The Conservation Atlas of Tropical Forests Africa

287 Pages·1992·71.097 MB·English

by  Jeffrey A. Sayer, Caroline S. Harcourt, N. Mark Collins (eds.)

THE CONSERVATION ATLAS
OF
TROPICAL FORESTS
AFRICA
Contributors
SIMON ANSTEY, WWF-International, Gland, ARTHUR GREEN, WWF, Korup National Park, DON MOORE, US Geological Survey, Eros Data
Switzerland Cameroon Center, Sioux Falls, USA
E.O.A. ASIBEY, World Bank, Washington, D.C., GLEN GREEN, Geology Department, Macalester TH. MULLER, National Herbarium and National
USA College, Saint Paul, Minnesota, USA Botanic Garden, Harare, Zimbabwe
SERGE BAHUCHET, Centre Nationale de MICHAEL GREEN, WCMC, Cambridge, UK DOMINIQUE N'Sosso, Ministry of Forest
Recherche Scientifique, Paris, France JOHN HALL, School of Agricultural and Forest Economy, Brazzaville, Congo
ROBERT BAILEY, Department of Anthropology, Sciences, Bangor, UK JOHN OATES, Hunter College, City University of
University of California, Los Angeles, USA ALAN C. HAMILTON, WWF, Godalming, Surrey, UK New York, USA
ANDREW BALMFORD, Large Animal Research ALEXANDER HARCOURT, Department of KATIE OFFERT, Nyungwe Forest Conservation
Group, University of Cambridge, UK Anthropology, University of California, Davis, Project, Rwanda
R.K. BAMFO, Forestry Commission, Accra, Ghana USA NICOLA O'NEILL, Swansea, Wales
RICHARD BARNES, Wildlife Conservation JOHN HART, Wildlife Conservation International, J.G.K. Owusu, Insitute ofRenewable Resources,
International, University of California, San Project Okapi, Epulu, Zaire Kumasi, Ghana
Diego, USA TERESE HART, Wildlife Conservation RISTO PAIVINEN, FINNIDA, Finland
RICHARD BARNWEU., WWF, Godalming, Surrey, UK International, Project Okapi, Zaire PRINCE PALMER, Forestry Division, Sierra Leone
JOSEPH B. BESSONG, Forestry Department, WILLIAM HAWTHORNE, ODA, Kumasi, Ghana ALEXANDER PEAL, Forestry Development
Yaounde, Cameroon PHILIPPE HECKETSWEILER, Institut Botanique, Authority, Liberia
NEIL BIRD, ODA, Kumasi Ghana Montpellier, France JEAN-YVES PIROT, IUCN Wetlands Programme,
A. BLOM, WWF, Epulu, Zaire BARRY HEWLETT, Tulane University, New Gland, Switzerland
K.T. BOATENG, Forestry Department, Accra, Orleans, USA ROGER POLHILL, Royal Botanic Gardens, Kew,
Ghana PETER HOWARD, Kampala, Uganda Surrey, UK
DENYS BOURQUE, Quebec, Canada MARK INFIELD, WWF-International, Gland, DEREK POMEROY, Zoology Department,
NEIL BURGESS, RSPB, Sandy, Bedfordshire, UK Switzerland Makerere University, Uganda
PETER BURGESS, Suffolk, UK GIL ISABIRYE-BASUTA, Kibale, Uganda G. PUNGESE, Department ofGame and Wildlife,
JOHN BURLISON, Nature Conservancy Council, MARTIN JENKINS, Cambridge, UK Accra, Ghana
Balloch, Scotland ANDY JOHNS, Kibale, Uganda S.J. QUASHIE-SAM, Institute of Renewable
TOM BUTYNSKI, Impenetrable Forest PETER JONES, -Department of Natural Resources Resources, Kumasi, Ghana
Conservation Project, Uganda and Forestry, Edinburgh University, UK SIMON RIETBERGEN, IIED, London, UK
G. CABALLE, Institut Botanique, Montpellier, SCOTT JONES, Bristol, UK ANNE ROBERTSON, National Museums ofKenya,
France CHRIS JUSTICE, NASA, Goddard Space Flight Nairobi, Kenya
JULIAN CALDECOTT, Cambridge, UK Center, Greenbelt, USA ALAN RODGERS, Cambridge, UK
PIERRE CAMPREDON, IUCN, Bissau, Guinea FRANCIS KAsISI, WWF-International, Gland, ALISON ROSSER, Cambridge, UK
Bissau Switzerland PER RYDEN, IUCN, Gland, Switzerland
RICHARD CARROLL, WWF, Dzanga-Sangha, RONALD KEAY, Cobham, Surrey, UK JACQUELINE SAWYER, IUCN, Gland, Switzerland
Central African Republic JACKIE KENDALL, NASA, Goddard Space Flight GOTZ SCHREIBER, World Bank, Washington,
JAVIER CASTROVIEJO, Asociacion Amigos de Center, Greenbelt, USA D.C., USA
Doftana, Seville, Spain OLIVIER LANGRAND, WWF, Antananarivo, HEINRICH STOLL, Bremen, Germany
KEVIN CLEAVER, World Bank, Washington, D.C., Madagascar DAVID STONE, Begnins, Switzerland
USA NIGEL LEADER-WILLIAMS, Large Animal SIMON STUART, IUCN, Gland, Switzerland
NONIE COULTHARD, RSPB, Sandy, Bedfordshire, Research Group, University of Cambridge, ROBERT SUSSMAN, Anthropology Department,
UK UK Washington University, St Louis, Missouri,
MICHAEL CROSBY, ICBP, Cambridge, UK DAMIEN LEWIS, London, UK USA
ALAN CROSS, UNEP/GRID, Geneva, Switzerland MICHEL LoUETTE, Musee Royal de l'Afrique IAN THORPE, School of Biology, University of
GLYN DAVIES, ODA, Nairobi, Kenya Centrale, Belgium East Anglia, UK
JEAN-PIERRE D'HuART, WWF, Brussels, Belgium RICHARD LoWE, Botany Department, University RAPHAEL TSILA, Ministry ofForest Economy,
CHARLES DOUMENGE, IUCN, Gland, Switzerland of Ibadan, Nigeria Brazzaville, Congo
FRAN<;:OISE DOWSETT-LEMAIRE, Liege, Belgium PETER LoWRY, Missouri Botanical Garden, St K. TUFOUR, Forestry Commission, Accra, Ghana
JOSEPH DUDLEY, Department of Biology and Louis, USA CAROLINE TuTIN, Lope Reserve, Gabon
Wildlife, University of Alaska, Fairbanks, USA H.F. MAITRE, Centre Technique Forestier AMY VEDDER, Wildlife Conservation
PAT DUGAN, IUCN Wetlands Programme, Tropical, Nogent-sur-Marne, France International, New York, USA
Gland, Switzerland CLAUDE MARTIN, WWF-International, Gland, FRED VOOREN, Forestry Department, University
CHRIS ELLIOTT, WWF-International, Gland, Switzerland ofWageningen, Netherlands
Switzerland JAMES MAYERS, WWF, Dar-es-Salaam, Tanzania JOHNWAUGH, IUCN, Washington, D.C., USA
JOHN FA, Irish Town, Gibraltar MANKoTo MA MBAELELE, Zaire Institue for CLIVE WICKS, WWF, Godalming, Surrey, UK
JULIA FALCONER, ODA, Kumasi, Ghana Nature Conservation, Kinshasa, Zaire ROGER WILSON, FFPS, London, UK
J. H. FRAN<;:OISE, Forestry Department, Accra, JEFF McNEELY, IUCN, Gland, Switzerland RON WITT, UNEP/GRID, Geneva, Switzerland
Ghana TOM MCSHANE,WWF-US, Libreville, Gabon PETER WOOD, RSPB, Sandy, Bedfordshire, UK
K. FRIMPONG-MENSAH, Institute of Renewable ERICA MCSHANE-CALUZI, WWF-US, Libreville, IpALAKA YOBWA, Forest Inventory and
Resources, Kumasi, Ghana Gabon Management Service, Kinshasa, Zaire
STEVE GARTLAN, WWF, Douala, Cameroon JEAN-BoNIFACE MEMVIE, Forest Service,
K. GHARTEY, Forestry Department, Accra, Libreville, Gabon
Ghana HADELIN MERTENS, WWF, Kinshasa, Zaire In addition authors and reveiwers are acknowl
DONALD GORDON, WCMC, Cambridge, UK ALAIN MONFORT, Liege, Belgium edged at the end of each chapter.
ii
THE CONSERVATION ATLAS
OF
TROPICAL FORESTS
AFRICA
Editors
JEFFREY A. SAYER
International Union for Conservation ofNature and Natural Resourees, Gland, SwitzerIand
CAROUNE S. HARCOURT
WorId Conservation Monitoring Centre, Cambridge, UK
N. MARK COLUNS
WorId Conservation Monitoring Centre, Cambridge, UK
Editorial Assistant: Clare Billington • Map Editor: Mike Adam
W orId Conservation Monitoring Centre, Cambridge
•
M
Theworld
~
Conservation
Union
WORLD CONSERVATlON
MACMILLAN
MONITORING CENTRE
ACKNOWLEDGEMENTS
This atlas was produced under the Forest Conservation Programme Contributors to the atlas are listed earlier and their labours are
of IUCN, The World Conservation Union .. IUCN's work in much appreciated. A work ofthis nature, however, inevitably rep
tropical forests receives financial support from the government of resents the labours of hundreds of people who have painstakingly
Sweden. Much of the research, editing and map preparation was documented the forests, researching their ecology and wildlife, and
done at the World Coqservation Monitoring Centre which is who have laboured over the production of the maps from field work
supported by IUCN, the World.Wide Fund for Nature (WWF) and to final printing. Heartfelt thanks are offered by the editors to all
the United Nations Environment Programme (UNEP); the Centre these unnamed people.
is also part of UNEP's Global Environment Monitoring System The editors would also like to thank all their colleagues at IUCN
(GEMS) towards which thls atlas is a contribution. and the World Conservation Monitoring Centre, without whose
IUCN is especially indebted to The British Petroleum Company dedicated work this project would not have been possible. In
p.l.c. for the original idea for the atlas and for the generous fund WCMC, particular thimks go to Harriet Gillett and Donald
ing which has enabled the research for the project to be undertaken. Gordon for information on conservation areas, to Simon Blyth and
Thanks also go to IBM, for providing a computer which was Gillian Bunting for work on the maps and to Barbara Brown, James
used for running the geographic information system (GIS) needed Culverwell, Brian Groombridge and Martin Jenkins for much
to compile the maps, and to the Environmental Systems Research appreciated and varied assistance. At IUCN, invaluable help was
Institute (ESRI) ofCalifornia whichprovided the ARC/INFO soft provided by Ursula Senn, Jacqueline Sawyer and Jill Blockhus.
ware for the project. Petroconsultants Ltd of Cambridge kindly Finally, Paul Woodman at the Royal Geographical Society gave us
made available 'MundoCart', a world digital mapping database considerable aid with, among other things, correct spellings of
which proved invaluable in the preparation of this atlas. ever-changing place names~
Copyright © IUCN 1992
Softcover reprint ofthe hardcover Ist edition 1992978-0-333-57757-8
All rights reserved. No reproduction, copy or transmission of this publication may be made without written permission. No paragraph of this publication
may be reproduced, copied or transmitted save with written permission or in accordance with the provisions of the Copyright, Designs and Patents Act
1988, or under the terms of any Iicence permitting Iimited copying issued by the Copyright licencing Agency, 90 Tottenham Court Road, London WIP
9HE. Any person who does any unauthorised act in relation to this publication may be Iiable to criminal prosecution and civil claims for damages.
First published in the United Kingdom by Macmillan Publishers Ltd., 1992
Distributed by Globe Book Services Ltd
Bronel Road, Houndmills, Basingstoke, Hants RG21 2XS
British Cataloguing in Publication Data
Sayer, Jeffrey A.
The Conservation atlas of tropical forests.
Africa.
I. Title 11 Harcourt, Caroline S. 111 Collins, N. Mark
574.5022
ISBN 978-1-349-12963-8 ISBN 978-1-349-12961-4 (eBook)
DOI 10.1007/978-1-349-12961-4
Acknowledgement of Sources
The sources of the country maps are given at the end of each chapter.
The sources of the illustrations and maps are given in footnotes and captions.
Designed by Robert Updegraff.
Map Production by Lovell Johns, Oxford
Typeset by BP Intergraphics, Bath, Avon.
Contents
Foreword 6
I:
PART THE 1SSUES
1 Introduction 9
2 History of Forests and Climate 17
3 Biological Diversity 26
4 Case Studies in Conserving Large Mammals 33
5 Forest People 43
6 Population, Environment and Agriculture 49
7 Timber Trade 56
8 Forest Management 62
9 The Protected Areas System 69
10 A Future for Mrica's Tropical Forests 81
PART 11: COUNTRY STUDIES
11 Benin and Togo 97
12 Burundi and Rwanda 102
13 Cameroon 110
14 Central African Republic 119
15 Congo 125
16 Cöte d'Ivoire 133
17 Eastern Africa 143
Djibouti Somalia
Ethiopia Sudan
Kenya Tanzania
18 Equatorial Guinea 161
19 Gabon 168
20 The Gambia and Senegal 175
21 Ghana 183
22 Guinea 193
23 Guinea-Bissau 200
24 Indian Ocean Islands 206
Comoros Reunion
Mauritius Seychelles
25 Liberia 214
26 Madagascar 221
27 Nigeria 230
28 Säo Tome and Principe 240
29 Sierra Leone 244
30 Southern Mrica 251
Angola Mozambique
Malawi Zimbabwe
31 Uganda 262
32 Zaire 270
Acronyms 283
Glossary 283
Index 0/ Species 284
General Index 287
Fo re wo rd
The loss of the world's tropical forests is one of today's most publicised, debated and least understood environmental issues.
Some articles give the impression that the destruction is so rapid and catastrophic that by the end of the century there will be
only scattered remnants of forest in increasingly embattled national parks. More than half the species that live on land are
inhabitants of the tropical forests and a simple extrapolation leads to dire conclusions about what forest clearance means for the
world's biological diversity.
But the situation is far more complicated than that. The statistics of total forest loss - 17 million hectares a year, an area
considerably bigger than Switzerland - mask an intricate pattern ofvariation from country to country. The causes offorest loss
also vary, though clearance for cultivation is generally the most important.
Deciding what policy to pursue is not easy for tropical governments who are striving to meet the needs of growing populations
and to secure economic growth that will allow them to end degrading poverty and provide food security, health care, education
and employment. For such nations, forest resources are vital. For many people the forests are the only hornes they have ever
known.
Used sustainably for meat, nuts, fruits, gums, wild rubber, fibre, medicines, rattans and carefully extracted timber, tropical
forests can provide a continuous supply of materials and income to human communities and at the same time maintain local
climate, regulate the run-off of rainfall and lock up some of the carbon dioxide, the accumulation of which is causing climatic
change. Used destructively the forests may give Gross National Product a quick boost but often leave local communities ruined.
Governments everywhere are reviewing their policies and moving towards sustainable management. They are negotiating
international conventions to conserve biological diversity and halt climate change. Conventions on Forests and Biodiversity are
also being discussed. Wise use is central to all these initiatives but conventions cannot work without sound knowledge of the
forests themselves: where they are, what species exists in them and what essential services they provide. It is a remarkable and
disconcerting truth that we lack much ofthis essential knowledge today.
In 1974 Reider Persson wrote, in a ground-breaking survey of the world's forest resources, 'we know quite a lot about the
mo on, but we do not know how much of the earth is covered by forests and woodlands.' His words are still true. The problem
is particularly acute for Africa. Although we have the capacity to use remote sensing to monitor in considerable detail what is
happening in tropical forests, no forest map has ever been produced for some countries and for many the statistics available from
different sources are contradictory.
This atlas is an attempt to present the facts on forest extent and loss in Mrica. It addresses the issues central to forest
conservation and sustainable use. What are the real causes of loss? What are the values of the forests to the people of Africa?
How can these values be translated into tangible benefits for the poor rural societies who live in and around the most diverse
forests?
The volume begins with an analysis of ecological history. Contrary to popular belief that tropical forests are ancient and
unchanging, those of Africa have changed a great deal with the past few tens of thousands of years in response to alterations in
climate and sea level. These dynamics need to be understood. The later chapters analyse the characteristics of today's forest,
the ways forest-dwelling peoples use them and the implications of agricultural and social trends. The role of the timber industry
as a potential force for conservation or destruction is evaluated.
The maps are the heart of the atlas. They have been much more difficult to compile than in our previous volume on the forests
of the Asia/Pacific region. Those for most of West Africa and large parts of Central Africa have never before been published.
These maps are based on satellite imagery obtained in the past few years and they give a new picture of the dramatic decline in
the forests of these areas. The continent is losing its forests faster than any other region. Thirty per cent have already gone and
the remainder are being eroded at 1 per cent per year. In Central Africa, where very large tracts offorest remain, they are being
fragmented and encroached upon by sma ll farmers. Even light disturbance makes them very vulnerable to fire. Finally, most of
Africa's closed forest occur under rainfall regimes which are marginal for this type of vegetation and as a consequence they are
more vulnerable to disturbance or small changes in climate than those of other regions.
This atlas is offered to all concerned with conservation and sustainable living in the forested zone of Africa. Those processes
will only come about if they are a priority of the peoples of Africa. Conservation programmes that seek to impose external views
are doomed to failure. There is a new emerging generation of African conservationists who are weIl aware of the materials and
cultural value ofthe forests to African societies. Many ofthem have contributed to this atlas. We hope that the atlas will be of
value to them and to their nations in ensuring that Africa's wonderful forests, and the diverse animallife they support, remain a
prized asset in the 21 st century.
MARTIN HOLDGATE
Director General
IUCN -The World Conservation Union
vi
PART I
Geological Time Scale
Eon Era Period Epoch TIme (Mo)
Holocene 65-
Quaternary 0.1
Pleistocene
1.8 225-
Pliocene
5
Neogene Miocene
Cenozoic
26 570-
Tertiary Oligocene
37
Eocene
Palaeogene
53 1000-
Poloeocene
65
lote CretDceous
Cretoceous 100
eorly Cretoceous
Phonerozoic 136
Mesozoic lote Jurassic
160
Jurassic middle Jurassic
176
eorly Jurassic
190
Triossic
225
2000-
Permion
280
Pennsylvanion
Corboniferous 315
Mississippion
345 2500-
Poloeozoic
Devonion
395
Silurion
430
3000-
Ordovicion
500
Combrian
570
Vendion
650
lote Riphean
Proterozoic Ripheon 900
middle Ripheon
Pre- 4000-
1300
combrion
eorly Ripheon
1600
eorly Proterozoic
2500
Archoeon Archoeon
4550 4550-
viii
1 Introduction
Africa is, essentially, a continent of woodlands and grasslands; it the coastline to deep inland, but agricultural and urban expansion
contains more than twice as much open woodland as elosed canopy have led to large-scale deforestation and fragmentation, graphically
forest. Indeed, satellite images of Africa show elearly that this is presented in Figure 1.2. The relict blocks of forest left at Gola in
the driest of the three main tropical continents (National Sierra Leone (chapter 29), Sapo in Liberia (chapter 25) and Tal
Geographie, 1990, pp. ii-iii). Rain forests now cover only ab out 7 in Cöte d'Ivoire (chapter 16), are now of global importance as the
per cent of the land area. Africa's rain forests represent slightly less last significant remnants of the structurally complex, species-rich
than one-fifth of the total remaining global resources, while Asia forests ofthe Upper Guinea zone.
holds slightly more than a fifth and Latin America still contains In Central Africa there still remains a vast, more or less contin
almost three-fifths. Asia's rain and monsoon forests are depleted uous expanse of rain forest. Although whittled away by fire and
by half (Collins et al., 1991), while those of tropical America agriculture on its borders, and by exploitation along the banks of
remain more intact covering at least four-fifths of their early 20th the great rivers of the region, large areas of little-disturbed forest
century extent. The figures in this Atlas reveal that the forests of remain. Indeed around 80 per cent of the rain forest on the conti
Africa are the most depleted of all with only one-third or so of their nent is concentrated in this region, particularly in Zaire. As Figure
historical extent still remaining. (See Table 10.1, which assurnes 1.3 indicates, this area of the continent still has the opportunity for
that areas elassified by White (1983) as forestlsavanna mosaics strategie planning for conservation and economic development.
were once completely forested.) Furthermore, West Africa's To the south, the main forest block gives way to dense miombo
forests are being lost faster than those of any other region. woodlands with scattered patches of dry deciduous forest.
In the 1990s Africa's forests are under severe and growing pres In East Africa the moist forest peters out as the elimate gradu
sures. Annual deforestation rates in Africa's elosed canopy forests ally becomes more arid. Increasingly, forest occurs only in strips
for the years 1976-80 were estimated to be ab out 0.61 per cent of . bordering rivers, along the tops of mountains, or on the wet coastal
the total elosed forestarea in 1980 (FAOfUNEP, 1981). FAO has hills. These fragmented forest patches share problems of severe
yet to finalise its statistics to a 1990 baseline but moist forest loss encroachment and exploitation, yet they harbour a high propor
is likely to be about 1 per cent per year (FAO, 1990). Annual defor tion of plant and anima I species which are found nowhere else in
estation is more serious in West Africa (2.1 per cent) than in the world. Many of these forests are the subject of individual con
Central Africa (0.6 per cent). There are indications that unplanned servation programmes, which are rearguard actions to save the last
deforestation, and environmental degradation in general, are elose remnants of pristine forest lands.
correlates of human population growth. As chapter 6 of this vol
urne reveals, Africa's population growth rate is now running at 2.9 Forest Classification
per cent (doubling time 24 years), an expansion that is resulting in White's memoir and map, published by Unesco, was the result of
massive demands for agriculturalland, water, fuelwood and other some 15 years of cooperation between Unesco and the Association
natural products. Notwithstanding this, as chapter 2 relates, the pour l'Etude Taxonomique de la Flore de l'Afrique Tropicale
forests of Africa are even now considerably more extensive than (AETFAT). AETFAT's Vegetation Map Committee, whose
they were during the most recent high latitude glacial advance members compiled the materials from which White worked,
around 18,000 years ago. ineluded many distinguished authorities. Building upon earlier
works such as the well-known Yangambi elassification of tropical
Africa (Trochain, 1957) and Keay's (1959) vegetation map of
FORESTS OF THE REGION Africa, White's elassification has withstood scrutiny for almost a
The limits of African tropical forests shown in this Atlas are based decade, and looks set to do so for several more. The greatest threat
on the recent definitive vegetation elassification provided by F. to its boundaries, predictably, is the rapid expansion of anthropic
White's memo ir and 1:5 million scale map (1983). As in the landscapes at the expense of natural vegetation.
Asia-Pacific Atlas (Collins et al., 1991), only the elosed canopy White's elassification identifies 16 major vegetation types or for
tropical forests are mapped. Selected forest types are shown, gen mations, all based on structure and physiognomy without recourse
eralised from White (1983), in Figure 1.1. to elimatic or other environmental considerations (Table 1.1).
Africa's elosed canopy tropical moist forests run from the man There is a wide diversity of woody vegetation types, ineluding for
groves of Senegal on the west coast of the continent to the mon est, thicket, shrubland, Afroalpine vegetation, scrubland, man
tane forests ofJebel Hantara ne ar the eastern tip ofSomalia. Most grove and bamboo; woodland being the most widespread (White,
of the countries of West Africa were once elothed in forest from 1983, p. 47). Africa differs from tropical Asia in the occurrence of
9