Spatial distribution of grassland soil organic carbon and potential carbon storage on the Qinghai Plateau

Abstract

Mapping the soil organic carbon (SOC) properties of terrestrial ecosystems is necessary to mitigate carbon flux. Here, we quantified grassland SOC contents and densities to evaluate the potential for increased storage through recovery on the Qinghai Plateau. The SOC contents of 41 paired soil profiles from areas of nondegraded and degraded grasslands were analyzed in 2012 using a dry oxidation method. The average SOC contents of nondegraded and degraded grasslands were 3.4 ± 0.3% and 2.4 ± 0.4% (p < 0.05). The SOC density changes varied from −5.5 to 13.2 kg/m2 in a future grassland restoration scenario. The predicted main regions of potential increasing SOC density were located in the counties Zhiduo, Qilian, Menyuan, Maduo, Gande and Zeku. Moreover, the potential SOC stock would increase by 0.83 pg due to grassland restoration, suggesting a key role of alpine grassland as carbon sink on the Qinghai Plateau.