Role of Plant Species and Ecological Patches in Conserving and Fixing Natural Landsʹ Soil Using Landscape Functional Analysis (LFA) (Case Study: Dehbar Rangeland, Torghabeh, Mashhad, Iran)

Abstract

Degradation of plant patches is considered as one of the indices for rangeland degrading health condition. Investigating the accuracy of triple indices (infiltration, stability and soil nutrient cycle) presented by LFA method seems necessary to determine its efficiency in semi-arid areas with the least cost. This study aims to investigate the role of vegetative species and growing forms on soil surface characteristics in Dehbar semi-steppe rangelands, Iran in 2014. So, eleven soil surface characteristics in different vegetative types each of 3 replicates were measured using landscape functional analysis (LFA). Then, the measured parameters were classified based on their sustainability, permeability and food chain continuum for each plant species. According to the results obtained from various analytical investigations, the ecological patches consisting of <em>Artemisia aucheri</em> (46.83%) and complex of <em>Artemisia aucheri </em>and <em>Agropyron intermedium</em> (with the amount of 41.7%) were higher than other forms of vegetative growth for soil sustainability. The complex of <em>Acantholimon sp.</em>, <em>Artemisia</em> <em>aucheri</em> and <em>Astragalus</em> <em>commixtus</em> had the lowest amount in terms of soil sustainability (38%). The comparison of soil permeability indices for different types of plant covers showed that the percentage of <em>Artemisia aucheri</em> (32.06%) and complex of <em>Artemisia aucheri </em>and <em>Agropyron intermedium</em> (33.5%) had the highest amount while all other patches were equal and had the lowest amount. In terms of food chain, the ecological patches such as<em> Artemisia aucheri</em> (25.63%) and complex of <em>Artemisia aucheri </em>and <em>Agropyron intermedium</em> (27.66%) had the highest amount. The complex of <em>Artemisia</em> <em>aucheri</em> and <em>Astragalus</em> <em>commixtus</em> (16.36%), the complex of<em> Acantholimon sp., Artemisia aucheri </em>and<em> Astragalus commixtus </em>(13.63%) and the complex of <em>Acantholimon sp. </em>and<em> Agropyron intermedium </em>(15.36%) had the lowest values (p≤0.01). Therefore, <em>Artemisia aucheri</em> (shrub) and a complex of <em>Artemisia aucheri </em>and <em>Agropyron intermedium</em> (grass) patches, introduced as ecological indicators for the study area, are suggested for rangelands restoration.