Zokor disturbances indicated positive soil microbial responses with carbon cycle and mineral encrustation in alpine grassland

Abstract

The alpine grassland is a fragile ecosystem sensitive to human disturbance; the Qinghai-Tibetan Plateau alpine grassland is an example with large areas that are currently suffering from degradation. Although subterranean mammals (e.g., the plateau zokor, Eospalax baileyi) are thought to contribute to grassland soil and plant degradation, they are native species and play positive roles in the alpine ecosystem as ecosystem engineers. However, little is known about their effect on soil microbial communities. Using Illumina sequencing of the 16S rRNA gene and the internal transcribed spacer 2 (ITS2) regions, we compared soil prokaryotic and fungal community composition and diversity in areas disturbed by plateau zokors during the grassland recovery process. We found an increase in the number of observed operational taxonomic units (OTUs) of soil prokaryotic and fungal microbes, while the community structure of the microbes became significantly divergent. Soil properties, plant cover, and aboveground biomass explained the majority of the changes in microbial communities, suggesting that the changes in soil and plant characteristics mainly regulate the response of soil microbes to zokor disturbance in alpine grasslands. Zokor disturbances result in positive soil microbial responses in phyla with carbon cycle and mineral encrustation associations, suggesting a positive role for soil microbial community functions. Our findings provide novel evidence that zokors are important ecosystem engineers essential for alpine ecosystem functions.