If you have recently taken a walk through the Arb prairies, you probably noticed the golden grasses swaying in the breeze and a few vibrant purple asters hiding in the thatch but did you realize that you were walking through one of the most diverse and endangered ecosystems on the planet? Although prairies may at first glance appear to be just a bunch of grass and some scattered weeds, they are hardly simple or ordinary. Prairies support an incredible diversity of life including hundreds of plant species as well as many birds, lizards, mammals, and insects (not to mention soil invertebrates, fungi, and microbes).
The North American prairie once stretched from the Rocky Mountains east to Illinois and Texas covering 170 million acres! Prior to European settlement, Minnesota contained over 18 million acres of tallgrass prairie. However, less than 2 percent of that original prairie remains today. Across the upper Midwest, virtually all prairie was plowed and converted to agricultural production making the North American prairie one of the world's most endangered ecosystems.
Despite significant efforts to protect the remaining bits of this rare ecosystem, prairies continue to be threatened by exploitation and degradation. Between 1987 and 1994 alone, the Minnesota Department of Natural Resources estimates that 800 acres of remaining high quality prairie were converted to agriculture or housing developments. Meanwhile, the absence of fire in many unmanaged prairies allows woody vegetation to invade and crowd out native prairie species.
While the outlook for prairies may seem bleak, there are signs of hope in our own backyard. Carleton owns and manages several remnant prairies in addition to the nearly 200 acres of prairie planted in the Arb. Although managing prairie is both time and work intensive, preserving this integral piece of our natural heritage is well worth the effort.
If you are interested in learning more about prairies and other topics related to natural history, e-mail Arboretum Director Nancy Braker (email@example.com) to join the student naturalist mailing list!