Driving from Missouri to Ohio today, I crossed the rural landscape of North America's Corn Belt. As one also observes on the Great Plains, the woodlands of this physiographic region cluster along the major creeks and rivers. However, the reason for this landscape feature differs between the two areas.
On the semiarid Plains, groves of cottonwoods and willows rise along the drainages since they provide the necessary soil moisture for tree growth; most trees (with the exception of some desert species) require at least 20 inches of annual precipitation. By contrast, the Corn Belt of the Midwest receives an average of 35 inches of precipitation each year and, prior to the arrival of European settlers, tallgrass prairie and more extensive forests covered the region. Clearing the land for agriculture, the settlers drained swamplands, plowed the prairie and cut away woodlands that were easy to reach and which cloaked ground suitable for crops. In essence, these practices left forest along the stream valley walls and immediately along the river or creek itself; if the floodplain was broad enough for crops, those riparian woodlands and swamp forests were also cut.
Today, corn fields stretch across the Glaciated Plain of the Midwest, broken only by highways, towns, cities and forested stream valleys. For the traveler, those scenic valleys offer welcome topographic relief amidst the flat agricultural terrain.
