Late quaternary vegetation history of Wilcox Pass, Jasper National Park, Alberta

Abstract

Five pollen zones are recognized in a radiocarbon and tephra dated core from an alpine site at an elevation of ca. 2355 masl in Wilcox Pass, Jasper National Park, and record Late Quaternary vegetation history. The two lower zones underlie material dated at 9600 ± 305 yr B.P. (GX-8785) and record early postglacial vegetation. The basal zone, WP1, containing an Artemisia dominated assemblage, represents tundra vegetation after deglaciation. In Zone WP2, arboreal pollen, mainly diploxylon pine, becomes dominant, and represents a lodgepole pine forest. The pollen assemblage of Zone WP3, which initially contains large amounts of haploxylon pine as well as Picea and Abies pollen, shows a transition from a forest with large amounts of whitebarkpine to vegetation resembling present-day subalpine forest. During this phase, temperatures were probably warmer than present. Zone WP4, beginning after the influx of Mazama tephra (6800 yr B.P.) to the site, records an expansion of the subalpine forest to higher elevations with a warmer climate. In Zone WP5, beginning about 2800 yr B.P., values of the main arboreal components fluctuate, indicating cooler temperatures and less favourable environmental conditions, probably associated with Neoglacial ice advances. The environmental trends observed from this record accord with those from other vegetation records in the Canadian Rockies.