Herbaceous wetland vegetation in the aspen grove and grassland regions of Saskatchewan

Wetland vegetation in the aspen grove and grassland regions of Saskatchewan was examined with respect to vegetation types and environmental control of species distribution. Species frequency and presence and a number of environmental gradients were measured in 246 stands. Association analysis of the vegetation data resulted in 27 vegetation groups, distinct on the basis of species present. Owing to overriding effects of disturbance, nine of these groups show close similarities to one or more of the others on the basis of dominant species. Water regime, salinity, and disturbance are the three major gradients influencing species distribution. Combinations of these three gradients comprise 23 environmental categories into which the vegetation groups fall. The occurrence of different vegetation groups in the same habitat type is due partly to environmental factors other than those considered in this study and partly to succession.