Habitat Utility Modeling of Organic (Wild) Pistachios (Pistacia Vera) with Maximum Entropy Method (MaxEnt) in Sarakhs Forest Area (Gonbadli under khorasan Province)

Organic (wild) Pistacia vera is a species of broadleaf forest. One of the most important natural forest habitatsin the world is located at northwest and southwest of the city of Sarakhs, Khorasan Razavi Province, Iran.In addition, the unique ecological features of this habitant and the economic value of organic pistachio greatly impact on the lives of people residing in this region and the country.Unfortunately, continuous over harvesting and drought-stricken development endanger natural life, regrowth and cultivation of this unique species.Understanding spatial distribution of this species plays a significant role for assessing regional protection and development; on the other hand, it can be helpful to recognize effective ecological factors on its habitat.Ttherefore, modeling this distribution is very important.In this paper, habitat modeling of this species is studied by method of maximum entropy according to edaphic, climatic and physiographic data in the city of Sarakhs (under district of Gonbadli). results of Jackknife test for surveying significance of variables shows that changes in soil properties such as gravel percentage, exchangeable sodium adsorption ratio, sodium content soil, gypsum, climatic factors (temperature and precipitation)and height above sea level are most important factors affecting the distribution of habitats.The accuracy of model is assessed by kappa coefficient for 0.72 and AUC 0.92 as well as result sreveals that maximum entropy method is an appropriate method for habitat modeling.