Bamboo invasion of broadleaf forests altered soil fungal community closely linked to changes in soil organic C chemical composition and mineral N production

Soil fungi play an important role in decomposing soil organic matter and facilitating nutrient uptake by plants, however, the relationship between fungal community and soil biogeochemical cycling during plant invasion is poorly understood. The objective of this study was to investigate the effects of Moso bamboo (Phyllostachys edulis) invasion into broadleaf forests on the soil organic C (SOC) chemical composition, fungal community and mineral N production. We collected soil samples in evergreen broadleaf forests, mixed bamboo-broadleaf forests and bamboo forests. Soil fungal community and SOC chemical composition were determined. Bamboo invasion decreased alkyl C but increased O-alkyl C contents. Soil fungal abundance (18S rRNA) was decreased, while their alpha diversity was increased by bamboo invasion. Additionally, bamboo invasion enhanced net N mineralization rate but reduced gross nitrification rate. The fungal community composition strongly correlated with alkyl C content, and alkyl C content explained 32% of the variation in the fungal abundance. Fungal community composition correlated with gross nitrification rate, with 43% of the variation in gross nitrification rate attributable to soil fungal abundance. Changes in soil fungal community caused by bamboo invasion into broadleaf forests were closely linked to changed soil organic C chemical composition and decelerated nitrate production.