Purpose

Understanding the microbial linkages among the soils, plants, and animals is crucial for maintaining the balance of the grazed grassland ecosystem. However, previous studies always focused on the biotopes of soil, phyllosphere, and feces separately and little has been known about microbial distributions and migrations among these biotopes. In this study, systematic surveys about the overlap and differentiation among various microbiotas of biotopes and how the environmental filter on microorganisms served for the ecosystem were conducted.

Materials and methods

Soil, phyllosphere, and feces samples were collected from grazed and ungrazed grassland in Inner Mongolia, China. High-throughput sequencing and qPCR were employed to obtain the genome data. The results were analyzed by various statistical tools such as genomic analysis and machine learning classification to describe the disparities and linkages among the microbiotas of three biotopes.

Results and discussion

Our findings revealed that the biotopes drove the distinct microbial community assemblages with various richness, β-diversity and composition. The substantial overlaps between soil and phyllosphere in fungi, bacteria and archaea indicated that soil played the role of the microbial source for the phyllosphere. Communal OTUs could be found between phyllosphere and feces. Nevertheless, Ascomycota were the only microorganisms migrating among all the biotopes massively. After the long-term impact of feces via grazing, the soil and phyllosphere microbiota also altered significantly.

Conclusions

Biotopes drive the discrepancy of microbiota distribution among the soil, phyllosphere, and feces. Soil could potentially perform as the microbial reservoir for the phyllosphere. The phyllosphere plays the role of bridge to link soil and feces biotope through its fluctuated condition. However, there was only fungal migration running through the ecosystem to link all the biotopes. These findings promoted our understanding of the biotope contribution to microbial migration and improved the knowledge of microbial linkages in the grazed grassland ecosystem.