Tree species diversity in urban areas of ijesa region of Osun State, Nigeria

Tree species diversity in the urban areas of Ijesa region of Osun State, Nigeria, was determined through the use of field visits and semi-structured interviews of residents in six urban communities that were selected from six Ijesa Local Government Areas of the state. In each community, three routes were selected from the centre of the community and used for the study. In each route, a 500m distance was measured out and at every 50m distance; an inventory of trees and houses situated within 10m radius of the centre of the road was carried out. Also in each route, 10 residents along the route were interviewed. Similarities in the occurrence of tree species were determined among the selected communities. Also, the indices of diversity were calculated on the identified tree species in each community. Results obtained revealed a density of 2,156 tree species, belonging to 34 species and 23 families. 64 % of the trees were preserved from wildlings. The trees were valued for the fresh air and shade they provided and their ethnomedicine importance. Overexploitation, browsing by animals, insects infestation, harbouring of reptiles and birds and unplanned land use were identified as disincentives to planting trees in urban areas of the region. High similarity but low diversity values were obtained on the occurrence and diversity of the identified trees in most of the communities used in this study. Strategies that would improve urban forestry in the region were prescribed.