Vegetation patterns within southern Alberta coulees

摘要

Native grassland communities located in coulees near Lethbridge, Alberta, were studied to identify the associations present and the environmental factors influencing them. The vegetation along 16 transects was described using point quadrants, with additional study sites analyzed for soil and environmental variables. The data were analyzed using detrended correspondence analysis and indicator species analysis (TWINSPAN) and the results are discussed in relation to recognized plant associations. The primary environmental factor affecting the distribution of these associations is a xericndash;mesic gradient, which is discussed in terms of site topography and the physiological requirements ofAgropyron smithiiandBouteloua gracilis. A disjunctFestuca scabrellacommunity is recognized and implications of this are discussed.