Forest degradation: An assessment of Gedo Forest, West Shewa, Oromia Regional State, Ethiopia – JBES

By: M.I. Zuberi

Abstract

The level of forest degradation was determined in Gedo Forest, one of the remaining Dry Evergreen Montane Forests in Ethiopia using line transects from East to West surrounding mountain escarpments locating 60 quadrats. Indicators of forest degradation eg. canopy cover, cover of forest floor, degree of damage by human activities, damage by grazing and browsing, condition of soil and moisture level were used to determine the state of degradation. About one third of the studied plots were found affected either by anthropogenic (opening of canopy cover, harvesting forest trees/parts) or by natural (aridity, poor soil) factors. The degraded forest sites had significantly low percentage of soil moisture. A total of 31 locally endangered and endemic plant species were identified in 60 quadrats of which 13 species (41.94%) were trees, 7 species (22.58%) were shrubs, 8 species (25.8%) were herbs and 3 species (9.67%) were climbers. These locally important 13 tree species were used as indicator to examine natural regeneration, only five species (Podocarpus falcatus, Prunus africana, Rhus glutinosa, Rhus vulgaris and Vepris dainellii ) had fairly high number of seedlings/saplings; but the four locally rare species, Haginia abyssinica, Cordia africana, Juniperus procera and Schefflera abyssinica were not represented by seedlings/saplings only few adult trees while Maytanus addat and Erthryna brucei had no seedling and saplings and Mellettia ferruginea and Dombeya longebracteolata had only 3 and 1 saplings respectively. Forest degradation As height and DBH(Diameter at breast height) of the trees increased, the number of individuals decreased showing a rather sharp reversed J shape distribution indicated by Podocarpus falcatus and Prunus Africana but for Cordia africana and Erthrynia brucei no regeneration, Juniperus procera had few individual in lower height class but none in higher classes, whereas Rhus glutinosa, Rhus vulgaris and Vepris dianellii had a number of individuals in the lower height class, but no representative individual from middle and higher classes. Results indicated respondents considered regeneration of trees species has been affected by cutting of trees for fuel and timber, herbivores damage/grazing and agricultural expansion.