ID a Grassland

What are tallgrass communities?

“Tallgrass communities” – also know as tallgrass prairies, savannas and meadows- are natural grasslands with a great diversity of grasses, wildflowers and animal life. In Ontario, tallgrass is teeming with wildlife, including:

  • over 200 species of plants, such as dense blazing-star and wild bergamot;
  • many birds, such as bobolinks, savanna sparrows and northern bobwhite quail;
  • mammals, such as deer, meadow voles, and badgers; and
  • a fascinating diversity of insects, from butterflies and damselflies to ants, leafhoppers and ladybeetles.

Prairie is a natural community that is dominated by grasses rather than by trees, as in a forest. Growing with the grasses are many other kinds of non-grassy herbaceous plants known by the collective name of “forbs”. On moist soils, prairie blends into marshlands dominated by sedges rather than grasses. Scattered shrubs may be present, however trees are absent.

The term “savanna” is applied to places where prairie-type vegetation grows within widely spaced trees.

Where are they? Where have they gone? The term “prairie” is usually associated with the central part of North America and many people are surprised to learn that prairie areas exist in southern Ontario. In Southern Ontario, tallgrass once covered approximately 1000 km2 – less than 3% remains! These sites are scattered sporadically across the landscape from Windsor to the eastern part of the province. However, it is in the southwest, the Carolinian life zone, that the largest areas of prairie remain. In fact, historical accounts and present day physical evidence tell us that prairie was once widespread in the extreme southwest of Ontario, primarily in Essex and Kent counties. Smaller prairie sites also are found in areas of Lambton and Brant counties, Haldimand-Norfolk, and near Toronto. The largest and best known remnants are at Windsor and Walpole Island.

Most tallgrass communities have been lost over the past 200 years due to human use of the land for agriculture and urbanization. The rich fertility of prairie soil, coupled with the fact that few trees are present, made these areas ideal for agricultural development. These areas support some of the most productive corn and soya bean operations in Ontario, much the same as wheat has replaced much of the native vegetation of the vast mid-continent prairie. Of the estimated one million square kilometres of tall grass prairie that once occurred in North America, less than one percent remains. Hence, conservation of remaining natural prairie and its rare species is vital.

Since prairie areas are so rare in Ontario, the flora and fauna associated with them are also uncommon in the province. Approximately 20% of plants designated as rare in Ontario are associated with prairie. Examples include Culver’s Root, Tall Ironweed and Prairie Rose. At Walpole Island, there are seven species of plants growing which are not known elsewhere in Canada. The Greater Prairie Chicken was present in the Windsor area until the late 19th century.

Why are they important?


  • is a globally imperilled ecosystem and one of the most endangered ecosystems in Canada;
  • provides habitat for a huge number of wildlife species, including more than 150 species that are officially designated as rare at the global, national or provincial level; and
  • is home to species such as northern bobwhite which is in danger of disappearing from Canada. Some tallgrass species, like the greater prairie chicken and the karner blue butterfly, have already disappeared from Canada.