Vegetation and Soil Development on a Recently Glaciated Area Near Mount Robson, British Columbia

Rapid retreat of the Robson Glacier since 1783 has produced a series of moraines well suited for study of vegetation and soil development. The terminal and five recessional moraines ranging in age from 180 to 50 years were suited in August 1963 in continuation of earlier work by W. S. Cooper. Vegetation development shows early dominance of Hedysarum and Dryas, followed by Salix, Arctostaphylos rubra, and other shrubs. Tress enter the stand early, but are largely confined to one species, Picea engelmanni. The vegetation of the two oldest moraines bears a superficial resemblance to the mature forest of the region, but differs greatly in floristic composition and structure. Soil Formation ranges from virtually none on the youngest moriane to a rudimentary podsolic B horizon on the oldest recessional moriane Accumulation of soil nitrogen appears to be slow, despite the existence of root nodules on Dryas octopetala, D. drummondii, and Hedysarum mackenzii.