Soil fertility determines whether ectomycorrhizal fungi accelerate or decelerate decomposition in a temperate forest.

ABSTRACT: Ectomycorrhizal (ECM) fungi can both accelerate and decelerate decomposition of organic matter in forest soils, but a mechanistic understanding of this differential influence is limited. Here, we tested how ECM fungi affect decomposition along a natural fertility gradient in a temperate forest of European beech. Trees were girdled to reduce belowground carbon supply to the soil. Girdling shifted soil fungal community composition and decreased hyphal biomass production and soil CO₂ efflux, indicating a reduced ECM fungal activity. Girdling also affected decomposition processes, but the effects depended on fertility. Our results indicate that ECM fungi decelerate decomposition under conditions of low fertility while under conditions of high fertility ECM fungi and their host roots

SUBMITTER: Mayer M 

PROVIDER: S-EPMC7614611 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature