Fairy rings harbor distinct soil fungal communities and high fungal diversity in a montane grassland

Abstract Increasing numbers of fungal species have been described recently from semi-natural grassland soils, raising the conservation interest of these species-rich habitats. Here, we characterize the soil fungal community inhabiting six fairy rings in a montane grassland of the Eastern Pre-Pyrenees through fungal DNA metabarcoding of ITS2 amplicons. Distinct soil fungal communities were observed outside of the rings compared to inside the ring areas. Higher abundances of fungi belonging to Pleosporales and Eurotiales were observed outside fairy rings, whereas zones belonging to the fairy rings showed higher abundances of Agaricales. Fungal diversity was higher inside the rings than outside. We found diverse saprotrophic or putative saprotrophic taxa associated with the studied rings, including the genera Clavaria, Psathyrella, Tricholoma, Amanita and Lycoperdon. These findings highlight the importance of particular keystone taxa in the structuring of fungal communities and their effect on the overall grassland fungal community.