Chanterelle mushroom productivity responses to young stand thinning

David Pilz, Jim Mayo, and Randy Molina, Oregon State University, Corvallis, OR

Chanterelles are one of the most widely collected edible ectomycorrhizal mushrooms in the forests of the Pacific Northwest. They are frequently sold to local food stores, restaurants throughout the United States, and European markets. Chanterelles fruit abundantly in young, dense, Douglas-fir forests west of the crest of the Cascade Range. On Federal lands, many of these forests are being thinned for timber production or to speed the development of late-successional stand characteristics. This study examines how young stand thinning will influence chanterelle production over time. Chanterelle fruiting significantly declined following thinning. The decline was greater in heavily thinned stands (more trees removed) than in lightly thinned stands. Ectomycorrhizal host tree removal, soil disturbance, and drier forest floor conditions likely contributed to the production of fewer mushrooms. Logging slash hid others that did fruit. We hypothesize that as trees in the thinned forests resume vigorous growth and their canopies close, that fruiting will return to previous levels or possibly higher, but no significant recovery trend was noted for 4 years following thinning. Long-term monitoring of site recovery, small-scale mapping of chanterelle patches (including adjacent live and cut trees), genetic studies, and soil surveys will further contribute to our understanding of how chanterelles respond to young stand thinning.

Keywords: Chanterelles, productivity, thinning, ectomycorrhizae