European Ocean Biodiversity Information System

[ report an error in this record ]basket (0): add | show Print this page

N and Si cycling in freshwater tidal marshes
Struyf, E.; Gribsholt, B.; Boschker, E.; Dehairs, F.; Meire, P. (2011). N and Si cycling in freshwater tidal marshes, in: Heip, C. et al. (Ed.) Aspects of coastal research in contribution to LOICZ in the Netherlands and Flanders (2002-2010). LOICZ Research & Studies, 38: pp. 155-161
In: Heip, C.; Laane, R. (Ed.) (2011). Aspects of coastal research in contribution to LOICZ in the Netherlands and Flanders (2002-2010). LOICZ Research & Studies, 38. Helmholtz-Zentrum Geesthacht: Geesthacht. 184 pp.
In: LOICZ Research & Studies. LOICZ International Project Office: Den Burg. ISSN 1383-4304

Available in  Authors 
    Vlaams Instituut voor de Zee: Open access 247052 [ download pdf ]

Keywords
    Chemical compounds > Silicon compounds > Silica
    Cycles > Chemical cycles > Geochemical cycle > Biogeochemical cycle > Nutrient cycles > Nitrogen cycle
    Tidal marshes
    Brackish water; Fresh water

Authors  Top 
  • Struyf, E.
  • Gribsholt, B.
  • Boschker, E.
  • Dehairs, F.
  • Meire, P.

Abstract
    Tidal marshes have high sediment surface areas, promoting processes affecting nutrient speciation, transformation and retention. In this project we performed whole-ecosystem 15NH4 + tracer addition experiments to quantify the fate and transport of ammonium through a tidal freshwater marsh. Combined with a mass-balance study, this approach allowed a simultaneous examination of transport and processing of nitrogen. We also performed additional studies on Si cycling in parallel to the N-labeling experiment. Our work shows that the large reactive surface of the tidal freshwater marsh vegetation is crucial for nitrogen transformation and assimilation. It clearly revealed the dominant role of microbes in initial nitrogen retention in marsh ecosystems. Parallel study of silica cycling revealed that tidal marshes act as biogenic Si recycling surfaces, importing biogenic Si while exporting dissolved Si. Export of dissolved Si is greatest during summer and spring, when dissolved Si concentrations in inundating waters are depleted by diatoms. Tidal marshes thus buffer estuarine dissolved Si in times of limitation. We can conclude that the studied marsh had an increasing effect on the Si:N ratio in flooding waters. Export of DSi and import of total dissolved nitrogen (DIN) contributed about equally to the increase of the Si:N ratio.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors