Short-term effects of retention forestry on the diversity of root-associated ectomycorrhizal fungi in Sakhalin fir plantations, Hokkaido, Japan

•Effects of tree retention on ectomycorrhizal fungal (EcMf) diversity were surveyed.•Conifer aggregated retention retained EcMf in the unharvested conifer plantations.•Broadleaved dispersed retention retained different EcMf from the conifer plantations.•Conifer seedlings shared ectomycorrhizal fungi with the retained broadleaved trees.•Tree retention mitigated the impacts of logging on EcMf diversity.