Comparison of Different Biodiversity Indexes in Different Sampling Designs (Case Study: Chahartagh Forested Reserve, Chaharmahal & Bakhtiari Province)

In this research we assessed species diversity of trees and shrubs in Chahartagh forest reserve using diversity, richness, equitability and dominance indexes derived. Based on random and systematic random sampling methods each method including 32 circle plots with 10, 15 and 20r area. We also derived the actual value of each index using 100% inventory and then compared statistical and actual amount of indexes. Regarding heterogeneity of variances, we used Gims-Hawell test for comparing averages. According to results, there are meaningful differences between different sampling methods and different plot areas. The results of single sampling t-test for comparing actual and statistical values of indexes show that just equitability index is not meaningful while other indexes(richness, diversity ad dominance) have meaningful differences compared to their actual values. Therefore, in conditions similar to Chaharagh reserve we could use equitability index derived from random sampling method for estimating trees and shrubs biodiversity status confidently but other indexes and sampling methods with some care.