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<br />
<br />24
<br />
<br />RESTORA nON OF LOW RIVER STAGES
<br />
<br />OVERVIEW OF RIVER-FLOODPLAIN ECOLOGY IN THE UPPER MISSISSIPPI RIVER BAS[N
<br />
<br />Restoration of periodic low river stages must be con-
<br />sidered as a management tool. Impoundment of the Missis-
<br />sippi and Illinois Rivers by low-head navigation dams and
<br />water diversions from Lake Michigan into the Illinois River
<br />do not allow water levels to drop as low as they did in the
<br />undisturbed rivers (Mills and others. 1966; Fremling and
<br />others. 1989), The pools created by the navigation dams are
<br />huge sediment traps. and levees exacerbate high sedimenta-
<br />tion rates by concentrating sediments in channel habitats
<br />rather than allowing them to deposit over the whole width
<br />of the floodplain (Bhowmik and Adams. 1989; Simons and
<br />others. 1974, 1975). Furthermore, the sediments delivered
<br />to the system remain flocculent and are easily resuspended
<br />by wind in shallow backwaters, Water-level management
<br />that provides periodic summer low river stages would dry
<br />and compact backwater sediments and reduce sediment
<br />resuspension, The effort would duplicate the techniques of
<br />moist soil management for waterfowl on a pool wide or even
<br />a systemwide scale.
<br />Management activities should be conducted to make
<br />the best of what the navigation system has to offer, Habitats
<br />that once occurred on a lateral gradient depending on flood-
<br />plain relief can be recreated, somewhat. on a longitudinal
<br />gradient created by the impounding effect of the dam at low
<br />flow. Upper pool areas might maintain flood-intolerant tree
<br />species. midpool areas may support ephemeral and perma-
<br />nent wetlands and mesic prairies, and lower pool areas can
<br />support permanent aquatic or managed habitats. This is. of
<br />course, a broad generalization. but the hydrologic gradient
<br />exists, and the water table is a major factor that must be con-
<br />sidered for the long-term success of any restoration plan.
<br />Basinwide initiatives addressing land use, disaster preven-
<br />tion. and habitat restoration must be developed to protect
<br />UMR resources in the long term,
<br />
<br />ACKNOWLEDGMENTS
<br />
<br />I am much indebted to the following people for their
<br />assistance with this project:
<br />
<br />Elmer R, Atwood. lIlinois Department of Conservation
<br />Andrew Bartels. Wisconsin Department of Natural
<br />Resources
<br />Theresa Blackburn. Iowa Department of Natural Resources
<br />James B, Cammerer, lIlinois Natural History Survey
<br />Fredrick A. Cronin. lIlinois Natural History Survey
<br />Jon Duyvejonck. U.S, Fish and Wildlife Service
<br />Patricia A, Gannon, lIlinois Natural History Survey
<br />Scott Gritters. Iowa Department of Natural Resources
<br />Robert Hrabik. Missouri Department of Conservation
<br />
<br />Jon Klingman. U,S, Army Corps of Engineers. Rock Island
<br />District
<br />
<br />Kristine Kruse, Minnesota Department of Natural
<br />Resources
<br />
<br />James Lennartson, U,S, Fish and Wildlife Service
<br />Kenneth Lubinski, National Biological Service
<br />Robert Maher, lIlinois Natural History Survey
<br />John C. Nelson. lIlinois Natural History Survey
<br />Thomas Owens, National Biological Service
<br />Brenda J. Plunk. Illinois Natural History Survey
<br />Walter PoPP. Minnesota Department of Natural Resources
<br />Richard E. Sparks. lIlinois Natural History Survey
<br />Mark Stapyro, Minnesota Department of Natural ReSOurces
<br />John K, Tucker. lIlinois Natural History Survey
<br />
<br />They provided species lists, original figures, editorial assis-
<br />tance. and information on all aspects of the paper, I also
<br />acknowledge the members of the Mississippi River
<br />Research Consortium and the Upper Mississippi River Con-
<br />servation Committee for their efforts to understand and pro-
<br />tect a remarkable resource and to promote river education.
<br />
<br />SPECIES LIST CITATIONS
<br />
<br />Other contributors to the SAST effort will provide
<br />additional information regarding UMR species composi-
<br />tion, I present citations that total over I ()() pages of species
<br />lists divided among four river reaches discussed in the text.
<br />Accounts of species are wide ranging in taxa and geogra-
<br />phy, They require the coordinated expertise of scientists
<br />from many disciplines to be effectively compiled, Ecologi-
<br />cal data gaps at the species level will have to be filled and
<br />cataloged for effective ecosystem management.
<br />
<br />UPPER FLOODPLAIN REACH
<br />
<br />I relied heavily on help with species lists from the
<br />upper floodplain reach from local researchers and manag-
<br />ers, James Lennartson (U.S, Fish and Wildlife Service) pro-
<br />vided information on birds and mammals, The LTRMP field
<br />stations provided current information on vegetation (Kris-
<br />tine Kruse, Minnesota Department of Natural Resources,
<br />Pool 4. personal commun.. 1993: Langrehr. [992; Shay and
<br />Gent. 1992) and fishes (Mark Stapyro. Minnesota Depart-
<br />ment of Natural Resources, Pool 4, personal commun.,
<br />1993; Andrew Bartels, Wisconsin Department of Natural
<br />Resources. personal commun,. 1993; Scott Gritters, Iowa
<br />Department of Natural Resources, personal commun.,
<br />1993),
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