Abstract
The ratio of nitrogen to phosphorus (N:P) is an important variable that has a close relationship with the ecological problems of nuisance algal blooms and eutrophication in aquatic environments in terms of nutrient limitation. Reservoirs generally have much higher retention efficiency for P than for N. This inherent dissimilarity in the N and P biogeochemical cycles likely results in N–P stoichiometric imbalance in downstream rivers and reservoirs, consequently causing an increase in the N:P ratio and aggravating P limitation. Here we determined the total N (TN) and total P (TP) concentrations in the cascade reservoirs of the Wujiang River and Lancangjiang River basins. The results show that TN:TP ratios in these 2 basins exhibited a common inverted V-shaped (∧) pattern downstream. We found that P is not only retained by reservoirs more efficiently than N but is also replenished at faster rates than N given anthropogenic impacts; consequently, the N–P imbalance caused by these impoundments is alleviated within a short distance downstream because of inputs of anthropogenic nutrients. Our research suggests that construction of cascade reservoirs does not necessarily lead to strict P deficiency and anomalously high N:P ratios downstream.
Original language | English |
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Pages (from-to) | 196-206 |
Number of pages | 11 |
Journal | Inland Waters |
Volume | 8 |
Issue number | 2 |
DOIs | |
State | Published - Apr 3 2018 |
Bibliographical note
Publisher Copyright:© 2018, © 2018 International Society of Limnology (SIL).
Keywords
- Lancangjiang River
- N-P imbalance
- TN:TP ratio
- Wujiang River
- cascade reservoirs
- nutrient retention
ASJC Scopus subject areas
- Aquatic Science
- Water Science and Technology