بررسي رابطه بين تنوع گونه اي و عوامل محيطي در مراتع پشتكوه استان يزد

Relationship between vegetation diversity and environmental factors in Poshtkouh rangelands of Yazd province

The current research was carried out to find the most effective environmental factors in plant species diversity. For this purpose, study was conducted in Poshtkouh rangelands of Yazd province. Sampling was done in homogeneous units, which these units resulted from overlaying of hypsometry, aspect, slope, geology and vegetation maps. Within each unit 3-5 parallel transects with 300-500 length, each containing 30-50 quadrates (according to vegetation variations) were established. Quadrate size was determined for each vegetation type using the minimal area method. Soil samples were taken from 0-30 and 30-80 cm in starting and ending points of each transect. Measured soil properties included gravel, texture, available moisture, saturation moisture, organic matter, lime, gypsum, pH, electrical conductivity and soluble ions (Na+, K+, Mg2+, Ca2+, C1-, CO f, HCO3 and Sc>4~)-To determine the most environmental effective factors on plant diversity, PCA method was applied. The results indicated that soil salinity, texture and available water play the main role in plant species diversity.