Studying the sffects of Grazing Capacity and Rangeland Conditions on Occurrence of Landslide in Subalpine Grassland (Case Study: Rangeland of Masoleh Watershed)

Subalpine rangeland as a rara avis ecosystem is very important because ofecological features. Consistency and resistance of this ecosystem is so frangible and itsnatural equilibrium is instable due to the effects of biotic and abiotic factors. The landslideas one of negative consequences in upland area is seen in Masoleh watershed (north ofIran). This study has investigated the roles of biotic factors playing in the occurrence of thelandslides in Masoleh rangeland. Hence, two sites such as exclosure and grazing areaswere analyzed and compared. The plot size was 1m² and totally, 128 plots were obtainedby minimal area method and statistical formula approach, respectively. The rangelandconditions were measured by six-factor method. Clipping and weighing method was usedto determine the grazing capacity. In order to do the landslide zonation, the landslide indexwas employed. Results showed that there were significant differences between speciesdensities and soil conservation factors in both exclosure and grazing areas. There might bemore than 1.2 overstocking in the grazing area. The rangeland conditions‟ classes anddistance from fold, effective biotic factors, geologic formation, soil texture and effectiveabiotic factors were the most influential factors on the landslide occurrence in subalpineecosystem of Masoleh. Regarding results of current research, the exclosure can protect thesoil from the landslide through increasing the perennial and endemic species. Decreasinglivestock and regulating the animal entrance and egress to reach the suitable circumstancesof vegetation covers and pull up the landslide occurrence are recommended in this area.