Multidimensional Insights into the Drivers of Aquatic CO2 Dynamics A River–Reservoir–Wetland Aquatic Continuum Study Within A Semi-arid Region

This study investigates the spatiotemporal dynamics of carbon dioxide (CO2) and its intrinsic mechanisms in the Bahe watershed, located in the semi-arid region of China. This dataset includes hydrochemical properties, heavy metals, dissolved organic matter (DOM) characteristics, phytoplankton properties, and CO2 concentration and partial pressure.The results revealed the significant spatial and temporal heterogeneity in average CO2 concentration and pCO2 in the diverse aquatic ecosystems—identifying key regulatory factors, including carbonate buffering and aquatic photosynthesis. DOM and heavy metals are linked to aquatic CO2 through a common biogeochemical pathway (biological carbon pump) and are important drivers of CO2 change. We believe that heavy metals are extensively involved in multiple biotic/abiotic processes and have a high potential to be able to signal CO2. The findings may benefit in deciphering the complex coupling of aquatic CO2 with biotic and abiotic factors, providing a multidimensional perspective for understanding the driving mechanisms of CO2 transport and transformation in the complex semi-arid aquatic continuum.