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| Titel |
Tracing the origin of dissolved silicon transferred from various soil-plant systems towards rivers: a review |
| VerfasserIn |
J.-T. Cornelis, B. Delvaux, R. B. Georg, Y. Lucas, J. Ranger, S. Opfergelt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 8, no. 1 ; Nr. 8, no. 1 (2011-01-18), S.89-112 |
| Datensatznummer |
250005347
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| Publikation (Nr.) |
 copernicus.org/bg-8-89-2011.pdf |
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| Zusammenfassung |
| Silicon (Si) released as H4SiO4 by weathering of Si-containing
solid phases is partly recycled through vegetation before its land-to-rivers
transfer. By accumulating in terrestrial plants to a similar extent as some
major macronutrients (0.1–10% Si dry weight), Si becomes largely mobile
in the soil-plant system. Litter-fall leads to a substantial reactive
biogenic silica pool in soil, which contributes to the release of dissolved
Si (DSi) in soil solution. Understanding the biogeochemical cycle of silicon
in surface environments and the DSi export from soils into rivers is crucial
given that the marine primary bio-productivity depends on the availability
of H4SiO4 for phytoplankton that requires Si. Continental fluxes
of DSi seem to be deeply influenced by climate (temperature and runoff) as
well as soil-vegetation systems. Therefore, continental areas can be
characterized by various abilities to transfer DSi from soil-plant systems
towards rivers. Here we pay special attention to those processes taking
place in soil-plant systems and controlling the Si transfer towards rivers.
We aim at identifying relevant geochemical tracers of Si pathways within the
soil-plant system to obtain a better understanding of the origin of DSi
exported towards rivers. In this review, we compare different soil-plant
systems (weathering-unlimited and weathering-limited environments) and the
variations of the geochemical tracers (Ge/Si ratios and δ30Si)
in DSi outputs. We recommend the use of biogeochemical tracers in
combination with Si mass-balances and detailed physico-chemical
characterization of soil-plant systems to allow better insight in the
sources and fate of Si in these biogeochemical systems. |
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