VEGETATION STRUCTURES AND RANGELAND CONDITION AND THEIR EFFECTS ON LIVESTOCK COMPOSITION IN MIESO DISTRICT OF WEST HARARGHE ZONE, EASTERN ETHIOPIA

Abstract

The current status of vegetation composition and condition of Ethiopian rangelands were highly deteriorated due to factors such as bush encroachment, alien invasive plant species, recurrent droughts, overgrazing, and expansion of cultivated land, which seems favoring unpalatable plant species and drought tolerant thorny bushes. Therefore, this study was aimed to study the vegetation structures and rangeland condition and their effects on livestock composition in Mieso District of West Hararghe zone. A random sampling procedure was used to collect vegetation data from 30 sample plots along four transect lines. Nested plot design was used a size 20m x 20m for trees, 5m x 5m for shrubs and 1m x 1m for herbaceous plant species. The density of plant species, DBH/DSH >2.5 cm and heights > 1m of woody species were collected. Shannon - wiener diversity Index (H’), Basal area (BA), and evenness (E) were estimated. Visual estimation of coverage/abundance values for woody and herbaceous species per plot was done. In addition, key informant interview and focus group discussions were conducted to collect data on herd dynamics and condition of the rangeland. The data were analyzed using SPSS version 21 software. In this study, a total of 97 species of vascular plants belonging to 39 families and 45 genera were recorded and identified. Trees, shrubs, herbs and grasses accounted for 23, 40, 18 and 16 species, respectively. The (H’) value of woody species was 2.4 with (E) value of 0.6, and (H’) for herbaceous species was 1.9 with (E) value of 0.5 in all sites. Fabaceae is the dominant Family followed by Poaceae, Euphorbiaceae and Tiliaceae which accounted for17.5%, 15.5%, 7.2%, and 6.2% of the plant species, respectively. Total BA of wood species was 4.14 m2 /ha. The condition of the rangeland indicated that non-palatable woody and herbaceous plant species are increasing and accounted for highest percentage (45.3% and 44.5% respectively) of the vegetation cover. Most of the respondents involved in household survey and focus group discussions believed that the rangeland vegetation composition had changed intensely in the past 10 or 20 years and resulted in herd composition dynamics of animals from grazers to browsers (camels and small ruminants). Community survey indicated that, 75% of the respondents mentioned that the status of their rangeland as fair (25.5) or poor (19.8) due to several disturbances pressure resulting in low feed production with the increased unpalatable species. The disturbances negatively diminished existing (native) species abundances, diversity and xv richness. Therefore, the rangeland of the study area requires immediate attention and implementation of appropriate conservation and management strategies. As such, there is a need for Integration of the traditional knowledge of the pastoralist community and their strong participation in order to improve the rangeland condition in the study area.