Assessment of Range Health Changes in Zagros Semi-Arid Rangelands, Iran (Case Study: Chalghafa- Semirom-Isfahan)

Rangeland health assessment provides qualitative information on ecosystem attributes. We examined changes in rangeland health in the Zagros semi-arid rangelands of Iran at fixed sites between 2001 and 2011, over the 10-year period. The rangeland fragments significantly declines in the quality of the vegetation, and changes in plant species were driven largely by seasonality, and to a lesser extent, amount of rainfall. Three indices of rangelands health (composition, function and stability) developed using site-based vegetation and landscape data. The results indicated that the majority of sites had intermediate values of the three indices, and few sites had either very low or very high values. The indices of composition and function were strongly correlated with the subjective ratings applied to each site at each measurement period. The results of this study highlight the difficulty of detecting change over extensive areas of rangeland, and of separating management induced effects from climatic effects in an environment which experiences wide spatial and temporal variation in rainfall. Results showed that soil surface resistance decrease and water flow pattern degradation were the most important causes in rangeland health decrease. Although, Chalghafa rangelands have enough rain falls to support habitation, humans had degraded the landscape. Moderate grazing is the best way to use the grazing land without severe reduction in abundance and biomass of species.