Spatial variation of soil chemical properties in relation to the canopy of two cushion plants Astragalus myriacanthus and Acantholimon spinosum in Yazd province

Soil and plants in natural ecosystems are always interacting with each other. The different structure and characteristics of plant species in an area in the long term affect environmental variables, especially on the soil. The aim of this study was to investigate the effect of two different plant species, Astragalus myriacanthus and Acantholimon spinosum, on some soil chemical properties in the different spatial locations. Soil sampling in early fall 2018 by randomly selecting 20 replicates (10 individuals of each species) from four locations (upward slope edge, downward slope edge, center and outside (as control)) in sycamore rangelands Naz, Yazd province, was done and a total of 80 soil samples were collected. Then, chemical properties of the soil including pH, EC, total organic matter (TOM), particulate organic matter (POM) and total nitrogen (TN) were measured in the laboratory. The effect of plant presence on soil properties showed that the parameters of organic matter (mean 1.66%), total nitrogen (mean 0.22%), electrical conductivity (mean 368.97 Ms / cm) and POM (with an average of 1.28%) in beneath A. myriacanthus significantly more than the soil outside the floor (with averages of 0.92%, 0.13%, Ms / cm 139.5, 58, respectively (P <0.05). TN and POM in upslope edge were significantly higher than other edges. In A. spinosum, there were no significsnt differences of TOM (1.77%), TN (0.23%), EC (215.46 Ms/cm) and pH (7.97) in beneath with outside the canopy. While the POM with an average of 1.49% had the highest amount under the canopy relative to the outside soil as well as other sampling sides. In general, this study expresses the different role of different cushion plants on the chemical and qualitative characteristics of the soil, which by recognizing this role can help to improve, develop and maintain their habitats.