Abstract
A total of 54 spp. of mosses and 18 spp. of liverworts were present on the bases (0-1.8 m) of 120 trees belonging to 6 host species in a cove forest. Of the epiphytic species occurring at a frequency of 20% or more, only 3 were restricted to just 1 host species, but 21 spp. showed strong single-host preferences. Epiphytic communities named after their host species were ordered using frequency-based coefficients of similarity as follows (with the most dissimilar communities at the 2 poles): red oak-red maple-beech-yellow birch-black birch-hemlock. This arrangement also represented a gradient of decreasing species richness of epiphytic communities. The ordering of epiphytic communities was correlated with a gradient of decreasing bark pH and in part with the water absorption capacities of the barks.