Forest stand age and the occurrence of chanterelle (Cantharellus) species in Oregon's central Cascade Mountains.

ABSTRACT

We describe watershed-scale habitat associations of three Cantharellus species with respect to stand age. During the 1998 autumn fruiting season we collected chanterelle sporocarps from 18 forest stands in and adjacent to the H.J. Andrews experimental forest in the central Cascade Mountains of Oregon. Sampled stands represented two age categories old growth ( approximately 350+ y) and 40-60-y-old second growth naturally regenerated from clear-cut harvest. Old growth and second growth stands were spatially paired to reduce the chance of spurious habitat relationships caused by unmeasured correlated variables. We found stand age to be a good predictor of the distribution of C. subalbidus and C. formosus, but only marginally useful for predicting the occurrence of C. cascadensis. The odds that a randomly located chanterelle sporocarp will be C. subalbidus, compared to other chanterelles, are 3-23.5 times higher in old growth than in second growth. Alternatively, there is only a 4-38% chance that a randomly located sporocarp will be C. formosus in old growth. C. cascadensis was found to be uncommon throughout the study area and showed no significant habitat associations. The abundance of C. cascadensis increased substantially with decreasing elevation indicating that landscape features other than stand age may be more useful in predicting its occurrence.