Influence of Environmental Factors on Distribution of Plant Species in Nodushan Rangelands of Yazd Province (Iran)

The purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelands of Nodushan, Yazd. The plant species cover and the environmental variables were measured at 9 sites. Soil samples were taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. Vegetation was classified using twoway indicator species analysis (TWINSPAN). Data was analyzed using the ordination method of canonical correspondence analysis (CCA). Results showed that soil texture, organic matter, gypsum, salinity, C/N ratio, and elevation greatly affected the distribution of vegetation. Anabasis aphylla reflected the high salinity and saturation moisture content of soils. Ephedra strobilacea reflected a high level of soil gypsum and a high C/N ratio. Artemisia aucheri was characterized by a gradient of increasing elevation, high organic matter, and available water. Determining the vegetation-environment relationships at these sites facilitates the improvement and reclamation of arid and semi-arid shrubland ecosystems.