Biochar mitigates the mineralization of allochthonous organic matter and global warming potential of saltmarshes by influencing functional bacteria

Abstract Saltmarshes are suffering from severe degradation due to anthropogenic activities, leading to the loss of blue carbon and greenhouse gas (GHG) emissions. Given the significant potential of biochar in mitigating climate change, adding biochar to saltmarshes would alleviate this situation. This study investigated the effects of different biochar (made from Spartina alterniflora, corn straw, and Laminaria japonica) and their aged biochar on the carbon fraction contents, GHG emissions, and microbial community structure of saltmarsh soils with allochthonous organic matter (Enteromorpha prolifera) addition. After 60 days of incubation, total organic carbon (TOC) loss and global warming potential (GWP) of biochar-amended soils were reduced by 67.29–124.33% and 4.91–123.24%, respectively (p