Details zur Publikation |
| Kategorie | Textpublikation |
| Referenztyp | Zeitschriften |
| DOI | 10.1029/2021GB007056 |
| Lizenz |
|
| Titel (primär) | Iron exports from catchments are constrained by redox status and topography |
| Autor | Tittel, J.; Büttner, O.; Friese, K.; Lechtenfeld, O.J.; Schuth, S.; von Tümpling, W.; Musolff, A. |
| Journal / Serie | Global Biogeochemical Cycles |
| Erscheinungsjahr | 2022 |
| Department | ASAM; SEEFO; FLOEK; ANA; HDG |
| Band/Volume | 36 |
| Heft | 1 |
| Seite von | e2021GB007056 |
| Sprache | englisch |
| Topic | T5 Future Landscapes T9 Healthy Planet |
| Daten-/Softwarelinks | https://doi.org/10.4211/hs.43601618877945c5a46b715aa98db729 |
| Supplements | https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2021GB007056&file=2021GB007056-sup-0001-Supporting+Information+SI-S01.pdf |
| Keywords | river; mineral phosphorus; carbon; soil; watershed; metal; groundwater; NOSC |
| Abstract | Fe(III) hydroxides stabilize organic carbon (OC) and P in soils.
Observations of rising stream Fe concentrations are controversially
posited to result from a flushing of iron-rich deeper soil layers or a
decrease of competing electron acceptors inhibiting Fe reduction ( and  ).
Here, we argue that catchment topography constrains the release of Fe,
OC, and P to streams. We therefore incubated organic topsoil and mineral
subsoil and modified the availability of  .
We found that Fe leaching was highest in topsoil. Fe, OC, and P
released at quantities proportional to their ratios in the source soil.
Supply of 
reduced Fe leaching to 18% and increased pore water OC:Fe and P:Fe
ratios. Subsoil, however, was an insignificant Fe source (<0.5%).
Here, the leached quantities of Fe, OC and P were highly
disproportionate to the soil source with an excess of released OC and P.
We tested if experimental findings scale up using data from 88 German
catchments representing gradients in  concentration and topography. Average stream Fe concentrations increased with decreasing 
and were high in catchments with shallow topography where high
groundwater levels support reductive processes and topsoils are
hydrologically connected to streams; but Fe concentrations were low in
catchments with steep topography where flow occurs primarily through
subsoils. OC:Fe and P:Fe ratios in the streams similarly varied by 
and topography. This corroborates the findings from the laboratory
experiment and suggests that catchment topography and competing electron
acceptors constrain the formation of Fe-reducing conditions and control
the release of Fe, OC, and P to streams. |
| dauerhafte UFZ-Verlinkung | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=25538 |
| Tittel, J., Büttner, O., Friese, K., Lechtenfeld, O.J., Schuth, S., von Tümpling, W., Musolff, A. (2022): Iron exports from catchments are constrained by redox status and topography Glob. Biogeochem. Cycles 36 (1), e2021GB007056 |
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