Study of the effect of environmental factors on vegetation diversity in Eshtehard rangelands

The effect of environmental factors on vegetation diversity was studied. Sampling was done using least area method. To measure the plant parameters according to each type area three 500 meter transects with 50 meter intervals between transects (due to the scarce vegetation cover) were established. In each plot, types and numbers of existing species and their percentages were determined. Also, profiles were dug at the beginning and end of each transect and soil specimens were sampled at 0- 20 cm depth. Among soil properties, the percentage of clay, silt, sand, organic matter, lime, acidity, electrical conductivity, calcium, magnesium, sodium and potassium were measured. After collecting data, Shanon-Winer species diversity and Simpson indices were determined using Ecological methodology Software. Finally, the most important factors effecting the species diversity variation were specified using Principle Component Analysis. The results showed that among the studied factors elevation, slope, soil depth and lime are the most effective ones.