Hydrological and biogeochemical controls on temporal variations of dissolved carbon and solutes in a karst river, South China

Abstract Background Understanding the responses of riverine dissolved carbon dynamics and chemical weathering processes to short-term climatic variabilities is important understand Surface-Earth under ongoing climate change. Temporal variations solutes stable isotope inorganic (? 13 C DIC ) were analysed during a hydrological year in Guijiang River, South China. We aimed unravel karst areas changes. Results Significant positive relationships found between rates factors (i.e. temperature discharge) over year. The total flux CO 2 consumption (760.4 × 10 3 mol/km /year) River was much higher than global mean flux, with capacity relative most other rivers. Chemical fluxes this area showed high sensitivity evasion warm–wet seasons lower those cold–dry seasons. Light ? values occurred high-flow conditions, corresponding temperatures IsoSource modelling revealed that biological could account for 53% all (DIC), controlling temporal variabilities. Conclusion This study quantitatively evaluated cycling karstic river systems demonstrated will have sensibility High discharges accelerate transport, relatively large quantities C-depleted being flushed into Meanwhile, also organic mineralisation, producing content soil , whose influx can shift Taken together, should be responsible dynamics.