THE REDEVELOPMENT OF PLANT COMMUNITY DIVERSTIY ON A SURFACE COAL MINE IN SOUTHWESTERN WYOMING (RECLAMATION, HABITAT, LANDSCAPE, SUCCESSION).

摘要

A study was initiated in 1981 to investigate the redevelopment of plant communities on a recontoured, surface-mined site in southwestern Wyoming. The landscape pattern of vegetation was compared with topographic position, the initial topsoil pattern, and cultural practices including shrub planting density, shrub planting pattern and topsoil treatments for the years 1982-1985. In addition, differences in vascular plant species diversity within these various factors and treatments were determined, along with the trend in intracommunity (alpha), intercommunity (beta) and landscape (gamma) diversity for the entire study area.;The influence of site factors and tested cultural practices on the differentiation of the landscape vegetation pattern generally declined over time. There were no persistent differences in diversity among any cultural treatments or topographic positions, with the exception of planting pattern. The vegetation classified by cultural treatment, topographic position, or the initial plant communities identified in 1982 showed strong successional convergence by 1985. This is reflected in a decline in beta and gamma diversity over the period 1984-1985. Alpha diversity remained stable over this same period, though species richness increased, indicating that a subset of species is becoming more dominant. The landscape vegetation pattern apparently converged to a rather uniform composition, increasingly dominated by perennial grasses, forbs and shrubs.