Water erosion plays an important role in lateral soil carbon transport. This knowledge is easy to understand. However, a recent study conducted in conterminous China shows that water erosion also significantly affect the vertical CO2 fluxes. The paper entitled Lateral transport of soil carbon and land−atmosphere CO2 flux induced by water erosion in China was published on PNAS.
The land of China is suffering water erosion for a long time, which caused 180 ± 80 Mt C⋅y-1 of soil organic carbon transport during the last two decades according to the study. Yue et al. estimated the erosion-induced land−atmosphere CO2 fluxes with national soil surveys on erosion rates. By comparison the difference between CO2 emissions before and after erosion, Yue et al. concluded that the erosion-induced carbon sequestration of atmospheric CO2 is about 45 ± 25 Mt C⋅y-1, which is equivalent to 8–37% of the terrestrial carbon sink in China. Additionally, the study shows the mountainous regions in China are the “hotspots” of carbon sink.
This study highlights the water erosion on carbon sink, and also allow us to achieve better understandings of terrestrial carbon accounting. It’s very inspiring and interesting that water erosion will cause carbon sequestration. Erosion is not as bad as we thought before, at least it brings significant carbon sink.
More information: Yue Yao et al. (2016). Lateral transport of soil carbon and land− atmosphere CO2 flux induced by water erosion in China. Proceedings of the National Academy of Sciences, 113(24), 6617-6622, doi: 10.1073/pnas.1523358113