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Prairie
Native prairie is dominated by a mixture of native
perennial grasses and wildflowers with some low growing shrubs. Prairie
grasslands are some of the richest plant communities in Manitoba. From early
spring when the first crocuses emerge to catch the warmth of the sun, to the
fall when the prairie grasses wave their golden stalks in the cooling breeze,
the prairie is constantly changing. Manitoba has two main types of prairie:
tall-grass and mixed-grass prairie. Before the arrival of European settlers, the
Red River Valley in south-central Manitoba was a sea of tall-grass prairie, a
complex ecosystem with an astonishing variety of grasses, flowers and wildlife.
Its name comes from its tall grasses that reached over two metres in height. In
this area, the loamy or clay-based soils and more than 50 mm (20") of
precipitation a year provided the ideal growing conditions for tall-grass
prairie. It was the most productive type of prairie in North America. Today
tall-grass prairie is one of the most endangered ecosystems in Canada. Less than
1% of Manitoba's tall-grass prairie remains.
Mixed-grass prairie lies to the west of the tall-grass
prairie, where there is less precipitation (25-30 mm or 10-20" annually)
and the soils are sandy or well-drained. The grasses here are mostly knee-high.
Mixed-grass prairie extends from the Interlake and southwestern Manitoba across
Saskatchewan to Alberta. While there is more mixed-grass prairie left in
Manitoba, much of it is being degraded through overgrazing and the introduction
of weeds. Weedy plants do not ordinarily occur in undisturbed prairie areas.
Only when the prairie sod has been disturbed will weed species become
established. The number and kind of weeds will depend on the degree and nature
of the disturbance.
Tall and mixed-grass prairie have many plant species in
common. In some places, the tall and mixed-grass prairies seem to blend together
and it is hard to tell which prairie type dominates. Most of Manitoba's
endangered plants and wildlife are found in native prairie habitats.
Prairie plants have special adaptations to overcome
extremes in temperature and moisture. Hairy or rolled leaves reduce moisture
loss; deep spreading root systems take advantage of available moisture and can
store great quantities of food. These types of adaptations are especially
important in surviving the periods of drought that are characteristic of the
prairies. Prairie animals are also specially suited for a grassland environment.
The short-eared owl, meadowlark, and savannah sparrow are examples of prairie
birds that nest right in the grass. Others, like the goldfinch and clay-coloured
sparrow, are more at home in small shrubs. Prairie birds tend to sing their
loud, clear songs from the air, rather than from perches, as forest birds do.
Because there are few trees, some prairie creatures make
their homes in dens or underground burrows. Bumble bees, foxes, badgers,
burrowing owls and some reptiles and amphibians spend part of their time
underneath the prairie. Voles, mice and shrews make grass nests in the ground.
Tawny colouration, plant-eating and burrowing habits, and an ability to survive
drought are characteristics which help prairie animals to thrive in a flat,
treeless environment.
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