EIPA01 10/24/05 1:36 PM Page i ECOLOGY From Individuals to Ecosystems •• EIPA01 10/24/05 1:36 PM Page ii •• •• EIPA01 10/24/05 1:36 PM Page iii ECOLOGY From Individuals to Ecosystems MICHAEL BEGON School of Biological Sciences, The University of Liverpool, Liverpool, UK COLIN R. TOWNSEND Department of Zoology, University of Otago, Dunedin, New Zealand JOHN L. HARPER Chapel Road, Brampford Speke, Exeter, UK FOURTH EDITION •• •• EIPA01 10/24/05 1:36 PM Page iv © 1986, 1990, 1996, 2006 by Blackwell Publishing Ltd BLACKWELL PUBLISHING 350 Main Street, Malden, MA 02148-5020, USA 9600 Garsington Road, Oxford OX4 2DQ, UK 550 Swanston Street, Carlton, Victoria 3053, Australia The right of Mike Begon, Colin Townsend and John Harper to be identified as the Authors of this Work has been asserted in accordance with the UK Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs, and Patents Act 1988, without the prior permission of the publisher First edition published 1986 by Blackwell Publishing Ltd Second edition published 1990 Third edition published 1996 Fourth edition published 2006 1 2006 Library of Congress Cataloging-in-Publication Data Begon, Michael. Ecology : from individuals to ecosystems / Michael Begon, Colin R. Townsend, John L. Harper.—4th ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-1-4051-1117-1 (hard cover : alk. paper) ISBN-10: 1-4051-1117-8 (hard cover : alk. paper) 1. Ecology. I. Townsend, Colin R. II. Harper, John L. III. Title. QH54.B416 2005 577—dc22 2005004136 A catalogue record for this title is available from the British Library. 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For further information on Blackwell Publishing, visit our website: www.blackwellpublishing.com •• •• EIPA01 10/24/05 1:36 PM Page v Contents Preface, vii Introduction: Ecology and its Domain, xi Part 1: Organisms 1 Organisms in their Environments: the Evolutionary Backdrop, 3 2 Conditions, 30 3 Resources, 58 4 Life, Death and Life Histories, 89 5 Intraspecific Competition, 132 6 Dispersal, Dormancy and Metapopulations, 163 7 Ecological Applications at the Level of Organisms and Single-Species Populations: Restoration, Biosecurity and Conservation, 186 Part 2: Species Interactions 8 Interspecific Competition, 227 9 The Nature of Predation, 266 10 The Population Dynamics of Predation, 297 11 Decomposers and Detritivores, 326 12 Parasitism and Disease, 347 13 Symbiosis and Mutualism, 381 14 Abundance, 410 15 Ecological Applications at the Level of Population Interactions: Pest Control and Harvest Management, 439 •• •• EIPA01 10/24/05 1:36 PM Page vi vi CONTENTS Part 3: Communities and Ecosystems 16 The Nature of the Community: Patterns in Space and Time, 469 17 The Flux of Energy through Ecosystems, 499 18 The Flux of Matter through Ecosystems, 525 19 The Influence of Population Interactions on Community Structure, 550 20 Food Webs, 578 21 Patterns in Species Richness, 602 22 Ecological Applications at the Level of Communities and Ecosystems: Management Based on the Theory of Succession, Food Webs, Ecosystem Functioning and Biodiversity, 633 References, 659 Organism Index, 701 Subject Index, 714 Color plate section between pp. 000 and 000 •• •• EIPA01 10/24/05 1:36 PM Page vii Preface A science for everybody – but not an easy science Nineteen years on: applied ecology has come of age This book is about the distribution and abundance of different types of organism, and about the physical, chemical but especially This fourth edition comes fully 9 years after its immediate pre- the biological features and interactions that determine these decessor and 19 years after the first edition. Much has changed – distributions and abundances. in ecology, in the world around us, and even (strange to report!) Unlike some other sciences, the subject matter of ecology is in we authors. The Preface to the first edition began: ‘As the cave apparent to everybody: most people have observed and pondered painting on the front cover of this book implies, ecology, if not nature, and in this sense most people are ecologists of sorts. But the oldest profession, is probably the oldest science’, followed by ecology is not an easy science. It must deal explicitly with three a justification that argued that the most primitive humans had to levels of the biological hierarchy – the organisms, the populations understand, as a matter of necessity, the dynamics of the envir- of organisms, and the communities of populations – and, as onment in which they lived. Nineteen years on, we have tried to we shall see, it ignores at its peril the details of the biology of capture in our cover design both how much and how little has individuals, or the pervading influences of historical, evolution- changed. The cave painting has given way to its modern equi- ary and geological events. It feeds on advances in our knowledge valent: urban graffiti. As a species, we are still driven to broadcast of biochemistry, behavior, climatology, plate tectonics and so on, our feelings graphically and publicly for others to see. But but it feeds back to our understanding of vast areas of biology simple, factual depictions have given way to urgent statements too. If, as T. H. Dobzhansky said, ‘Nothing in biology makes of frustration and aggression. The human subjects are no longer sense, except in the light of evolution’, then, equally, very little mere participants but either perpetrators or victims. in evolution, and hence in biology as a whole, makes sense Of course, it has taken more than 19 years to move from except in the light of ecology. man-the-cave-painter to man-the-graffiti-artist. But 19 years ago Ecology has the distinction of being peculiarly confronted it seemed acceptable for ecologists to hold a comfortable, object- with uniqueness: millions of different species, countless billions ive, not to say aloof position, in which the animals and plants of genetically distinct individuals, all living and interacting in a around us were simply material for which we sought a scientific varied and ever-changing world. The challenge of ecology is to understanding. Now, we must accept the immediacy of the develop an understanding of very basic and apparent problems, environmental problems that threaten us and the responsibility in a way that recognizes this uniqueness and complexity, but seeks of ecologists to come in from the sidelines and play their full part patterns and predictions within this complexity rather than being in addressing these problems. Applying ecological principles is not swamped by it. As L. C. Birch has pointed out, Whitehead’s recipe only a practical necessity, but also as scientifically challenging as for science is never more apposite than when applied to ecology: deriving those principles in the first place, and we have included seek simplicity, but distrust it. three new ‘applied’ chapters in this edition, organized around the •• •• EIPA01 10/24/05 1:36 PM Page viii viii PREFACE three sections of the book: applications at the level of individual remain a meeting-ground for the naturalist, the experimentalist, organisms and of single-species populations, of species inter- the field biologist and the mathematical modeler. We believe that actions, and of whole communities and ecosystems. But we all ecologists should to some extent try to combine all these facets. remain wedded to the belief that environmental action can only ever be as sound as the ecological principles on which it is based. Hence, while the remaining chapters are still largely about the Technical and pedagogical features principles themselves rather than their application, we believe that the whole of this book is aimed at improving preparedness for One technical feature we have retained in the book is the incor- addressing the environmental problems of the new millennium. poration of marginal es as signposts throughout the text. These, we hope, will serve a number of purposes. In the first place, they constitute a series of subheadings highlighting the detailed struc- Ecology’s ecological niche ture of the text. However, because they are numerous and often informative in their own right, they can also be read in sequence We would be poor ecologists indeed if we did not believe that along with the conventional subheadings, as an outline of each the principles of ecology apply to all facets of the world around chapter. They should act too as a revision aid for students – indeed, us and all aspects of human endeavor. So, when we wrote the first they are similar to the annotations that students themselves edition of Ecology, it was a generalist book, designed to overcome often add to their textbooks. Finally, because the marginal notes the opposition of all competing textbooks. Much more recently, generally summarize the take-home message of the paragraph we have been persuaded to use our ‘big book’ as a springboard or paragraphs that they accompany, they can act as a continuous to produce a smaller, less demanding text, Essentials of Ecology (also assessment of comprehension: if you can see that the signpost published by Blackwell Publishing!), aimed especially at the first is the take-home message of what you have just read, then you year of a degree program and at those who may, at that stage, have understood.