Abstract Evaluating multiple competing biotic and abiotic processes and how they interact with carbon dioxide (CO 2 ) in aquatic systems, is critical to understanding regional and global carbon cycles. Here, we used an aquatic continuum of the Bahe watershed, within a semi‐arid region, to establish a comprehensive conceptual framework for identifying CO 2 drivers from measured hydrochemical properties, heavy metals (HMs), dissolved organic matter (DOM) characteristics, and phytoplankton properties. The results revealed that dissolved CO 2 (cCO 2 ) showed large spatiotemporal variability. Our results highlight that carbonate buffering coupled with aquatic photosynthesis, collectively regulated the CO 2 dynamics. Additionally, DOM and HMs have biogeochemical pathways that are common to CO 2 dynamics (i.e., the biological carbon pump). In particular, HMs were found to have a high potential for signaling CO 2 dynamics. The findings contribute to a better understanding of the carbon dynamics in an aquatic continuum in a semi‐arid region, together with the underlying mechanisms.
Shao et al. (Mon,) studied this question.