Response of soil microbes to Carex meyeriana meadow degeneration caused by overgrazing in inner Mongolia

Abstract

Carex meyeriana lowland meadow is one of the most important grassland compositions in Hulun Buir and Northeastern China, until now, substantial part of C. meyeriana meadow in Hulun Buir has been degraded due to overgrazing. In order to clarify the effects of overgrazing on plant communities, soil physicochemical properties and microorganisms of C. meyeriana meadow, long-term unused and overgrazing C. meyeriana meadow were selected as research objects. The important value of C. meyeriana and soil physicochemical properties were determined, and soil microbes were measured by high-throughput sequencing techniques. The results showed that long-term overgrazing would lead to increasing plant diversity, but the advantage of C. meyeriana, soil organic matter and total nitrogen content were significantly reduced. At the same time, the differences in community diversity of soil bacteria from 0 to 30 cm tended to decrease, while fungal tend to heterogeneity, and fungal communities occupied a dominant position in the change of microorganisms. In addition, metagenomics sequencing results showed that overgrazing mainly affected the functional genes of bacteria, most of the differential genes were related to the energy cycle and metabolism, but had no impact on the normal function of soil carbon and nitrogen cycles.