Prediction of Juniperus excelsa M.Bieb. geographical distribution using by climate data under the conditions of current and future in Semnan Province

The climate is determinative of the soil and flora and fauna of a region and in wide scale causes variation in ecosystem and the species combination. In this study, distribution of Juniperus excelsa were studied on the current and future climate condition(2050, 2070) under two climate change scenarios of Rcp2.6 and RCP8.5 with the GCM dataof HadGEM2-ES by using of MaxEnt model. 22 variables of climate and topography in 160 sites were employed . The resultsshowed that in addition to height above sea level, precipitation in coldest season and annual mean temperature are the next important variables on Juniperus excelsa distribution. Also the results show that if the current trend of climate change continues, habitat area of species under the scenario of RCP2.6 till 2070, increases in middle habitat class (82.4%), in good and very good habitat classes, 31.3, 67.3 percent, respectively, and will be reduced and under the scenario of RCP8.5, faces with too much decreasing the area (in middle, good and very good habitat classes, 76.5, 98 and 100 percent, respectively). According to the results , the models like MaxEnt, with acceptable accuracy have enough performance in evaluation of species distribution and can be used for strategies of conservation by the experts.