Effect of grazing intensity on vegetation and soil physio-chemical properties (Case study: in rangelands of Kolash village, ParsAbad, Ardabil province)

To study the effect of grazing gradient in rangeland degradation, the effect of three grazing intensity (light, medium and heavy) on the indicators of vegetation and soil physio-chemical properties in the rangeland of Kolash village of ParsAbad in Ardabil province was evaluated. In each grazing intensity, three transects and in each transect 10 plots of one m² was taken. In each plot the parameters of production and species composition and density, the canopy cover of each species, litter, bare soil and stone and gravel was recorded. Soil samples from a depth of 0 to 30 cm in the plots of first, fifth and tenth of each transect was collected as the one sample. The soil parameters such as pH, electrical conductivity, magnesium, calcium, potassium, lime, phosphorus, organic carbon, organic matter, MWD and the percentages of sand, silt and clay was measured. One-way analysis of variance and Duncan test were used for testing of all parameter means equality and grouping of treatments, respectively. The results showed by increasing grazing intensity, production (p