Grazing Exclusion Effect on Soil and Vegetation Properties in Imam Kandi Rangelands, Iran

摘要

Most of the rangeland of Urmia in Iran is degraded and will require considerable reclamation to achieve a desirable state. The aim of this study was to evaluate the effects of 14 years of grazing exclusion on vegetation and soil properties in Imam Kandi rangelands. Sampling in both grazing exclosure and grazed areas were conducted using a systematic randomized sampling method. Six 100-m long transects were randomly located in each area and ten 1 X 1 m sampling plots were located along each transect. Within each plot, species presence, canopy cover, species yield, and plant densities were measured. Soil cores were taken in the center of each vegetation sampling plot at 030 cm and 3060 cm depths. Organic matter, nitrogen content, the amounts of phosphorus and potassium, electrical conductivity (ECe), pH, the percentage of CaCO3, and soil texture were determined for each sample. Results indicate differences in plant canopy cover, species composition, and yield between the grazing exclosure and the control site. All plant growth forms at the exclusion site differed from those at the grazed site. Biomass of perennial grasses, perennial forbs and annual forbs was greater at the exclusion site than at the grazed site, and biomass of annual grasses and shrubs at the control site was greater than at the exclusion site. Overall grazing exclosure site improved the vegetation composition and soil quality parameters ECe, pH, organic matter, nitrogen, phosphorus, and potassium content relative to the grazed site.