Conserving Biodiversity in East African Forests: A Study of the Eastern Arc Mountains

200 Pages·2002·0.28 MB·English

by  William D. Newmark (auth.)

Ecological Studies, Vol. 155
Analysis and Synthesis
Edited by
I.T. Baldwin, Jena, Germany
M.M. Caldwell, Logan, USA
G. Heldmaier, Marburg, Germany
O.L. Lange, Wiirzburg, Germany
H.A. Mooney, Stanford, USA
E.-D. Schulze, Jena, Germany
U. Sommer, Kiel, Germany
Ecological Studies
Volumes published since 1996 are listed at the end of this book.
Springer-Verlag Berlin Heidelberg GmbH
W.D. Newmark
Conserving Biodiversity
in East African Forests
A Study of the Eastern Arc Mountains
With 66 Figures and 31 Tables
, Springer
William D. Newmark
Utah Museum of Natural History
University of Utah
1390 E. Presidents Cirele
Salt Lake City, Utah 84112-0050
USA
Cover illustration: Biodiversity is the totality of life. Shown here are representative
plant and animal species that occur in the Eastern Arc Mountains
ISSN 0070-8356
ISBN 978-3-642-07629-9
Library of Congress Cataloging-in-Publication Data.
Newmark, William Dubois.
Conserving biodiversity in East African forests : a study of the eastern arc
mountains / W.D. Newmark.
p. cm. - (Ecological studies, ISSN 0070-8356 ; voI. 155)
Includes bibliographical references.
ISBN 978-3-642-07629-9 ISBN 978-3-662-04872-6 (eBook)
DOI 10.1007/978-3-662-04872-6
1. Biodiversity conservation - Tanzania. 2. Biodiversity
conservation - Kenya. 3. Forest ecology -Tanzania. 4. Forest ecology - Kenya.1. Title. II.
Ecological studies ; v. 155.
QH77.T3 N48 2001
333.95'16'09676-dc21 2001049699
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Preface
Tanzania is one of the most biologically diverse nations in the world. Traveling
from west to east across Tanzania, one encounters an incredible array of
ecosystems and species. Beginning at Lakes Victoria, Tanganyika, and Nyasa
that form much of the western boundary of Tanzania, one finds the most
diverse and some of the most spectacular concentrations of endemic fish in any
of the world's lakes. Moving further inland from the lakes, one meets the
woodlands and plains of Serengeti, Ngorongoro, Tarangire, and Lake Manyara.
The assemblages and movements of large mammals in these protected areas
are unparalleled worldwide. Traveling yet further to the east, one comes to
Mount Kilimanjaro, the highest mountain in Africa. Mount Kilimanjaro is of
sufficient height to not only contain seven major vegetation zones, but also
maintain permanent glaciers. Finally, shortly before arriving at the Indian
Ocean, one encounters the Eastern Arc Mountains, a series of isolated and
geologically ancient mountains, which due to their height and proximity to the
Indian Ocean intercept sufficient precipitation to support, in many areas, moist
tropical forest. The Eastern Arc Mountains are among the richest sites
biologically in all of Africa and harbor unusually high concentrations of
endemic species - species whose geographic distribution are restricted to
these mountains.
Unfortunately, much of Tanzania's biodiversity is threatened by habitat
alteration, destruction, and exploitation. The Eastern Arc forests face some of
the most severe threats to any of Tanzania's biologically unique sites. Yet, with
careful planning and management, Tanzania should be able to conserve its
rich and unique natural heritage for the benefit of both present and future
generations.
The purpose of this book is to synthesize existing information on the
biodiversity of the Eastern Arc Mountains, outline processes that are
adversely affecting this diversity, and suggest potential approaches for
promoting its conservation. I have attempted to illustrate concepts and use
East African examples whenever possible so as to increase the relevance of
VI Preface
this book to users in East Africa, particularly natural resource managers and
university students. While the geographic focus of this book is the Eastern
Arc forests, the problems, principles, and approaches discussed in
relationship to conserving biodiversity have applicability to nearly all tropical
forests worldwide.
Acknowledgements I thank Ernst -Detlef Schulze, Tuomo Niemela, Eric
Rickart, Diane Davidson, Saidi Mbwana, Jon Lovett, Kim Howell, Alan Rodgers,
Hakon Fottland, Stig Johansson, Jan H0iseth, the faculties of forestry from
Sokoine University of Agriculture and Olmotoni Forestry Institute, and the
staff of the Tanzania Forestry Research Institute for their comments and
suggestions on various sections and outlines of this book. I also thank Alan Tye,
Stig Johansson, Norbert Cordeiro, William Stanley, Steven Goodman, Norman
Myers, Tuula Kurikka, Paul Bloch, Kim Howell, Ron Botterweg, Christopher
Ruffo, Jan H0iseth, Luc Lens, Paula Williams, Veli Pohjonen, Thomas Brooks, S.
Iddi, Peter Tattersfield, Christopher Conte, Michael Sheridan, and Marc De
Meyer for information and data, and Garold Sneegas and Roz Newmark for
scanning and printing photographs. Finally, I would like to acknowledge
Hakon Fottland whose initial and continuing support for this book was central
to its development.
Support for writing this book has come from the Catchment Forestry Project
and the Tanzanian Forestry and Beekeeping Division. The Danish Inter
national Development Agency, the Field Museum of Natural History, the
Chicago Zoological Society, the Sophie Danforth Conservation Fund, the
National Geographic Society, Earthwatch Institute, and the John D. and
Catherine T. MacArthur Foundation provided assistance for field research. I
thank Herbert Kingazi, Simon Mfikwa, Thomas Mtui, Budda and Keya
Acharya, Ian and Sheila Stone-Wigg, John Ellis, Simon Hill, Tony Dugan, and
Bertie Amritanand for all of their past assistance, many meals, and permission
to work on the Ambangulu, Monga, Kwamkoro, and Bulwa tea estates, and the
East Usambara Conservation Area Management Programme and the Tanzania
Forestry and Beekeeping Division for permission to work within the Amani
Nature Reserve. Finally, I thank the Tanzania Commission for Science and
Technology and the Serengeti Wildlife Research Institute for permission to
conduct field research in Tanzania and Kim Howell and Ramadhani Senzota
for serving as local contacts.
The author gratefully acknowledges the following publishers for permission
to use tables and figures in this book.
Table 2.5 Dobson AP Conservation and Biodiversity. p. 94. Copyright
Scientific American Library. Used with permission by W.H. Freeman and
Company.
Preface VII
Table 3.5 Eastwood A, Bytebier B, Tye H, Tye A, Robertson A, Maunder M The
conservation status of Saintpaulia. Curtis's Botanical Magazine, Vol 15, p. 59,
Table 1. Copyright 1998 Bentham Moxom Trust. Blackwell Publishers.
Table 3.7 L0rup JK and Hansen E Effect of land use on the streamflow in the
southwestern highlands of Tanzania. IAHS Publication, Vol 240, p. 232, Table 3.
Copyright 1997 International Association of Hydrological Sciences.
Table 4.4 Newmark WD Tanzanian forest edge micro climatic gradients:
dynamical patterns. Biotropica, Vol 33, p. 9. Copyright 2001 The Association
for Tropical Biology.
Table 4.5 Newmark WD Tanzanian forest edge microclimatic gradients:
dynamical patterns. Biotropica, Vol 33, p. 10. Copyright 2001 The Association
for Tropical Biology.
Table 4.9 Sheil D Naturalized and invasive plant species in the evergreen
forests of the East Usambara mountains, Tanzania. African Journal of Ecology,
Vol 32, p 67. 1994. Original material taken from: Cronk QCB Plant Invaders: The
Threat to Natural Ecosystems. Copyright 1995 Kluwer Academic Publishers.
Ruffo CK, Mmari C, Kibuwa SP, Lovett J, Iversen S, Hamilton AC Preliminary list
of plant species from the East Usambara forests in Hamilton AC and Bensted
Smith R (eds) Forest conservation in the East Usambara Mountains, Tanzania,
p. 170. Copyright 1989 IUCN. Iversen ST 1991. The Usambara Mountains, NE
Tanzania: Phytogeography of the vascular plant flora. Acta Universitatis
Upsaliensis Symbolae Botanicae Upsalienses 29:3.
Figure 1.2 Reid WV and Miller KR Keeping options alive: The scientific basis
for conserving biodiversity. p. 5. Copyright 1989 World Resource Institute.
Figure 2.1 Muhongo S Neoproterozoic collision tectonics in the Mozambique
Belt of East Africa: evidence from the Uluguru mountains, Tanzania. Journal
of African Earth Sciences, Vol 19, p. 157. Copyright 1995 reprinted with
permission from Elsevier Science.
Figure 2.14 Stocking M and Perkin S Conservation-with-development: an
application of the concept in the Usambara Mountains, Tanzania. Trans
actions of the Institute of British Geographers, Vol 17, p. 342. Copyright 1992
Institute of British Geographers.
Figure 4.11 Newmark WD Tanzanian forest edge micro climatic gradients:
dynamical patterns Biotropica, Vol 33, p. 6. Copyright 2001 The Association
for Tropical Biology.
VIII Preface
Figure 4.13 Lens L, van Dongen S, Wilder CM, Brooks TM, and Matthysen E
1999. Fluctuating asymmetry increases with habitat disturbance in seven bird
species of a fragmented Afrotropical forest. Proceedings of the Royal Society
of London, Series B Biological Sciences, Vol 226, p. 1244, Figure 1. Copyright
1999 Royal Society of London.
Figure 6.3 Kivumbi CO and Newmark WD The history of the half-mile
forestry strip on Mount Kilimanjaro in Newmark WD (ed.) The Conservation
of Mount Kilimanjaro, p. 82. Copyright 1991 IUCN.
Salt Lake City, Utah
October 2001 W.D. Newmark
Contents
1 What Is Biodiversity? ...................... 1
1.1 Introduction ..... 1
1.2 Defining Biodiversity 2
1.2.1 Genetic Diversity 2
1.2.2 Species Diversity 3
1.2.3 Ecosystem Diversity 3
1.2.4 Ecological and Evolutionary Processes 3
2 The Eastern Arc Mountains
and Their Biological Significance 5
2.1 Geography 5
2.2 Geology 5
2.3 Soils 7
2.4 Climate . 8
2.5 Forest Cover 10
2.6 Protected Area Coverage 11
2.7 Level of Knowledge About Biodiversity 13
2.8 Evolutionary and Ecological Significance 15
2.9 Geographic Comparisons of Species Richness
and Endemism ....................... . 16
2.10 Critically Endangered, Endangered and Vulnerable Species 18
2.11 Relationship Between Global Threatened Status
and Endemism ............. . 24
2.12 Forest Loss in Africa and Tanzania 24
2.12.1 Forest Loss in the Eastern Arc Mountains 25
2.13 Primary Causes of Forest Loss
in the Eastern Arc Mountains 26
2.13.1 Small-Scale Agricultural Expansion 26
2.13.2 Commercial Logging ....... . 30