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.

本研究以中国半干旱区灞河流域为研究对象，探究二氧化碳（CO₂）的时空动态变化及其内在作用机制。本数据集涵盖水化学参数、重金属含量、溶解性有机质（DOM）特征、浮游植物属性，以及CO₂浓度与分压数据。研究结果显示，不同水生生态系统的CO₂平均浓度与分压均存在显著的时空异质性，并明确了碳酸盐缓冲作用、水生光合作用等关键调控因子。溶解性有机质与重金属可通过共同的生物地球化学途径（生物碳泵）与水生CO₂产生关联，亦是驱动CO₂浓度变化的重要因素。我们认为，重金属广泛参与多种生物与非生物过程，具备作为CO₂变化指示指标的较高潜力。本研究结果有助于解析水生CO₂与生物、非生物因子间的复杂耦合关系，为理解复杂半干旱水生连续体中CO₂迁移转化的驱动机制提供多维视角。