We investigated the relationship between cyanobacteria and geosmin occurrence in the Paldang Lake watershed, South Korea, by examining samples from the Bukhan and Namhan Rivers weekly from 2011 to 2015. Cyanobacteria were detected in summer, when water temperatures reached 20°C or more. Merismopedia, non‐nitrogen‐fixing cyanobacteria, dominated the Namhan River, which had high nitrogen concentrations. In the Bukhan River, Dolichospermum, nitrogen‐fixing cyanobacteria, was dominant. Temporary nitrogen inflow into the Bukhan River due to rainfall transformed the cyanobacterial community from one dominated by nitrogen‐fixing cyanobacteria (Dolichospermum) to one dominated by non‐nitrogen‐fixing cyanobacteria (Microcystis). Geosmin was highly correlated with Dolichospermum in the Bukhan River (r = 0.947, P < 0.01) and its concentration changed in accordance with Dolichospermum cell counts. In the Merismopedia‐dominated Namhan River, geosmin concentrations were low, suggesting that the cyanobacterial community composition affects geosmin levels.

中文翻译：

---

韩国帕当湖流域的蓝细菌发生和土臭素动力学

我们通过检查2011年至2015年每周从北汉河和南汉河采集的样本，调查了韩国帕当湖流域中蓝细菌与土臭素发生之间的关系。夏天在水温达到20°C或更高时检测到蓝细菌。Merismopedia，非固氮蓝细菌，占主导地位的南汉江，具有高的氮浓度。在布汉河中，固氮蓝细菌Dolichospermum占主导地位。由于降雨而暂时流入北汉河的氮将蓝细菌群落从一种固氮蓝藻（Dolichospermum）变为一种非固氮蓝藻（Microcystis）。）。土汉素与布汉河中的Dolichospermum高度相关（r  = 0.947，P  <0.01），并且其浓度根据Dolichospermum细胞计数而变化。在以梅里斯佩迪亚（ Merismopedia）为主的南汉河（Namhan River）中，土工素的浓度较低，这表明蓝细菌群落组成会影响土工素的水平。