Abstract:
Grazing is the most important factor af ecting vegetation and soil properties in range lands. It
has a critical impact on range land biodiversity and vegetation composition. Use of enclosuresarea in many parts of semiarid range lands of the world has gained widespread acceptanceasmeans to restore degraded range land ecosystems. Therefore, this study assesses the ef ect of
range land enclosures on vegetation composition and species diversity and soil physico-chemical properties in semi-arid range lands of Meyumuluke districts in East HarargheZone, Oromia Region of Ethiopia. For the vegetation and soil data collection, line transect
technique was used for enclosure and communal grazing area in this study. In both enclosureand communal grazing areas a total of 36 quadrants of 20mx20m were established along12parallel line transects by 200m interval. These 20mx20m quadrants were used for woodyvegetation data collection. Within quadrants of 20mx20m again five 5m×5m(for shrub) andfive 1mx1m (for herbaceous and soil) sub-quadrants were established, four at the corners oneat the center. This forms the total of 180 (5mx5m) and 180 (1mx1m) for both enclosureandcommunal grazing areas. T-test was employed to compare mean dif erences betweenenclosures and communal grazing areas. Enclosure area enhances herbaceous speciesdiversity and reduces the woody species compared to communal grazing area. The result
indicated that Shannon diversity index and species richness of woody vegetationweresignificantly (P<0.05) higher in communal grazing area, while, the Shannon diversityindexand species richness of herbaceous vegetation were significantly (P<0.05) higher in enclosurearea compared to communal grazing area. Likewise textural dif erences were also observedbetween enclosure and communal grazing area. Where the study revealed that, sandfraction was significantly (P<0.05) higher in communal grazing, while, silt fractionwassignificantly (P<0.05) higher in enclosure area. The soil chemical property suchas soil
organic matter, nitrogen and soil reaction of the enclosure area were significantly (P<0.01)higher as compared to communal grazing area. In general the result of this study showed that the establishments of enclosure area in semi-arid range land has positive ef ectsonherbaceous vegetation composition that could also, improve soil properties whileit
reducing the diversity of woody vegetation.
