Scattered woody species diversity in different land use types in Mana district, Jimma Zone, Southwest Ethiopia

Abstract

Scattered wood species are found in different land use systems in diverse density. Those isolated woody species are declining in different land uses. The study was conducted to assess isolated woody species diversity in different land use types of Mana district, Jimma zone, Southwest Ethiopia. The study was conducted from October 2018 to September 2019. Three study sites were selected based on the presence of crop land, pasture land and coffee farm. Transect line laid at a distance of 500m systematically and along this transect plots laid at an interval of 200m in study sites. Fifty four (54) sample plots having an area of 100m×100 m, laid along transect lines. Descriptive statistics was used to show the population density, tree height, DBH and basal area (BA) for each isolated woody species. The evenness and diversity of woody plants was analyzed using the Evenness Index (E) and Shannon-Wiener Diversity Index (H’). Sorenson’s similarity index was used to calculate the similarity of different land use types in richness of isolated woody species. A total of 56 scattered woody species belonging to 49 genera and 33 families were identified and documented from three land uses. Out of identified woody species, 46 (82.143%) species were trees, 10 (17.85%) species were shrubs. The Fabaceae was the most dominant family followed by Euphorbiaceae and Moraceae. In terms of species diversity grazing land is more diversified (with H’ 3.3, E=0.889). The highest similarity index showed in current study 0.864 between coffee farm and pasture land. In study areas some scattered woody species were decreasing due to human activities. Therefore; Practices which aimed at maintaining these scattered woody species should be encouraged and applied to support the conservation of those species in different land uses.