A late February snow was falling hard on my prairie. The voice on the radio said that it had something to do with moist air riding the jet stream north from the Gulf of Mexico. The physical connection between prairie and river ecosystems starts here. In a few months the prairie snow will melt, quickly soak into the glacial sand, and become a part of the groundwater. Flowing underground a few meters each day, the water that fell as prairie snow will eventually emerge through the porous bed of a drainage ditch known as Ten Mile Creek. Dredged to within an inch of its life, the creek will also carry a little of whatever is sprayed on the nearby potato fields and cranberry marshes. As a ditch, it is valued only for what it can carry away. Magically, as my prairie water flows under a small bridge on Rangeline Road, the State of Wisconsin reclassifies this same drainage ditch as a trophy trout stream-one of the best in this part of the state. Twenty two miles later, the water that started as snow on my prairie will join the Wisconsin River and slowly make its way back to the Gulf of Mexico.
The prairies and rivers of the Midwest are cousins that share the same birthday. They both took their current form about eleven thousand years ago when the last great ice sheet melted. As cousins, they share many traits and at the same time, each is unique. They both evolve gradually over time. The prairie slowly becomes a forest, until fire sets back succession. Rivers develop meanders as a graceful sign of aging, until floods or engineers straighten them out.
The sun is an important link between the two ecosystems. The river owes its existence to the energy the sun gives to water as it evaporates. Water molecules gain potential energy as rising currents of air lifts them higher in the sky. It's the release of this energy, through falling rain or snow, which powers the river from beginning to end. The prairie captures its solar energy with chlorophyll. Through ingenious alchemy, light is changed into sugar, and over time, into buffalo. Some animals transfer energy from one ecosystem to another. A duck may store energy collected from feeding on river plants, only to "release" that energy to a fox on the edge of a prairie pothole.
On a prairie, the winter temperatures can drop to 40 below and summer highs can be above 100 degrees. A daily temperature fluctuation of 40 degrees is not unusual. Flowing river water is rarely over 80 degrees and is never below freezing. Water temperature rarely changes more than a few degrees on any given day.
In Midwest rivers, most water currents flow south, along the way creating whirlpools and eddies. The air currents that give the prairie it character most often flow from the west and occasionally spawn tornadoes or dust devils. Weather satellites reveal rivers of moisture in the lower atmosphere that can carry as much water as the Amazon does.
In both the river and the prairie, form follows function. The shape of a trout, which lives in fast flowing water, is sleek and hydrodynamic. The blue gill, which prefers quiet backwaters, is more saucer-shaped. On a prairie, the efficient design of a harrier allows it to hang motionless over its next mouse meal, while the fast wings of the prairie chicken helps it avoid becoming lunch.
Human impact can be seen in both ecosystems. The snowmobile that hums through a prairie winter is sibling to the personal watercraft that screams down the rivers all summer. Spotted knapweed found its way from Europe to the North American prairie and is laying much of it to waste. The zebra muscle, a hitchhiker in the ballast water of ships, has quickly spread through most watersheds of the Midwest. The tires abandoned along a prairie road came from the same factory-maybe the same car, as the tires washed up on the riverbank. Prairies have long ago been sliced and diced by surveyors to encourage private land ownership. Many prairies currently enjoyed by the public, as national parks and wildlife areas, were at one time privately owned. Only when the farms failed did they get any public protection. Rivers have always been held in common-which is not to say that they got the better deal. Until recently, rivers served as an inexpensive sewer for industries and towns alike. Attitudes are changing. Today many people are working to protect both rivers and prairies. Considering the many links they share between them, that only makes sense.
Asking me whether I prefer prairie or river is like asking a parent which child they love more. I get the same thrill watching the sunrise over an open prairie as I do marveling at the moon from a canoe. The waves of wind-blown August grasses calm me as much as watching the ripples in a trout stream. The call of a sandhill crane reaches that same primitive spot deep in my brain whether I'm standing on the bank of the Wisconsin River or in the middle of the Buena Vista Grasslands. Rivers and prairies have both played an important role in making me who I am. For me, this is the most valuable connection of all.
for Global Environmental Education