Diatom taxa and assemblages for establishing nutrient criteria of lakes with anthropogenic hydrologic alteration. (August 2016)

• Record Type: Journal Article
• Authors: Zhang, Yali; Huo, Shouliang; Li, Renhui; Xi, Beidou; Li, Hua; He, Zhuoshi; Pang, Chengfang
• Is Part Of: Ecological indicators. Volume 67(2016)
• Page Start: 166
• Page End: 173
• Publication Date: 2016-08
• Subjects: Phosphorus -- Nitrogen -- Diatoms -- Nutrient criteria -- Hydrological connectivity; Environmental monitoring -- Periodicals; Environmental management -- Periodicals; Environmental impact analysis -- Periodicals; Environmental risk assessment -- Periodicals; Sustainable development -- Periodicals; 333.71405
• DOI: 10.1016/j.ecolind.2016.02.048
• Languages: English
• ISSNs: 1470-160X

Abstract

Abstract: 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 x /L in isolated lakes. Hydrological river-lake connectivity differed significantly in ecological nutrient criteria with more TN/TP criteria and less NO x criteria in connected lakes. Given the ecological significance and biological integrity, diatom-based statistics can provide more reliable change points (thresholds) for nutrient criteria than Chl a -nutrient relationships.