Ecological Campus Tour
Anderson Prairie
This section of the web site was orginally created by the Environmental Seminar class of 2002.
Iowa Before Agriculture
Tallgrass prairie was once the dominant ecosystem in Iowa. In fact, of its 36 million acres, over 30 million (> 80%) were prairie. The plant composition of the prairie led to the formation of the deep, rich soils that cover most of Iowa. This fertile soil proved to be both a blessing and a curse. While the land provides the livelihood of many and food for many more, the natural heritage of Iowa has suffered. Since the settlement and conversion of the land to agriculture in the late nineteenth century, over 99.9% of the prairie has been lost.
Currently, efforts are being made to preserve and restore prairie sites all across Iowa. Prairie preserves such as Hayden Prairie near Lime Springs and the Loess Hills in western Iowa are two prominent examples of this. The Iowa Department of Transportation, along with the University of Northern Iowa are piloting a program to establish native prairie vegetation in roadside ditches. Clearly, prairie is important to Iowans, and with further education and restoration movements, it will continue to be so in the future.
Quick Facts about Anderson Prairie
- The upper half of the 24.7 acre Anderson Prairie was planted in 1988 to control erosion.
- The lower half was planted in 1998.
- Baker Village, constructed in 1998, was built on a weed base, therefore little prairie was disturbed.
- Hickory Ridge, behind the prairie, used to be an oak savanna until an absence of grazers allowed woody species to invade.
- The prairie is divided into 18 plots, many of which are burned on a 3 year rotation to maintain the natural process of fire.
Prairie Construction: Where's the Grass?
- Planted grasses do not appear to flourish because the first couple of years they expend energy in root formation rather than above ground growth.
- A good stand of prairie grass may take three to four years to establish itself.
- Introduced plants have optimal growth in the spring; conversely, prairie plants grow best in the summer after soil temperatures rise.
- Forbs (wildflowers) often are planted at higher rates as they take longer to appear than grasses because they struggle to compete with thick grass growth.
More Then a Bunch of Weeds
Prairie originally covered almost one fifth of North America. It is divided into three distinct regions. The tallgrass prairie region ranges from southern Texas, through Iowa, north to Manitoba. The height and species of grasses are determined by precipitation levels each region receives.
The prairie ecosystem is home to an exceptional variety of plants and animals. Within the prairie one can find over 500 species of plants (both grasses and wildflowers known as forbs), countless species of insects, 34 species of amphibians, and 90 species of reptiles. Birds such as the burrowing owl, wild turkey, and Ferruginous hawk may be found there. Large mammals once dominated the prairie and included bison, pronghorn, and bears. Smaller mammals such as prairie dogs, pocket gophers, jackrabbits, and various mice abound.
Finding Our Roots
Native prairie plants are resilient in harsh and often unpredictable climates as a direct result of their extensive root systems. Prairie plants, such as big bluestem, may have roots extending up to 25 feet into the ground. In comparison, non-native grasses and crops such as corn struggle to grow even one foot into the soil. These deep roots are able to reach nutrients and water that are not accessible to other plants, thus allowing them to thrive under extreme conditions. This explains why prairie plants remain green even through hot, dry summers.
Disturbing Disturbances
Unlike many ecosystems, prairie can survive under seemingly devastating circumstances. The presence of fire and large grazing animals are essential to the health and existence of the prairie. Fire removes built up organic matter from the surface and destroys woody invaders and weeds. The sun can then warm the soil and stimulate plant growth. Native plants have evolved to withstand fire, mainly due to their extensive roots. Fire also allows for accelerated nutrient cycling. Herbivores are responsible for a variety of disturbances, which are also beneficial. Large herds of bison, and other grazing animals, kept excessive growth under control through their feeding. The actions of their hooves, accompanied with wallowing, loosened and turned the soil allowing for nutrients, water, and air to penetrate. Smaller mammals, such as prairie dogs, refreshed the soil through burrowing.
Practical Prairie Perks
Prairie provides benefits that enhance the soil. Extensive root systems provide a strong anchor to prevent erosion of top soil. The roots extend to such a depth that they are able to derive nutrients and water from the soil that are inaccessible to other plants, thereby out-competing weedy invaders. Nutrients and organic matter are recycled into the soil as plants die and decay.
Water quality is improved through the makeup of the prairie ecosystem. The combination of roots and soil act as a filtration system. Initially, water is absorbed quickly because of the porous nature of the soil which comes about as plant roots grow and invertebrates burrow. Then, because of the fine particles, water stays in the soil for longer periods of time and increases soil moisture content. Finally, the water is purified as it leeches through the soil and reaches the groundwater supply.
The clean water and rich soil provide optimal growth opportunities for a variety of plants. These plants offer an abundant supply of food for a wide variety of animals. These include berries for birds, grasses and clover for herbivores, and pollen for insects. Larger animals, in turn, prey on the smaller organisms. All creatures of the prairie find shelter within the diverse landscape. Birds can be found nesting in the protection of the dense ground cover. Animals even move into previously occupied locations, such as abandoned prairie dog towns and pocket gopher holes.
Oak Savanna
An oak savanna is a community of scattered oak trees (Quercus spp.) above a layer of prairie grasses and forbs. The trees are spread out enough so that there is no closed canopy and the grasses and forbs receive plentiful amounts of sunlight. The savanna is a transition ecosystem between the tallgrass prairie and woodland environments, so it is an important habitat for both woodland and prairie animals and insect species.
A savanna relies on periodic disturbances such as fire, grazing and drought to flourish. Such disturbances prevent other trees from establishing themselves and turning the habitat into a forest community. Oak trees and prairie grasses are resilient to fire while the trees of a woodland community are not. Oak trees have extremely thick bark that protects them from fire, and prairie grasses have evolved to thrive after a fire. Therefore, fire allows the oaks and grasses a competitive advantage over other trees that may try to invade the savanna. Without fire, tree saplings begin to grow in the savanna and are able to take over, shading out and eliminating the grass and forb species. Soon, where there used to be an oak savanna, there is now a woodland habitat. Oak savannas have become practically extinct because European settlers suppressed natural fire cycles and the fires set by Native Americans. Farming and development has also helped obliterate the oak savanna ecosystem.
Oak savannas are important because they are beautiful, dynamic environments with diverse plants and animals that have evolved complex relationships over time. Since savannas are transitions from prairie to woodland, they have extremely high diversity in flora and fauna. Diversity is a measure of health and stability, so it is important that habitats with diverse native plants and animals exist.
Information provided by the National Park Service.
Hickory Ridge
Hickory Ridge is fifty acres of land adjacent to Anderson Prairie and Baker Village. The area takes its name from the large number of native hickory trees growing on the hilltop. The tree line at the foot of the hill marks the shoreline of a river during the time that glacial ice was melting to the west of Decorah. Note that there is a deposit of striated sand below the tree line, and a more steep and rocky slope above. The property offers a walking trail complete with a wooden bridge over a stream. The trail begins behind the College Barn and is a closed loop with an exit to Anderson Prairie. In addition to the hiking trail, a mile long paved trail now passes along the north edge of the property. Hickory Ridge provides habitat for many animals including deer, turkey, owls, squirrels and even the occasional fox.
Lindeman and Birge Ponds
This relatively shallow man-made pond is named for Dr. Raymond L. Lindeman, a young ecologist who did pioneer work on the energy flow in natural systems in the 1940's. Several pairs of wood ducks have been observed raising their large families on this pond. Lindeman Pond is approximately 5,700 square meters in surface area and has a mean depth of 1.76 meters. The Pond is fed from two sources: draining from the surrounding watershed and Decorah city water used in the air conditioning system of Miller Dormitory on the campus. Raymond Lindeman passed away after a long illness on June 29, 1942. This pond on the Luther College campus was a focus of a research project called: Lindeman Pond, the living limnologic legend. The study was completed by Ryan Good and Mark Debowski in the summer of 1997 for the Pew Scholars Program.
The Hoslett Field Study Area is named in honor of the late Dr. Sherman Hoslett, a professor who taught biology at Luther College for nearly 30 years. Dr. Hoslett was one of the pioneers in the teaching of ecological concepts in natural history and field biology. For many years he and his students conducted research on the systematics and ecology of mammals in Northeast Iowa. Birge and Juday Ponds were gravel pits in the late 1940's. They were abandoned shortly after the young son of the operator was killed here when an excavating machine toppled on him. The maximum depth of Birge Pond is 20 feet, and the maximum for Juday is 9 feet. Both were used for a time as dumps and are therefore dangerous for swimming. The refuse on the bottom now serves as good habitat for some species of aquatic life. One unusual resident of Birge Pond is the phantom midge, an insect about 1/2 inch long.
A number of beaver live in the ponds, as shown by a large pile of willow branches cut for food, several mud trails, and gnawed stumps. Some animals should remain in the ponds as long as they are not disturbed by man and there is a supply of young willow trees.
E. A. Birge and Chancey Juday were nationally known limnologists at the University of Wisconsin. Birge published over 400 papers on aquatic biology during the first half of the 1900's, and later became president of the University.
Roslien Woodlands
The 105-acre Roslien Woodlands is located northwest of the intersection of U.S. Highway 52 and Pole Line Road on the edge of Decorah. David J. Roslien earned his master’s and doctoral degrees in biology at Iowa State University. He accepted a faculty position with the biology department in 1965 and taught until 1985. In 1985, he was named vice president for college advancement. He was named executive vice president 1994-95 and served as interim president 1995-96. From 1997 until his retirement, he served again as vice president for college advancement, overseeing a capital campaign that raised more than $55 million. Roslien and his wife Joy, who retired in 1999 as director of the college’s health service, are residents of Decorah. Named in his honor, the Roslien Woodlands is a college resource for outdoor education, recreation and biological research. The 105-acre tract includes 70 acres of recently establishing woodlands and 35 acres of older woodlands. The college designed a forestation project to develop a natural area for field study of plant and animal life, prevent erosion of the hillside and provide habitat for wildlife. In consultation with the state forester, the college created a tree-planting plan based on soil types and topography. More than 46,000 trees were planted during Earth Week in April 1990. Other improvements included removal of fences and earthwork to fill eroded areas and gullies. In 1991, 26 acres were improved to eliminate undesirable species, poor quality trees and damaged trees. The college developed nature trails for walking, cross country skiing and horseback riding.
Information provided by Luther College CHIPS.
David J. Roslien
Roslien Woodlands has two ponds, although they rarely hold water. Leopold Pond has a small dam constructed to catch the runoff from the hills to the north. Such farm ponds are often fenced to prevent the erosion damage which results when cattle are allowed free access. The pond is named for Aldo Leopold, a pioneer conservationist who wrote "Sand County Almanac" and "Round River". Gravel Pit Pond was formed when gravel was removed in 1974 and 1975 for use in construction of highways 9 and 52. Shortly after the removal of gravel, the pond regraded and landscaped.
Although Northeast Iowa is called the "driftless" area, and very little glacial evidence can be found in or east of Decorah, there is abundant glacial material on the north side of the ridge through which the highway has been cut. Much of the sand, gravel, and boulders uncovered at the time of highway construction has now been covered with vegetation, but close observation along the ditches will disclose many rocks and pebbles of glacial origin.
Information provided by Decorah Trails and Trolls: Luther College Press, 1976
