Spatial Patterns of Species Diversity in Kenya
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Spatial Patterns of Species Diversity in Kenya Boniface Oluoch Oindo CENTRALE LANDBOUWCATALOGUS 0000 0873 5504 Promotoren Prof. Dr.Herber t H.T. Prins Professor of Tropical Nature Conservation and Vertebrate Ecology Prof. Dr.Andre w K. Skidmore Professor of Vegetation and Agricultural Land Survey, ITC, Enschede Co-promotor Dr.Ja nd e Leeuw Senior Scientist, ITC, Enschede Promotie commissie: Prof. Dr.R . Leemans Wageningen University Prof. Dr. Ir. A. Stein Wageningen University Prof. Dr.P.J . Curran Southampton University Prof. Dr.J .va n Andel Groningen University r,vVO...^?ol,3l0D Spatial Patterns of Species Diversity in Kenya Boniface Oluoch Oindo Thesis to fulfill the requirements for the degree of doctor on the authority of the Rector Magnificus of Wageningen University, Prof. Dr. Ir. L. Speelman to be publicly defended on Wednesday 12th December 2001 at four o'clock afternoon in the auditorium of ITC, Enschede ;^v^ V£ ^ \M^ Doctoral thesis (2001) ISBN 90-5808-495-7 Wageningen University, The Netherlands 2001Oindo , B.O ITC Dissertation No. 85 This study was carried out at the International Institute for Aerospace Survey and Earth Sciences (ITC) P.O. Box 6 7500AA Enschede The Netherlands. ru yO/^OS!?o»i ?o ' , . 3/0^ Propositions Oindo, B.O. (2001) Spatial Patterns of Species Diversity in Kenya. Ph.D. Thesis, Wageningen University and ITC. 1. The satellite-derived vegetation index can measure environmental factors influencing species diversity of a given region (TTzz's Tlwsis). 2. A reliable measure of herbivore species diversity can be derived from the inverse relationship between the body size of species and its local abundance (TltisJliesis). 3. An understanding of the species concept is fundamental to measuring biological diversity. 4. Species diversity can change in response to both natural processes and human actions (Johnson NC, Mark A], SzaroRC & Sexton WT, 1999,Ecological Stewardship. A commonreference for ecosystem management, Vol.1, Elsevier Science Ltd). 5. Planning of conservation priorities requires understanding of interaction between historical and ecological processes (Fjeldsa J, 1994, Biodiversity and Conservation3: 207-226). 6. A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise (AldoLeopold, 1949,A Sand County Almanac,and Sketches Here and Tliere, Oxford University Press, New York). 7. The one who possesses intellectual honesty is characterized by a readiness to challenge what one believes to be true and to pay attention to other evidence available. 8. The most important limit you must know is your own. To my parents and brothers, who supported and encouraged me to pursue education Acknowledgements During the three and half year period I have been doing this Ph.D. research, I can confidently say that it has really helped me improve my understanding of scientific method. It is my humble feeling that this is my major academic achievement during this period. The completion of this thesis would have not been possible without the support and cooperation of many individuals and institutions. I highly appreciate the generous financial support extended to me from the Netherlands Fellowship Programme through ITCfo r thesucces s of this research. I wish to express my gratitude to my promoter Prof. Andrew Skidmore who facilitated and encouraged me to undertake this Ph.D. research immediately after my M. Sc. degree course at ITC. During the entire course of my study, he was very understanding and ready to provide constructive suggestions to my research. I acknowledge his motivating scientific support during my studies, hiscritica l review of submitted papers and his stimulating confidence in my abilities. I greatly benefited from the Ph.D. tutorials he introduced in ACE Division. I learnt a lot from these tutorials and they improved my approach and thinking on many issues related to scientific research, social, economic and management of resources. His wife, Eva,so n Ben and daughter Tansy were also friendly and hospitable tom yfamil y andme . I am very grateful to Prof. Herbert H.T. Prins for accepting to supervise my study. I greatly benefited from his perspective on what science is. He was very supportive, friendly and promptly reviewed my papers and gave me useful suggestions and constructive criticisms. Many thanks go to Dr.Ja n de Leeuw for being my co-promoter. I benefited from his effective guidance during my M.Sc . degree research that gave me a good foundation for Ph.D. research. Ials o thank himfo r helping me during my Ph.D. qualifying phase to select good research questions that greatly contributed toth e success of this thesis. I acknowledge many publications onbiodiversit y Ireceive d from him. I wish to thank Dr. Rolf A. de By for accepting to be in my Ph.D. supervisory committee. I sincerely appreciated the support I got from him and consistent friendship. My Ph.D. research really benefited from hiscompute r programming skills and knowledge on bird species in general, which contributed greatly to successful publications of two chapters of this thesis. I also thank him for translating my summary to Dutch. I thank my employer, Department Resource Surveys and Remote Sensing (DRSRS), Ministry of Environment and Natural Resources, for allowing me to take study leave and pursue this research. My sincere gratitude goes to the Director Mr. Hesbon Mwendwa Aligula of DRSRS for the encouragement, support and a good letter of recommendation, which enabled me to get the Ph.D. scholarship. I am indeed grateful to all members of Aerial Survey Section and support staff who participated in the collection of data from 1977 to 1997. I am also grateful to all members of Data Management Section who helped in data processing. In this respect, I highly acknowledge the help of Mr. Evanson C. Njuguna and Mrs. Mary Stella Barasa. I am very grateful to Dr. Elisabeth Kosters and Ms. Loes Colenbrander for their support and consistent friendship. I also received considerable support from Messrs. Job Duim, Benno Masselink, Gerard Leppink, Bert Riekerk as well as Daniella Semeraro, Carla Gerritsen, Marga Koelen, Fely de Boer, Ronnie Geerdink, Ceciel Wolters. In connection with my accommodation in ITC International Hotel, I acknowledge the support of Ms. Bianca Haverkate, Saskia, among others. Support from my long-term officemates, Dr. Liu Xuehua and Mr. Laurent Sedogo are highly appreciated. I must also acknowledge the moral support I received from friends Dr. Iris van Duren, Dr. Wilber Ottichilo and Messrs. Eric Timponjones, Henk van Oosten, Charles Situma, Dan Kithinji Marangu, Charles Ataya, Patrick Chege Kariuki, Connel Oduor, Joseph Gathua and Felix Mugambi. I also thank Dr. Wietske Bijker for organizing our Ph.D. tutorials as well as those who participated for their nice contributions. I would like to express my heartfelt appreciation for the spiritual, moral and material support that I received from the Enschede English Congregation of Jehovah's Witnesses. The congregation contributed a lot to my spiritual progress as well as that of my family and I really enjoyed the congregation's privileges and responsibilities. I thank all brothers and sisters for the love they extended to my family and special thanks go to Sister Chrissie Johnson and Brothers John Ton, Alexander Gathier, Joop Buitenhuis and Rueben Chetty for being always ready to take my family and me to the meetings and assemblies. Finally, I wish to thank my wife Isabel and sons Brian and Eric for their love, cooperation and patience during the period of my study. via Table of Contents Acknowledgements vii Contents ix Chapter 1 1 General introduction Chapter 2 6 Body size and abundance relationship: An index of diversity for herbivores B.O. Oindo, A.K. Skidmore &H.H.T . Prins (Biodiversityand Conservation 10: 1921-1929(2001) Chapter 3 17 Body size and measurement of species diversity in large grazing mammals B.O. Oindo (inpress, African Journal ofEcology) Chapter 4 32 Interannual variability of NDVI and species richness in Kenya B.O.Oind o &A.K . Skidmore (inpress, International Journal ofRemote Sensing) Chapter 5 49 Predicting mammal species richness and abundance using multi-temporal NDVI B.O. Oindo (inpress, Photogrammetric Engineering &Remote Sensing) Chapter 6 64 Mapping habitat and biological diversity in the Maasai Mara Ecosystem B.O. Oindo, A.K. Skidmore &P . De Salvo (inpress, International Journal ofRemote Sensing) Chapter 7 85 Environmental factors influencing bird species diversity in Kenya B.O.Oindo , R.K. deBy &A.K . Skidmore (AfricanJournal ofEcology 39(3): 295-302(2001) ix Chapter 8 98 Interannual variability of NDVI and bird species diversity in Kenya B.O. Oindo, R.K. deBy &A.K . Skidmore (InternationalJournal ofApplied Earth Observation& Geoinformation, Vol.2-Issue 3/4-2000) Chapter 9 114 Patterns of herbivore species richness and current ecoclimatic stability B.O.Oind o (inpress, Biodiversity and Conservation) Chapter 10 136 Synthesis:pattern s and theories of species diversity Summary 147 Samenvatting 149 Curriculum Vitae 151 Appendix 1 152 CHAPTER 1 GENERAL INTRODUCTION The extinctions of species resulting from human activities throughout the world have caused great concern in the scientific community and among the general public. This disappearance of species has been decried as a loss of plants and animals with potential agricultural and economic value, as a loss of medical cures not yet discovered, as a loss of the Earth's genetic diversity, as a threat to the global climate and the environment for human existence, and as a loss of species that have as much inherent right to exist as does Homo sapiens (Huston, 1994). The attention given this issue has led to the addition of a new word, biodiversity (a contraction of 'biological diversity'). Diversity is a concept that refers to the range of variation or differences among some set of entities; biodiversity is commonly used to describe the number, variety and variability of living organisms (Groombridge, 1992).