eco-geographical evaluation of onobrychis species distribution related by soil and climate in kermanshah province

iran is one of the most important centers of diversity for onobrychismill. genus. onobrychis species collected from different habitates of kermanshah province during 2010-2012 were evaluated and the relationship among their eco-geographical distribution, geographical and ecological characteristics was analyzed using arcgis.  the results showed that most of the species of onobrychis grow in the southern part of kermanshah province. also, they are found in the cold semi-arid and semi-humid climates. additionally, some species have been extended to the central areas. the highest and lowest altitudes of the onobrychis habitats studied were 500 - 2050 m which indicates that they are of highlands genera. the studied species are adapted in regions with an annual mean temperature of 7.5-12.5 ◦c and a precipitation of under 400 mm, which refers to the adaptation of this species to the cold and dry areas. this study showed that onobrychis scrobiculata has the highest distribution in the province which refers to its wide adaptation to variuos environmental conditions. also, the distribution of some species were observed only in certain habitat conditions that due to existance of erosion factors in these areas, will probably leads to  their extinction. therefore, in order to conserve  these valuable genetic resources, a strong emphasis should be placed on the habitat of onobrychis.