Roles of N:P Ratios on Trophic Structures and Ecological Stream Health in Lotic Ecosystems
AbstractLittle is known about the functions of N:P ratios in determining trophic structures and ecological health in lotic ecosystems, even though N:P ratios have been frequently used as a stoichiometric determinant in ambient water for trophic allocation of low-level organisms such as phytoplankton or zooplankton. In this study, nutrients (N, P) and sestonic chlorophyll (CHL) from 40 different streams in the Geum-River watershed were measured from 2008 to 2011. Fish compositions and stream health were also assessed, based on the multi-metric modeling of an index of biological integrity. Land use patterns in these watersheds were a key factor regulating nutrient contents and N:P ratios in ambient water, and also influenced empirical relationships between N:P ratios (or nutrients) and sestonic CHL. Land use patterns in forested, urban and wastewater treatment plant regions were associated with significant differences in stream N:P ratios, and the ratios were mainly determined by phosphorus. Sestonic CHL was significantly correlated with nutrient level (N, P); the ratios had a positive linear relationship with the proportion of omnivores, and a negative relationship with the proportion of insectivores. A similar trend in the N:P ratios was observed in indicator fishes such as N. koreanus and Z. platypus. Overall, the N:P ratio may be a good surrogate variable of ambient concentrations of N or P in assessing trophic linkage and diagnosing the ecological stream health in aquatic ecosystems. View Full-Text
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Yun, Y.-J.; An, K.-G. Roles of N:P Ratios on Trophic Structures and Ecological Stream Health in Lotic Ecosystems. Water 2016, 8, 22.
Yun Y-J, An K-G. Roles of N:P Ratios on Trophic Structures and Ecological Stream Health in Lotic Ecosystems. Water. 2016; 8(1):22.Chicago/Turabian Style
Yun, Young-Jin; An, Kwang-Guk. 2016. "Roles of N:P Ratios on Trophic Structures and Ecological Stream Health in Lotic Ecosystems." Water 8, no. 1: 22.
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