The Prairie Ecosystem in the Loess Hills

Prairies are one of three distinct ecosystems found in the Loess Hills of Iowa.

Definition of a Prairie

Prairies are landscapes where the soil, weather, and other conditions favor grasses over trees. Although prairie areas can be found anywhere along the Loess Hills, they dominate the southern and western slopes. These areas are exposed to hot summer afternoon sun and drying winds that make most plants wither and die. Grasses dominate the area because they can survive dry climates, fire, and grazing better than trees. Prairie plant adaptations include a deep root system and narrow leaves that reduce water loss, allowing them to survive where other plants can't.

Native Prairie Life

The prairie’s sunny environment supports hundreds of plant species. Big and little bluestem, Indiangrass, and sideoats grama are some of the native grasses found here, while blazing star, coneflowers and compass plant are common flowers. To help pollinators (ex., bees, butterflies) find their flowers, prairie plants flower at different times and increase their flowering height to keep flowers above the thick prairie vegetation. (Spring species can be shorter because the grasses haven't had time to grow and block out the flowers.)

Yucca and skeleton weed, two plants that are usually found in states to the south and west of Iowa, are at home here. Tucked among these unusual but native plants are some equally unusual animals including the Great Plains skink, plains pocket mouse, spadefoot toad, and prairie rattlesnake. The Loess Hills of western Iowa is at the far eastern edge of their normal habitat range.

Within the Loess Hills working landscape, the prairies serve several purposes.
1. They act as tourist destinations and educational areas.
2. They provide habitat for rare and endangered species.
3. They area a source of food for cattle, bison, and elk.

Human Impact on the Prairies

Human settlement of the Loess Hills has had a dramatic effect on the prairie habitat. As humans settled the area, they reduced the frequency and size of fires in order to protect their lives and property. This allowed cedar trees, sumac, and dogwood to become established in some areas, reducing the prairie habitat. Many of the gentler eastern slopes have been plowed for crop cultivation. People wanting dramatic views from their windows build homes along the western ridge tops. Construction causes an increase in erosion.


Explore More: Working Landscapes
Copyright 2004, Iowa Public Television
The Explore More project is supported by funds from the
Roy J. Carver Charitable Trust
and the USDE Star Schools Program.