Comparing the effects of different rangeland utilization on carbon sequestration in the Kermanshah Province, Iran

Due to the vast area and biodiversity, rangelands contribute to carbon sequestration, depending on grazing management and utilization. This research was conducted on six rangeland sites including Paveh, Ravansar, Javanrood, Einelcosh, Siahkamar, Varmenjeh, and Koohsefid in Kermanshah Province. There utilization types were included as exclosure, heavy grazing, and land use change from rangeland to rainfed orchard. The objective was to evaluate carbon sequestration capacity through different rangeland utilization. The plant biomass sampling including canopy cover and plant root as well as plant litter were carried out in the field along three transects of 50 m using plots. Soil sampling was also done in 0-20 and 20-40 cm soil depths. Plant organic carbon was determined by flame method and SOC was measured by the Walkley and Black method. The results explored that plant biomass variation through different land-use practices and utilization is significantly attributed to carbon sequestration, so that the highest level of carbon stock for plant biomass (4.7 tha-1) and soil (114.5 tha-1) was obtained in the exclosure site, while heavy grazing caused the lowest value of organic carbon in both plant biomass (1.3 tha-1) and soil (53.4 tha-1). In addition, the land use change from rangeland to rain-fed orchard led to 86.8 tha-1 organic carbon storage in both soil and plant biomass.