Maziar Haidari - Young Researchers and Elite Club, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
Dorna Rezaei - M.Sc. student of forestry, University of Yazd, Yazd, Iran

Silvicultural operation need to notice the species diversity. To this study Gomarlang district inmarivan region, northern zagros forest was selected. In this study 30 circle sample plots (500 m2)were collected by random method. In every sample plot the kind of species and number of treesand shrub were recorded. In the sample plots the micro plots of 5 m by 5 m (i.e. area of 25 m2)were designed and Herbaceous and shrub information was recorded then. Species diversityindexes including Shannon Wiener (H׳), Simpson (1-D) and Margaleff (R1) were used to evaluateplant diversity in each sample plot. Data analyzing was done by Past and EcologicalMethodological software's. Results showed that 8 tree species, 8 shrub species and 64 herbspecies observed in the site study. The plant species that identified in the studied region belongedto 16 trees and shrub species in 9 families. Overall results showed that the presence of 80 plantspecies in the study area indicates the high biodiversity in the Northern Zagros forest andherbaceous layer had the highest richness, evenness and diversity.

Northern zagros, Marivan, Gomarlang, Species diversity, Tree, Shrub, Herb