ECTOMYCORRHIZAE OF DOUGLAS-FIR AND WESTERN HEMLOCK SEEDLINGS OUTPLANTED ON EASTERN VANCOUVER ISLAND

Ectomycorrhizal colonization of container-grown Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings was determined in a container nursery near Nanaimo, British Columbia, and after one growing season under a range of field conditions on eastern Vancouver Island. The percentage of Douglas-fir and western hemlock short roots colonized by ectomycorrhizal fungi in the nursery was highly variable, but over 99% of the ectomycorrhizae were formed by Thelephora terrestris Ehrh.:Fr. Between 72 and 93% of the new roots were ectomycorrhizal after one field season, and Thelephora terrestris remained the dominant fungus in most cases. Rhizopogon vinicolor like ectomycorrhizae were also common on new roots of Douglas-fir. Cenococcum geophilum Fr. was less common. Douglas-fir seedlings formed 33 morphologically distinct ectomycorrhizae on eight sites within one growing season in the field. Western hemlock formed nine types on a single site.