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

Phragmites australis and silica cycling in tidal wetlands
Struyf, E.; Van Damme, S.; Gribsholt, B.; Bal, K.; Beauchard, O.; Middelburg, J.J.; Meire, P. (2007). Phragmites australis and silica cycling in tidal wetlands. Aquat. Bot. 87(2): 134-140. dx.doi.org/10.1016/j.aquabot.2007.05.002
In: Aquatic Botany. Elsevier Science: Tokyo; Oxford; New York; London; Amsterdam. ISSN 0304-3770; e-ISSN 1879-1522, more
Peer reviewed article  

Available in  Authors 

Keywords
    Chemical compounds > Silicon compounds > Silica
    Environments > Aquatic environment > Marine environment > Intertidal environment
    Materials > Biogenic material
    Separation processes > Dissolution
    Water bodies > Inland waters > Wetlands > Marshes
    Phragmites australis (Cav.) Trin. ex Steud. [WoRMS]
    Belgium, Zeeschelde [Marine Regions]
    Fresh water
Author keywords
    biogenic silica dissolution; Phragmites australis; tidal marsh ecology

Authors  Top 
  • Beauchard, O.
  • Middelburg, J.J., more
  • Meire, P., more

Abstract
    Tidal marshes have recently been shown to be important biogenic Si recycling surfaces at the land-sea interface. The role of vegetation in this recycling process has not yet been quantified. In situ and ex situ decomposition experiments were conducted with Phragmites australis stems. In a freshwater tidal marsh, litterbags were incubated at different elevations and during both winter and summer. Biogenic Si (BSi) dissolution followed a double exponential decay model in the litterbags (from ca. 60 to 15 mg g-1 after 133 days), irrespective of season. Si was removed much faster from the incubated plant material compared to N and C, resulting in steadily decreasing Si/N and Si/C ratios. Ex situ, decomposition experiments were conducted in estuarine water, treated with a broad-spectrum antibiotic, and compared to results from untreated incubations. The bacterial influence on the dissolution of dissolved Si (DSi) from P. australis stems was negligible. Although the rate constant for dissolved Si dissolution decreased from 0.004 to 0.003 h-1, the eventual amount of BSi dissolved and saturation concentration in the incubation environment were similar in both treatments. P. australis contributes to and enhances dissolved Si recycling capacity of tidal marshes: in a reed-dominated small freshwater tidal marsh, more than 40% of DSi export was attributable to reed decomposition. As the relation between tidal marsh surface and secondary production in estuaries has been linked to marsh Si cycling capacity, this provides new insight in the ecological value of the common reed.

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