Biogeography: A Study of Plants in the Ecosphere

473 Pages·1993·23.024 MB·English

by  Joy Tivy

Biogeography
A Study of Plants in the Ecosphere
Third Edition
Joy Tivy
Joy Tivy
Biogeography
A Studyo jP lants in the Ecosphere
Third Edition
Routledge
Taylor & Francis Group
LONDON AND NEW YORK
first published 1993 by Pearson Education Limited
Published 2014 by Routledge
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Copyright© 1993, Taylor & Francis.
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Notices
Knowledge and best practice in this field are constantly changing. As new research and
experienceb roaden our understanding, changes in research methods, professional
practices, or medica !treatment may become necessary.
Practitioners and researchers must always rdy on their own experience and knowledge
inevaluating <md using any information, method~, compounds, or experiments described
herein.lnusing such inrormation or methods they should be mindrul of their own safety
and the safety ofothers, including parties for whom they have a professional
responsibility.
To the fullest extent of the law, neither the Publisher nor the authors, contributors, or
editors,assume any liability for any injury and/or damage to persons or property as a
maller ofproductsliability, negligence or otherwise, or from any use or operation of any
methods, products, instructions, or ideas contained in the material herein.
ISBN 13: 978-0-582-08035-5 (pbk)
British Library Cataloguing in Publication Data
A CIP record for this book is available from the British Library
Library ofC ongress Cataloging-in-Publication Data
A C[P record for this book is available from the Library of Congress
Contents
Prefacet o the First Edition v
Prefacet o the SecondE dition ix
Prefacet o the Third Edition
Xlll
Acknowledgements
XVIi
Chapter 1 Introduction 1
PART! THE BIOSPHERE
Chapter 2 Theb iosphere 12
Chapter 3 Environmentavl ariables 33
Chapter 4 Historicalb iogeography 55
Chapter 5 Biomassc haracteristics 79
Chapter 6 Biological productivity 107
Chapter 7 Theb iologicalc ycle 129
Chapter 8 Biomassc hangea nds oil development 150
PART II ECOSYSTEMS
Chapter 9 Tropicala ndt emperatefo reste cosystems 174
Chapter1 0 Boreale cosystems 196
Chapter1 1 Grasslande cosystems 212
Chapter1 2 Deserte cosystems 228
Chapter13 Islande cosystems 246
Chapter1 4 Mountaine cosystems 258
iii
Contents
Chapter1 5 Aquatic ecosystems 272
PART III BIOTIC RESOURCES:U SE AND MISUSE
Chapter1 6 Ecosystems tability andd isturbance 292
Chapter1 7 Humani mpact:e cosysteme xploitation 311
Chapter1 8 Humani mpact:e nvironmentapl ollution 331
Chapter1 9 Managede cosystems 347
Chapter2 0 Theu rbane cosystem 371
Chapter2 1 Conservation 382
Assignments 399
Glossary 405
References 411
Index 441
tv
Preface to the first edition
Biogeographyis the 'Cinderella'o f geography.I t is still a relatively neglecteda nd
underdevelopedf ield of study at both school and university, despite the
considerableli p-service that has beenp aid to its significance.M any have drawn
attention to its value in providing (within the framework of the early formulated
and recently 'rediscoverede' cosystemc oncept)a n integratedh olistic approacht o
environmentals tudies. Some have accordedi t the distinction of being the 'vital'
link between physical and Iiuman geography. Others have enthusiastically
advocated( without necessarilyd emonstrating)it s potential as a meanso f unifYing
a subjectw hosep eripheralo rganso ften seemt o be growing at a rate greatert han
that of its body! That biogeographyi s slowly gaining greater recognition is
unquestionable. However, there are still all too few British or American
universities where, in generalp hysical geographyc ourses,i t receives or attracts
the same attention as either climatology or geomorphology- and fewer still
where it can be pursueda t a more advancedH onours level. In the latter cases
instruction is often relegated to departmentso f biology, botany, zoology or
pedology. Those who go so far as to profess biogeographya re 'rare', indeed
some would say 'odd' species. English textbooks on the subject, written by
geographers,c an be counted on one hand. A large proportion of its most
elementary data must be distilled from non-geographicala nd often highly
specialiseda nd technical biological sources.A nd developmentsin the latter have
long outstrippedt hosei n biogeography.
There are good reasonsi f not necessarilyv alid excusesf or this stateo f affairs.
First, becauseo f the range of phenomenaw ith which the biographeri s faced, his
field of study is less amenable to isolation and systematisationt han other
brancheso f physical geography,s uch as climatology, hydrology or geomorphol-
ogy. Biogeographyi s not easy to define or delimit precisely; and the distinction
betweeni t and the closely related subject of ecology often tends to be more a
function of scalea nd emphasist hat of contento r method.S econd,t he majority of
teachersa nd studentso f geographyw, hethera t schoolo r university,k now muchl ess
aboutt he naturea nd scopeo f biogeographyth an aboutp ractically any othera spect
of their subject. Opportunities to combine a study of biology and geography
v
Prefoce to the first edition
are limited. Unfamiliarity (exacerbatedb y a high degreeo f urbanisation)w ith even
the most commonp lants hast endedt o createa psychologicalb arrier which makes
the averageg eographys tudentc hary of involving him- or herselft oo deeply in a
field which requirest he acquisition of a whole lot of new and apparentlyh ighly
'technical't erms (amongw hich Latin namess eemt o be the most daunting!) and
concepts. And the continuing emphasisi n many, particularly school, texts on
'explanatory'd escriptionso f the vegetationo r soils of the world, often completely
divorced from any concretet erms of reference,h as done little to overcomet his
'built-in' resistancea nd to stimulatei nteresti n the subject.
This book is the product of a long period of 'experimentationi'n the teaching
of biogeographya t various levels to university students,m any of whom had no
previous training in biology, or for that matter in any of the physical sciences.I ts
aim is twofold. The first is to summarisea nd explain (in a way which it is hoped
will be comprehensivea nd palatablet o teachersa nd studentsa t sixth form and
university levels) those biological processesa nd concepts which the author
considersb asic to the understandingo f the principal characteristicso f, and the
complex interrelationshipsw ithin, the 'organic world' or 'biosphere'. In the
interestso f clarity an attempth asb eenm adet o cut a path throught he terminology
jungle of ecology and to be selective,i ndeeda s sparinga s possible,i n the use of
uncommona nd!o r exotic plant and animal names.T he secondis to bring together
the basesa nd aspectso f biogeographyw hich at presentc an only be obtainedf rom
a great number of widely scattereds ourcesa nd, in doing so, to bridge the gap
between the earlier traditional zonal study of vegetation and soil and modern
developments,p articularly in plant ecology. The theme is that of organic
resourcesa, nd the reciprocalr elationshipb etweent hesea ndm an. Throughout,t he
emphasisis on plants,a s the primary food producersw hich form the essentialli nk
betweenm an and his physicale nvironment.T he first half of the book is concerned
with a systematica nalysis of the effect of environmental( ecological) factors -
climate, soil, biological competition, animals and man on the functioning,
evolution and adaptation,a nd distribution of plants.T he secondh alf dealsw ith the
nature of vegetation and a considerationo f the principal characteristicso f the
structurea nd function of the major types of ecosystems- marine,f orest, grassland
and desert - and the potentialities and problems of their particular organic
resourcesfo r use by man through time.
It is hoped that this book will go some way to answeringt he perennialc ri de
ca:ur of the aspiring student of biogeographyf or a basic textbook which would
provide a starting-pointa nd a guide to the highly ramified highways and byways
of a vast and complex field. In its compilation the author has drawn on and
selectedf rom a wide variety of sources.H owever, it was decidedi n the interesto f
readabilityt o omit numberedr eferencesin the text. The lists of referencesa re not,
nor were they intendedt o be, comprehensiveT. hey do, however,i nclude all those
sourceso n which each chapterh as been based,a nd they were selecteda s those
mostv aluablea nd relevantt o further elucidationa nd a deepers tudy of the subjects
underc onsideration.
Finally the author would like to acknowledge her indebtednesst o those
generationso f geographys tudentsa t the Universities of Edinburgh and Glasgow
VI
Preface to the first edition
whose lively interest and constructive CrItIcIsm in the classroom and extreme
fortitude in the field were a continuing sourceo f inspiration. Without them, and
the constante ncouragemenot f long-suffering friends and colleagues,t his book
would neverh ave beenw ritten.
VI1
This pagei ntentionallyl eft blank
Preface to the seconde dition
In the decades ince the first edition of this book was publishedb iogeographyh as
'come of age', and what David Watts has called 'The new biogeography'h as
emerged to take its place as a generally accepteda nd reasonablyr espectable
membero f the geographicaal cademice stablishmen-t Cinderellah as gone to the
ball! Developmenti n Britain has been particularly marked along three closely
related fronts. One is in the teachingo f the subject.T he numbera nd diversity of
courseso ffered at the higher educationall evels have multiplied. There are now
few university or college geography departments which do not include
biogeographya s an integral element in their basic introductory and common
physical geographyc ourses.T he numbera nd range of option coursesi n the field
have proliferated at an almost exponentialr ate. And at least one membero f staff
professingb iogeographyi s now a sine qua non of any self-respectingu niversity
geographyd epartment.U ndoubtedly, as Watts notes, the growth in the scope
and range of the subject during the 1970s has been encouraged by the
concurrent increase in joint Honours degrees, the development of new
multidisciplinary coursesi n the life and environmentals ciences,a nd in resource
management,to all of which biogeographyh as contributed an often important
integrative element. In addition, teaching at introductory levels in universities
and colleges has been greatly facilitated and stimulated by the increase in
numberso f young second-and third-generationb iogeographersc oming into the
profession; and not least by the publication of several basic, and happily
complementary,t extbooks of which those by Cruickshank,C urtis and Trudgill,
Pears,S immonsa nd Watts, are importantm ilestones.
Unfortunately, in spite of these trends in higher education,t he feedbacki nto
school examinations yllabusesh as not yet had any really marked impact. A recent
report by the GeographicalA ssociation on 'Biogeographyi n the Sixth Form'
deplores the fact that its treatmenta t school level is, if not neglectede ntirely,
variable; it is still too descriptiveo f zonal world types of soil and vegetationa nd is
not yet sufficiently ecological in its approach;w hile its integrative potential is
ix