Introduction

The main objective of this study is to survey the effective environmental factors on distribution plant species using LFA method in north and south of Valuyeh summer rangeland, Iran. The both aspects in height of 1600 to 2200 m used the 14 transects 50 meters and 70 plots 1×1 along transect and in the direction of the predominant slope downstream towards the area. It carried out a systematic - Random sampling and recognized plant species in the plots. Also, it elevated 11 surface soil parameters, such as soil cover, basal canopy cover, litter cover, Cryptogam cover, Crust broken-ness, Erosion type & severity, Deposited materials, Soil surface roughness, Surface resist. Then the DCA and CCA analysis is used to determine the effects of environmental factors on distribution of vegetation. The result showed that the important affective factors on distribution of vegetation in two north and south aspect are elevation, slope and stability respectively.