Study of some index species - environmental factors relationships in mid Taleghan rangelands

The aim of this research was to find plant – site factor relationships in mid Taleghan rangelands to determine the most important effective factor in the distribution of the understudy plants. For this purpose, in indicator region of every vegetation type plant sampling was done by random–systematic method. Plot size was determined by minimal area method and plot number was assigned according to vegetation changes of the study area. In each sampling point the characteristics of elevation, slope and aspect were recorded. Also, at the starting and ending points of each transect soil samples were gathered from 0-30 cm. The following soil properties were determined in laboratory; soil texture, phosphorous, potassium, nitrogen, organic matter, lime, pH and EC. To find the relationship between vegetation and environmental factors PCA (Principal Component Analysis) was made. The results indicated that there is significant relation between distribution of plant types and environmental factors. Our findings showed that elevation, slope, texture, lime, phosphorous and soil depth have meaningful impact on distribution of plant types in mid Taleghan rangelands.