Relationship between vegetation diversity and environmental factors in Taleghan rangelands

The first step in ecosystem management is the determination of effective factors on species distribution and diversity. In this paper the relationship between species diversity of Taleghan rangelands and environmental factors has been investigated. For measuring vegetation data, according to sensitivity of species diversity parameter to plot number and area, the proper area of sampling plot was determined by least area method and the number of plot after the primary sampling was determined by statistical method according to vegetation variations. Then, sampling in each unit was done along three 150 meter transects. 15 plots (1 m2), established along each transect in 10 meter distances. The kind and the amount of existing species and the percentage of vegetation cover were determined in each plot. At the beginning and at the end of each transect, a profile was dug and soil. Sampling was done from 0-30 centimeter. Among soil properties, clay, silt, sand, organic material, lime, PH, EC, azote, phosphorous, acidity, Electrical conduction potassium, were measured, After collecting data, Shanon-Winer species diversity and Simpson indices were determined using Ecological methodology Software. To determine the major factors affecting species diversity variations, Principle component analysis was used. The results showed that among studied factors aspect, texture, lime, potassium and depth of soil had the most influence on species diversity.