WETLANDS IN AGRICULTURAL AREAS Complementary measures to reduce nutrient transport to inland and coastal waters By: Ekologgruppen July 2000 Life fund beneficiary: Lunds kommun Tekniska förvaltningen Sweden Start date: 960701 Project No: LIFE96ENV/S/346 Reporting period: NV/S/346 960701-991031 FINAL REPORT Front page: Wetland in the watershed of Kävlinge river (1999). Photographs: All photographs have been taken by Ekologgruppen, except figure No 10 and 11(right) which were taken by Olle Nordell Ekologgruppen i Landskrona AB Contributory authors: Tette Alström, Karl Holmström, Johan Krook, David Reuterskiöld, Cecilia Torle, Lena Tranvik and Bengt Wedding E-mail: [email protected] Investigations: Studies of biological diversity, David Reuterskiöld (vegetation), Johan Krook and Cecilia Torle (macroinvertebrates), Martin Granbom (birds) Analysis of water chemistry: Bengt Wedding in co-operation with the laboratory at Lunds sewage plant Thanks to Lars Jacobsson for constructive comments on the manuscript and to Emilie Björling for valuable linguistics comments. Life-coordinator: Lars Jacobsson Lunds kommun, Tekniska förvaltningen, Park- och naturkontoret Byggmästaregatan 4, S-222 37 Lund, Sweden Tel +46-46-35 50 00, Fax +46-46-35 67 10 E-mail: [email protected] Wetlands in agricultural areas Final report TABLE OF CONTENTS SUMMARY..............................................................................................................................1 1. INTRODUCTION .................................................................................................................3 Background............................................................................................................................3 Incentives...............................................................................................................................3 Aim .......................................................................................................................................4 Presentation of the working area..............................................................................................4 2. PROJECT MANAGEMENT AND MAIN TASKS ..................................................................6 Project management ...............................................................................................................6 Organisation .......................................................................................................................7 Finances.............................................................................................................................7 Discussion of the organisational and financial prerequisites ...................................................8 Main tasks............................................................................................................................10 Discussion of other interests on which implementation of the project depends ......................11 3. TECHNICAL ACTIONS AND RESULTS............................................................................13 Wetlands..............................................................................................................................13 Construction .....................................................................................................................13 Type of wetland................................................................................................................14 Number and area of wetlands.............................................................................................16 Distribution of wetlands ....................................................................................................16 Technical problems ...........................................................................................................18 Conflicts with other interests .............................................................................................19 Buffer-strip establishment .....................................................................................................20 New wetlands and bufferstrips in agricultural areas – discussion..............................................21 What is the limit of creating wetlands in a watershed?.........................................................21 Can limiting factors be adjusted? .......................................................................................21 How should buffer strip establishment be carried out?.........................................................23 Conclusions..........................................................................................................................23 4. ENVIRONMENTAL BENEFITS .........................................................................................24 Investigations .......................................................................................................................24 Retention of nutrient and suspended matter ............................................................................24 Biological diversity in constructed wetlands ...........................................................................29 Bird life............................................................................................................................29 Benthic macroinvertebrate fauna........................................................................................30 Vegetation........................................................................................................................31 Benefits of buffer strips.........................................................................................................33 Other environmental effects of wetland and buffer strip implementation...................................33 Hydrological aspects.........................................................................................................33 Recreational aspects..........................................................................................................33 Historical aspects..............................................................................................................33 Conclusions..........................................................................................................................34 5. DISSEMINATION ..............................................................................................................35 6. TOTAL COSTS OF A LARGE SCALE PROJECT................................................................38 Costs above the Life budget ..................................................................................................38 Main expenses......................................................................................................................38 Financial support and subsidies..............................................................................................39 The costs of a single wetland .................................................................................................39 Value for money...................................................................................................................39 Conclusions..........................................................................................................................40 7. LIFE – COST SUMMARY...................................................................................................41 Wetlands in agricultural areas Final report 8. GENERAL CONCLUSIONS................................................................................................43 Results and experiences ........................................................................................................43 Environmental benefits......................................................................................................43 Other experiences .............................................................................................................43 Problems and difficulties ...................................................................................................43 General views on large scale wetland implementation .............................................................44 LITERATURE ........................................................................................................................45 Annexes: 1. The process of wetland construction 2. Wetlands constructed 3. Buffer-strips constructed 4. Bird study - list of species 5. Invertebrate study - list of species 6. Vegetation study - list of species Separate annexes: Extended Summary (Layman's version of Final report) - Wetlands in agricultural areas - experiences from a Life project Account of Life project economy (Financial report) In this report the term “wetland” comprises traditional wetlands (shallow, more or less permanent waters) as well as ponds. 1 Wetlands in agricultural areas Final report Summary A project based on a regional co-operation with ten municipalities involved to improve water quality, reduce nutrient transport and increase biodiversity in intensively cultivated farmland, is presented. Establishment of wetlands and buffer-strips which improve the nutrient-reducing capacity of the landscape, are used as a complement to efforts within sewage treatment and agriculture. The measures are implemented in full scale within the watersheds of the Höje and Kävlinge rivers in the Southwest part of Sweden