Kelbessa, Ensermu (Professor)Soromessa, Teshome (PhD)Bantiwalu, Shambel2018-07-102023-11-092018-07-102023-11-092010-06http://etd.aau.edu.et/handle/123456789/7600This study was conducted on Sanka Meda Forest in Guna district, Arsi Zone, Oromia National Region in southeast Ethiopia, which is a dry everygreen afromontane type of forest. The objective of the study was to assess floristic composition, vegetation structure, regeneration pattern and to make a phytogeographical comparison of the forest under study with some similar forests in Ethiopia. Systematic sampling method was used to collect vegetation data from seventy 20m x 20m sapling plots for woody species and five 2m x 2m subplots with in each main plot for herbaceous plants. The sampling plots were placed at every 200 m intervals along the nine transect lines laid at 400 m a part. The floristic composition and population structure data for woody species, DBH > 7cm and height > 2m, sampling (DBH < 7cm and 1 – 2m height) and all seedlings with a hight < 1m and their regeneration status were recorded in each plot. The vegetation classification was performed using PC – ORD software package. The quantitative species diversity, richness and evenness were computed to describe plant diversity in each community type. Species abundance, cover, and environmental variables (altitude, aspect) were recorded in each sampling plot. A total of 139 vascular plants and a lichen species belonging to 118 genera 63 families were identified. The Asteraceae family had the highest number of species with 21 species and 14 genera followed by Lamiaceae with 10 species and 8 genera. Four plant community types: Croton macrostachyus-Lepidotrichilia volkensii, Maytenus undata, Juniperus procera and Osyris quadripartita-Budleja davidii were recognized. Jaccard’s similarity coefficients were below 0.5 for all communities, indicating the prevalance of low similarities among the communities. Thus, all the communities identified are important interms of floristic diversity and sensitive from conservation point of view.Woody species densities for mature individuals were 1060.71 stems ha-1, 416.50 stems ha-1 for saplings and 734.64 stems ha-1 for seedlings. The basal area of the forest was 34.70m2 ha-1. The floristic composition species were priorized for conservation using population structure, important value index and rejuvenation as criteria. The population structure and their regeneration behavior in the forest revealed that there is a need for conservation priority for woody plant species with poor regeneration status. The prevailing of strong anthropogenic disturbances in the area implies the need for its immediate conservation action in order to ensure the sustainable utilization of the forest. Keywords /Phrases: Afromontane forest, floristic composition, plant community, population structure, phytogeographical comparison, regenerationenAfromontane forestfloristic compositionplant communitypopulation structurephytogeographical comparisonregeneration.Thesis