North America’s SerengetiPublished 11:21pm Monday, September 12, 2011
By TERRI GORDON
Off the Water
“It’s the Serengeti of North America,” said Sarett Nature Center director Chuck Nelson, discussing the vast prairie system native to much of the United States. “There never has been a thicker population of animal mass, and plant mass, than the prairie.”
While there are differing views on precisely how much of this system remains today, it is generally agreed that at least 90 percent of the 750 million acres of prairie once covering North America are gone. The number is even greater for tall grass prairies that once grew in parts of Michigan and Indiana.
According to Nelson, prairies grow where there is “less rainfall than evaporation.” There is just not enough moisture to support trees, and the ecosystem is dominated by grasses and flowers.
The next driest habitat is a desert. There are three types of prairie in North America; short-grass prairies are the driest — and its grasses the shortest.
“Think of the old cowboy and Indian movies for that habitat,” said Wendy Jones of Fernwood Botanical Garden and Nature Preserve. “They were found from western Montana down through western Texas.”
Mid-grass prairies of little bluestem, switch grass and Canada wild rye covered the Dakotas, the western parts of Nebraska, Kansas and Oklahoma and central Texas. “(This) is the setting for the filming of ‘Dances with Wolves,’” Jones said.
The prairies found throughout Minnesota, Iowa and Missouri, and in parts of Illinois, Indiana and Wisconsin are tall grass prairies. Tall grass prairies also grew in parts of southern Michigan.
“Michiana is on the eastern edge of the historic tall grass prairie range,” explained Jones, “with pockets scattered throughout the deciduous forests that once covered the area.”
The closest native tall grass prairie was called Wolf Prairie, and according to Jones, would have grown just west of Berrien Springs, along the southwest side of Niles, and on the northwest side of South Bend, before it found and followed the Kankakee River into Illinois.
Plants in the tall grass prairie grow as high as 12 feet. Big bluestem and Indian grass are the most common grasses. Compass plant, cup plant, prairie dock, tall coreopsis and tall sunflower comprise the dominant flowers.
While rainfall is the prairie’s dictate, fire is its insurance. The fires that periodically sweep through the grasslands help maintain them. Since prairie plants have deep root systems, they are not affected by the fires and only grow stronger in their wake.
“Burns are a natural and essential part of the prairie ecosystem,” explained Jones, “fertilizing the soil with nutritious ash, cracking open seed cases so they can germinate, clearing dead growth so the sun can reach the soil quickly, and kill invasive species and trees.”
In nature, these fires are started by lightning, but there is evidence that humans have also long burned prairies — to clear pathways through them, to control them and to flush game from them for food. And there was plenty of game.
“Buffalo and antelope were the keystones,” said Nelson, pointing out that glaciers affected the kind number of species in the habitat. “There are numerous small mammals. There are about 10 different gopher families, and the wolf, the coyote and the fox all have a great time in the prairie. There’s all kinds of prairie birds, like the plain-colored sparrow and the Henslow sparrow.”
One tree that can withstand the prairie’s burning is the burr oak. Thus, small stands provide respite from the sun, and shelter for pioneers crossing the prairies. Early towns often grew around the tree stands.
Both Sarett and Fernwood have restored prairies that they have planted, and that they maintain with controlled burns. While Sarett’s prairie is relatively new, Fernwood’s reconstruction began in 1976 as a bicentennial project. To preserve the local plant genotype, seeds were collected from prairie remnants within a 50-mile radius of Fernwood, started in the greenhouse, and then the seedlings were transplanted to the prairie. More than 100 plant species, many of them threatened or endangered, are found in Ferwood’s prairie.
“The prairie is lovely to visit any time between May and October, with different flowers coming into bloom almost weekly,” said Jones. “A few ‘peak’ times would be early June, late July and early-August and mid-September.”
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