The effects of grazing on grassland in central Saskatchewan

The grasslands of the present study area lie in the ecotone between Fescue grasslands to the north and the Canadian mixed prairie to the south. Most of the sites sampled lie within 12 miles of Saskatoon. The grasslands in the south of Saskatchewan have been investigated by Clarke (1930), Clarke and Tisdale (1936, 1945), Clarke et al. (l942, 1943),and Coupland (1950), and they have been shown by the identity of the dominant species to be a northward extension of the mixed prairie (Stipa-Bouteloua Association) as classified by Weaver and Clements (l938) and by Clements and Shelford (1939). A study undertaken immediately to the north of Saskatoon has shown the grasslands of that area to be dominated by Festuca scabrella (Coupland and Brayshaw 1953). F. scabrella does not occur as a dominant in mixed prairie, and for that reason these northern grasslands may not be considered a part of the mixed prairie and are here considered as another Association. The purpose of the present research was to ascertain the ecology of the species and communities of the grasslands within the tension zone between the two grassland Associations. Both relict and grazing disclimax sites were studied. It was consid­ered that a study of these grasslands would yield information on the relationships between the two Associations. The field work was conducted during the summer of 1952, and greenhouse work and laboratory analysis of samples collected during the summer was completed during the following winter. A complete list of the plant species referred to is included (Appendix 1). The nomenclature followed in this paper is that of Hitchcock and Chase (1950) for the grasses, and of Fernald (1950) for other species. Exceptions to this practice are stated.