Investigating Climatic Factors Affecting the Distribution of Pistachio Forests in Mond Basin

Pistachio is an aridity plant in bio-climatic zones of Irano-Turanian. Low rainfall and long dry season usually separated this area from other parts of regions. The purpose of this research is to evaluate different types of Pistachio (Acer cineracens- Pistachio, Amygdalus- Pistachio, Pistachio atlantica and Ziziphus- Pistachio) using multivariate statistical methods in Mond basin. Twenty six monthly climatic variables based on their ecological importance were selected from 18 synoptic stations within and out of basin and were distinguished by using Principal component analysis method, so that the 26 original variables were reduced into 3 components. Temperature, rain, and radiation-wind component were allocated, 56.3, 26.5 and 6.4 percent and totally 89.2 percent from total variance. Then forest type map of Pistachio were exactly graded as interpolation of climatic values and component score and based on this, the key climatic elements effective to Pistachio distribution were analyzed. The results showed that habitat of Pistachio types were moderate, semi hot and semi-arid, hot and semi dry and hot, dry. The elevation range of vegetation types in the basin was 900-2600 meters above sea level. Due to the specific conditions prevailing in the basin (low altitude and high humidity), various types of Pistachio have not been seen in hot and humid temperatures region.