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| Titel |
Continuous In-Stream Assimilatory Nitrate Uptake from High Frequency Sensor Measurements |
| VerfasserIn |
Michael Rode, Muhammad Rehan Anis, Markus Weitere |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250125858
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| Publikation (Nr.) |
 EGU/EGU2016-5508.pdf |
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| Zusammenfassung |
| Recently developed in situ sensors provide new opportunities to measure changes in stream
concentration at high temporal frequencies that historical have not been feasible. In this study
we used multi-parameter sensor measurements to relate assimilatory uptake to metabolic
rates and calculate continually uptake rates for two stream reaches and a whole stream
network. Two years of continues 15 min data from a forest and agricultural stream
reach of the Selke river (463km2) revealed strong correlation between assimilatory
uptake and GPP for the forest (r2=0.72) and agricultural (r2=0.56) stream reach. The
slopes of these regressions were in good agreement with predicted assimilatory
N-uptake based on additional metabolism data. Mean yearly assimilatory uptake
rates were 6.4 times higher in the agricultural stream (mean 68.5 mgNm−2d−1,
max 270 mgNm−2d−1) than in the forest stream (mean 10.7 mgNm−2d−1, max
97.5 mgNm−2d−1). Percentage daily assimilatory uptake amounted up to 47.4 %
in the whole mainly agricultural watershed, whereas the total yearly assimilatory
in-stream uptake was 9.0% of total nitrogen load of the watershed. This value was
lower in the forest dominated upstream watershed (4.8%) and higher in the lower
agriculture dominated watershed (13.4%). High frequency measurements offer exploring
continues nutrient uptake metrics for streams with strongly deviating site characteristics. |
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