Plant succession on an active tundra mud slump, Garry Island, Mackenzie River Delta, Northwest Territories

Abstract

The vegetation in the latter stages of an active mud slump of known age on Garry Island, Mackenzie River Delta, N.W.T., is described using principal-component analysis. Three associations are recognized. Senecio congestus and isolated hummocks with dwarf shrub – heath vegetation dominate during the first 4 years after exposure. The Arctagrostis latifolia – Senecio congestus association that dominates after 4 years represents the second stage of development after the disappearance of recognizable hummocks. The Arctagrostis latifolia – Eriophorum scheuchzeri association that dominates after 6 years is the third stage in the revegetation sequence and represents further stabilization of the mud slump surface. The frequency of hummock-associated species is greatly reduced. The rapid rate of natural revegetation, in such a mud slump where the headwall had been receding, would suggest that man-induced reseeding programs, in all probability, would not speed up the process.