Elevations change fungal communities of the bulk soil, rhizosphere and root of <i>Rhododendron delavayi</i> Franch (Ericaceae) by affecting soil properties in a karst area, southwest China

Rhododendron delavayi is a natural shrub with importance in preventing rocky desertification in the karst regions of Bijie city of China. The structure of fungal communities in bulk soil, rhizosphere and roots of R. delavayi at three elevations was analyzed by ITS2 amplicon sequencing. The results showed that the soil pH was highest at 1448 m, while the content of available phosphorus, total nitrogen and total phosphorus was lowest at 1821 m. The Shannon of fungal communities in bulk soil was higher than roots at 1448 m. Ascomycota and Basidiomycota were the most dominant phyla present in bulk soil, rhizosphere and root endophyte. The pH was positively related to Chytridiomycota and Glomeromycota in bulk soil at 1643 m. Ammonium-nitrogen significantly influenced the fungal communities in bulk soil, while the elevations impacted the diversity of fungal communities by affecting available phosphorus content in bulk soil and roots. In summary, elevation significantly affected the diversity and structure of fungal communities by affecting soil pH and nutrient levels, and the fungal communities helped R. delavayi in adaptating to different elevations.