Tom's Blog

Wednesday, August 15, 2012

Manitoba’s Tall Grass Prairie Preserve

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.
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.)
Aspen groves such as this one are being controlled by girdling.
 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.
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.


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