Abstract for M054

Central Lowlands Tallgrass Prairie
Prairies à graminées hautes des basses terres centrales

M054 describes tallgrass prairie in central North America, in Canada found primarily in the Red River valley and adjacent parkland areas of southern Manitoba. Tallgrass prairie occurs as extensive grasslands south and west of the limit of tree growth in the eastern Great Plains and also forms the grassland patches that occur between forest/woodland groves in this part of the Great Plains Parkland vegetation zone. M054 is dominated by tall (up to 2 m) perennial grasses, such as big bluestem (Andropogon gerardii), prairie dropseed (Sporobolus heterolepis), yellow Indiangrass (Sorghastrum nutans) and old switch panicgrass (Panicum virgatum). Other important grasses include plains porcupine grass (Hesperostipa spartea), mat muhly (Muhlenbergia richardsonis), little bluestem (Schizachyrium scoparium), prairie junegrass (Koeleria macrantha) and slender wildrye (Elymus trachycaulus). Prairie cordgrass (Spartina pectinata), bluejoint reedgrass (Calamagrostis canadensis), slim-stemmed reedgrass (C. stricta) and sedges (Carex spp.) often occur on moist sites. Forbs can be abundant and often have high local diversity. Common forbs in the Canadian range include downy false indigo (Amorpha canescens), prairie pasqueflower (Anemone patens), purple prairie-clover (Dalea purpurea), narrow-leaved purple coneflower (Echinacea angustifolia), sunflowers (Helianthus spp.), eastern yellow stargrass (Hypoxis hirsuta), blazing stars (Liatris spp.), black-eyed Susan (Rudbeckia hirta), blue-eyed-grasses (Sisyrinchium spp.), goldenrods (Solidago spp.), asters (Symphyotrichum spp.) and golden alexanders (Zizia aurea).

In Canada, M054 occurs primarily in a subhumid continental temperate climate with cold winters and warm summers. Mean annual temperatures average approximately 2.8˚C, and precipitation averages approximately 525 mm. Soils associated with stands of M054 are primarily developed in deep fine-textured sediments within the basin of glacial Lake Agassiz in southern Manitoba. However, tallgrass prairie also occurs on dry, shallow rocky sites and coarse-textured sands and gravels in southwestern Ontario and near Lake of the Woods in northwestern Ontario. Tallgrass prairie, in its broad definition, ranges southward to Texas and eastward to Michigan and Ohio. Historically, grazing, fire and periodic drought influenced species composition and distribution of native tallgrass prairie, but most has been converted to annual cropland so very few unaltered examples persist on the landscape.