March 22, 2017

Mangroves

  • Mangrove refers to a type of tree growing in coastal, estuarine environments
  • Tidal (mangal) swamp, mangrove forest refers to the whole mangrove community
  • The mangrove forest comprises trees and shrubs belonging to some 12 genera of flowering plants in 8 different families
  • Mangroves grow in all tropical regions of the world

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Boot Key Mangroves” by Phil’s 1stPix under Flickr

The Mangrove Environment

  • Live in shallow, salty water
  • Low oxygen concentration of sandy, thick mud they grow in
  • These conditions have resulted in specialized adaptations

Mangrove Zonation

  • Three kinds of mangroves common in the Turks and Caicos, Florida and Bahamas
    • Red mangrove-(grow on oceans edge)
    • Black mangroves-a bit upland from red – pneumatophores
    • White mangroves-highest elevations, furthest upland

Mangrove Adaptations

  • Prop or Aerial roots ( Red Mangrove )
    • These help to stabilize the plant in shallow sediments and bring oxygen to otherwise waterlogged roots
  • Tough succulent leaves with internal water storage
  • Some species excrete salt at the leaves surface- makes them glisten (Black Mangrove)
  • Some excrete salt through special glands on their leaves ( White Mangroves )
  • Some separate fresh water from salt water at the roots through reverse osmosis
  • Black mangroves have finger-like projecting roots called snorkels or pneumatophores
    • These protrude from the soil around the trees trunk

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mangroves by sarangib under CC0 Public Domain

Mangrove Reproduction

  • The mangrove seed germinates while still on the tree. (No dormant seed stage)
  • The seed elongates and eventually drops off into the water
  • Because of its weight distribution, it floats upright
  • Carried by water currents until it hits shallow water (Can be long distance)
  • Seed hits bottom and puts out roots to anchor itself
  • Eventually grows into a tree

Mangrove Benefits

  • Protect Uplands from erosion (from wind, waves, and floods). Root systems stabilize the shorelines
  • Filter water to maintain water clarity and quality
  • Important nursery grounds
  • Habitat for adult species as well

Environmental Threats

  • Waterfront development for homes, resorts, other commercial uses
  • Destroyed just because people think they’re “ugly” or “smelly” or “wild”
  • Florida has lost over 44% of its coastal wetlands including mangroves and saltmarshes since the 1940’s

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“Mangroves in Kannur, India” under GNU Free Documentation License