Kathie and I attended the 2012 North American
Prairie Conference, which was held at the University of Manitoba, in Winnipeg,
Canada in early August. I have submitted a report on this conference to the Prairie Promoter (the newsletter of The Prairie Enthusiasts).
The present blog will deal only with our field trip to the Tall
Grass Prairie Preserve in southeastern Manitoba.
The Tall Grass Prairie Preserve consists of about 12,000
acres in the southeast corner of Manitoba, just north of the Minnesota line.
Although Nature Conservancy of Canada (NCC) has taken the lead in management of
the Tall Grass Prairie, the Preserve originated in 1989 through the cooperative
efforts of Canada’s Critical Wildlife Habitat Program partners: NCC, Manitoba Naturalist
Society, Canadian Wildlife Service, Manitoba Habitat Heritage Corporation,
Manitoba Conservation, World Wildlife Fund, and Wildlife Habitat Canada.
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A
lone bur oak stands in the middle of a field of Andropogon gerardii.
This far north and west, this is the only species of oak that is
present. |
The prairie area here, one of the flattest on the continent,
was formed by Glacial Lake Agassiz, which arose from one of the last great
glacial movements of the Pleistocene. Flowing through this area is the sluggish
Red River of the North. In this area, minimal drainage developed; rivers and
streams meander extensively, few lakes occur, and flooding is common. Although
most of the flatland has been plowed for agriculture, there are numerous beach ridges and sand
deposits that stand a few feet or inches above the surrounding land. Prairie grasses such as big bluestem
thrive.
Presettlement there were large
areas of such tall grass prairie, and it is here that the remnants have
been preserved and protected. The habitat alternates between wet and dry,
making for a complex vegetation. Strange to see two species of Pedicularis almost side by side, the dry
mesic species P. Canadensis on top of
a slight sand ridge, and the wet mesic P. lanceolata a
few inches away in a swale.
The plant species checklist we were given for this area had
over 200 species, and this was just the common prairie plants. Noteworthy among
this list is the endangered Western Prairie Fringed Orchid (
Plantanthera praeclara). The Tall Grass
Preserve is the only Canadian location for this attractive plant. Another
endangered species is the small white lady slipper orchid (
Cypripedium candidum), found in wet meadows in the southern block
of the Preserve. Other species considered rare or of special interest include
Great Plains Ladies Tresses (
Spiranthes
magnicamporum), Culver's Root (
Veronicastrum
virginicum; listed as endangered in Manitoba)
Riddell's Goldenrod (
Solidago Riddellii), Two-flowered Cynthia (
Krigia biflora), Whorled Loosestrife (
Lysimachia quadriflora), Whorled Milkwort (
Polygala verticillata), and Wild Geranium (
Geranium maculatum). Also noteworthy is the rare
Poweshiek skipper butterfly, which in
Canada is found only within this Preserve.
After an hour bus ride we stepped into the middle of the
tall grass prairie. Because of the terrain, this area was less suited for
agriculture than other locations, and the first settlers avoided it. The
Ukraines, an ethnic group that arrived late to Manitoba, were stuck with this land and settled around the
area of Tolstoi and Gardenton. The ethnic heritage is still maintained,
and there is a fine Ukraine Museum right at the edge of the prairie.
Although tall grass prairie is the vegetation of choice,
this area also has extensive groves of aspen. Apparently this far north aspen
is less invasive than in our area, and it is only lightly controlled. In fact,
a common vegetation type in the three prairie provinces (Manitoba,
Saskatchewan, and Alberta) is called Aspen
Parkland. However, we were shown a small aspen grove that had been killed
by girdling. (Their technique for girdling is similar to ours, except that they
use a crowbar instead of a modified truck spring.)
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Aspen groves such as this one are being controlled by girdling.
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A large wildfire had swept through this area in the spring,
and the vegetation was very lush, with a high diversity of plant species.
Without trying hard, our group of knowledgeable botanists easily found 30 or 40
species (no one kept count). The terrain of this prairie resembled in many ways
Faville Grove Sanctuary in Jefferson County. However, a number of species that
are quite prevalent at Faville, such as the Silphiums, are completely absent
here. Then again, prairie dropseed, prevalent at Faville, is also a signature
species here.
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Laura, the knowledgeable field trip leader, explaining the ecology of the Tall Grass Prairie Preserve |
After a fine lunch served by the Ukrainians, we spent the
afternoon learning about the rotational grazing that NCC is carrying out.
Grazing is combined with prescribed fire to manage the prairie. Local ranch
owners provide the cattle, and NCC takes care of the water supply for the animals. We were shown an installation where water was brought into drinking troughs
by means of a pump powered by solar energy. We also had time to visit a new
Nature Center that NCC had just opened.
In addition to seeing such nice prairie remnants, we were
delighted to talk with so many knowledgeable prairie people.