Uncovering the Role of Land Use Intensity in Shaping Forest and Grassland-Specific Soil Fungal Communities.

Soil fungal communities are shaped by land use intensity (LUI) and environmental conditions, but their combined effects remain unclear. Using data from 300 forest and grassland plots across Germany from 2021, we analysed fungal taxa relative abundance and associations with environmental variables. Soil conditions, soil fungal diversity, and community composition were linked to ecosystem variables and differed significantly across LUI levels. Forests showed greater variation in soil conditions across LUI levels; grasslands displayed the most pronounced differences in fungal diversity. In forest ecosystems, taxa belonging to the classes Leotiomycetes and Sordariomycetes (all Pezizomycotina) were indicators under both high and low LUI levels (R > 0.55, p < 0.005). High LUI in forests was characterised by a higher ratio between Basidiomycota and Ascomycota. In grasslands, high LUI levels were associated with more indicator taxa from Mortierellomycota and fewer from Glomeromycota compared to low LUI levels (R > 0.6, p < 0.005). This is the first comprehensive study addressing differences in soil fungal communities between grasslands and forests and across management intensities in Europe. Our findings suggest differential response of the two ecosystems to changes in LUI, with forests having more resilient traits in terms of soil fungal community richness and composition, while grassland fungi appear more sensitive to management practices.