A comparison of ectomycorrhiza communities from three conifer species planted on forest gap edges

We examined the ectomycorrhiza communities on lodgepole pine (Pinus contort a var. latifolia Engelm), white spruce (Picea glauca (Moench) Voss), and su balpine fir (Abies lasiocarpa (Hook.) Nutt) seedlings planted together on m ature-forest edges in northwestern British Columbia. We examined 32 seedlin gs of each tree species, grouped by pairs along the north and south edges o f eight gaps. We found 74 morphotypes in total, with an average of 52 morph otypes per tree species. Morphotypes with emanating hyphae or strands made up 60% of the overall ectomycorrhiza community. Multihost fungi averaged al most 60% of total morphotypes in species comparisons, although some of the multihost fungi appeared to have tree host preferences. The average communi ty similarity, based on morphotype abundance, was 52% between conifer speci es, and 37% for morphotypes with emanating hyphae or strands. Within plante d groups, between seedlings 1-2 m apart, community similarity ranged from 2 to 40% for morphotypes with emanating hyphae or strands. In mature, mixed forests, the infrequent occurrence of many multihost ectomycorrhizae create d a wide range in the probability of hyphal linkages between neighboring se edlings.