Table Of ContentEcological 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 
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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
Description: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