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

Abstract

We examined the ectomycorrhiza communities on lodgepole pine (Pinus contorta var. latifolia Engelm), white spruce (Picea glauca (Moench) Voss), and subalpine fir (Abies lasiocarpa (Hook.) Nutt) seedlings planted together on mature-forest edges in northwestern British Columbia. We examined 32 seedlings of each tree species, grouped by pairs along the north and south edges of eight gaps. We found 74 morphotypes in total, with an average of 52 morphotypes per tree species. Morphotypes with emanating hyphae or strands made up 60% of the overall ectomycorrhiza community. Multihost fungi averaged almost 60% of total morphotypes in species comparisons, although some of the multihost fungi appeared to have tree host preferences. The average community similarity, based on morphotype abundance, was 52% between conifer species, and 37% for morphotypes with emanating hyphae or strands. Within planted 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 created a wide range in the probability of hyphal linkages between neighboring seedlings.Key words: ectomycorrhizae, community similarity, multiple host, host specificity, Pinus contorta, Picea glauca, Abies lasiocarpa