Habitat prediction model medicinal species of Rheum ribes L. with Maximum Entropy model in Chahtorsh rangeland of the Yazd province

Rheum ribes species is one of the important medicinal plants in the world. In this study were used maximum entropy method (Maxent) and the MAXENT software to this prediction habitat map. Measure environmental variables was soil variables including gravel percentage, pH, electrical conductivity, percent lime, gypsum, organic matter, soluble salts (Ca+, Na+, K+, Mg2+, CL, HCO3, SM and SO2), sand, clay and silt and variable topography (slope, aspect and elevation) and rainfall variable. Those were effective variables on the presence of species. The model classification accuracy using the area under the curve (AUC) was 95% (good Level), and kappa coefficient was obtained 0.92 that measuring from the agreement of prediction maps with ground truth, which is at a high level. The results of this study showed that the habitat of this species is in the soils with low pH (less than 8), clay Low (less than 40%), coarse texture and organic matter more than 4.0 percent. And the presence of this species has inverse relationship with a pH of both the depth and the clay first depth and with has directly relationship to organic matter of both depths.