ECOLOGICAL, FLORISTIC AND ETHNOBOTANICAL STUDIES IN AND AROUND WEJIG-MAHGO-WAREN MASSIF FOREST PATCHES IN SOUTHERN TIGRAY, ETHIOPIA Mebrahtu Hishe Gidey Addis Ababa University Addis Ababa, Ethiopia May 2019 ECOLOGICAL, FLORISTIC AND ETHNOBOTANICAL STUDIES IN AND AROUND WEJIG-MAHGO-WAREN MASSIF FOREST PATCHES IN SOUTHERN TIGRAY, ETHIOPIA Mebrahtu Hishe Gidey A Dissertation Submitted to the Department of Plant Biology and Biodiversity Management Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy (Biology: Botanical Science) Addis Ababa University Addis Ababa, Ethiopia May 2019 Abstract Ecological, Floristic and Ethnobotanical Studies in and around Wejig-Mahgo-Waren Massif Forest Patches in Southern Tigray, Ethiopia Mebrahtu Hishe Gidey, PhD Dissertation Addis Ababa University, 2019 There is a declining trend of biodiversity in general and plant diversity in particular. This trend is leading to the loss of the associated indigenous and local botanical knowledge in Ethiopia, which is more severe in the northern highlands than elsewhere in the country. The purpose of this research was to study vegetation composition, soil seed bank and to document associated ethnobotanical and management practices applied by the forest fringe communities in and around Wejig-Mahgo-Waren Massif Forest area. Vegetation data were collected from a sample of 150 quadrats (each 20 m x 20 m) placed in ten transect lines, which were systematically laid. All vascular plant species were recorded. Diameter at breast height was measured and seedlings and saplings were counted and recorded. Height and percentage cover abundance were estimated. Soil samples were collected from 75 quadrats down to 0-5 cm and 5 -10 cm depth. Stratified random sampling of 309 informants was performed for collection of data on indigenous knowledge, of social classes associated with the forest and the resources in it. Thirty key informants were purposively selected with the help of local administrators, elders and other community members for collection of ranking exercises. For collection of ethnobotanical data, semi- structured interview, guided field walks and focus group discussions were applied. Basal area, density, frequency, importance value index, Shannon-wiener diversity index, cluster analysis and ordination were computed on ecological data. Density, composition, depth distribution and Sorensen coefficient of similarity were computed for soil seed bank analysis. Ethnobotanical analytical tools, including preference ranking, informant consensus factor, fidelity level, direct matrix ranking and cultural significance index were employed to describe the reciprocal relationship between the forest vegetation and forest fringe communities. Vegetation study revealed a total of 264 plant species belonging to 162 genera and 82 families. Woody (45.45%) species were higher than herbs (42.04%). Asteraceae (27 species, 32.93%), Poaceae (24 species, 29.27%) and Fabaceae (23 species, 20.05%) were the dominant families in terms of number of species. Five plant communities were identified in the forest vegetation, namely Cadia purpurea – Carissa spinarum, Olea europaea subsp. cuspidata – Juniperus procera, Dodonaea angustifolia – Acacia abyssinica, Erica arborea – Myrsine africana and Acacia etbaica – Acacia tortilis. The highest (3.87) and the least (3.21) Shannon-Wiener diversity indices were found in communities two and five, respectively. Altitude, slope, livestock grazing and human impacts were the factors influencing species distribution. From soil samples, the total number of species recorded was 54, representing 42 genera and 23 families. The number of viable seeds in the soil samples corresponded to a seed bank density down to 10 cm was 1115 m-2. Herbs (85.16%) and woody species (14.84%) were the plants counted from the germination assay. Soil Seed bank and standing vegetation shared 36 species and their similarity was 23 %. The informants viewed the forest as an important entity for attraction of rain and for wildlife habitation followed by beekeeping and foraging as well as for sourcing straw and fuelwood. Of 79 plant species differentiated as useful to the community, 52 (66%) were used in traditional medicine (human and livestock), 28 (35%) as livestock fodder/ forage and 27 (34%) were recognized as honeybee forage. The highest informant consensus factor values were calculated for dermatological ailments (0.98,) followed by external injuries, bleeding and snakebites (0.92). The highest fidelity level (96.15%) was recorded for Verbascum sinaiticum followed by Withania somnifera (89.47%). Deforestation, agricultural expansion, fuelwood collection, grazing and settlement in decreasing order were considered responsible for forest resources depletion. Both the associated indigenous knowledge and the forest resources were under pressure. Thus, to restore the forest in the shortest possible time, restoration strategy that combines planting of seedlings of indigenous species and natural restoration techniques need to be applied. Keywords/phrases: Multiuse, Plant communities, Restoration, Tigray, Wejig-Mahgo-Waren Forest iii DEDICATION This dissertation is dedicated to the local people of the study area who maintained the forest and their indigenous botanical knowledge, even at the worst drought times. iv “A nation that destroys its soils destroys itself. Forests are the lungs of our land, purifying the air and giving fresh strength to our people.” (Franklin D. Roosevelt, 29 Jan 1935) v Acknowledgements First and foremost, it gives me a great pleasure to express my gratitude to my supervisors Prof. Zemede Asfaw, Prof. Sebsebe Demissew, Dr. Mirutse Giday and Dr. Bikila Warkineh for their unreserved guidance, support, effective follow-up of the research work and comments starting from the time of proposal writing to dissertation preparation. Prof. Zemede Asfaw has started his follow up when I was at Adigrat University by accepting me as his PhD fellow when I secure admission to the PhD programme of his department (Plant Biology and Biodiversity Management). He was motivating me to follow a holistic approach in conducting my research to include different components, such as plant taxonomy, plant ecology, restoration ecology and ethnobotany. He has always been ready to help me by providing pertinent materials. His quick response with appropriate comments is highly appreciated. The devotion to help and the deep wishes for his students to be competent enough is incredible. Prof. Sebsebe Demissew has inspired me with the course Phylogeny of Angiosperm when we had a field trip to Chilimo forest, Oromia Regional State. He crossed all through the forest at mid-day, but we, the young, were exhausted. At times, he was advising us until dark period around our bed that was unforgettable. That time gave me a lesson for the PhD dissertation field trip to tolerate all the challenges faced. He has checked all my greenhouse seedlings and specimens collected from the field, even at his rest times with very cordial cooperation. He also helped me to collaborate with Prof. Brita Stedje (Oslo University, Norway) on the identification of Thymus serrulatus from Tigray region. vi Dr. Mirutse Giday was very positive with each of my pieces of achievements that he encouraged me to continue as interested as possible. I was glad to go to his office whenever I needed help and gave me all the necessary expertise. He reads the entire document starting from the proposal to the dissertation line by line and I have really benefited from his follow up. Dr. Bikila Warkineh was happy to communicate with me whenever time allowed him to help me. He always asked me about the dissertation, even outside his office and discussed all issues, as well as level of achievements. He encouraged me to work hard and finish at the possible time. He organized different trainings for students in capacity as chairman of the Plant Biology and Biodiversity Management department and that helped me a lot. I would like to extend my deepest thanks to Addis Ababa University for covering the cost of the work. I would also like to acknowledge my department, Plant Biology and Biodiversity Management, for safeguarding students‟ rights very well. I would like to thank my home university (Adigrat University), for the full sponsorship and assistance throughout the PhD work. Prof. Daniel Potter, University of California, USA, is heartily acknowledged for buying Garmin GPS, Clinometer and Compass and his strict follow up until handover by DHL. I would like to extend my deepest gratitude to Prof. Zerihun Woldu (AAU) for the R software training that helped me much in the analysis of plant ecology. Dr. Tamrat Bekele, Dr. Ermias Leulekal, Dr. Tigist Wondimu (all from AAU), Dr. Ermias Aynekulu (Kenya) and Prof. Demel Teketay (Botswana), are also deeply acknowledged for their persistent encouragement during my course and research works. The executive secretary of our department, W/ro Yirgalem Haileselassie has also been offering a great help, like a mother throughout the PhD work. All PhD fellows are also highly acknowledged for their incredible friendship and support. vii I would like to extend my deepest gratitude to the staff members of the National Herbarium (ETH), Ato Melaku Wondafrash, W/o Shewangziw Lemma, Ato Wege Abebe, Ato Shambel Alemu and Ato Fisseha Getachew for their cooperation in all aspects of the herbarium work, besides their enthusiastic and cordial encouragements. The staff of Plant Physiology laboratory,