Grazing strategies of muskoxen (Ovibos moschatus) during winter in Angujaartorfiup Nunaa in western Greenland

Terrain and vegetation use by muskoxen (Ovibos moschatus) during winter was examined through surveys of fecal pellet groups in western Greenland in 1994. Being virtually free of snow, Kobresia myosuroides steppe and dry and moist shrub heath were used extensively by muskoxen. Use varied among the three heath vegetation types in relation to the proportion of shrubs to graminoids, with most use being made of K. myosuroides steppe. Density of fecal pellet groups varied from 300 groups/ha at a graminoid biomass of ca. 30 g/m2 to > 2500 groups/ha where biomass exceeded 100 g/m2. Within K. myosuroides steppe, density of fecal pellet groups was < 500 groups/ha on narrow ridges compared with > 2000 groups/ha on wider steppe formations. Adaptation by muskoxen to grazing steppe-like vegetation throughout the Late Pleistocene may explain the extraordinarily rapid growth of the population in this grass steppe landscape in western Greenland.

Vegetation patterns and environment of some alpine plant communities on Lakeview Mountain, southern British Columbia

Selected alpine plant communities of Lakeview Mountain in Cathedral Provincial Park of southern British Columbia were examined, as well as the corresponding abiotic factors of soils and microclimate. Multivariate analysis of percentage cover data revealed three major community types, dominated by Kobresia myosuroides (Vill.) Fiori, by Carex scirpoidea Michx., or by Carex scirpoidea and Carex capitata L. codominating. Abundant small-scale patterns in the form of significant associations between species were detected in all communities. Possible mechanisms generating these positive and negative associations are discussed and it is suggested that the species themselves, as well as abiotic factors, may be strong determinants of vegetation patterning. Species morphology, especially the root systems, may be the more important feature. The relative competitive abilities of these three major dominants may be a critical factor affecting the distribution of communities at the study site.