Cohabitation of species in an artificial grass-legume community on ski-slopes on Whistler Mountain, British Columbia, Canada.
Abstract
Species establishment after 3 years on artificially revegetated ski-slopes and the nature of species associations were investigated in relation to altitude, slope angle and soil properties. The overall establishment of seeded species from the grass-legume mixture had been satisfactory. Three of the seeded species, Festuca rubra, Phleum pratense and Trifolium hybridum had cover values greater than their relative abundance in the seed mixture, whereas the remaining seeded species, Agrostis alba [stolonifera], A. tenuis [capillaris], Poa compressa and Trifolium repens, were under-represented in the sward. Analysis of variance was used to detect significant variations in the relative abundance of the four most abundant species in relation to altitude and slope angle. In productive habitats F. rubra and T. hybridum attained large cover values and constrained the establishment of the slower growing species, A. tenuis and P. pratense. The latter species were more abundant in resource-poor sites where competition from the productive species was reduced. The vigorous, rhizomatous growth of F. rubra contributed to its dominance in the sward; its positive associations with P. pratense, detected by contact sampling and association analysis, were likely a result of differential rooting strategies. The tussock habit of both A. tenuis and P. pratense restricted their co-habitation in productive sites where competition from F. rubra and T. hybridum is suggested to be most intense.<new para>ADDITIONAL ABSTRACT:<new para>Spp. establishment after 3 years on artifically revegetated ski-slopes, and the nature of spp. associations, were investigated in relation to alt., slope angle and soil properties. 95% of the area had become revegetated by 1983, of which 90% cover over all alt.-slope angle combinations was occupied by sown spp. Cover by Festuca rubra, Phleum pratense and Trifolium hybridum exceeded their relative abundance in the seed mixture, whereas Agrostis alba, A. tenuis [A. capillaris], Poa compressa and Trifolium repens were under-represented in the sward. Unsown vascular plants comprised 5% of total cover and included Dactylis glomerata and Phalaris arundinacea. F. rubra and T. hybridum attained greater cover on gently-sloping medium-alt. sites, while the slower growing spp. A. capillaris and P. pratense established better on sites of increasing slope angle at higher alt. It is suggested that the rhizomatous growth of F. rubra contributed to its dominance in the sward, and that A. capillaris and P. pratense were restricted by the tussock growth habit on productive sites.