Simulation of Grassland SOC under Future-Climate Scenarios in Gansu, China

Abstract

The impacts of global warming on the grassland carbon cycle are increasingly severe. To explore the spatiotemporal variation in grassland soil organic carbon (SOC) and its response to climate change in Gansu Province, in this study, we designed five future-climate-scenario simulations (2019–2048), based on the baseline (1989–2018), according to the IPCC Fifth Assessment Report. The CENTURY biogeochemistry model was used to estimate the SOC of Gansu Province. One-way ANOVA and an error analysis were used to verify the model. Meanwhile, a Pearson coefficient diagram was used to analyze the main influencing factors of SOC. The results revealed that there was a good agreement between the observed and predicted SOC. The quarterly and inter-annual SOC trends of the five future-climate-scenario simulations were similar to those of the baseline simulation. The most extensive SOC storage occurred in the central Gannan region, in the simulation B scenario (temperature increase of 2 °C, no change in precipitation, and double the CO2 concentration). Temperature had a significant negative effect on SOC. Precipitation had a weak impact on SOC. The results indicate that SOC was more sensitive to temperature than to precipitation.