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

Abstract

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