Multivariate Analysis of Rangeland Vegetation in Relation to Edaphical and Physiographical Factors

In this study, distribution and establishment of semi-steppe rangelands vegetation in related to the most important environmental parameters as edaphically and physiographical factors be considered using DCA,CCA and TWINSPAN.Generally rangelands vegetation dependent to the matrix of environmental factors which be classified to edaphical, physiographical and climatically ones.Vegetation has an important role in rangelands that ecologically balance the tropical relations among food chains. So determining the rangeland flora, their pattern and distribution and the most abiotic important factors affecting the species maintaining rangelands need to apply multivariate analysis for the nature of data using in such a these studies. Using Pc-Ord software in 26704 ha, we classified the rangelands vegetation into 15 ecological species groups among four altitudinal stratum form 2400 to 2800 meters. These groups also respond to the most important factors such as sand and nitrogen in 2400-2500 m.,slope,aspect,elevation,clay,K in 2500-2600,elevation,slope,Caso4,EC,C/N,P and sand in 2600-2700 m.,elevation, CaCO3 and sand in 2700-2800 are the most important factors forming the vegetation of semi-steppe rangelands.