤微生物群落多样性和丰度的关键环境因子。然而，草地中的微生物多样性与河流的空间距离关系更大。这些结果为农牧区土壤微生物群落组成、结构和功能的变化提供了理论依据。
