Assessment of rangeland functionality involving field- based and remotely- sensed approaches (Case study: Steppe and Semi-Steppe rangelands of Isfahan South and West)

Assessing the structure and functionality of rangelands is required to detect early changes in the ecosystem and assist managers to evaluate the effects of their management practices. This study was aimed to evaluate the functionality of steppe and semi-steppe rangelands in Isfahan province using field and remote sensing approaches. For this purpose، the functionality and land degradation status in 50 sub-basins were identified using the field- based landscape function analysis (LFA) method in 15 sites in steppe rangelands of Shahreza in south of Isfahan with very poor conditions، and also 21 sites with very poor، poor and moderate conditions in the semi-steppe rangelands of Aghcheh in west of Isfahan. The remotely- sensed leakiness index (LI) was calculated on the basis of the 50 sub-basins and a DEM map of the study area and also NDVI and SAVI vegetation indices were extracted from Landsat TM images in June 2009. The results showed that the outputs of the LFA method had positive and negative relationships with vegetation indices and LI with a 95% confidence level (P-value<0. 05)، respectively. Hence، in broad arid and semi-arid rangelands of Iran، these functionality indices can be used to prioritize rangeland functionality levels and protect these natural lands from degradation in the future using appropriate monitoring programs at the sub-basin scale.