Early Succession Patterns with a Native Species Seed Mix on Amended and Unamended Coal Mine Spoil in the Rocky Mountains of Southeastern British Columbia, Canada

Abstract

A randomized block field experiment was established to compare the effects of “native” soil and mine spoil substrates on the early successional phases and diversity of a high-elevation native species introduction program. Two seeded and two nonseeded treatments were applied. Each replicate of the seeded treatments received a seed mix composed of 42 native species. A total of 54 vascular plants established: 11 grasses, 4 sedges, 38 forbs, and 1 shrub. Year-to-year turnover rates of species ranged from 0 to 88%. In the fifth year, the mean maximum total cover for each treatment was SNS–8%, SS–65%, NSNS–25%, and NSS–82%. “Native” soil treatments yielded the fastest rate of vegetation establishment and the highest maximum cover. Early seral grasses dominated the vegetation cover although, with time, their percentage declined relative to the forbs. Three general successional process models were observed. Random colonization and facilitation were evident in the nonseeded treatments while facilitation and tolerance were most evident in the seeded treatments. Convergence in diversity measurements R, H‘, and J’ was observed.