The ectomycorrhizal fungal communities react differently to climatic, edaphic and spatial variables depending on their host species

<jats:title>Abstract</jats:title><jats:sec><jats:title>Aim</jats:title><jats:p>Ectomycorrhizal (ECM) fungal community structures can vary across sites at a regional scale (>1,000 km), affected by abiotic and biotic environments, dispersal abilities of the fungi, or ecological drift, even among forests of the same host tree species. The spatial patterns of such variation may differ among associated host species and their growth environments, but our knowledge about this remains limited. In the present study, we aimed to investigate whether the ECM fungal community structures (i.e. species richness and species composition) at the regional scale and their driving factors vary across hosts.</jats:p></jats:sec><jats:sec><jats:title>Location</jats:title><jats:p>Japan.</jats:p></jats:sec><jats:sec><jats:title>Taxon</jats:title><jats:p>ECM fungi associated with <jats:italic>Fagus crenata</jats:italic> and <jats:italic>Castanopsis sieboldii</jats:italic>.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Using DNA metabarcoding of fine roots, the ECM fungal communities of 15 <jats:italic>Fagus crenata</jats:italic> forests across their distribution range were characterised. The resultant community structure of ECM fungi, as well as the relative effects of edaphic, climatic and spatial factors on community composition were compared with those of 12 <jats:italic>Castanopsis sieboldii</jats:italic> forests investigated in a previous study.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>ECM fungal community composition differed between the two Fagaceae hosts. The spatial pattern of ECM fungal community composition also differed between hosts. Specifically, the spatial variation in community composition across sites was smaller in <jats:italic>F</jats:italic>. <jats:italic>crenata</jats:italic> forests than in <jats:italic>C</jats:italic>. <jats:italic>sieboldii</jats:italic> forests. The spatial pattern of ECM fungal communities of <jats:italic>F</jats:italic>. <jats:italic>crenata</jats:italic> forests was explained by climatic and edaphic factors, while that of <jats:italic>C</jats:italic>. <jats:italic>sieboldii</jats:italic> forests was explained by spatial and edaphic factors.</jats:p></jats:sec><jats:sec><jats:title>Main conclusions</jats:title><jats:p>On a regional scale in Japan, the spatial pattern of ECM fungal communities and its driving factors varied between two Fagaceae host species. Our results provide an example that the difference in associated host leads to the difference in environmental response among ECM fungal communities.</jats:p></jats:sec>