Ecological Indicators   2016 年 67 卷

2016.08.01

Stressor-response models offer guidance for concentration-based nutrient criteria in lakes under human intervention. Diatom-based statistics from biological responses were incorporated to derive taxon-specific and community-level change points (thresholds) of phosphorous and nitrogen in 77 Yangtze floodplain lakes. Diatom metrics relating with conductivity were adopted as response variables, since conductivity explained the maximum variation (38.1%) in diatom assemblages via Bootstrapped regression trees. Nonparametric change-point analysis and Threshold Indicator Taxa ANalysis showed threshold responses of diatom community structure at 0.05-0.08 mg TP/L in connected lakes and 0.02-0.04 mg TP/L in isolated lakes. Distinct community change points of sensitive diatoms occurred at 0.96-1.63 mg TN/L in connected lakes and 0.52-0.63 mg TN/L in isolated lakes. Diatom community structures of tolerant taxa were substantially altered beyond 0.22-0.23 mg/L in connected lakes and 0.52-0.69 mg NO