Assessing structure and function of range ecosystems is required for proper management of this valuable resource. Range health is known as a simple and effective method for evaluating the effects various management practices on rangeland function. This method uses 17 indicators to assess ecological processes status in rangeland ecosystems including site stability, hydrologic function and biological integrity. Remote sensing techniques are widely used to assess rangeland ecosystems because direct field methods are costly and time-consuming. This study aimed to evaluate function status of Ghamishlou (located in Steppe zone) and Meidanak rangeland (located in Semi-Steppe zone in Fereidonshahr), using rangeland health method and leakiness index (LI) as a remotely- sensed function metric. Three grazing zones were selected in Ghamishlou National Park including places grazed with “wild herbivores”, “wild herbivores and livestock”, and “only livestock” and 9 site replications were selected in each place. Three range places with various grazing pressure were selected in Semi-Steppe rangelands of Meidanak including 6 “slightly grazed”, 8 “moderately grazed” and 8 “severely grazed” sites. All the 17 rangeland health indicators were evaluated in each site, scored and -0/85) and SAVI index (r = -0/61) in Ghamishlou area. LI also had high negative linear correlation with land cover (r= -0/87 ) and NDVI (r = -0/79) in Meidanakarea. This study indicated high the potential of both field- based health and remote sensing techniques for assessing ecosystems functionality in Steppe and Semi-Steppe rangelands. Keywords: Rangeland ecosystem, Reference site, Hydrologic function, Leakiness index, OLI sensor
