The alpine tundra vegetation of Signal Mountain, Jasper National Park

• Published in: Canadian Journal of Botany
• Main Authors: Hrapko, Julia O., Roi, George H. La
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1978
• Subjects: Plant Science; Cassiope tetragona; Dryas octopetala; Tundra
• Online Access: http://dx.doi.org/10.1139/b78-038; http://www.nrcresearchpress.com/doi/pdf/10.1139/b78-038

Signal Mountain forms the NW terminus of the Maligne Range in the Main Ranges E of the Continental Divide in the Canadian Rocky Mountains. The summer climate of the alpine zone on Signal is cooler and moister, with narrower temperature ranges, than that of Jasper townsite in the montane zone. Parent materials are Precambrian sandstones and conglomerates, with some siltstones and slates. Soils are Regosols, Brunisols, and Gleysols of pH 4.5 to 6.5. The alpine flora includes 157 vascular, 57 bryophyte, and 53 lichen species. Quantitative sampling of the major alpine community types (ct's) of Signal was followed by a 780-m transect study from the tree line on the dry, exposed SW slope to the tree line on the moist, protected NE slope. Dwarf shrubs predominate in most but not all ct's. Dryas octopetala is dominant in eight relatively xerophytic, lichen-rich, and chionophobous ct's where snow cover is shallow. Salix arctica, S. nivalis, Antennaria lanata. Carex nigricans, Cassiope tetragona, C. mertensiana, Phyllodoce glanduliflora, and Arctagrostis arundinacea are dominant or codominant in five relatively mesophytic and chionophilous ct's where snow cover is deeper and more persistent. The ct's and their habitats are described, compared on a community ordination, and their distribution and abundance are plotted on the alpine transect.