Investigation on relationship between plant diversity and environmental factors in Eshtehard rangelands

The first step in suitable management of rangelands is to find the factors affecting distribution and diversity of plants. The current research was carried out to find environmental factors affecting plant species diversity in Eshtehard rangelands. Within each sampling unit، two parallel transects and one vertical transect with 750 m length، each containing 15 quadrates (according to vegetation variations) were established. In each vegetation type، quadrate size was determined using the minimal area method. Soil samples were taken from 0-20 cm and 20-80 cm in starting and ending points of each transect. Measured soil properties include gravel، texture، organic matter، lime، pH and electrical conductivity. To determine the most environmental effective factors on plant diversity، Principle Component Analysis (PCA) method was applied. The results indicated that texture، lime، EC، and gravel percentage play the main role in plant species diversity.