Peck,
J.E. 1997b. The association of commercially harvestable bryophytes and
their host species in northwestern Oregon. Bryologist, 100(3): 383-393.
The associations between commercially harvestable mosses and their host trees or shrubs were evaluated in 20 sites in the Cascade and Coast Ranges of northwestern Oregon. In the Cascade Range, harvestable mosses were found on 150 Acer circinatum, 15 A. macrophyllum, 21 Alnus rubra, and several Acer sinuata, Corylus cornuta, Holodiscus discolor, Oemleria cerasiformis, Rhamnus purshiana, Taxus brevifolia, and Vaccinium parvifolium. In the Coast Range, 162 Acer circinatum, 11 Alnus rubra, 21 Menziesia ferruginea, 13 R. purshiana, and 71 Vaccinium parvifolium had harvestable quantities of moss. Host surface area, epiphyte biomass, species richness, and species composition differed among hosts. In both the Cascade and Coast Ranges, trees and large shrubs had higher mean species richness per sample than small shrubs. Decreasing mean species richness parallels decreasing host surface area. Although species-composition differed between tree trunks and shrub stems, there were no significant differences in epiphyte mass or species richness when accounting for surface area. Seventeen epiphyte species demonstrate host preferences based on frequency of occurrence and abundance, particularly Orthotrichum lyellii for Acer circinatum and Neckera douglasii for Alnus rubra. Host preference was not always consistent between mountain ranges. Host specificity was virtually absent.