Modeling of soil organic carbon in the north and north-east of Iran under climate change scenarios

Abstract

The changes of soil organic carbon and soil carbon decomposition are influenced by temperature and precipitation changes. In the present study, the changes of soil organic carbon under climate change scenarios were estimated by the Rothamsted Carbon model in different land-use areas in the north and north-east of Iran. The total soil organic carbon was observed 106.2 tC/ha in the study area. RothC model was used to simulate the change of SOC at 980 original 50 km × 50 km grids under A2 and B2 climate scenarios during the upcoming decades the study area. Future temperature and precipitation data under both scenarios were predicted by LARS-WG weather generator model based on the IPCC AR4. The simulated results of soil organic carbon illustrated that over the period 2010-2065, SOC will decrease in the study area. The simulation of soil organic carbon strongly suggests that SOC levels will decline due to temperature increase and decline in precipitation, particularly in cultivated lands. SOC is expected to decrease under A2 climate scenario by 8.3 tC/ha and 13.36 tC/ha by the years 2030 and 2065, respectively. Likewise, under the B2 scenario, SOC will have decreased by 8.58 tC/ha and 13.81 tC/ha by the years 2030 and 2065, respectively.