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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.
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