Floristic Composition and Structural Analysis of Woodland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia
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Floristic Composition and Structural Analysis of Woodland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia Zerihun Tadesse Gemeda Addis Ababa University Addis Ababa, Ethiopia June 2015 Floristic Composition and Structural Analysis of Woodland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia Zerihun Tadesse Gemeda A Thesis submitted to The Department of Plant Biology and Biodiversity Management in Partial Fulfillment of the Requirements for the Degree of Master of Science (Biology: Botanical Science) Addis Ababa University Addis Ababa, Ethiopia June 2015 ADDIS ABABA UNIVERSITY GRADUATE PROGRAMMES This is to certify that the Thesis prepared by Zerihun Tadesse Gemeda, entitled: Floristic Composition and Structural Analysis of Woodland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia and Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science (Plant Biology and Biodiversity Management) complies with the regulations of the University and meets the accepted standards with respect to originality and quality. Signed by Examining Board: Name Signature Date 1. _________________________ (Examiner) ___________________ _________________ 2. _________________________ (Examiner) ___________________ _________________ 3. _________________________ (Advisor) ____________________ _________________ 4. ________________________ (Advisor ) ___________________ __________________ 5. _____________________ ___(Chairman) _______________ _________________ ABSTRACT Floristic Composition and Structural Analysis of Wooddland Vegetation in Ilu Gelan District, West Shewa Zone of Oromia Region, Central Ethiopia Zerihun Tadesse, MSc Thesis Addis Ababa University, 2015 This study was conducted on Dirki and Jato woodland in Ilu Gelan District, West Shewa Zone of Oromia Region, 195 km west of Addis Ababa, to identify floristic composition, structure and community types of the vegetation. Systematic sampling method was used to collect vegetation data from 54 (20 m x 20 m). To collect data for herbaceous plants, five 1 m x 1 m subplots were laid in each of the main plot, where four were at the corners and one at the center. Diameter at breast height was measured for woody species taller than 2 m while height and cover/abundance values were visually estimated. Shannon - Wiener Diversity Index was used to calculate species diversity, richness and evenness whereas Soresen’s Similarity ratio was used to measure similarity between the vegetation and four other related woodlands. Two hundred and thirteen species were recorded from the sample plots, where Fabaceae, Asteraceae and Poaceae were the most dominant families with 23, 22 and 12 species respectively. Eleven endemic and two near endemic species were recorded from the study area. Based on IUCN Red Data List, nine species were least concern, three were near threatened while one was vulnerable. Three plant community types were recognized from the study area. Total density and basal area calculated for woody species were 5,145.83 individuals ha-1 and 18.96 m2 ha-1 respectively. Population structure and regeneration status of selected woody species were assessed and results revealed that some species had regeneration problems and need management measures. Key words/phrases: Endemic, floristic composition, plant community type, structural analysis, Woodland Vegetation. III ACKNOWLEDGEMENTS I would like to express my deepest gratitude to my advisors Prof. Ensermu Kelbessa and Dr. Tamrat Bekele for their continuous guidance, advice, constructive criticism, comments and motivations made to me during this work. I would also like to express my great acknowledge to my instructors Prof. Zemede Asfaw, Prof. Sileshi Nemomssa and Prof. Sebsebe Demissew who have given me constructive directions and encouragements during their actual class contact. My deepest gratitude also goes to Addis Ababa University for accepting me to follow my MSc study, Cheliya District Administration particularly the Education Office for facilitating to me financial support, and Ilu Gelan District for allowing me to carry out the study around there and providing me necessary information. I express my thanks to my friend Zewdie Kassa (PhD student) who prepared map of the study area and assisted me to use R software for data analysis. I would also share my thanks to my colleague, Deresa Abetu, with whom I was collecting data from the study area. I never forget my classmate students and my friends Desalegn Chala and Duguma Fulea with whom I have spent the lovely period. Finally, I am very much indebted to express my thanks to my wife w/ro Almaz Zelalem and my children Hire Zerihun, Nardos Zerihun, Fenayit Zerihun and Diribe Senbeto for their encouragements, technical and moral supports during my study. IV Tables of Contents Page List of Figures .......................................................................................................................................... VIII ABSTRACT ................................................................................................................................................. III ACKNOWLEDGEMENTS ......................................................................................................................... IV List of Figures ............................................................................................................................................ VIII List of Tables .............................................................................................................................................. IX List of Appenices .......................................................................................................................................... X List of acronyms .......................................................................................................................................... XI CHAPTER ONE ........................................................................................................................................... 1 1 INTRODUCTION ..................................................................................................................................... 1 1.1 Background ......................................................................................................................................... 1 1.2 Statement of the Problem .................................................................................................................... 2 1.3 Objectives ........................................................................................................................................... 3 1.3.1 General objective ......................................................................................................................... 3 1.3.2 Specific objectives ....................................................................................................................... 3 1.4 Research Questions ............................................................................................................................. 3 CHAPTER TWO .......................................................................................................................................... 4 2 LITERATURE REVIEW .......................................................................................................................... 4 2.1 Vegetation ........................................................................................................................................... 4 2.2 Vegetation Type of Ethiopia ............................................................................................................... 4 2.3 Woodland Vegetation ......................................................................................................................... 5 2.3.1 Combretum-Terminalia Woodland and Savannah ....................................................................... 6 2.3.2 Acacia-Commiphora Woodland .................................................................................................. 7 2.4 Biodiversity and Threats on Biodiversity in Ethiopia ......................................................................... 7 2.5 Plant Community Types ..................................................................................................................... 8 2.6 Plant Species Diversity, Species Richness and Evenness ................................................................... 9 2.7 Importance Value Index (IVI) and Dominance .................................................................................. 9 CHAPTER THREE .................................................................................................................................... 11 3 MATERIALS AND METHODS ............................................................................................................. 11 3.1 Description of the Study Area ........................................................................................................... 11 3.1.1 Location ..................................................................................................................................... 11 V 3.1.2 Topography ................................................................................................................................ 13 3.1.3 Climate ......................................................................................................................................