Investigating the Effects of Grazing Management and Rehabilitation on Diversity and Plant Genetic Resources in Semirum_Isfahan Province

Among different vegetation indices, the plant species diversity is an index is affected by grazing management.In large scale studies, it has been proven that, plant species diversity, as a principle component of biodiversity, is impressive in the ecosystem sustainability. The main purpose of this approach is surveying and comparing two different grazing intensity and its effect on diversity. The study site is Semirum township located in southwest of Isfahan. The preferred sampling method was Random-systematic and the parameters were density, canopy cover, plant production and range condition. In overall, 52 sites have been selected, which 28 sites were under moderate grazing intensity and the rest (24 sites) were under heavy grazing intensity. Proceedings implemented in sites with true management included control of grazing time, grazing intensity and vegetation rehabilitation through planting native suitable seeds. Non-parametric indices for calculating species richness were Margalof, Menhinick, Jacknife as well as counting methods and the indexes for evenness were Camargo, Smith and Wilson and Modified Nee. The floristic list was provided according to each species position in climax stage of succession. Both sites with moderate and heavy grazing intensity were similar in environmental conditions. Based on the correlation analysis, the species richness had positive and the evenness had negative significant correlation with vegetation cover, perennial plants production and range condition. Generally, management treatments have had considerable effect on enhancement of climax species, peculiarly Bromus tomentellus dominance, which upgrade range condition and also cause abating evenness in protected sites.