ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES DEPARTMENT OF BIOLGY Floristic Composition and Structural Analysis of Komto Afromontane Rainforest, East Wollega Zone of Oromia Region, West Ethiopia By Fekadu Gurmessa June 2010 Addis Ababa I ADDIS ABABA UNIVERSITY SCHOOL OF GRADUATE STUDIES DEPARTMENT OF BIOLGY Floristic Composition and Structural Analysis of Komto Afromontane Rainforest, East Wollega Zone of Oromia Region, West Ethiopia A Thesis presented to the School of Graduate Programme of Addis Ababa University in a partial fulfillment of the Degree of Masters of Science in Biology (Botanical Science stream) By Fekadu Gurmessa II CONTENTS PAGE TABLE OF CONTENTS……………………………………………………..........................i LIST OF TABLES ................................................................................................................................ iii LIST OF FIGURES ............................................................................................................................... iv LIST OF PLATES ................................................................................................................................. iv LIST OF APPENDICES ....................................................................................................................... iv ACRONYMS ......................................................................................................................................... v AKNOWLEDGEMENTS .................................................................................................................... vii ABSTRACT ........................................................................................................................................ viii 1. INTRODUCTION .............................................................................................................................. 1 1.1 Background of the Study .............................................................................................................. 1 1.2 Statement of the Problem ............................................................................................................. 4 1.3 Objectives ..................................................................................................................................... 5 2. LITERATURE REVIEW ................................................................................................................... 6 2.1 Vegetation of Ethiopia ...................................................................................................................... 6 2.2 Biodiversity and threats on biodiversity in Ethiopia .................................................................... 8 2.3 The Plant community types ........................................................................................................ 10 2.3.1 Species diversity, richness and similarity ............................................................................ 11 2.4 Regeneration and Recruitment of Vegetation ................................................................................ 12 3. MATERIALS AND METHODS ..................................................................................................... 14 3.1 The Study Area ........................................................................................................................... 14 3.1.1 Location ............................................................................................................................... 14 3.1.2 Topography ......................................................................................................................... 14 3.1.3 Climate and agroclimatic zones ........................................................................................... 15 3.1.4 Soil ....................................................................................................................................... 16 3.1.5 Human population ............................................................................................................... 17 3.1.6 Land use and agriculture ..................................................................................................... 17 3.1.7 Vegetation ........................................................................................................................... 18 3.1.8 Wildlife ................................................................................................................................ 19 3.1.9 Drainage .............................................................................................................................. 20 3.2 Method ........................................................................................................................................ 20 i 3.2.1 Reconnaissance survey ........................................................................................................ 20 3.2.2 Sampling design .................................................................................................................. 20 3.2.3 Vegetation data collection ................................................................................................... 20 3.2.4 Data analysis ........................................................................................................................ 22 3.2.4.1 Multivariate analysis of vegetation data ....................................................................... 22 3.2.4.2 Diversity and similarity indices .................................................................................... 22 3.2.2.3 Structural analysis ........................................................................................................ 23 4. RESULT AND DISCUSSION ......................................................................................................... 25 4.1 Plant Species Richness of Komto Forest .................................................................................... 25 4.1.1 Endemism ............................................................................................................................ 29 4.1.2 Commercially important tree species .................................................................................. 30 4.2. Vegetation Classification ........................................................................................................... 30 4.2.1 Achyrospermum schimperi-Croton macrostachyus Community type ................................. 32 4.2.2. Solanecio gigas-Ficus sur Community type ...................................................................... 32 4.2.3 Justicia schimperiana-Acanthus eminens community type ................................................. 33 4.2.4 Periplocca linearifolia-Dracaena afromontana community type ....................................... 33 4.3 Species Diversity, Evenness and Richness of the Plant Communities ....................................... 35 4.4 Similarity among plant communities .......................................................................................... 36 4.5 Structure of the Forest ................................................................................................................ 37 4.5.1 Tree and shrub density ......................................................................................................... 37 4.5.2 Size class distributions ........................................................................................................ 38 4.5.2.1 Basal area...................................................................................................................... 40 4.5.2.2 Vertical structure .......................................................................................................... 43 4.5.3 Importance Value Index ...................................................................................................... 44 4.5.3.1 Density, Frequency and Dominance ............................................................................. 44 4.5.3.2 Dominant species of Komto Forest .............................................................................. 47 4.5.4 Population structure ............................................................................................................. 47 4.5.5 Phytogeographical comparison ........................................................................................... 49 4.5.6 Regeneration status of Komto Forest .................................................................................. 51 5. CONCLUSION AND RECOMMENDATION ............................................................................... 53 5.1 Conclusion .................................................................................................................................. 53 5.2 Recommendation ........................................................................................................................ 54 6.REFERENCES .................................................................................................................................. 56 ii LIST OF TABLES Table 1 Land use pattern of Wayu Tuka District: .................................................................. 17 Table 2 Families with their corrosponding number of genera and species. ........................... 25 Table 3 Species not reported from Wollega floristic region (WG) on Floa of Ethiopia and Eritrea. ......................................................................................................................