Removal of litter and humus layers and herb vegetation dominated by the grass Deschampsia flexuosa ("sod-cutting") in Scots pine (Pinus sylvestris) stands enhanced numbers of species and sporocarps of ectomycorrhizal fungi, particularly in middle-aged and old stands. Three and a half years after sod-cutting soil conditions and the ectomycorrhizal flora in a middle-aged secondary stand on non-podzolic sandy soil came to closely resemble the nutrient-poor soil conditions and rich ectomycorrhizal flora in a spontaneously established Scots pine stand in a drift sand area. Sporocarps of ectomycorrhizal species, among which Cantharellus cibarius, CoItricia perennis, Rhizopogon luteolus, Suillus bovinus and Tricholoma albobrunneum were observed in the sod-cut plots, and not in the control plots. Sod-cutting on a podzolic soil was less effective due to higher nutrient concentrations and lower pH in the mineral soil compared to non-podzolic soil. After sod- cutting on podsolic and non-podsolic sandy soil, the tree roots recovered in the mineral soil up to a depth of 60 cm. The ectomycorrhizal colonization potential also increased after the treatment.Addition of litter and humus layers to existing ectorganic layers ("sod-adding") in young and middle-aged stands did not affect numbers of species and sporocarps of ectomycorrhizal fungi and ectomycorrhizal development in the mineral soil up to a soil depth of 60 cm, but reduced ectomycorrhizal colonization potential.Ectomycorrhizal succession during stand development is mainly driven by soil processes, whereas tree ageing plays a less important role.Laboratory experiments were carried out to provide a lower-level explanation for the results of the field experiments. Development of Laccaria bicolor, R. luteolus and S . bovinus on Scots pine seedlings on forest soils in growth chambers was largely in accordance with field observations. Extracts of Scots pine needles and shoots and roots of the grass D. flexuosa containing considerable amounts of nitrogen and phenolic compounds ...