PRJNA284199
Wetland soil Raw sequence reads
Underground injection of CO2 is a frequently discussed option to translocate anthropogenic CO2 emissions, but the environmental consequences of leakages are poorly understood. As a natural analogue, we studied a floodplain wetland area where localized long-term emanations of cold volcanic CO2 (mofettes) altered soil formation and led to stable hypoxia, as well as increased soil C storage (up to 47.3 w.-% C). We hypothesized that CO2 degassing is associated with functional changes in the mofette soil biome, resulting in increased C input and/or impeded mineralization. With a multi-pronged approach, involving depth-resolved C isotope geochemistry, soil activity, metatranscriptome and metagenome analysis, we identified significant differences in mofette C and energy flow compared to an unaffected floodplain wetland soil.