Effects of physiologic activities of plankton on CO 2 flux in the Three Gorges Reservoir after rainfall during algal blooms.

The nutrient supply to the freshwater system may be changed by rainfall, which also encourages the cyclic succession of microorganisms. However, in a highly dynamic land-water reservoir, the microbial metabolic changes brought on by the changes of water nutrients following rainfall are not clearly documented. The study selected the Three Gorges Reservoir (TGR) backwater region during algal bloom seasons as the study area and time, and used the Biolog-EcoPlates technique to examine the heterotrophic metabolism conditions of the water before and after rain. The field monitoring assessed how biotic and abiotic variables affected CO ₂ flux at the water-air interface. The tests conducted in the laboratory investigated the water-integrated metabolic process was affected by post-rainfall environmental changes. The results showed that the average flux of CO ₂ at the water-air interface before rainfall was -489.17 ± 506.66 mg·(m ² ·d) ^-1 , while the average CO ₂ flux reached 393.35 ± 793.49 mg·(m ² ·d) ^-1 after rainfall. This is mostly explained by the heterotrophic metabolic variability of plankton in response to changes in the aqueous environment brought on by precipitation. These discoveries help us better understand how biological metabolisms after rain affect the CO ₂ flux at the water-air interface and reservoir greenhouse gas (GHG) emission equivalents can be evaluated more accurately.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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