VASCULAR PLANTS DIVERSITY AND ETHNOBOTANY WITH EMPHASIS TO TRADITIONAL MEDICINAL AND WILD EDIBLE PLANTS IN DUGDA DAWA DISTRICT OF BORANA ZONE, OROMIA REGIONAL STATE, ETHIOPIA Mersha Ashagre Eshete Addis Ababa University Addis Ababa, Ethiopia April 2017 VASCULAR PLANTS DIVERSITY AND ETHNOBOTANY WITH EMPHASIS TO TRADITIONAL MEDICINAL AND WILD EDIBLE PLANTS IN DUGDA DAWA DISTRICT OF BORANA ZONE, OROMIA REGIONAL STATE, ETHIOPIA Mersha Ashagre Eshete A Thesis Submitted to The Department of Plant Biology and Biodiversity Management Presented in Fulfillment of the Requirements for the Degree of Doctor of Philosophy (Plant Biology and Biodiversity Management) Addis Ababa University Addis Ababa, Ethiopia April 2017 i ADDIS ABABA UNIVERSITY GRADUATE PROGRAMMES This is to certify that the thesis prepared by Mersha Ashagre Eshete, entitled: “Vascular Plants Diversity and Ethnobotany with Emphasis to Traditional Medicinal and Wild Edible Plants in Dugda Dawa District of Borana Zone, Oromia Regional State, Ethiopia”, and submitted in fulfillment of the requirements for the Degree of Doctor of Philosophy (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 Research Supervisors: Name Signature Date 1. _____________________ _________________ _____________ 2.______________________ _________________ _____________ 3._____________________ _________________ ______________ 4.____________________ __________________ _______________ _____________________ ___________________ ________________ Chair of Department or Graduate programme Coordinator ii Abstract Vascular Plants Diversity and Ethnobotany with Emphasis to Traditional Medicinal and Wild Edible Plants in Dugda Dawa District of Borana Zone, Oromia Regional State, Ethiopia Mersha Ashagre, PhD Dissertation Addis Ababa University, 2017 This research is aimed at documentation and analysis of plant diversity in Dugda Dawa District along with the ethnobotanical knowledge associated with traditional medicinal and wild edible plants used by the local people. Vegetation data were collected from 60 plots laid preferentially, 20 m x 20 m for trees and shrubs and 1m x 1m subplots for herbs. Woody species with a diameter at breast height (DBH) > 3 cm were counted and cover abundance values estimated. Shannon-Wiener diversity index was used to assess species richness and evenness. Both Sorensen's similarity coefficient and Jaccardʼs index of similarity were used to measure similarities among communities in Dugda Dawa District vegetation, and only Sorensen's similarity coefficient to measure between this and other woodland vegetations types in Ethiopia. A hierarchical cluster analysis with PC-ORD was used to identify plant communities and synoptic values for detection of the dominant species for naming each plant community type. Frequency, density, DBH, basal area and importance value indices (IVI) of woody species were also computed. Ethnobotanical data were collected by interviewing 392 informants (290 males and 102 females). Guided field walk and discussion (group or individual discussion) were used in collecting the data.Quantitative approaches were used to determine informant consensus factor (ICF), fidelity level (FL), and use value (UV). Ethnomedicinal knowledge apprehended by different informant categories was compared using t-tests with R- software. The study area yielded 343 vascular plant species of which 12 were endemic and four were new records for the floristic region belonging to 227 genera and 81 families. The vegetation was classified into four community types, namely Prunus africana - Calpurnia aurea, Ehretia cymosa - Juniperus procera, Boscia mossambicensis - Lannea schimperi and Celtis africana - Podocarpus falcatus community types based on hierarchical cluster analysis. The overall Shannon- Wiener diversity and evenness values of Dugda Dawa District vegetation were 4.87 and 0.54 respectively. The percentage distribution of individual shrub and tree species across different DBH classes indicated relatively high proportion (53.9%) of individuals in DBH class 3 - 10 cm. Four representative woody plant population structures were identified. Results of the ethnobotanical study revealed 127 medicinal plant species in 123 genera and 82 fanilies; and 71 wild edible plant species belonging to 52 genera and 37 families in different vegetation formations of the study area. The family Fabaceae with 10 (7.9%) species of medicinal and 7 (9.9%) species of wild edibles was dominant followed by the Lamiaceae (7, 5.5%) species of medicinal plants and Anacardiaceae ( 7, 9.9%) species of wild edibles were the families represented by more species in the district. Plants in which leaves are used as medicine and fruits are used as wild food were more dominant (36.6% and 65.4% respectively) than other plant parts in the district. Significant difference (P < 0.05) was seen in the mean number of medicinal plants reported by informants in different age classes, education levels, and experiences. Similarly significant difference (P < 0.05) was observed in the mean number of wild edible plants reported by informants in different age classes and experiences. The highest ICF value (0.93) was recorded for human musculoskeletal and nervous system disease category. The highest fidelity level values were recorded for Ocimum urticifolium (97%) and Cyphostema serpens (97%). Dry evergreen afro-montane forest vegetation which encompasses community one, two and four in Dugda Dawa District is under great anthropogenic pressure including selective cutting of big trees in community four, medicinal plants (e.g. Prunus africana and Zanthoxylum chalybeum) as well as wild edible plants (e.g. Cordia africana and Syzygium guineense) which need strict conservation measures. Thus, priority conservation action should be given to the dry afromontane vegetation type which encompasses plant communities one, two, and four as they contain high plant species number (295) and high useful species (214) though the other vegetation types are also under threat and community - based conservation activities should be applied to create sustainable usage of resources. Warburgia ugandensis and Psophocarpus grandiflorus should be given cultivation and chemical analysis priority for their medicinal and food values respectively. Key words: Dugda Dawa District, ethnobotany, medicinal plants, plant diversity, wild edible plants iii DEDICATION This thesis is dedicated to the people of Dugda Dawa District who showed their willingness to share their knowledge on the use of traditional medicinal plants and wild edible plants used by the community. iv Acknowledgments Above all, I thank the Almighty God for providing me this opportunity and granting me the capability to proceed successfully. This thesis appears in its current form due to the assistance and guidance of several people. I would therefore like to offer my sincere thanks to all of them. First and foremost I want to thank my PhD advisors, Professor Zemede Asfaw (AAU) and the late Professor Ensermu Kelbessa (AAU), for accepting me as a PhD student, providing their unreserved guidance, support, suggestions, effective followup of the research work, and detailed reading and correcting of all the drafts of my thesis work to this end. I also thank Dr. Ermias Lulekal who read and commented on my final draft thesis after kindly accepting to come in as an advisor replacing Professor Ensermu. I want to express my deep gratitude to Madawalabu University for sponsoring and giving the chance to attend my PhD study. I would like to extend my deepest thanks to the Graduate Programmes of Addis Ababa University for funding the cost of all field expenses. I am grateful to the inhabitants of Dugda Dawa District, particularly the traditional medicine practitioners and wild edible users who wholeheartedly shared their knowledge on medicinal plants and wild edible plants, together with their wonderful kindness throughout my stay in the study area. I thank my brother Mr. Debebe Ashagre and his family for the provision of his motor bicycle and Mr. Gobu Ture for his help as a driver and field guide. All staff members of the Department of Plant Biology and Biodiversity Management (AAU) are also deeply acknowledged for their persistent encouragement during my course and research works. I would like to pass my gratitude to my friend Mr. Shiferaw Belachew for his valuable support during data analysis and all rounded help and Mr. Boneya Udessa for his contribution in introducing me with the inhabitants of the study area. I would like to extend a heartfelt thanks to a number of friends, colleagues and people whom I faced during the course and research work, and from whom I received support on various aspects of this study. And finally, my lovely wife, dear Atsede Dejene, without your support and encouragement, I could not have finished this work, it was you who kept the fundamentals of our family, and I understand it was difficult for you, therefore, I can just say thanks for everything. I am very much indebted to my children Saron Mersha (MSc in Medical Anatomy and lecturer in Bule Hora University), Siwan Mersha (4th year student in Hawasa University), Kalkidan Mersha, Yehasab Mersha, and Mahilet Mersha for their encouragement and support throughout the study period, and sharing all the pains and gains I faced during this study. v Table of Contents Contents Page DEDICATION.............................................................................................................................