Nutrient uptake during low-level fertilization of a large, seventh-order oligotrophic river
| Autor: | Genevieve M. Hoyle, Peter R. B. Ward, Hassen A. Yassien, G. Wayne Minshall, Paul J. Anders, Charlie Holderman |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
010504 meteorology & atmospheric sciences 010604 marine biology & hydrobiology Phosphorus chemistry.chemical_element Aquatic Science 01 natural sciences Nitrogen Human fertilization Nutrient chemistry Environmental chemistry Botany Total nitrogen Total phosphorus Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 75:569-579 |
| ISSN: | 1205-7533 0706-652X |
| Popis: | Uptake of nitrogen (total nitrogen (TN), NH4-N, and NO3-N) and phosphorus (total dissolved phosphorus (TDP) and total phosphorus (TP)) was quantified June through September 2009–2011 using whole-river fertilization in a seventh-order, P-limited river (Kootenai River, Idaho, USA), at discharges up to three orders of magnitude greater than previously studied. Mean uptake length (Sw) and uptake velocity (Vf) values were similar for dosed TDP and NH4; both had steep gradients indicating rapid uptake, while NO3-N did not. TP remained higher than reference levels. TN showed no clear pattern. Autotrophs accounted for 28% of daylight mean NO3-N uptake compared with 72% by heterotrophs. Nutrient uptake was strongly associated with chlorophyll accrual and epilithon growth rates. Mean midsummer epilithon growth and N rates roughly tripled late summer rates. TDP uptake length (Sw = 5.7 km) showed a slow increase with increasing stream order consistent with published findings. Mean TDP uptake velocity (Vf = 32 mm·min−1) was eight times greater than previously seen in smaller streams. Vf (10.9 ± 5 mm·min−1) and Sw (16.8. ± 7 km) for NO3-N increased with increasing river order and discharge. |
| Databáze: | OpenAIRE |
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