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Mangroves and Salt Marshes

, Volume 1, Issue 1, pp 3–10 | Cite as

Sedimentation in Mangrove Forests

  • Keita Furukawa
  • Eric Wolanski
Article

Abstract

The tidal currents in mangrove forests are impeded by the friction caused by the high vegetation density. The tidal currents are also complex comprising eddies, jets and stagnation zones. The sediment particles carried in suspension into the forest during tidal inundation are cohesive, mainly clay and fine silt, and form large flocs. These flocs remain in suspension as a result of the turbulence created by the flow around the vegetation. The intensity of sedimentation is largest for trees forming a complex matrix of roots such as Rhizophora sp. and smallest for single trees such as Ceriops sp. The flocs settle in the forest around slack high tide. At ebb tides the water currents are too small to re-entrain this sediment. Hence the inundation of coastal mangrove forests at tidal frequency works as a pump preferentially transporting fine, cohesive sediment from coastal waters to the mangroves. Mangroves are thus not just opportunistic trees colonising mud banks but actively contribute to the creation of mud banks.

Dense vegetation flocculation flow modelling tidal pumping turbulence 

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Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Keita Furukawa
    • 1
    • 2
  • Eric Wolanski
    • 2
  1. 1.Port and Harbour Research InstituteNagase, YokosukaJapan
  2. 2.Australian Institute of Marine ScienceTownsville MCAustralia

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