Ecological threshold of phosphorus load in Baiyangdian Lake based on a PCLake model and ecological network analysis

作者：Yong Zeng, Gaiguo Liu, Jiaxin Li, Yanwei Zhao, Wei Yang · 发表于：The Science of The Total Environment · 年份：2024 · DOI：10.1016/j.scitotenv.2024.170091 · 被引用次数：9 · 研究领域：Sustainability and Ecological Systems Analysis、Ecosystem dynamics and resilience、Aquatic Ecosystems and Phytoplankton Dynamics

Ecological thresholds are a useful indicator for implementing ecological management. Many studies determine the thresholds for nutrient loads in lakes based on the maximum allowable concentration of chlorophyll a (Chla), although this neglects the overall performance of the ecosystem. A PCLake model of Baiyangdian (BYD) Lake in northern China was constructed with six ecological network analysis (ENA) indicators that characterized the ecosystem function, system maturity, and food web structure to quantify the overall status of the BYD ecosystem. To my knowledge, this is the first study on the system level responses of the BYD Lake to phosphorus load interference. Different phosphorus load scenarios were designed to simulate the ecological responses of BYD Lake. The simulated results were employed to calculate the ENA indicators. Ecological thresholds were determined through the driving response relationship between the phosphorus load gradient and the ENA indicators. The results show a non-linear transition response of ENA indicator under phosphorus load gradient. As phosphorus load increases, D/H, SOI, and FCI decreases while A/DC, TPP/TR, and TPP/TB increases. This indicates that the overall structure and function of the ecosystem will deteriorate if phosphorus load increases. The phosphorus load thresholds for the overall performance of BYD Lake were 0.50–1.32 mg m−2 d−1, slightly wider than that of Chla (0.53–1.26 mg m−2 d−1). The model results clearly indicate that there ...