Document Type : Research Paper

Authors

• reza siahmansour
• Morteza akbarzadeh
• Ehsan Zandi Esfahan

Abstract

This research was carried out at the Zagheh research station in Lorestan province. A number of 440 individuals in each year and 2200 individuals in five years were cut and weighted inside and outside the exclosure. The difference in weight between the individuals outside and inside the exclosure indicates the amount of consumption. According to the results, there is a significant difference between the mean value of forage production and consumption in months and in different species (P<0.01). For the average of four years, the highest and lowest forage production was recorded in the third and second year, respectively.   On average, forage production was calculated to be about 1,177 kg per year. On average during four years, 80% of the production was used by livestock. In all years, the highest amount of forage was produced in May. Ono.melanotricha, As. Remotijogus and As.bungei are consumed up to the basal area, while the highest consumption rate for Cen.virgata was obtained in June. Perennial grasses of the study site like Hor. bulbosum, Br.tomentellus, Festuca ovina, Stipa wiesnerii are also under severe grazing pressure. Under heavy grazing over a season, some species like Picris strigosa are not able to rejuvenate and their roots are shattered with little stress.  Therefore, the imbalance between production and exploitation and inappropriate distribution is a major factor in the degradation of vegetation and rangeland ecosystems.

Keywords

• forage consumption
• Exclosure
• rangeland
• Seasonal changes
• Lorestan province