Conservation by restoration: the management concept for a river-floodplain system on the Danube River in Austria

1. One of the last remnants of a functional alluvial landscape on the Danube extends from Vienna to the Slovakian frontier. It is recognized as an ecosystem extremely worthy of protection and therefore has been designated as a National Park (‘Alluvial Zone National Park’). 2. However, surface connectivity has been reduced and floodplain habits have been fragmented. At present, lateral exchange processes of matter are restricted to short-term flood pulses, while most of the year backwater processes are de-coupled from the river system. 3. A very high species diversity is recorded for this section, with a high proportion of endangered species in all groups, ranging from 16% for riparian vascular plants to 100% for amphibians and reptiles. High diversity is mainly a result of the remaining spatial array of water bodies of different age across the river-floodplain complex (between-channel diversity). 4. A successful conservation strategy for this floodplain area requires a management scheme based on a solid conceptual foundation of the key processes in river-floodplain systems. Re-establishing hydrological dynamics is recognized as the most vital step, because other processes are influenced by the flow regime and resulting connectivity. Therefore, a large-scale pilot project has been developed for a segment of the free-flowing section to restore gradually the hydrological connectivity between the river and its floodplain. 5. The side-arm system will be reconnected to the main channel by lowering parts of the riverside embankments. After implementation, the side-arm system will be integrated with the flow regime of the river for more than half of an average year (at present: <8 days per year). 6. A key challenge in the evaluation of the effects of restoration is the development and testing of an appropriate monitoring scheme, which has to include a wide range of physical, chemical, geomorphic, and ecological parameters. © 1998 John Wiley & Sons, Ltd.

[1]  F. Swanson,et al.  An Ecosystem Perspective of Riparian ZonesFocus on links between land and water , 1991 .

[2]  Leslie A. Real,et al.  The Sustainable Biosphere Initiative: An Ecological Research Agenda: A Report from the Ecological Society of America , 1991 .

[3]  Thomas Hein,et al.  HYDROLOGICAL CONNECTIVITY AND FLOOD PULSES AS THE CENTRAL ASPECTS FOR THE INTEGRITY OF A RIVER-FLOODPLAIN SYSTEM , 1995 .

[4]  Klement Tockner,et al.  Ecological Aspects of the Restoration Strategy for a River-Floodplain System on the Danube River in Austria , 1997 .

[5]  Richard E. Sparks,et al.  Need for Ecosystem Management of Large Rivers and Their Floodplains These phenomenally productive ecosystems produce fish and wildlife and preserve species , 1995 .

[6]  John Pastor,et al.  Overview of case studies on recovery of aquatic systems from disturbance , 1990 .

[7]  Charles C. Coutant,et al.  A GENERAL PROTOCOL FOR RESTORATION OF REGULATED RIVERS , 1996 .

[8]  Laura L. Jackson,et al.  Ecological Restoration: A Definition and Comments , 1995 .

[9]  Clifford N. Dahm,et al.  An Ecosystem View of the Restoration of the Kissimmee River , 1995 .

[10]  Claude Amoros,et al.  Restoration ecology of riverine wetlands: I. A scientific base , 1995 .

[11]  F. Schiemer,et al.  ENDANGERED FISH SPECIES OF THE DANUBE RIVER IN AUSTRIA , 1989 .

[12]  Claude Amoros,et al.  The reversible process concept applied to the environmental management of large river systems , 1987 .

[13]  W. Junk.  The flood pulse concept in river-floodplain systems , 1989 .

[14]  G. Petts,et al.  Historical Change of Large Alluvial Rivers: Western Europe , 1989 .

[15]  T. O. Crist,et al.  Critical Thresholds in Species' Responses to Landscape Structure , 1995 .

[16]  C. Nilsson,et al.  Fragmentation and Flow Regulation of River Systems in the Northern Third of the World , 1994, Science.

[17]  U. Humpesch,et al.  Long-Term and Seasonal Aspects of the Water Quality of the River Danube within the Region of Vienna (Austria) , 1990 .

[18]  Peter B. Bayley,et al.  Understanding Large River-Floodplain EcosystemsSignificant economic advantages and increased biodiversity and stability would result from restoration of impaired systems , 1995 .

[19]  J. Stanford,et al.  Ecological connectivity in alluvial river ecosystems and its disruption by flow regulation , 1995 .

[20]  W. Admiraal,et al.  Present state of the water quality of European rivers and implications for management. , 1994 .

[21]  J. Ward.  RIVERINE LANDSCAPES: BIODIVERSITY PATTERNS, DISTURBANCE REGIMES, AND AQUATIC CONSERVATION , 1998 .