Publication Details |
| Category | Text Publication |
| Reference Category | Journals |
| DOI | 10.1029/2022WR032329 |
Licence  |
|
| Title (Primary) | Disentangling in-stream nitrate uptake pathways based on two-station high-frequency monitoring in high-order streams |
| Author | Zhang, X.; Yang, X.; Hensley, R.; Lorke, A.; Rode, M. |
| Source Titel | Water Resources Research |
| Year | 2023 |
| Department | ASAM |
| Volume | 59 |
| Issue | 3 |
| Page From | e2022WR032329 |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Data and Software links | https://doi.org/10.48758/ufz.12911 |
| Supplements | https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2022WR032329&file=2022WR032329-sup-0001-Supporting+Information+SI-S01.docx https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2022WR032329&file=2022WR032329-sup-0002-Movie+SI-S01.gif |
| Keywords | high-order streams; nitrate uptake pathways; high-frequency measurements; two-station approach; diel patterns |
| Abstract | In-stream nitrate (NO3-) uptake in rivers involves complex autotrophic and heterotrophic pathways, which often vary spatiotemporally due to biotic and abiotic drivers. High-frequency monitoring of NO3- mass balance between upstream and downstream measurement sites can quantitatively disentangle multi-path NO3- uptake dynamics at the reach scale. However, this approach remains limited to a few river types and has not been fully explored for higher-order streams with varying hydro-morphological and biogeochemical conditions. We conducted two-station 15-min monitoring in five high-order stream reaches in central Germany, calculating the NO3--N mass balance and whole-stream metabolism based on time series of NO3--N and dissolved oxygen, respectively. With thorough considerations of lateral inputs, the calculated net NO3--N uptake rates (UNET) differed substantially among campaigns (ranging from -151.1 to 357.6 mg N m2 d-1, with cases of negative values representing net NO3--N release), and exhibited higher UNET during the post-wet season than during the dry season. Subtracting autotrophic assimilation (UA, stoichiometrically coupled to stream metabolism) from UNET, UD represented the net balance of heterotrophic NO3--N uptake (UD > 0, the dominance of denitrification and heterotrophic assimilation) and NO3--N release (UD < 0, the dominance of nitrification/mineralization). This rarely reported uptake pathway contributed substantially to UNET patterns, especially during post-wet seasons; moreover, it appeared to exhibit various diel patterns, and for UD > 0, diel minima occurred during the daytime. These findings advance our understanding of complex reach-scale N-retention processes and can help develop future modeling concepts at the river-network scale. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=24829 |
| Zhang, X., Yang, X., Hensley, R., Lorke, A., Rode, M. (2023): Disentangling in-stream nitrate uptake pathways based on two-station high-frequency monitoring in high-order streams Water Resour. Res. 59 (3), e2022WR032329 10.1029/2022WR032329 |
|
