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 rangelandsof nodushan, yazd. the plant species cover and the environmental variables were measured at 9 sites. soil sampleswere taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. vegetation was classified using twowayindicator species analysis (twinspan). data was analyzed using the ordination method of canonicalcorrespondence analysis (cca). results showed that soil texture, organic matter, gypsum, salinity, c/n ratio, andelevation greatly affected the distribution of vegetation. anabasis aphylla reflected the high salinity and saturationmoisture content of soils. ephedra strobilacea reflected a high level of soil gypsum and a high c/n ratio. artemisiaaucheri 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 ofarid and semi-arid shrubland ecosystems.