Document Type : Research Paper

Author

• bahram Gholi Nejad

Abstract

This study was aimed to determine the variation of species diversity, richness and evenness of plant species under various managements (different range conditions) in five vegetation types. After determining vegetation types, range condition was measured applying the method of society for range management (SRM). In order to assess species diversity, richness and evenness, canopy cover percentage and species density were determined along transects within plots. Species diversity was determined using Simpson index, Shannon-wiener function and Hill index(N₁ and N₂) and species richness was determined by Margalef, Minhinnick,  Bootstrap and  Jack-Knife methods and species evenness was  measured  using Simpson, Camargo, Smith-Wilson and  Nay revised index. Mean comparison test (non-paired t-student test) was used to determine the relationship between species diversity, richness and species evenness under different conditions. The results showed that in various managements with changes in range condition, a trend of regular changes could be observed between vegetation cover and range condition. In other words, the value of estimated indices of species diversity and evenness was higher in good range condition as compared to the fair and poor range condition; however, the maximum value of species richness was related to good, fair, and poor conditions, respectively. Results of mean comparisons showed a significant difference between good and poor condition for most of the indices used in species diversity, richness and evenness, while there was no significant difference between good and moderate condition.

Keywords

• diversity
• richness
• evenness
• rangeland management
• Mouchesh
• Kurdistan