investigation of production and utilization of bromus tomentellus boiss. in kordan rangeland of alborz province

to evaluate the vegetative and productive characteristics and forage utilization by livestock at different stages of bromus tomentellus boiss.phonology, this experiment was carried out during five years in kordan rangeland of alborz province rangelands. so starting the grazing season and livestock entering, any remaining amount of forage grazing was harvested until a month intervals, and utilization rate was determined by subtraction between harvested forage and fenced plot forage. finally, in order to study the effect of harvest months on the production and utilization of specie under investigation in the study area, data were analyzed. in overall, the results of this study were showed that highest production was belong to third and fourth years and least production was belong to first year. the utilization changes were similar to production changes. in addition, growth and production period bromus tomentellus boiss.was spring. the growth and production this plant was maximum in april and then reduced in july. the forage of this plant in may and june has been strongly grazing in the study area. in july the utilization rate this plant was decreased. it seems that the complete growth stages, this species have a woody and livestock grazing has less on it. thus reduce the amount consumed by livestock.