Habitat modeling of Ephedra

Ephedra strobilacea species is valuable plant in terms of forage and soil and water conservation, and also has many applications in medicine. In this study, potential habitat for this species was modeled using Maxent method in Poshtkouh Yazd Rangeland, and was introduced the factors important that effecting on the distribution of this species and their potential ecological range. For this purpose, the information related to the species presence point using field survey, data on soil variables using geostatistical methods, topographical information from a digital elevation model maps and climate information from maps available were prepared. Layers environmental variables were prepared by using GS and ARC GIS software. The correlations between environmental variables were evaluated and of 24 environment variables suitable been diagnosed to enter the model and software Maxent3.3. The results showed that E. strobilacea is a gypsophyte, Because the second depth gyps is most important indicator influence on the habitat prefer of this species (35- 40 %). Next variables affecting in this species presence are variables of first depth gyps (5-35 %), Lime of both depth (5-45%), the sand of both depth (45-90 %), Ca of the first depth (5- 40%) and EC is less than 10 dS m. Also, the most probability of the establishment and distribution of this species is in the low slope areas (less than% 10 %). The accuracy and the ability of predictions model was assessed good for this species based on the area under the curve (AUC = 0.98). Kappa coefficient from the comparing actual and prediction maps obtained 0.88 that it was very good level.