Role of traditional enclosures on the diversity of herbaceous vegetation in a semi-arid rangeland, southern Ethiopia
2010
Angassa, A. | Oba, G. | Treydte, A.C. | Weladji, R.B.
Grazing management and seasonality strongly influence the recovery potential of herbaceous vegetation in semi-arid rangelands of southern Ethiopia after history of heavy grazing. We investigated effects of management (enclosures versus grazed landscapes), age of enclosures and seasonality related to rainfall (i.e., independent variables) on herbaceous biomass, grass basal cover, herbaceous species abundance, species richness and diversity in a savanna rangeland of southern Ethiopia. We further assessed the relationship between the herbaceous biomass and species richness. Management significantly affected most of the herbaceous response variables (i.e., comparing enclosures and open grazed). Herbaceous biomass, grass basal cover, herbaceous species richness and diversity were greater in enclosures than in grazed areas. Rainfall was also influential on herbaceous biomass, grass basal cover, abundance of herbaceous species, herbaceous species richness and diversity. Herbaceous biomass, abundance and diversity did not however vary with the age of enclosures, while herbaceous species richness appeared to decrease as the age of enclosures advanced. Grass basal cover initially decreased and later on increased with the age of enclosures, so that the older enclosures disclosed improvement of grass basal cover.
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