Vegetation Diversity and Soil Physico-chemical Properties Under Traditional Management of Rangeland in Eastern Ethiopia

The changes of herbaceous vegetation (composition, diversity, richness, evenness, and biomass production) and soil physico-chemical attributes of Harshin rangelands, eastern Ethiopia were examined under continuously open grazed areas and three ages of enclosures group arranged along chronological sequence into: < 5 years (young), 5-10 years (mid) and > 10 years (old). The herbaceous species composition showed a clear pattern of difference between the enclosure and open access grazed areas with desirable species being more prevalent in the enclosures and the undesirable ones being dominant in the open access grazed areas. The principal component analyses (PCA) of herbaceous species composition were accounted distinct across the open grazing young, mid and old enclosure management types. The diversity, richness and biomass production of herbaceous species were significantly different in the study area. The principal component analysis (PCA) of soil physico-chemical attributes showed distinct separation in relation to open grazing and three age enclosure areas. Overall, we found that the increased biomass production in the old enclosures may threat the herbaceous species diversity by dominating by only few species and hence affected the plants which are susceptible for species inter-competition.