The impact of spatial isolation and local habitat conditions on colonization of recent forest stands by ectomycorrhizal fungi

•Isolation of recent forests limits colonization by ectomycorrhizal (EcM) fungi.•Isolated recent forests are less diverse than connected recent and ancient forests.•EcM fungal community composition is driven both by isolation and edaphic variables.•Highly-dispersive species dominate EcM fungal communities of isolated forests.