THE ECOLOGY AND PHYTOGEOGRAPHY OF THE BRYOPHYTES OF CAPE-BRETON HIGHLANDS NATIONAL-PARK, CANADA

Cape Breton Highlands National Park possesses a bryophyte flora of 369 species, including 272 mosses and 97 hepatics. This is a large flora for such a limited area, comprising about 51% of the known bryophyte f lora of the Gulf of St. Lawrence region and 74% of the flora of Nova S cotia. The eleven habitats studied show a wide range of numbers of com ponent species. Low elevation stream gullies, forested cliffs, and dec iduous forests show the greatest diversity while lake margins, disturb ed habitats, and bogs all show low species diversity. The flora of the park is dominated by a strong boreal element (63%) with only a modera te representation of temperate species (22%). The park contains a smal l, but significant, proportion of arctic and montane elements (6%). Tw enty-nine rare or phytogeographically significant species occur in the park. They are restricted to 6 habitat types, being most frequent in forested cliffs and low elevation stream gullies. The high species div ersity and presence of numerous rare species in the park may be attrib uted to several factors, including diverse physiography and geology, a s well as glacial history.