Comparison of ectomycorrhizal–basidiomycete communities in red spruce versus northern hardwood forests of West Virginia

Abstract

Sporocarps of Basidiomycetes belonging to families containing some species known to form ectomycorrhizae were enumerated in 12 plots (16 .times. 16 m) subdivided into contiguous 2 .times. 2 m quadrats during the growing seasons of 1981-1983. Plots were distributed equally between homogeneous second-growth red spruce stands and heterogeneous northern hardwood stands in southeastern West Virginia. A few major species accounted for most of the abundance, while most species fruited rarely, but abundance and phenology varied broadly from year to year, apparently in response to rainfall and temperature. Fungal species composition, spatial frequency, and sporocarp density in the two forest types differed as would be expected in light of the symbiotic nature of the fungi and trees considered. Of 54 fungal species encountered over 3 years, 19 occurred exclusively in spruce plots, 27 occurred exclusively in hardwood plots, and 8 occurred in both forest types. In both forest types, approximately 40% of the species were Russulaceae. Species frequency and sporocarp abundance were greater in spruce plots than in hardwood plots. The Shannon-Wiener index, the dominance-diversity curve, the species-area curve, and ordination confirmed that fungal species richness, equitability, and diversity were greater in the mixed-hardwood plots, which hosted many rare fungal species, than in the single-species coniferous plots, which were determined by a few ubiquitous fungal species.