Influence of Excluding Grazing on Vegetation Attributes at the Eastern Slopes of West Bank

Abstract

The influence of excluding grazing on range vegetation attributes was studied at the Eastern Slopes of West Bank. Vegetation attributes were compared at a grazed plot and an ungrazed plot in the years 2004 and 2005. Results showed that plant density in the excluding grazing area was (518.9 Plants m-2) higher (p <0.05) than that in grazed plot (194.4 plants m-2) in the year 2005. In addition, total plant cover averaged 94% and 93% in ungrazed plots while 54% and 68% in grazed plots during the years 2004 and 2005 respectively. By April, 70% of plant biomass was already utilized by grazing ruminants, and subsequently induced change in the botanical composition by increasing unpalatable species like: Sarcopoterium spinosum, Asphodelus aestivus, Echinops polyceras, and Eryngium creticum in grazed plot. At the ungrazed plot, palatable species such as Medicago spp, Bromus spp, Hordeum spp, Aegilops spp, Poa bulbosa and Avena sterilis were dominant. In addition, vegetation in the ungrazed plot was more diverse than in the grazed plot, moreover, excluding grazing increased species richness by 57 %. Results indicated that overgrazing induced vegetation retrogression and reduced the length of the grazing period for two months only. In conclusion, selection of suitable grazing management, mainly grazing time and stocking rate, at rangelands in Southern West Bank is an urgent practice that should be implemented to stop the vegetation retrogression trend of these rangelands