Effects of various grazing intensities on quantitative and qualitative forage characteristics of Artemisia sieberi (Case study: Ghooshe and Lookeh in Semnan Province)

This study aimed to investigate effects of grazing on forage quality and quantity of Artemisia sieberi in two rangelands of Semnan province. Three sites with different grazing intensities including reference, key and critical areas were selected in each rangeland. Plant shoots were collected from 15 plant individuals and 90 plant samples were collected for chemical analysis. The results showed that heavy grazing in Goosheh had significant effects on protein, P, metabolizable energy, DMD, ADF and production of the plant species. Although moderate grazing in key areas had no significant impact on plant production per hectare and leaf to stem ratio, heavy grazing reduced the production (75%), canopy cover (72%) and leaf to stem ratio (55%). Protein content was identified as the most sensitive parameter to grazing, as it was declined 20 and 44 percent under moderate and heavy grazing, respectively. Moderate grazing had no significant effect on the measured parameters in Lookeh rangeland but the species protein content declined significantly (50%) under heavy grazing pressure. Although dry matter digestibility and metabolizable energy of the species reduced 28 and 21 % respectively under heavy grazing, its ADF was increased by 21 %. Canopy cover percentage, leaf to stem ratio and A. sieberi production also were reduced by 60, 43 and 56 percent respectively under heavy grazing pressure. The results showed that although the quantity and quality of A. sieberi decreased significantly under heavy grazing, no evidence of these negative impacts were found under moderate grazing condition.