Diatom taxa and assemblages for establishing nutrient criteria of lakes with anthropogenic hydrologic alteration

详细信息    查看全文

• 作者：Yali Zhang^a ; ^b ; Shouliang Huo^b ; ^{huoshouliang@126.com" class="auth_mail" title="E-mail the corresponding author} ; Renhui Li^c ; Beidou Xi^b ; ; Hua Li^c ; Zhuoshi He^b ; Chengfang Pang^d
• 关键词：Phosphorus ; Nitrogen ; Diatoms ; Nutrient criteria ; Hydrological connectivity
• 刊名：Ecological Indicators
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：67
• 期：Complete
• 页码：166-173
• 全文大小：1740 K

文摘

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.