Teshome Abate*1 , Abule Ebro2
Abstract
Tree play crucial role in arid and semi arid rangeland and pastoralists depend heavily on woody plants for multiple uses. However, there is limited information regarding to woody plants in Rayitu rangeland of South East Ethiopia. The objectives of the study were to document traditional use of woody plants, assess woody plant structure and examine relationship between woody plants density with rangeland condition parameters, bare ground cover, and biomass production. A structured questionnaire (90 households), focused group discussions and field observations were used to gathered data. Data on woody plant composition, density, frequency, canopy cover, plant height, desirability and browsing effect was gathered from 72 belt transects (50mx4m) laid across three grazing types and two elevation zones. The most dominant use of woody plants was for construction (91%), followed by browse (68%) and medicinal purposes (25%). About 80% of the respondents replied the woody plant vegetation cover has declined. Drought (52.8%), deforestation for the expansion of farmland (39.2%) and construction purposes (26.8%) were the major causes. A total of 45 woody species were identified in the grazing area. The mean density of woody species (plants/ha) were (p <0.05) highest in communal (2654) and in enclosure grazing sites (2668) than in benchmark (2042). Both the household and the field vegetation studies confirmed that communal and enclosure rangelands are encroached by bush. Acacia tortilis, Acacia bussie and Commiphora erythraea were the encroaching woody plants in grazing sites. Most of the woody species had the highest abundance in the height class > 2–5 m regardless of grazing type and altitude belt. Emphasis on conservation of desirable plants and control of bush encroachment through selective thinning are recommended.