Distribution and Dynamics of Phytoplankton in Jukryeong Wetland, Sobaeksan National Park, Korea

This study was conducted in 2022 and 2023 to determine the distribution and dynamics of phytoplankton in the Jukryeong Wetland of Sobaeksan National Park. A total of 193 phytoplankton species composed of eight taxa were found. Among these, 66 species of Euglenophyta, 62 species of Chlorophyta, and 26 species of Charophyta were identified, making them the most important taxa among the taxonomic groups. The abundances of Chlorophyta and Charophyta were highest in spring and lowest in summer and then increased again during fall. The total standing crops of Euglenophyta will increase by approximately 5.8 times in 2023 compared to 2022. Regarding the correlation between environmental factors and Chlorophyta, water temperature (r = 0.12), pH (r = 0.05), and EC (r = 0.18) were significant; however, the correlation coefficients were very low. Charophyta was highly correlated with pH (r = -0.4), EC (r = 0.39), and Euglena algae with water temperature (r = 0.66). Charophyta had high correlation coefficients with pH (r = -0.4) and EC (r = 0.39), while Euglenophyta had high correlation coefficients with water temperature (r = 0.66). The dominant species were Aphanocapsa delicatissima, Dictyosphaerium pulchellum, Dictyosphaerium ehrenbergianum, and Trachelomonas volvocina. Among the dominant species, Tr. volvocina was the only species that consistently appeared as a dominant and subdominant species for two years and was highly correlated with water temperature (r = 0.76) and pH (r = 0.74). In a comparison of existing studies, the number of Chlorophyta species has increased rapidly compared to the past, Euglenophyta and Bacillariophyta have appeared as taxa that did not appear in the past, and species that appeared in the past have been replaced by different species of Charophyta. These results indicate that many changes have occurred in the water environment of the Jukryeong Wetland, either artificially or naturally.