Lichen Zonation on Coastal Rocks in Gwaii Haanas National Park Reserve, Haida Gwaii (Queen Charlotte Islands), British Columbia

Abstract

The occurrence of 43 marine lichen species on intertidal rocky shores of southern Haida Gwaii (Queen Charlotte Islands), British Columbia is described and related particularly to elevation on the shore (duration of seawater immersion) and exposure to waves. In the area of Gwaii Haanas National Park Reserve and Haida Heritage Site on Moresby Island, rockdwelling marine lichens are distributed in zones much as they are elsewhere in the world, although some species found abundantly only in Haida Gwaii give the local shores a unique appearance. In common with other areas, there is a conspicuous black band of Verrucaria species (in this case, nine species plus other black lichens) at the upper edge of the intertidal zone. A conspicuous white band of Coccotrema maritimum above the black band is a unique feature of this flora. The unusually large percentage of endemic, near-endemic or disjunct lichen species and their phytogeography suggest that at least the headland rocks along the west coast were refugia during the last glacial maximum. Verrucaria striatula and V. sandstedei are reported for the first time from British Columbia. Erratum for figure included.