ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES ENVIRONMENTAL SCIENCE PROGRAM FLORISTIC COMPOSITION AND STRUCTURE OF YANGUDI-RASSA NATIONAL PARK VEGETATION, NORTHEASTERN ETHIOPIA BY SEMERE BEYENE A THESIS SUBMITED TO SCHOOL OF GRADUATE STUDIES OF ADDIS ABABA UNIVERSITY, IN PARTIAL FULFILMENT OF MASTERS DEGREE IN ENVIRONMENTAL SCIENCE FEBRUARY, 2010 ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES ENVIRONMENTAL SCIENCE PROGRAM FLORISTIC COMPOSITION AND STRUCTURE OF YANGUDI-RASSA NATIONAL PARK VEGETATION, NORTHEASTERN ETHIOPIA BY SEMERE BEYENE APPROVED BY THE EXAMINING BOARD: ___________________________________ ___________ CHAIRMAN, DEPARTMENT’S GRADUATE COMMITTEE ______________________________________ ____________ ADVISOR ______________________________________ ____________ EXAMINER ______________________________________ ____________ EXAMINER ________________________________________ ____________ EXAMINER Acknowledgments First and foremost, unconditional thanks and appreciation goes to my principal advisor Dr. Mekuria Argaw (Ph.D.) and Dr. Gemedo Dalle (Ph.D.) for their continual follow-up and guidance from start-up of proposal writing up to the end of this study in its present form. Equally important is his heart-felt and fatherhood approach has had paramount significances to my personal well-beings, in part. Especially Mekuria Argaw (Ph.D.) helped me in finding sponsors for financial support. I would like to thank the Institute of Biodiversity Conservation (IBC) and Addis Ababa University (AAU) for funding the project. I also acknowledge assistance from the staff members of the Yangudi-Rassa National Park head office in Gewane. I would also like to thank staff members of the National Herbarium, Addis Ababa University, particularly W/t Shewangziwe Lemma and Ato Melaku Wondafrash for their help during the identification of plant specimens. My special thanks goes to colleagues and friends, Ato Solomon Debele, Ato Befikadu Woldetsadik, Ato Bilhat Leta for sharing their experience and provision of useful materials that are important for this work. Last but not least, many thanks go to my family, particularity my beloved mother W/o Abrhet Abate, Gebreyesus and Bashay Amare. iii TABLE OF CONTENTS ACKNOWLEDGMENTS ................................................................................................................ III LIST OF TABLES ............................................................................................................................ VI LIST OF FIGURES .......................................................................................................................... VI LIST OF APPENDIXES .................................................................................................................. VI ABSTRACT .................................................................................................................................... VIII 1. INTRODUCTION ........................................................................................................................... 1 1.1. BACKGROUND AND JUSTIFICATION ............................................................................................... 1 1.2. OBJECTIVES .................................................................................................................................. 4 1.2.1. General objective ................................................................................................................. 4 1.2.2. Specific objectives ................................................................................................................ 4 1.2.3. Research Questions ............................................................................................................. 4 2. LITERATURE REVIEW ............................................................................................................... 5 2.1. DEFINITIONS AND CONCEPTS OF DRYLANDS ................................................................................. 5 2.2. DISTRIBUTIONS OF THE DRYLANDS ............................................................................................... 6 2.3. BIODIVERSITY IN ETHIOPIA .......................................................................................................... 7 2.4. MAJOR ECOSYSTEMS OF ETHIOPIA ............................................................................................... 7 2.4.1. The dryland vegetation in Ethiopia ..................................................................................... 8 2.5. FLORISTIC COMPOSITION AND STRUCTURE .................................................................................. 10 2.6. SPECIES DIVERSITY, EVENNESS AND SIMILARITY......................................................................... 11 2.7. PLANT POPULATION STRUCTURE ................................................................................................. 12 2.8. FREQUENCY AND IMPORTANT VALUE INDEX ............................................................................... 13 2.9. TECHNIQUES OF VEGETATION DATA ANALYSIS ......................................................................... 14 2.9.1. Classification ..................................................................................................................... 14 2.10. ENVIRONMENTAL FACTORS AND VEGETATION IN ETHIOPIA ...................................................... 17 3. MATERIALS AND METHODS .................................................................................................. 20 3.1. THE STUDY AREA ....................................................................................................................... 20 3.1.1. Location and description ................................................................................................... 20 3.1.2. Climate ............................................................................................................................... 22 iv 3.1.3. Geology and soil ................................................................................................................ 23 3.1.4. Vegetation .......................................................................................................................... 24 3.1.5. Wildlife and habitats .......................................................................................................... 24 3.1.6. Land use ............................................................................................................................. 25 3.2. METHODOLOGY.......................................................................................................................... 25 3.2.1. Reconnaissance Survey ...................................................................................................... 25 3.2.2. Sampling Design ................................................................................................................ 25 3.2.2.1. Vegetation data collection .......................................................................................... 26 3.2.3. Vegetation data analysis .................................................................................................... 27 3.2.3.1. Plant community determination ................................................................................. 27 3.2.3.2. Structural data analysis ............................................................................................... 28 3.2.3.3. Plant diversity analysis ............................................................................................... 30 4. RESULTS AND DISCUSSION .................................................................................................... 32 4.1. FLORISTIC COMPOSITION ............................................................................................................ 32 4.2. WOODY SPECIES ......................................................................................................................... 32 4.2.1. Vegetation structure .......................................................................................................... 33 4.2.1.1. Woody species density ............................................................................................... 33 4.2.1.2. Basal area (BA) .......................................................................................................... 34 4.2.1.3. Frequency ................................................................................................................... 35 4.2.1.4. Importance Value Index ............................................................................................. 36 4.2.1.5. Population structure of the dominant woody plant species ........................................ 37 4.2.1.6. Regeneration status of the Yangudi-Rassa National Park vegetation ........................ 39 4.3. EXISTING PLANT COMMUNITIES ................................................................................................. 40 4.4. SPECIES DIVERSITY ..................................................................................................................... 50 5. CONCLUSION AND RECOMMENDATIONS ......................................................................... 52 5.1. CONCLUSION .............................................................................................................................. 52 5.2. RECOMMENDATIONS .................................................................................................................