Assessing hydromorphological degradation of sand-bottom lowland rivers in Central Europe using benthic macroinvertebrates Inaugural-Dissertation zur Erlangung des Doktorgrades Dr. rer. nat. des Fachbereichs Biologie und Geografie an der Universität Duisburg-Essen vorgelegt von Christian K. Feld geboren in Emsdetten Februar, 2005 Tag der mündlichen Prüfung: 19.07.2005 Gutachter: 1. PD. Dr. Daniel Hering, Essen 2. Prof. Dr. Elisabeth I. Meyer, Münster Die der vorliegenden Arbeit zugrunde liegenden Experimente wurden am Institut für Ökologie in der Abteilung Hydrobiologie der Universität Duisburg-Essen durchge- führt. 1. Gutachter/in: PD Dr. Daniel Hering, Universität Duisburg-Essen, Essen 2. Gutachter/in: Prof. Dr. Elisabeth I. Meyer, Westfälische Wilhelms-Universität Münster 3. Gutachter/in: -- Vorsitzender des Prüfungsausschusses: Prof. Dr. Kuttler, Universität Duisburg-Essen, Essen Tag der mündlichen Prüfung: 19.07.2005 Acknowledgements First of all I would like to thank my advisor Prof. Dr. Helmut Schuhmacher for the offer to prepare my thesis in his department at the University of Duisburg-Essen. I’m especially grateful to PD Dr. D. Hering for his exceptional and always constructive guidance through the last years. This includes the opportunity to work in several international and national research projects. Thank you very much Daniel! Numerous helping hands have contributed to this thesis by assistance during the field and lab work. Special thanks to Marta Wenikajtys and Jörg Tenholtern for company and help during the long-term sample trips throughout the Central European lowland and the lab processing of many samples. I’m grateful to Dr. Armin Lorenz and Peter Rolauffs for their contribution to the identification of the benthic invertebrates and together with Dr. Jochem Kail for numerous stimulating discussions. Thanks also to Dr. Jochem Kail and Tanja Pott- giesser for proofreading. I would like to thank Dr. V. W. Framenau, Western Australian Museum, Perth, Australia, for numerous valuable comments on and linguistic revision of Chapters 3 and 4. Thanks to Dr. Barbara Bis, University of Lodz, Poland, for the cooperation and assistance during the field trips in Poland. Thanks also to Barbara for managing my car being repaired! For their cooperative readiness for help, I would like to thank the following members (and former members) of the Department of Hydrobiology, University of Duisburg-Essen: Sandra Kramm, Dr. Armin Lorenz, Carolin Meier, Dr. Steffen Pauls, Peter Rolauffs, Dr. Mario Sommerhäuser, and Jörg Strackbein. Special thanks are due to the AQEM and STAR partners, particularly to Dr. Piet F. M. Ver- donschot, Alterra Wageningen, The Netherlands, and Dr. Leonard Sandin, SLU Uppsala, Sweden, for providing their unpublished data. And finally, a special thank is due to my parents Elisabeth and Hugo Feld, and to Tanja Pottgiesser for their extensive support and their encouraging trust in my work. This thesis was derived from the data of two research projects funded by the European Un- ion through the 5th Framework Programme: Energy, Environment, and Sustainable Develop- ment; Key Action Water: ‘The development and testing of an integrated assessment system for the ecological quality of streams and rivers throughout Europe using benthic macroin- vertebrates’ (AQEM; Contract No.: EVK1-CT 1999-00027) and ‘Standardisation of River Classifications’ (STAR; Contract No.: EVK1-CT 2001-00089). The research in Poland (‚The definition of macroinvertebrate-based reference conditions’ DEMARECO; Aktenzei- chen: H 150 5506 9999 10605) was funded by the German Research Foundation (‘Stifterverband für die Deutsche Wissenschaft’). The analysis of the German monitoring data (Chapter 2) was partly supported by the Länderarbeitsgemeinschaft Wasser (LAWA; Project No.: O 3.02). I’m grateful to all agencies who made their data available for this study. Contents Contents 1 Introduction ....................................................................................... 1 1.1 The European Water Framework Directive (EU WFD)...........................................1 1.2 The need for advanced assessment systems ...........................................................2 1.3 The application of multi-metric assessment systems ..............................................2 1.4 The role of spatial scales ......................................................................................3 1.5 Scope of this thesis...............................................................................................4 2 Delineation of German and Central European lowland stream types ................................................................................................... 6 2.1 Scope ...................................................................................................................6 2.2 Summary..............................................................................................................7 2.3 Introduction .........................................................................................................7 2.4 Material and methods...........................................................................................8 2.4.1 Data source and preparation..................................................................................8 2.4.2 Statistical analysis..............................................................................................10 2.5 Results ...............................................................................................................10 2.5.1 German monitoring data .....................................................................................10 2.5.2 AQEM lowland data ...........................................................................................12 2.6 Discussion..........................................................................................................16 2.6.1 German monitoring data .....................................................................................16 2.6.2 AQEM lowland data ...........................................................................................18 2.7 Conclusions........................................................................................................20 3 Identification and measure of hydromorphological degradation in Central European lowland streams....................................................21 3.1 Scope .................................................................................................................21 3.2 Summary............................................................................................................21 3.3 Introduction .......................................................................................................22 3.4 Material and methods .........................................................................................23 3.4.1 Data collection ...................................................................................................23 3.4.2 Stream characteristics.........................................................................................24 3.4.3 Selection of sampling sites .................................................................................27 3.4.4 Evaluation of stream type assignment and hydromorphological degradation.........27 3.4.5 Development of a Structure Index for German lowland streams ...........................28 3.4.6 Statistical analysis..............................................................................................29 3.5 Results ...............................................................................................................31 3.5.1 Stream type assignment ......................................................................................31 I Contents 3.5.2 Evaluation of hydromorphological degradation: All stream types ........................ 31 3.5.3 Evaluation of hydromorphological degradation: German stream types ................. 36 3.5.4 Development of a Structure Index for German lowland streams ........................... 36 3.6 Discussion ......................................................................................................... 39 3.6.1 Stream type assignment ...................................................................................... 39 3.6.2 Evaluation of hydromorphological degradation: All stream types ........................ 40 3.6.3 Evaluation of hydromorphological degradation: German stream types ................. 41 3.6.4 Development of a Structure Index for medium-sized sand bottom rivers in the German lowlands................................................................................................ 42 4 Linking macroinvertebrate taxa and derived ecological metrics to hydromorphology and land use at different spatial scales in Central European lowland rivers: a multivariate approach .............. 44 4.1 Scope................................................................................................................. 44 4.2 Summary............................................................................................................ 44 4.3 Introduction ....................................................................................................... 45 4.4 Material and methods......................................................................................... 46 4.4.1 Study site..........................................................................................................