Your linked paper still didn't answer the "why" for me. This one posits a clearer answer: microbial respiration in sediment as it dries out is the leading cause

Your linked paper still didn't answer the "why" for me. This one posits a clearer answer: microbial respiration in sediment as it dries out is the leading cause of CO2 flux [1]. If I understand the process, exposed lakebed leaves soil organic matter for microbes to digest and as a byproduct they output CO2. [1] https://www.ufz.de/export/data/2/265343_Masterarbeit_Lelaina_Teichert_042021.pdf https://www.ufz.de/export/data/2/265343_Masterarbeit_Lelaina...