Abstract:
Seedlings of Gaultheria shallon, Pseudotsuga menziesii, Rhododendron macrophyllum and Tsuga heterophylla were grown together in the greenhouse in soils from three young managed Douglas-fir forests in the Oregon Coast Range. The main objectives were 1 )to evaluate the ability of ericaceous plants and overstory conifers to share compatible mycorrhizal fungi in order to assess potential mycorrhizal linkages and 2)to determine the influence of edaphic factors on patterns of mycorrhizal colonization.
Ericoid mycorrhizal fungi were quantified in the Ericaceae to confirm their assumed presence in soils of the Pacific Northwestern region of the United States. Nine ectomycorrhizal types were recognized on the conifer hosts and two on the Ericaceae. All nine EM types occurred on both conifer species and the two EM types on the ericaceous hosts resembled types
associated with the conifer hosts. Ectomycorrhizal fungi occurred on all conifers and 26% of the Ericaceae in the study. Ericoid mycorrhizas developed on all Ericaceae. The influence of edaphic factors and host specificity on patterns of mycorrhizal colonization are discussed in relation to mycorrhizal associations and plant community dynamics.
