Great Rivers Partnership - UMR - Iowa

The Upper Mississippi River Program

Lower Cedar River: Maintaining Life's Diversity

Despite covering only about 1,070 square miles, the watershed of the Lower Cedar River in southeastern Iowa shelters a remarkable assemblage of life’s diversity. Two globally rare plant communities – swamp white oak savannas and rich peat fens – can be found there, and its sandy soils provide habitat for more than 400 documented plant species. In addition, it harbors 70 percent of the reptile and amphibian species found in Iowa, including rare massasauga rattlesnakes and stinkpot and ornate box turtles. A herpetological conservation area – Iowa’s first – will be designated along the Lower Cedar.

The oak savannas established themselves when fire and seasonal floods kept the forests more open. Now, without adequate fire, their trees grow in an unnatural density, preventing new oaks from becoming established. Meanwhile, the Cedar River floods unnaturally, causing declines in populations of some plants and animals. Reed canary grass, garlic mustard and other non-native plant species pose another ecological threat.

The Nature Conservancy is working in multiple ways to preserve and restore the habitats and water quality upon which the watershed’s biological diversity depends.

At its 372-acre Swamp White Oak Preserve, a prime example of white oak savanna located on a low sand terrace along the Cedar River, and at the 137-acre Greiner Family Nature Preserve, where oak savanna, sand prairie and open sandy areas are all essential to rare nesting turtles, the Conservancy is engaged in pioneering floodplain savanna restorations. Intensive management efforts at the two preserves include prescribed fire, removal of non-native species and planting of native species. The Conservancy shares with partners a long-term goal of conserving and restoring 5,000 acres of swamp white oak and floodplain savannas within the watershed.

Another aspect of the Conservancy’s work is its efforts to demonstrate through the Pike Run Creek Watershed Project that agricultural uses and freshwater ecosystems can be compatibly sustained. Pike Run Creek, a tributary of the Lower Cedar, provides habitat for uncommon species of fish such as pirate perch, grass pickerel and black-striped topminnows. Although the creek’s water quality remains high, oxygen levels are declining and the character of the streambed is changing as excess nutrients and sediments enter the stream.

With a $390,000 gift from the Monsanto Fund, the Conservancy has spearheaded a multi-partner effort to promote the use of techniques – among them, filter strips and riparian forest buffers – that will protect the creek’s waters. Scientific monitoring of the creek will provide a basis for assessing the project’s effects. Project partners include the Muscatine Soil and Water Conservation District, Iowa Soybean Association, Iowa Department of Natural Resources, University of Iowa and two federal agencies, the Natural Resource Conservation Service and the Environmental Protection Agency.

The Conservancy’s Upper Mississippi River Program has selected the Lower Cedar River as a priority conservation site, thus providing an avenue for sharing throughout the Upper Mississippi River basin lessons learned about the conservation of floodplain savannas and the use of small watershed partnerships to promote sustainable agriculture within healthy freshwater ecosystems.

The Conservancy’s Upper Mississippi River Program, Lower Mississippi River Program and Great Rivers Partnership seek to advance the Conservancy’s national and global efforts to protect the Earth’s critically important freshwater resources for the benefit of the people and other living things that depend upon them for life.

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