Spatiotemporal distribution of fruitbodies of ectomycorrhizal fungi in an Abies firma forest

 Spatial associations between ectomycorrhizal (ECM) fungi and their presumed host trees, and spatiotemporal associations among ECM fungi were surveyed for 3 years in an Abies firma-dominated forest in central Japan. A total of 39 species in 13 genera of ECM fungi were recorded, with more species in the Russulaceae than any other family. Russula ochroleuca, Russula sp.1 and Strobilomyces confusus tended to produce their fruitbodies on the forest floor directly under the crown of A. firma, whereas those of Inocybe cincinnata, Gomphus floccosus and G. fujisanensis were aggregated in limited areas outside the A. firma crown. Interspecific spatial associations were analysed for Russula sp.1, which was the most dominant species, and three other frequent species, I. cincinnata, S. confusus and R. ochroleuca. Pairwise, Russula sp.1 with I. cincinnata, with S. confusus or with R. ochroleuca showed an association which was exclusive, overlapping or independent, respectively. Fruiting phenologies differed in that S. confusus showed a peak density in the summer, whereas the other three species peaked in the autumn. These results suggest that the formation of ECM fruitbodies can be partitioned among the species both spatially and temporally. Accepted: 7 July 1998