The Current State of Riparian Vegetation: The Dabbis River of Ambo Woreda, West Shoa Zone, Oromia Regional State, Ethiopia
By: Diriba Oljira Gemeda, Habtamu Ashagre, M.I. Zuberi
Key Words: Riparian vegetation, River, Habitat degradation, Vegetation cover, Ethiopia.
J. Bio. Env. Sci. 8(3), 153-167, March 2016.
The status of riparian vegetation along the Dabbis River of West Shoa, Ethiopia was assessed in selected plots by examining vegetation types, vegetation change, soil cover, soil quality and water quality. Rapid survey of these indicators and systematic sampling was used to collect data from 72 plots both upstream-downstream and left-right sides of the river. These were compared to determine the less degraded and degraded plots and abundance, diversity and dominance of vegetation were calculated by using Shannon Diversity index to assert these findings. The results indicated about 55 % of the plots were covered mainly by herbs/grasses, about 57.0 % had poor soil, in nearly 55 % of plots water was mucky and dark in colour, whereas in about 90 % of the plots river was shallow. When all the indicators combined about 75 % of the plots, both up- and down-stream and left- and right- sides were found more or less degraded. Laboratory analysis indicated that soil structure, pH and moisture content were different between the less degraded and degraded sites. Evidence indicated that sites away from villages had less plots with bare land and herb (18%) and relatively more trees (5.6%) while river side by the city of Ambo had more plots with herb cover or bare land (22%) and less tree cover (only 1.9%). Though Shannon-Simpson indices and evenness indicated more or less similar diversity between the less degraded and degraded plots, the former were more rich. The main reason of the degradation of the riparian vegetation was identified as cutting trees and removing vegetation for fuel, agricultural field expansion and livestock grazing. The local community, typical farming and natural ecosystem dependent, were found to have knowledge about the degradation of the riparian vegetation and their utility and usefulness. The need of community participation and government involvement for management of riparian vegetation was indicated.