Grazing Impact on Vegetation and Some Soil Chemical Properties in Kojour Rangelands, Noushahr, Iran

It is important to know soil properties, particularly its chemical aspects, for the proper management of rangeland ecosystems. The aim of this study is to find the impacts of grazing on vegetation and some soil chemical properties, in three areas, the key, reference, and critical, located in rangelands of Kojour river basin in the southwestern of Noushahr, Iran. The vegetation cover data was collected from 20 1m x 1m quadrats in each area through random-systematic method in the early of grazing season. The soil data was sampled from two depths (0-10, 10-30 cm) before and after grazing. Some factors such as the organic carbon, the percentage of soil organic matters, total nitrogen, absorbable phosphorus and potassium, pH, and buffer density were measured. The results showed an inverse relationship between the grazing intensity and the amount of carbon, nitrogen, and soil organic matter, however, a direct relation exists between the grazing intensity and the amount of soil potassium, phosphorus, pH and the ratio of carbon to nitrogen. The result for vegetation data showed that more grasses and forbs present in the reference site and shrubs increased with an increase in grazing intensity. Reference site also had more species of palatability classes of I and II but more species of class III and unpalatable species were found in critical area.