Species richness of ectomycorrhizal fungi in cutblocks of different sizes in the Interior Cedar-Hemlock forests of northwestern British Columbia: sporocarps and ectomycorrhizae

<jats:p> We investigated the species richness of ectomycorrhizal fungi based on epigeous sporocarps in an Interior Cedar-Hemlock forest in northwestern British Columbia in gap sizes of 49-4526 m<jats:sup>2</jats:sup>, 3-4 years following harvest. We also determined ectomycorrhizal diversity on Pinus contorta var. latifolia Engelm. and Tsuga heterophylla (Raf.) Sarg. seedlings 2 years after outplanting. Ectomycorrhizal fungal richness, based on epigeous sporocarps, decreased exponentially as gap size increased. There were sporocarps of 15 species along 475 m of transect in gaps larger than 900 m<jats:sup>2</jats:sup>, which was approximately 13% of the number of species present in neighboring forests (115 species along 300 m of transect). These data have implications for foresters who would be interested in managing forests for both timber and edible mushroom harvesting. Ectomycorrhizal richness on seedlings decreased slightly at increasing distances from the edge of the intact forest. The maximum richness was found at 7 m or less from the forest edge for both tree species. The decrease in richness with distance from the forest was associated with an increase in the proportion of Thelephora mycorrhizae in the samples. The number of types of ectomycorrhizae on root systems and the number of species producing epigeous sporocarps were not correlated. These results confirm the importance of sampling both sporocarps and root tips to achieve an accurate estimate of the ectomycorrhizal fungal community in forest ecosystems. </jats:p>