عنوان مقاله [English]
In studies of the effects of grazing on pasture plants, shoots and underground properties should be checked simultaneously.So the impact of different grazing intensities on the biomass of Festuca ovina species and the relationship between shoot and root biomass examined in Bijar protected area.After determining three grazing treatments with similar topographic characteristics, sampling of vegetation was done in random- systematically using 1 × 1 m plots within the 2 transects with 100 m in each treatments. Linear regression was extending to determining the relation between aboveground biomass and belowground biomass in each treatment. Statistical analyses were conducted by ANOVA. The result showed strong linear relationships between aboveground and belowground biomass in all the treatments. In addition with grazing intensity, relative contribution of aboveground biomass and belowground biomass were decreased and increased respectively. Relative proportion of aboveground biomass was significantly more in heavy grazing (67%) than both none and moderate grazing treatments (63% and 61.5% respectively). In addition relative contribution of belowground biomass was lower in heavy grazing treatment (33%) and it was 38.4 and 37.0% for moderate and none grazing treatments. The results indicate that grazing caused a significantly reduced effect on shoots and underground biomass.Heavy grazing and light grazing reduced below ground biomass (83.1 and 51.1%) compared to the none grazing area. Total biomass in grazed treatments, moderate grazing and heavy grazing was estimated at 69.7, 64.3 and 48.1 kg/ha. In general, different intensities of grazing effects on shoot biomass decreased, especially underground organs of this species. It is essential for administrators to protect the soil and prevent the death of this important species.