Investigation on the preference value of 4 species of semi- steppe rangelands of Iran

In this study, the preference value of four rangeland species of semi steppe regions of Iran including were measured preference index of different species in three stages of vegetative, flowering and seed ripening Poa bulbosa, Bromus tomentellus, Noaea mucronata and Stachys inflate were investigated. The study was conducted during vegetative growth, flowering, and seeding stages in semi steppe rangelands of Cheshmeh Anjir, Karsanak, and Jashloobar. One-way ANOVA was applied to analyze the data. The results of combined analysis of variance showed that the preference value of the mentioned species differed significantly among the studied sites as well as studied species, while no significant differences were obtained among phenological stages. Interaction effects of region×species (R×S), species×phonological stage (S×PS) and species×phonological stage×region(S×PS×R) were significant, indicating multiplicative diversity of data. According to the results of Duncan's Multiple Range Test at 5% level of probability the highest preference value was recorded for Poa pulbosa and Bromus tomentellus. The lowest preference value was obtained for Stachys inflate and Noaea mucronata. The comparison of preference value in three studied sites showed that Poa bulbosa in Cheshmeh Angir site and Stachys inflata in Karsank site had the highest and lowest preference value, respectively. It is due to the different species composition and climatic conditions of the sites. Generally, the obtained results of this study showed that the preference value changes of Poa bulbosa did not differ significantly during different months.