摘要：The Churchill area has many examples of gravel-dominated, human-induced disturbances such as gravel pits and pads. These disturbances have occurred in a geographically small area with high biological diversity and detract from the aesthetics of this tourist destination. Eight treatments consisting of combinations of peat moss, seeding, fertilizer, snow fencing, and microrelief alteration were installed to improve the growth conditions on three gravel pits and two gravel pads ranging from predominantly tundra to predominantly boreal forest ecosystems. Plant-related assessments of the treatments (density, frequency, and cover) were made after the first and second growing seasons. Twenty-six species of plants were considered to be successful colonizers by at least one of the following criteria: >2% cover, >20% frequency, or >10 stems m −2 . Androsace septentrionalis L., Carex L. spp., and Dryas integrifolia Vahl were the only taxa to meet all three criteria in both years. Differences related to the sites (i.e., seed bank, seed source, and substrate conditions) were greater than treatment differences. At three of the sites, seeded treatments had significantly more seedlings than the non-seeded treatments. These three sites were species-poor prior to revegetation testing and were dominated by the seeded species. The other two sites were dominated by species from the seed bank or from seed rain. Total seedling density on seeded plots increased by 17% compared to the controls while cover did not increase appreciably in the short term. Six native species were tested and three ( Anemone multifida Poir., Hedysarum mackenzei Richards., and Linum lewisii Pursh) considered suitable for future use, adding to those tested by Firlotte (1998) in the Churchill region. It was determined that seed bank and potential for seed rain had a major influence on the success of seeding as opposed to substrate improvements alone.
