JYVÄSKYLÄ STUDIES IN BIOLOGICAL AND ENVIRONMENTAL SCIENCE 254 Antti Kanninen Aquatic Macrophytes in Status Assessment and Monitoring of Boreal Lakes JYVÄSKYLÄ STUDIES IN BIOLOGICAL AND ENVIRONMENTAL SCIENCE 254 Antti Kanninen Aquatic Macrophytes in Status Assessment and Monitoring of Boreal Lakes Esitetään Jyväskylän yliopiston matemaattis-luonnontieteellisen tiedekunnan suostumuksella julkisesti tarkastettavaksi yliopiston Ylistönrinteellä salissa YAA303 marraskuun 23. päivänä 2012 kello 12. Academic dissertation to be publicly discussed, by permission of the Faculty of Mathematics and Science of the University of Jyväskylä, in Ylistönrinne, hall YAA303, on November 23, 2012 at 12 o'clock noon. UNIVERSITY OF JYVÄSKYLÄ JYVÄSKYLÄ 2012 Aquatic Macrophytes in Status Assessment and Monitoring of Boreal Lakes JYVÄSKYLÄ STUDIES IN BIOLOGICAL AND ENVIRONMENTAL SCIENCE 254 Antti Kanninen Aquatic Macrophytes in Status Assessment and Monitoring of Boreal Lakes UNIVERSITY OF JYVÄSKYLÄ JYVÄSKYLÄ 2012 Editors Timo Marjomäki Department of Biological and Environmental Science, University of Jyväskylä Pekka Olsbo Publishing Unit, University Library of Jyväskylä Jyväskylä Studies in Biological and Environmental Science Editorial Board Jari Haimi, Anssi Lensu, Timo Marjomäki, Varpu Marjomäki Department of Biological and Environmental Science, University of Jyväskylä Cover picture by Antti Kanninen URN:ISBN:978-951-39-4953-2 ISBN 978-951-39-4953-2 (PDF) ISBN 978-951-39-4952-5 (nid.) ISSN 1456-9701 Copyright © 2 0 1 2 , by University of Jyväskylä Jyväskylä University Printing House, Jyväskylä 2012 ABSTRACT Kanninen, Antti Aquatic macrophytes in status assessment and monitoring of boreal lakes Jyväskylä: University of Jyväskylä, 2012, 50 p. (Jyväskylä Studies in Biological and Environmental Science ISSN 1456-9701; 254) ISBN 978-951-39-4952-5 (nid.) ISBN 978-951-39-4953-2 (PDF) Yhteenveto: Vesimakrofyytit boreaalisten järvien tilan arvioinnissa ja seurannassa Diss. Water management legislation requires the status assessment and monitoring of freshwaters to be based on the changes in biota by anthropogenic disturbances. Despite long research traditions, the methods and metrics for ecological assessment and monitoring of boreal lacustrine macrophytes have not been well established and hence require evaluation. The first aim of this study was to evaluate two commonly used field survey approaches and remote sensing as macrophyte monitoring methods. Secondly, the best-suited metrics for status assessment were appraised. In addition, the responses of macrophytes to anthropogenic land-use in the catchment and to rehabilitation measures were studied. Macrophyte species were more cost-effectively detected by a phytolittoral species inventory than by using a transect method, making the former better suited for surveys of biodiversity and rare taxa. However, the ecologically important zonation of vegetation can be quantified with transects, favouring the latter for ecological assessment. Aerial photograph interpretation produced life-form-level, not taxonomically exact, information on macrophytes, making it useful for evaluating long-term changes of vegetation in response to management. A metric based on remote sensing data was found applicable for comparing macrophyte abundance among lakes and hence in bioassessment. The general taxonomic metrics were able to unify assessments across pressure gradients. Therefore, despite being more sensitive to methodological variation, conceptually sound general measures, rather than conventional stressor-specific indicator metrics, should be used as primary tools in the bioassessment of freshwaters. Status grading of macrophytes was in accordance with other present biota and biotic sediment records in showing significant changes in the ecological condition of a managed, eutrophic lake. Macrophyte metrics, especially general taxonomic metrics, showed a stronger response to land-use in the direct vicinity of the lake shoreline than in the whole catchment. This may have implications for optimal targeting of mitigation measures. Keywords: remote sensing, survey methods, Water Framework Directive Antti Kanninen, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland Author’s address Antti Kanninen Department of Biological and Environmental Science P.O. Box 35 40014 University of Jyväskylä Finland [email protected] Supervisors Dr. Heikki Hämäläinen Department of Biological and Environmental Science P.O. Box 35 40014 University of Jyväskylä Finland Professor Seppo Hellsten Finnish Environment Institute P.O. Box 413 90014 University of Oulu Finland Reviewers Professor Heikki Toivonen Finnish Environment Institute P.O. Box 140 00251 Helsinki Finland PhD Nigel Willby School of Natural Sciences University of Stirling Stirling FK9 4LA Scotland Opponent Dr. Frauke Ecke Department of Aquatic Sciences and Assessment Swedish University of Agricultural Sciences P.O. Box 7050 750 07 Uppsala Sweden CONTENTS LIST OF ORIGINAL PUBLICATIONS ABBREVIATIONS 1 INTRODUCTION ................................................................................................... 9 1.1 Macrophyte communities of boreal lakes .................................................. 9 1.2 Ecological status assessment of freshwaters ........................................... 10 1.3 Macrophytes in lake status assessment ................................................... 11 1.4 Methods for monitoring macrophytes ..................................................... 13 1.4.1 Field surveys ................................................................................ 13 1.4.2 Remote sensing ............................................................................ 13 1.5 Aims of the study ........................................................................................ 14 2 MATERIAL AND METHODS ............................................................................ 16 2.1 Study lakes ................................................................................................... 16 2.2 Macrophyte species data (I–VI) ................................................................. 17 2.3 Remote sensing data (II, III) ....................................................................... 19 2.4 Palaeobiology and other biological data (VI) .......................................... 20 2.5 Explanatory data ......................................................................................... 20 2.6 Numerical methods .................................................................................... 21 2.6.1 Multivariate methods for community composition ............... 21 2.6.2 Macrophyte metrics for species data ........................................ 21 2.6.3 Ecological quality ratios (EQRs) ................................................ 22 2.6.4 Methods for relating macrophyte metrics to explanatory variables and sample size ........................................................... 23 2.6.5 Classification methods of remotely sensed data ..................... 23 3 RESULTS AND DISCUSSION ............................................................................ 25 3.1 Optimal species survey protocols (I) ........................................................ 25 3.2 Remote sensing as a monitoring method (II, III) .................................... 26 3.3 Methods and metrics for evaluating macrophyte status (II, IV, V, VI).... 27 3.4 Implications for lake management (III, V, VI) ........................................ 31 4 CONCLUSIONS ................................................................................................... 33 Acknowledgements ..................................................................................................... 35 YHTEENVETO (RÉSUMÉ IN FINNISH) ................................................................. 37 REFERENCES ............................................................................................................... 40 LIST OF ORIGINAL PUBLICATIONS The thesis is based on the following original papers, which will be referred to in the text by their Roman numerals I-VI. I Kanninen A., Vallinkoski V.-M., Leka J., Marjomäki T.J., Hellsten S. & Hämäläinen H. 2012. A comparison of two methods for surveying aquatic macrophyte communities in boreal lakes: implications for bioassessment. Aquatic Botany, In press. II Valta-Hulkkonen K., Kanninen A., Ilvonen R. & Leka J. 2005. Assessment of aerial photography as a method for monitoring aquatic vegetation in lakes of varying trophic status. Boreal Environment Research 10: 57–66. III Valta-Hulkkonen K., Kanninen A. & Pellikka P. 2004. Remote sensing and GIS for detecting changes in the aquatic vegetation of a rehabilitated lake. International Journal of Remote Sensing 25: 5745–5758. IV Kanninen A., Hellsten S. & Hämäläinen H. 2012. Comparing measures of taxonomic composition and stress-specific indices in status assessment of lacustrine macrophytes. Submitted manuscript. V Alahuhta J., Kanninen A. & Vuori K.-M. 2012. Response of macrophyte communities and status metrics to natural gradients and land use in boreal lakes. Aquatic Botany 103: 106–114. VI Kauppila T., Kanninen A., Viitasalo M., Räsänen J., Meissner K. & Mattila J. 2012. Comparing long-term sediment records to current biological quality element data – Implications for bioassessment and management of a eutrophic lake. Limnologica 42: 19–30. Author contributions: I The original idea was by Antti Kanninen (AK), with contributions from Veli-Matti Vallinkoski (VMV), Jarkko Leka (JL) and Heikki Hämäläinen (HH). AK, VMV and JL collected the field data. AK performed all analyses except the bootstrapping, which was conducted by Timo J. Marjomäki. AK wrote most of the paper, with comments from all other authors. II The original idea was by Kirsi Valta-Hulkkonen (KVH) and AK. All authors performed the field surveys jointly. Riitta Ilvonen (RI) and KVH were responsible for the digital image processing and interpretation. AK defined the measures of vegetation abundance. All authors interpreted the results. KVH and AK wrote most of the paper with comments from RI and JL. III The original idea was by KVH. KVH and AK planned the study. AK performed the field survey. KVH was responsible for the digital image processing and interpretation and created the biomass model. AK created the DEM. KVH and AK wrote the paper and Petri Pellikka made revisions to it. IV The original idea was by HH, with contributions from AK. AK and HH planned the study design, AK collated and processed data, Seppo Hellsten (SH) contributed the regulated lake data, and AK performed all analysis. AK wrote most of the paper with revisions from HH and comments from SH. V Janne Alahuhta (JA) was responsible for the study idea. All authors planned the study design. AK and JA jointly collated the macrophyte data. JA processed vegetation and catchment data and AK was responsible for water quality and lake position data. AK performed NMS-analysis and JA conducted all other statistical analyses. The results were interpreted together with JA and AK. JA and AK wrote the manuscript jointly, with comments from Kari-Matti Vuori. VI The original idea was by Tommi Kauppila (TK) and AK. TK, AK and Matias Viitasalo (MV) planned the study. The subfossil diatom and akinete data was analysed by MV and Johanna Räsänen, respectively. Kristian Meissner (KM), AK and TK performed numerical analysis of the subfossil chironomid data and TK of the diatom data. Jukka Mattila and TK performed sediment dating. TK was responsible for the sediment chemistry data. AK was responsible for collating the current biological and water quality data – including performing the macrophyte field survey – and their analysis. TK, AK and KM wrote most of the paper, with comments and methodological sections from other authors.