Spatiotemporal aspects of silica buffering in restored tidal marshes
Jacobs, S.; Struyf, E.; Maris, T.; Meire, P. (2008). Spatiotemporal aspects of silica buffering in restored tidal marshes. Est., Coast. and Shelf Sci. 80(1): 42-52. dx.doi.org/10.1016/j.ecss.2008.07.003 In: Estuarine, Coastal and Shelf Science. Academic Press: London; New York. ISSN 0272-7714; e-ISSN 1096-0015, more |   |
| Keywords | Chemical compounds > Silicon compounds > Silica
Cycles > Chemical cycles > Geochemical cycle > Biogeochemical cycle > Nutrient cycles
Environment > Ecosystems > Aquatic environment > Land types > Wetlands
Eutrophication
Restoration
Topographic features > Landforms > Coastal landforms > Tidal flats
ANE, Scheldt Estuary [Marine Regions]
Marine/Coastal; Brackish water | | Author keywords | wetlands; restoration; tidal flats; nutrient cycles; eutrophication; silica; Schelde estuary; Belgium; 51°03'53''N; 4°08'55''E |
| Abstract | Losses of pelagic diatom production resulting from silica limitation have not only been blamed for toxic algal blooms, but for the reduction in ability of coastal food webs to support higher trophic levels. Recent research has shown the importance of advective seepage water fluxes of dissolved silica (DSi) from freshwater marshes to pelagic waters during moments of riverine Si-limitation. In this study, we investigated the potential impact of recently installed new tidal areas along the Schelde estuary, located in former polder areas and characterized by so-called controlled reduced tidal regimes (CRT). Nine mass-balance studies were conducted in a newly constructed CRT in the freshwater Schelde estuary. During complete tidal cycles both DSi and amorphous silica (ASi) concentrations were monitored at the entrance culverts and in different habitats in the marsh. A swift DSi-delivery capacity was observed despite the shifted spatiotemporal frame of exchange processes compared to reference marshes. As silica-accumulating vegetation is not yet present, and difference with reference marshes’ deliveries is surprisingly small, we indicate diatomaceous debris and phytoliths to be the main silica source. Although further research is necessary on the driving forces of the different processes involved, restoration of former agricultural areas under CRT-regime provide the potential to buffer silica in the estuary. |
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