Handbook of vegetation science FOUNDED BY R. TÜXEN H. LIETH, EDITOR IN CHIEF Volume 15/1 Vegetation of inland waters Vegetation of inland waters Edited by J. J. SYMOENS Kluwer Academic Publishers DORDRECHT - BOSTON - LONDON Library of Congress Cataloging in Publleation Data Vegetation of inland waters / J.J. SYloens. editor. p. CII. -- (Handbook of vegetat i on sc I ence ; pt. 15/1) Includes index. ISBN 9061931967 1. Freshwater flora. I. SYlloens. J. J. (Jean-Jacques) II. Series: Handbook of vegetatlon science ; 15/1. QK105.V44 1988 581.5·2632--dc19 87-33796 CIP lSBN-13: 978-94-010-7887-0 e-lSBN-13: 978-94-009-3087-2 DOT: 10.1007/978-94-009-3087-2 Kluwer Aeademie Publishers ineorporates the publishing programmes of Dr W. Junk Publishers, MTP Press, Martinus Nijhoff Publishers, and D. Reidel Publishing Company. Distributors for the United States and Canada: Kluwer Aeademie Publishers, 101 Philip Drive, Norwell, MA 02061, USA for all other countries: Kluwer Aeademie Publishers Group, P.O. Box 322, 3300 AH Dordreeht, The Netherlands Copyright © 1988 by Kluwer Aeademic Publishers, Dordreeht. Softcover reprint of the hardcover I st edition 1988 All rights reserved. No part of this publieation may be reprodueed, stored in a retrieval system, or transmitted in any form or by any means, mechanieal, photoeopying, re eording, or otherwise, without the prior written perrnission from the copyright owners. CONTENTS Series Editor's preface Vll ~~ a List of Contributors Xlll Water as an environment for plant life, by R. G. Wetzel 1 Methods of exploration and analysis of the environment of aquatic vegetation, by H. L. Golterman, R. S. Clymo, E. P. H. Best and J. Lauga 31 Photosynthesis of aquatic plants under natural conditions, by M. S0ndergaard 63 Structural aspects of aquatic plant communities, by C. den Hartog and G. van der Velde 113 The phytosociological approach to the description and classifi- cation of aquatic macrophytic vegetation, by E. P. H. Best 155 Algal communities of continental waters, by J. J. Symoens, E. Kusel-Fetzmann and J. P. Descy 183 Vegetation processes in swamps and flooded plains, by C. M. Breen, K. H. Rogers and P. J. Ashton 223 The vegetation of fens in relation to their hydrology and nutrient dynamics: a case study by J. T. A. Verhoeven, W. Koerselman and B. Beltman 249 Water flow and the vegetation of running waters, by F. H. Dawson 283 Analysis of flora and vegetation in rivers: concepts and appli- cations, by G. Wiegleb 311 Aquatic plants in extreme environments, by J. M. Melack 341 Index 379 v SERIES EDITOR'S PREFACE By 1988 the Handbook of Vegetation Science is well on its way to completion. With 7 volumes in circulation, 3 volumes in the press, and most of the remaining volumes in preparation it appears that the total task can be completed in the early 'nineties. I am especially thankful to Professor Symoens for accepting the task of editing the volume on aquatic vegetation. The main emphasis of work in phytosociology is devoted to land plants, yet the landscape analysis remains incomplete without the consideration of rivers and lakes. Avolume on inland aquatic vegetation must therefore be most helpful to the land vegetation analyst and not only to the specialist on aquatic vegetation. Professor Symoens succeeded in drafting the most competent team for his task. I am sure that all colleagues working in vegetation analysis will be grateful to them that they have taken the time and energy to complete their chapters. Handbook articles are not easy to write and certainly not easy to edit. The major aquatic components in the landscape are treated. The vegetation analysts will welcome the fact that certain physiological and ecological processes of water plants are covered for which otherwise they would have to consult the limnological literature. This volume, together with the forthcoming volume on wetlands, should completely cover the inland aquatic vegetation problematic. Again I thank all contributors and the editor for this volume. Mr Wil Peters and the staff of Dr W. Junk Publishers deserve our special gratitude for their continuous co-operation. It is very gratifying to see and feel the service Dr W. Junk grants our profession. This was recently expressed during the editorial board meeting of the journal Vegetatio held in Berlin on the occasion of the 14th Botanical Congress. On behalf of the editors of the handbook I can certainly express the same gratitude. I expect for this volume the same success as the previous volumes have had. I expect it to be of help to the professionals in the field as well as to the research student. Osnabrück, October 1987 H. LIETH vii FOREWORD Water is life! It is generally accepted that life on our planet originated in water, even though it is not possible to state without doubt whether it arose in sea, estuarine or inland waters. When some living organisms left the aquatic environment, they retained an aquatic medium within their cells; the average water content of biomass, terrestrial organisms included, is about 70% and many species, such as man, can only tolerate a very limited decrease in their hydration level. However, the aquatic environment often escapes man's full percep tion and consequently man's understanding and research effort. Whilst during the neolithic revolution, man replaced his gathering activities by cultivating the soil and his hunting activities by raising domesticated animals, he mostly continued to exploit the aquatic resources by capturing natural stocks; fishing is but a form of gathering. In spite of the huge extent of water ecosystems - more than two third s of our planet - aquaculture, i.e. the culture or farming of aquatic plants and animals, has lagged far behind agriculture and, even now, is but a relatively limited source of human food on a worldwide scale; the application of science and technology to aquaculture is very recent. Several reasons have been advanced to explain this backward state of the aquatic sciences: it has been suggested that man, as a terrestrlal animal, has achieved a better understanding of the life strategies and a greater mastery of the production mechanisms of terrestrial plants and anirnals than of the organisms which dwell in an aquatic environment. This part of the Handbook of Vegetation Science should contribute to a better understanding of the environmental conditions offered to plant life by inland waters, of the characteristics and adaptations of the plants which colonize the latter, and of the structural and functional features of their plant communities. Although the general principles of ecology and biocenotics are cornmon to both aquatic and terrestrial communities, the water en- lX x vironment is less accessible to the observer's eye: it requires specialized methods and equipment of investigation as soon as the depth goes beyond a few decimeterso Although the biochemical pathways of photosynthesis are fundamen tally the same in water and land plants, the assimilation of carbon dioxide from several forms of dissolved inorganic carbon is a feature peculiar to aquatic plant life. The most important forms of life and growth of aquatic plants were identified long ago by the analysts of vegetation structure, but a more detailed analysis of the morphological responses of the plants to the totality of environmental factors shows the adaptative richness of water vegetation. It is noteworthy that water, due to its high density, is a very favourable medium for sustaining plants; submersed plants have no need to develop a large mechanical structure to provide support and can thus concentrate their activity in the development of productive chlorophyll-containing eelIs. This explains the rapid growth of many aquatic plants. It also explains why aquatic plants can so easily become troublesome weeds. The phytosociology of aquatic plant communities - macrophytic or microphytic - is faced with problems which do not arise in terrestrial communities. In the aquatic habitat where many macrophytes and most microphytes are not bound to the soil, the plants may be transported by water currents and the assemblage present in any given water sample may consist of populations derived from different habitats and adapted to respond to substantially different sets of conditions. Several com munities may occur in the same place as a mixture and should be treated with a synusial approach. Two environmental factors peculiar to the aquatic medium play a decisive role in two types of water habitats: the highly variable hydro logical regime in the flooded plains and the water current in the fluviatile habitats. Some species of water plants are able to colonize extreme aquatic environments: e.g. autotrophic prokaryotes, the cyanobacteria (most of them commonly known as blue-green algae), live in waters with tem ·e! peratures up to 73 All this justifies devoting separate volumes of the Handbook of Vegetation Science to Aquatic Vegetation; this volume, 15/1 to the Vegetation of Inland Waters and volume 15/2 will be devoted to the Wetlands of the World. We thank the authors of the individual chapters in this volume for their excellent treatment. There was an unforeseen delay in putting together all chapters due to the fact that they were written by over committed specialists who nevertheless agreed to give us the fruits of their knowledge, their experience and their reflections on perspectives xi for future research. The diversity of their approaches contributes to the richness of this volume, even if they do not hold identical views on some points. As the editor of this volume, I wish to express once more my sineere thanks to all of them for their contributions. J. J. SYMOENS LIST OF CONTRIBUTORS P. J. Ashton, National Institute for Water Research, C.S.I.R., P.O. Box 395, Pretoria 0001 (South Africa). B. Beltman, Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, 3512 PN Utrecht (The Netherlands). E. P. H. Best, Centre for Agrobiological Research, P.O. Box 14, 6700 AA Wageningen (The Netherlands). C. M. Breen, Institute for Natural Resources, University of Natal, P.O. Box 375, Pietermaritzburg 3200 (South Africa). R. S. Clymo, School of Biological Sciences, Queen Mary College, University of London, London El 4NS (England). F. H. Dawson, River Laboratory, Freshwater Biological Association, East Stoke, Wareham, Dorset BH20 6BB (England). C. den Hartog, Laboratory of Aquatic Ecology, Catholic University, Toernooiveld, 6525 ED Nijmegen (The Netherlands). J. P. Desey, Unite d'Ecologie des Eaux douces, Facultes universitaires N.-D. de la Paix, rue de Bruxelles 61, B-5000 Namur (Belgium). H. L. Golterman, Station biologique de la Tour du Valat, Le Sambuc, F-13200 Arles (France). W. Koerselman, Department of Plant Ecology, University of Utrecht, Lange Nieuwstraat 106, 3512 PN Utrecht (The Netherlands). E. Kusel-Fetzmann, Institut für Pflanzenphysiologie, Universität Wien, Althanstrasse 14, A-1091 Wien (Austria). J. Lauga, Centre d'Ecologie des Ressources renouvelables, Centre national de la Recherche scientifique, 29, rue Jeanne Marvig, F-31000 Toulouse (France). J. M. Melack, Department of Biological Sciences and Marine Science Institute, U niversity of California, Santa Barbara, California 93106 (U.S.A.). K. H. Rogers, Botany Department, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2001 (South Africa). J. J. Symoens, Laboratorium voor Algemene Plantkunde en Natuur beheer, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel (Belgium).