2026-01-22 中国科学院（CAS）
＜関連情報＞
- https://english.cas.cn/newsroom/research_news/earth/202601/t20260122_1146366.shtml
- https://www.pnas.org/doi/10.1073/pnas.2522643123
地球規模の土壌塩分濃度の上昇が無機炭素濃度の変化に及ぼす影響 The contribution of increased global soil salinity to changes in inorganic carbon
Xiaofang Jiang and Xian Xue
Proceedings of the National Academy of Sciences Published:January 21, 2026
DOI:https://doi.org/10.1073/pnas.2522643123
Significance
Soil inorganic carbon is an important part of the atmospheric carbon cycle. Salinized soil is particularly important to explain the lack of a carbon sink. In this study, we find that soil salinity makes an important contribution to inorganic carbon storage. In many cases, there is a positive correlation between soil salinity and inorganic carbon storage. This is of great significance for coping with global climate change and land degradation.
Abstract
Soil salinization poses a serious environmental challenge, but the impact of global salinity on SIC (Soil Inorganic Carbon) remains unclear. Using 94,515 samples from 0 to 200 cm depth, combined with subregional classification (such as soil type, land use, climate, geomorphology, and soil texture) which helps address spatial heterogeneity, we obtain relatively accurate global distribution data for EC (Electrical Conductivity) and SIC. EC of 0 to 40 cm layer positively influences SIC in most taxonomic subregions, which may be due to the inorganic CO2 absorption influenced by pH and salinity. EC of 80 to 100 cm layer sometimes negatively influences SIC due to the increase of soil depth. When EC is below 4 dS/m, EC often positively influences SIC. When EC increases by 2 to 4 dS/m, the mean global SIC in 0 to 20, 20 to 40, and 80 to 100 cm layers increases from 66.15, 78.75, and 117.39 to 174.47 to 190.38, 132.76 to 154.98, and 149.14 to 161.37 g/kg, respectively. The increase is relatively high but similar overall, which deserves high attention. These findings elucidate the dynamics of carbon–salt coupling in the soil–atmosphere–water system, offering pivotal scientific insights for carbon-neutrality strategies.
