2025/07/25 by Guan, Haizhao, Niu, Yiyuan, Zu, Chuanjin +1
#FOS: Biological sciences #Quantitative Methods (q-bio.QM)
paper · doi:10.48550/arxiv.2507.19553
Eutrophication and harmful algal blooms, driven by complex interactions among nutrients and climate, threaten freshwater ecosystems globally, particularly in densely populated Asian regions.Understanding interactions among water temperature, nutrient levels, and chlorophyll-a (Chl-a) dynamics is crucial for addressing eutrophication in freshwater ecosystems. However, many existing studies tend to oversimplify these relationships, often neglecting the non-linear effects and long-term temporal variations. Here, we conducted multi-year field monitoring (2020-2024) of key environmental factors, including total nitrogen (TN), total phosphorus (TP), water temperature, and Chl-a, across three reservoirs in Guangdong Province, China: Tiantangshan (S1), Baisha River (S2), and Meizhou (S3). Chl-a concentrations showed significant spatiotemporal variability, ranging from 1.2 to 11.8 ug/L, with a general increasing trend indicative of progressing eutrophication. Strong positive correlations were found between Chl-a and TN, TP, and temperature. Long-term data revealed TN as a more influential driver than TP for Chl-a proliferation in these systems. Based on the collected data, we developed and calibrated a dynamic multi-factor hydro-ecological model. The model accurately reproduced the observed Chl-a patterns (R2 > 0.85), identifying synergistic effects between temperature and nutrients. The model offers a robust theoretical basis for predicting Chl-a dynamics and supports science-informed management strategies to mitigate eutrophication in subtropical reservoirs.