Sustaining the Allideghi Grassland of Ethiopia: Influences of Pastoralism and Vegetation Change
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Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2009 Sustaining the Allideghi Grassland of Ethiopia: Influences of Pastoralism and Vegetation Change Almaz Tadesse Kebede Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Other Forestry and Forest Sciences Commons Recommended Citation Kebede, Almaz Tadesse, "Sustaining the Allideghi Grassland of Ethiopia: Influences of Pastoralism and Vegetation Change" (2009). All Graduate Theses and Dissertations. 309. https://digitalcommons.usu.edu/etd/309 This Dissertation is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. SUSTAINING THE ALLIDEGHI GRASSLAND OF ETHIOPIA: INFLUENCES OF PASTORALISM AND VEGETATION CHANGE by Almaz Tadesse Kebede A dissertation submitted in partial fulfillment of the requirements of the degree of DOCTOR OF PHILOSOPHY in Range Science Approved: D. Layne Coppock John A. Bissonette Major Professor Committee Member Eugene W. Schupp Patricia D. Moehlman Committer Member Committee Member Fredrick D. Provenza R. Douglas Ramsey Committee Member Committee Member _________________________ Byron Burnham Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2009 ii Copyright © Almaz Tadesse Kebede 2009 All Rights Reserved iii ABSTRACT Sustaining the Allideghi Grassland of Ethiopia: Influences of Pastoralism and Vegetation Change by Almaz Tadesse Kebede, Doctor of Philosophy Utah State University, 2009 Major Professor: Dr. D. Layne Coppock Department: Wildland Resources The Allideghi Wildlife Reserve in the Amibara District of Afar Regional State, Ethiopia, has international significance for harboring endangered Grevy’s Zebra and other wildlife dependent on grasslands. The reserve is increasingly used by pastoral people and their herds. Impacts of livestock on native vegetation include direct effects of grazing and indirect effects from livestock-facilitated dispersal of an invasive plant, Prosopis juliflora. The main research objective was to determine effects of pastoralism and vegetation change on prospects for sustaining the Allideghi Wildlife Reserve as grassland habitat for Grevy’s Zebra. Methods included use of driving surveys to quantify resource use by herbivores, vegetation analysis, and engagement with local people. Resource-use patterns of livestock across the Allideghi grassland were often positively affected by proximity of water, while that for wild ungulates was often negatively affected by proximity of people. Livestock concentration at a major borehole iv has created a large piosphere with concomitant reductions in herbaceous standing-crop, productivity, and species richness; plant species have shifted from grasses to forbs in severely grazed sites. Vegetation further from the borehole was resilient in response to moderate grazing pressure in terms of species composition and productivity. Since being introduced at a nearby commercial plantation in the 1970s, P. juliflora has been dispersed to the Allideghi Wildlife Reserve via livestock; cattle, sheep, and goats eat the pods and deposit seeds in manure at settlements and favored foraging areas. Prosopis juliflora greatly reduced species richness and basal cover of native herbaceous vegetation in the Allideghi grassland. Analysis of remotely sensed images from the past 30 years indicated major land-use change in the district due to agricultural expansion as well as land-cover change due to Prosopis encroachment and heavy grazing. Recent efforts have been undertaken by various agencies to control P. juliflora, via harvest in the district, but this has yielded variable and often negative results. Without a concerted effort to limit livestock grazing and control spread of P. juliflora, the future for the grassland and wildlife at the Allideghi Wildlife Reserve is grim. Agencies and policy makers need to promote science- and community-based approaches to help rectify the situation. (311 pages) v ACKNOWLEDGMENTS I want to express my deep appreciation to a number of people and institutions that have helped make my degree program at Utah State University (USU) successful. My gratitude goes to my home institution, the Ethiopian Ministry of Agriculture and Rural Development (MoARD), for giving me a leave of absence for the entire study period, and for providing me with the necessary logistics (vehicles and drivers) that enabled the field work to be carried out. I would like to especially thank Mr. Tesfaye Hundessa, the former general manager of the Ethiopian Wildlife Conservation Organization (EWCO), Mr. Tadesse Hailu, the former head of the Ethiopian Wildlife Conservation Department (EWCD), Dr. Kifle Argaw, the head of the Ethiopian Wildlife Protection Authority, and their staff, for moral and technical support. I am very grateful to USU for granting me the tuition waivers that markedly reduced the expense for my education. I am also very thankful to Professor Peter Model and Professor Marjorie Russell, Wildlife Trust (New York), and the Global Livestock Collaborative Research Support Program (GL-CRSP) of the U.S. Agency for International Development (USAID), for their financial support throughout my study period in the United States. I gratefully acknowledge the African Wildlife Foundation [AWF (Nairobi, Kenya)] for funding the field research in Ethiopia and buying my field equipment. I am very much indebted to Dr. Patricia Moehlman and Dr. Layne Coppock for their help to garner my financial support overall. I am very grateful to my major professor, Dr. Layne Coppock, for his invaluable professional guidance throughout the study. His patience and detailed comments on the vi various chapter drafts were crucial to finalize the dissertation. I also thank all my supervisory committee members, Drs. John Bissonette, Eugene Schupp, Patricia Moehlman, Fredrick Provenza, and Douglas Ramsey, for their helpful comments on my dissertation. I would like to also express my special appreciation to Susan Durham for her advice concerning data analysis and Chris McGinty for his technical assistance for analysis of satellite images. Dr. Douglas Ramsey was very helpful in procuring satellite images for my study area free of charge. I am thankful to the staff of the Melka-Werer Agricultural Station who gave me access to their meteorological data and reports. The National Herbarium of Addis Ababa University was very helpful in identification and confirmation of my plant specimens collected from the Allideghi Plain. I am also grateful to the Department of Biology at Addis Ababa University for allowing me to use the laboratory facility to dry and weigh plant biomass and to sieve seed from soil samples. The private livestock corporation ELFORA gave me permission to conduct vegetation analysis and erect exclosures within their holding grounds at the Allideghi Plain. The ELFORA staff also helped protect my exclosures from vandalism throughout the period of field work. Other support personnel and local community members contributed to my success. I thank the drivers who were assigned to assist me with my resource use assessments. I express my gratitude to the local people at the Allideghi and Uduala Issae villages, especially Ali Debay, Gebaba Enhaba, Abdo Mohammed, Ahmed, Mohammed Ahadu, and others who helped guide and protect me in the study area. I am also grateful to the people at Melka Werer, Amibara, and Shelko as well as those living at the Allideghi Plain, who supplied useful information for understanding local values and vii attitudes concerning natural resources. I appreciate the respective bureau heads and/or experts at Amibara District (Afar Regional State), federal agencies (EWCD, EARO), and non-governmental institutions (FARM Africa, CARE-Ethiopia) for providing me with their insights on natural resource and policy issues. My friend, Steven Huckett, was always there for me during my study period. He provided truly amazing help to me during the difficult times of my pregnancy—thank you so much, Steve. I would also like to thank Hiruy Abdu, Whitney Milligan, Leslie Morris, Mical Weldesilassie, and Mussie Habtesilassie for their friendship and encouragement. I am also very grateful to the Habesha community here in Utah who made my life enjoyable through social gatherings during holidays and special occasions. I offer special thanks to my mother, Yibrehu Gebrewold, who sent me to school when I was only four years, four months, and four days old. She understands the value of education. My mother never was able to enjoy formal education except for her limited writing and reading skills. I am also thankful to my relatives in Ethiopia for their help and encouragement all the years when I have been in school. I am very thankful to my in-laws for providing me with moral support and encouragement and taking care of my son, Yoel, when I was in Ethiopia for my field work. Last but not least, I am very grateful to my husband, Mekbeb Eshetu Tessema, for his love and encouragement throughout the study period. Without his support, completion of my study would not have been possible. Yoel was a blessing for both of us. Almaz T. Kebede viii CONTENTS Page ABSTRACT ....................................................................................................................... iii ACKNOWLEDGMENTS .................................................................................................