Abstract for CM332

Great Plains Rough Fescue Prairie
Prairies de fétuque de Hall des Grandes Plaines

CM332 describes prairie grasslands at the northern edge of the North American Great Plains that, in later seral stages, are dominated by a single species, plains rough fescue (Festuca hallii). Rough fescue prairie is primarily found in Alberta and Saskatchewan, less commonly in Manitoba, with a few occurrences in North Dakota and Montana. CM332 occurs as extensive grasslands south of the limit of tree growth in the west-central prairies and also forms the grassland patches that occur between forest/woodland groves in this part of the Great Plains Parkland vegetation zone. Natural stands are dense, mid-height (approximately 20-40 cm) and strongly dominated by plains rough fescue. Other common graminoids include northern porcupine grass (Hesperostipa curtiseta), needle-and-thread grass (H. comata), thick-spike wildrye (Elymus lanceolatus), slender wildrye (E. trachycaulus ssp. subsecundus), western wheatgrass (Pascopyrum smithii), Hooker’s oatgrass (Avenula hookeri), prairie junegrass (Koeleria macrantha), mat muhly (Muhlenbergia richardsonis) and upland sedges such as blunt sedge (Carex obtusata), needle-leaved sedge (C. duriuscula) and long-stolon sedge (C. inops ssp. heliophila). A variety of forbs and shrubs occur but may be restricted in abundance by the dense grass. Species composition and abundance shift with disturbances such as livestock grazing, fire or invasion by non-native species.

CM332 occurs in a continental temperate climate with cold winters and warm summers. Mean annual temperatures average approximately 2.5˚C, and precipitation varies from approximately 350 to 540 mm. This climate is cooler and moister than that supporting the mixedgrass prairie to the south (CM051 [Great Plains Mixedgrass Prairie]). CM332 usually occurs on level to rolling terrain at elevations <1000 m ASL. Stands are found in a variety of upland or valley settings. Most stands are on Black or Dark Brown Chernozemic soils with loamy to clayey textures but may also develop on sandy sites and on Solonetzic soils with an impervious hardpan layer.