The diversity of ectomycorrhizal (EcM) communities in 16 stands of Salix repens L. growing under a variety of environmental conditions was studied by repeated sampling of EcM sporocarps and ectomycorrhizas, to assess the possible correspondence between above- and below-ground views of fungal taxa. Above- and below-ground views were also related to soil chemistry. Sporocarps of 78 taxa of EcM fungi belonging to 12 genera were found. The majority of the species found, especially those of the Cortinariaceae, were host-specific for Salicaceae. Canonical correspondence analysis (CCA) based on fungal species showed that only pH and the concentration of available phosphorus significantly contributed to the variation explained. CCA based on fungal genera indicated that pH and moisture significantly contributed to the variation explained. Fifteen different EcM morphotypes were recognized and morphotype composition was different on two sampling dates. CCA based on morphotype composition yielded different results depending on sampling date. The numbers of EcM sporocarps and root tips were not correlated (on either sampling date). Diversity above ground (species and genus) was also not correlated with morphotype diversity below ground on either sampling date. Therefore, neither diversity nor abundance of above-ground EcM fungi can be used to assess below-ground EcM diversity or abundance. Lack of correlation in below-ground parameters on different sampling dates indicates substantial variation. Causes for temporal variation are discussed. The importance of investigating both above- and below-ground variability in EcM communities is stressed.
