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2 OVERVIEW OF RIVER-FLOODPLAIN ECOLOGY IN THE UPPER MISSISSIPPI RIVER BASIN system that caused these effects. Several of the authors also recommend ways to restore the floodplain to a more natural state. Chapters 2-4 focus on various topics for the Missis- sippi River. Chapters 5 and 6 discuss the Missouri River. and the last two chapters encompass the whole basin. In Chapter 2. Charles Theiling gives an ecological overview of the upper Mississippi River system, including the Illinois River. He focuses on resource and habitat trans- formations resulting from floodplain development and the impact of these changes on endemic plants and animals. He also provides management options to address the significant loss of floodplain habitat. Theiling emphasizes the need to monitor newly acquired areas for restoration and to use this infonnation to better manage large floodplain ecosystems. In Chapter 3. Yao Yin and John Nelson examine how changes in the upper Mississippi River have impacted floodplain forests, The presettlement bottomland forests were diverse in age structure and high in species richness because the Mississippi River and its tributaries meandered freely within the floodplain environment. Human-induced changes to the river system through construction of naviga- tion dams significantly changed natural hydrologic patterns within impounded reaches of the upper Mississippi River, Agriculture and urban development are the major causes for rapidly diminishing forests throughout most of the upper Mississippi River floodplain. Yin and Nelson suggest that management goals should be to restore the diversity of for- ests by regulating river flows with ecologic considerations, coupled with artificial regeneration. In Chapter 4. Jon Duyvejonck reviews species popula- tion status and trends of the upper Mississippi River over a I DO-year period. focusing specifically on mussels and fishes. Both groups are important ecologically and econom- ically and have been impacted by introduction of exotic spe- cies, poor water quality. and changes to the floodplain for navigation and development. These changes significantly impacted the abundance of particular species. In Chapter 5, David Galat, John Robinson. and Larry Hesse illustrate how the lower Missouri River exhibits char- acteristics of large floodplain rivers, and how these charac- teristics have been altered by human intervention. The authors then focus on opportunities to restore the river sys- tem. One of their observations is that mitigation efforts on the Missouri River do not yet embody a holistic view of considering the entire basin when attempting to restore the essential structural and functional aspects of the river. How- ever, success in recreating a self-sustaining Missouri River ecosystem is more likely if individual mitigation and resto- ration projects are planned within the context of the entire basin. In Chapter 6. Larry Hesse provides an overview of the human-induced changes to the physical and biologic char- acter of the middle Missouri River. A critical conclusion from Hesse is 'The Missouri River ecosystem is in chronic decline. The future will see many new threatened and endangered species, The task of recovering such a large ecosystem is overwhelming if it is approached one species at a time. The only hope is to proactively provide the mini- mum requirement for the survival of this system. Appropri- ately timed flooding of a portion of the floodplain, restored sediment transport, and increased width of the navigation channel are essential to stabilize the ecosystem and begin to recover native species." In Chapter 7. John Smith focuses on the importance of the Missouri. Mississippi. and Illinois Rivers to wildlife species, The species include amphibians and reptiles. birds and mammals. as well as federally listed species under the Endangered Species Act. Smith notes that the flood of 1993 provides an unprecedented opportunity to study the dynam- ics associated with flood events in regulated riverine wet- land ecosystems. Effective management of big rivers will require placing environmental and natural resource values into proper perspective with respect to other river uses. Finally. Chapter 8 is an annotated bibliography of pub- lications pertinent to the ecology of the upper Mississippi and Missouri River drainage basins developed by Rex Johnson. Craig Milewski. and Kenneth Higgins, The papers selected emphasize wetlands, riparian zones, and the eco- logic impact of human modifications to the floodplain and riverine ecosystems. A summary oflhe characteristics of the upper Mississippi River and Missouri River drainage basins is also provided. As a whole. these chapters reveal the complexity of interactions among all the physical and biologic elements of floodplain systems. which are among the world's most pro- duclive ecosystems. The chapters also reveal how intri- cately life adapts to its physical environment. and how altering the natural hydrograph, reducing the sediment load. or varying the seasonal temperature change of the river sys- tem can have cascading ecologic impacts. However. there is hope for restoring the basin's large floodplain rivers. As John Smith states. "Ecosystem management and biodiver- sity issues have received much attention from resource agencies in recent years. and the flood of 1993 has provided an opportunity to explore alternative scenarios of river man- agement to help restore the river-floodplain linkage that is so vital to the functional integrity of the river ecosystem... flood way restoration should not be viewed as an end in itself, but rather as one of a range of river management prac- tices designed to restore the functions and values of the riv- erine system." Ecologic restoration of these systems will require rees- tablishing the river-floodplain connection through a return to a more natural hydrograph and acquiring land to provide habitat patches for native and Federal or State listed species, Finally, sound scientific research must continue in order to better understand the physical, chemical. and biologic processes shaping these river systems and to provide for sound, long-term management of these areas.