Population Density of Cordia africana Lam. across Land Use Gradients in Jimma Highlands, Southwest Ethiopia

Abstract

This study was conducted to assess the population density of Cordia africana across land use gradients in the Jimma Highlands of southwest Ethiopia. A transect with a length of 23 km with 1km buffer was established across different land use types. The transect was stratified into different land use types (cropland, semi-forest coffee, natural forest, woodland, pasture, plantation). The study plots were randomly distributed in different land use types along the transect. The population density, diameter at breast height and height of each Cordia africana tree were taken from the one hectare plot. The biomass of the tree was calculated by using nondestructive allometric equation (AGB = 0.0673(ρD 2 H) 0.976 ) and aboveground live carbon storage in the tree was estimated at 50% of the AGB. The highest population density was recorded from SFC system followed by cropland. Cordia africana was not recorded from pastureland and plantation forests. The highest aboveground live carbon storage in the biomass of the tree was also found in SFC system followed by woodlands. There was significant population density difference between the two levels of protections (t = 5.34, P = 0.003). There was also significant difference between the two levels of protections in aboveground carbon storage (t = 3.219, P = 0.023) in C. africana. The traditional coffee management system in Ethiopia has contributed to the conservation of C. africana species which is highly threatened in the wild. Strengthening the sustainability of SFC management system in the study area is important for the conservation of C. africana and other related species which are threatened in the natural forests.