Comparison of preference values of Festuca ovina species at different grazing times and different regions of semi-steppic rangelands of Iran

In range management practices it is impotant to understnd growing and production of key speceis as well as changes in their preference values according to seasons and habitat characteristics. The aim of this study is comparison of preference values of Festuca ovina species at different times and different regions of semi-steppic rangeland of Iran in 2006 to 2009. Random sampling with one square meter frames was emplyed to study vegetation during different growing monthes. Preference index method was used to determine the preference value of F. ovina. To calculate preference index, the ratio of the species in the diet and in the species composition were used. To compare preference value in different places and times randomized complete design with combined analysis in year and place was conducted. The results showed that among the studied sites and between the months are significant difference at α=0/05. Changes in preference values of F. ovina indicated that value of preference of this species increased until August and then decreased in September.