Floristic composition of woody species and their ecosystem services in urban vegetation at four campuses of Addis Ababa University, Central Highlands of Ethiopia

Abstract

• Hundred-one woody species belonging to 79 genera and 42 families were identified. • Fabaceae was represented by 11 species, followed by Rosaceae with seven species. • Indigenous species made up 47%, followed by 46% exotic and 7% endemic species. • Four community types were identified with an average value of H' = 2.69. • The decline of indigenous trees calls for immediate conservation efforts. Urban vegetation is significantly influenced by human activities, which often alter its floristic composition. This study aimed to assess the floristic composition of woody species across the four campuses of Addis Ababa University (AAU) in Ethiopia. A systematic sampling method was used to collect vegetation data in the study area. A total of 101 woody species belonging to 79 genera and 42 families were identified. The family with the highest number of species was Fabaceae (11%), followed by Rosaceae (7%). Of the total species, 47 were indigenous, 46 were exotic, and eight were endemic to the flora. The eight endemic woody species recorded were Erythrina brucei, Euryops pinifolius, Gymnanthemum rueppellii, Laggera tomentosa, Millettia ferruginea, Orbivestus leopoldi, Polyscias farinose, and Solanecio gigas . Four major community types were identified: Acacia melanoxylon - Erythrina brucei, Cordia africana - Fraxinus excelsior, Albizia schimperiana - Morus alba, and Grevillea robusta - Millettia ferruginea . Community type 1 exhibited the highest levels of species richness, evenness, and diversity, followed by community type 3. Tree species accounted for the largest portion of diversity at 55%. The findings indicate a decline in indigenous trees at the early stage, raising concerns about the future of existing vegetation. Thus, further research on the regeneration status, ecological and cultural importance of woody plant diversity at AAU and nearby urban areas is essential.