The vegetation of the Canadian Prairie Provinces II. The grasslands, Part 1
The grasslands of the Prairie Provinces can be conveniently divided into three categories: the dry grasslands, the mesic grasslands, and the meadows. Dry grasslands occur on sands and on the Brown Soils, the mesic grasslands on Dark Brown and Black Soils, and meadows on gleyed soils. Distribution patterns of species and plant communities in relation to climate and substrate are discussed. The influence of grazing at different levels of intensity on various grassland types is shown to result in recognizable facies. A classification of the dry grasslands is presented. Grasslands on sand soils are classified as Calamovilfetea longifoliae, of which the Order Calamovilfetalia longifoliae occurs in the Prairie Provinces. The various associations in this Order are discussed and lifeform spectra are given. The grasslands on heavier soils are classified as the Class Astragaleto-Stipetea comatae, a North American Class in the Class-group Festuco-Stipea. Two Orders are recognized: Eriogonetalia flavi occurs on highly calcareous, usually eroded or stony soils, Stipo-Boutelouetalia on Brown Soils. The various associations in the Orders are discussed and their lifeform spectra tabulated. The grassland biocoenose is discussed in some detail, and it is pointed out that the carrying capacity of the dry grasslands is low, and is reflected in small animal populations.