Iowa Conservation Summary
Iowa has been called “The Land Between Two Rivers,” with the Mississippi River forming its eastern boundary and the Missouri River its western. Between these mighty rivers lie a variety of natural communities, including tallgrass prairie, savanna, deciduous forests, and various wetlands, lakes, streams and smaller rivers. The rich back soil of the prairies and wetlands attracted the first Euro-American settlers, who converted it into the prime farmland that now dominates the landscape. A century and a half of farming since has left only small, fragmented remnants of Iowa’s plant and animal communities: less than one percent of the tallgrass prairie remains intact; only four percent of the wetlands, 18 percent of the surface waters and 43 percent of the forest remain.
Rare Species and Characteristic Habitats
These remnants of native habitat harbor over 90 percent of the state’s plant and animal diversity. Most of the existing prairies are small and surrounded by agricultural fields. Hayden Prairie, a 240-acre state preserve in northeast Iowa and one of the larger prairie tracts, has over 200 species of plants including prairie bush clover, a federally threatened species. The Powesheik skipperling butterfly, which is a federal candidate species, and the regal fritillary butterfly have also been found at Hayden.
The Loess Hills, on the east side of the Missouri River floodplain, has the largest prairie tracts left in the state, ranging in size from a few acres to three-thousand acres. The Loess Hills landform is a narrow band of exceptionally thick loess deposits, from 60 feet to 150 feet in depth, that extends parallel to the Missouri River for 200 miles. More than 640,000 acres are included in this landform and the terrain is characterized by steep slopes, bluffs, narrow ridge crests, steep-sided ravines and a dense network of drainageways. More than 700 species of plants have been found in the prairies and woodlands of the Loess Hills of western Iowa. Although several tracts over 1,000 acres are owned by public agencies or conservation organizations, 96 percent of the landform remains in private ownership.
Well over half of the nearly 400 cold-air (algific) talus slopes in the upper Midwest occur in northeast Iowa. Due to their unique geologic structure, these slopes maintain a narrow range of temperatures during the year. They stay cold in summer due to the unique system of airflow through the fractures in the rock and vents at the bottom of the slope. The summer air temperature as it flows over the crevices and caves in the surface of the slope is 50 degrees Fahrenheit or cooler; in some cases it is below 35 degrees in June. In winter, the air temperature drops and airflow through the algific talus slope stops, allowing the groundwater to again freeze in the caves and crevices. These slopes provide habitat for 15 rare snails and plants, including the federally endangered Iowa Pleistocene snail and the threatened northern monkshood.
Public and Private Conservation Efforts
About two percent of Iowa’s 36 million acres are permanently protected. This includes five national wildlife refuges, 85 state parks, 10 state forests, 453 wildlife management areas, four federal flood control reservoirs, and 19,000 miles of interior rivers. All 99 counties in Iowa have County Conservation Boards with land acquisition and management programs. Private conservation organizations like The Nature Conservancy and the Iowa Natural Heritage Foundation have acquired or helped acquire thousands of acres for the protection of plant and animal communities. Iowa has designated 12 bird conservation areas encompassing more than 800,000 acres.
Challenges
Continued loss, degradation and fragmentation of habitat due to urban expansion and intensification of row crop agriculture will continue to stress plant and animal populations. The viability of prairie butterflies is threatened by continued isolation of small populations. Introduced invasive species, such as garlic mustard and leafy spurge, reduce plant and animal diversity by producing monocultures that replace native species. Tree and shrub invasion of prairie communities threatens to choke out prairie species. Aquatic communities are threatened by hydrologic changes like urban expansion and the resulting runoff from impermeable surfaces, stream channelization, sediment deposition, and high levels of nutrients in runoff.
Iowa’s Future
In 2006, Iowa’s legislators proposed the concept of sustainable funding for Iowa’s natural resources, indicating that this is an important issue for all of Iowa. Secured funding for natural resources would result in such benefits as cleaner water, positive economic impacts, sustainable agriculture and soils, and outdoor recreation opportunities close to home where Iowans can enjoy and appreciate healthy activities, nature, and Iowa’s beauty. During the 2007 session, the Legislative Council appointed an Interim Study Committee to evaluate reports, statistical data, and funding recommendations to address Iowa’s immediate and future needs. This statewide effort and awareness will help ensure the conservation of Iowa’s remaining natural communities for generations to come.
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