Analysing rangeland function and structure using remote sensing data and field-based LFA method
Assessing the structure and functionality of rangeland is required to detect early changes in the ecosystem and assist managers to evaluate the effects of their management practices. The both field methods and remote sensing indices can be used to assess rangeland functionality. Rangeland ecosystems are formed by many vegetation patches with different ability to conserve vital resources such as water and nutrients. Landscape Function Analysis (LFA) is a relatively new method to assess the functionality of rangeland ecosystems by assessing soil stability, nutrient cycling and infiltration of a particular site derived from 11 soil surface indicators. Assessing rangeland functionality by remote sensing data also decrease the cost of assessment procedures and measurements error and enhance the accuracy of the results. This study aimed to evaluate the functionality of Steppe and Semi-Steppe rangelands in Isfahan province using field and remote sensing approaches. Three sites in Steppe rangelands of Shahreza with very poor condition and also 3, 4 and 7 sites with very poor, poor and moderate condition, respectively, in Semi-Steppe rangeland of Aghcheh were selected. One transect was established directly downslope in each site randomly and a continuous record of all patch/ inter-patches (including their names, lengths and widths) were recorded. Also in all patches, 11 indicators of soil surface characteristics were measured with three replications and their status were scored according to LFA method and then the functionality indices of all sites including soil stability, infiltration and nutrient cycling were measured accordingly. The landscape functions of studied area were also assessed by some remote sensing indices including leakiness index (LI), Weighted Mean Patch Size (WMPS) index, Lacunarity index and proximity index. Landsat 5 (TM sensor) satellite images obtained at 1/6/2009 was used to calculate the indices....