The effect of refuge trees on a paper birch ectomycorrhiza community

Live trees within forest disturbances could support refugia populations of ectomycorrhizae fungi from which to reestablish ectomycorrhiza communities during forest succession. The effectiveness of refuge paper birch trees (Be tula papyrifera Marsh.) in maintaining a forest ectomycorrhiza community on birch seedlings, both in clearcuts and forests, in northwest British Colum bia was examined. Seedlings next to refuge birch trees in clearcuts had equ al levels of average morphotype richness and eveness as seedlings next to m ature birch trees in forests. Seedlings outside of the rooting zone of refu ge trees had significantly less average morphotype richness in both clearcu ts and forests, decreasing by 38 and 15%, respectively. The ectomycorrhiza communities were also more unique (lower community similarity) next to refu ge trees than for seedlings away from refuge trees, especially in clearcuts . These treatment effects could be explained by differences in the ability to disperse and establish between early-stage, multi-stage, and late-stage ectomycorrhiza fungi. The results suggest refuge trees would be effective i n forest management as sources of inocula for multi-stage and late-stage fu ngi.