Is close-to-nature forest management preserving ectomycorrhizal diversity in beech forests?

Ectomycorrhizal (ECM) fungi play a central role in nutrient cycling and tree functioning, yet their responses to forest management remain insufficiently resolved, particularly under close-to-nature silvicultural systems. We assessed ECM fungal diversity and community composition across European beech forests representing two close-to-nature management approaches (single tree selection and irregular shelterwood), unmanaged forest reserves, and medium-intensity management (uniform shelterwood) in three European countries. To capture complementary aspects of ECM communities, we combined DNA metabarcoding of soil (for the DNA metabarcoding-based ECM community) with morphotyping and molecular identification of colonised root tips (for the morphotype-based ECM community). Observed richness showed no significant differences among silvicultural systems using either approach but was associated with environmental variation, particularly climatic gradients. Strong spatial structuring of ECM community composition was evident, with substantial variation among forest locations. Our results suggest that ECM fungal communities in beech forests might be primarily shaped by broad environmental gradients and spatial variation rather than by differences in forest management, highlighting the importance of site conditions and host persistence in structuring belowground symbiotic communities.