Habitat-specific changes of plant and soil microbial community composition in response to fairy ring fungus Agaricus xanthodermus on the Qinghai-Tibet Plateau

• A new fairy ring fungus was reported in this study. • Fairy ring fungi influence plants and soil microbes by promoting soil nutrients. • The effect of fairy ring fungi on plants and soil microbes depends on the habitat type. Fairy rings are common in diverse global biomes and often appear as lush vegetation in one to three concentric zones caused by the spread of mycelia in grassland ecosystems. However, the underlying mechanisms and environmental adaptation of fairy rings remain largely unclear. In this study, two fairy rings (A and B) caused by Agaricus xanthodermus were sampled on the Qinghai-Tibet Plateau during a time when fairy rings are most obvious. By conducting a vegetation survey and high-throughput sequencing, the changes of plants and soil microorganisms to fairy ring fungi were examined. Plant above-ground biomass at both fairy rings was greatly increased by fairy ring fungi, but the response of dominant plant species is different at two fairy ring sites. In addition, bacterial and fungal communities significantly varied within distinct sampling zones across the fairy rings, and showed variable genus-specific responses at two fairy ring sites. At fairy ring A, soil available N:P ratio was essential in shaping the structure of plant and microbial community, while soil available N concentration was the most important predictor at fairy ring B. Taken together, our results indicated Agaricus xanthodermus fairy rings have variable effects on alpine meadow plants and soil microbes at different habitats. We propose that the impacts of fairy ring fungi on plants and microbes are determined by the level of soil available N concentration and available N:P ratio. These results contribute to a better understanding of the mechanisms through which fairy rings affect the vegetation of alpine meadows.