Sunday, July 22, 2007

Getting to the root of mangroves

Three NAKED facts

naked fact #1: Mangrove trees have weird roots!
Question: Can you describe the different kinds of weird roots that you see?
Stilt roots (Rhizophora)
Pencil-like roots (Avicennia)
Knee roots (Bruguiera)

Thoughtful question: Can you think of reasons why mangrove trees have such strange roots?
Imagine you had to stay all your life on the soft squishy mud without moving. And the tide comes in and covers you up. And waves wash against you. What do you think you need to have?
  • To grow upright and not fall over? Stilt roots!
  • To breathe when the tide is high? Pencil-like roots! (Stilt roots are breathing roots too!)
Mangrove trees have shallow roots. Those with pencil-like breathing roots form a kind of raft, with thick roots growing horizontally and the pencil-like parts growing upright from these thick roots.
naked fact #2: You can tell what kind of mangrove tree it is by the kind of roots it has!

After explaining, you can remind them along the way and perhaps get them to guess. If they get it right a lot of time you can congratulate them and say they are now very good with mangrove trees!

Stilt roots (Rhizophora)
Straight pencil-like roots (Avicennia)
Conical pencil-like roots (Sonneratia)
Knee roots (Bruguiera)

naked fact #3: Mangrove trees are the root of life, and source of your seafood!

The tangle of roots in the mangroves results in a rich variety of marine life in the mangroves.
  • Animals to settle on the roots (clams, snails, barnacles), as well as seaweeds.
  • These provide food for other animals.
  • Small animals hide among the roots where bigger animals can't get at them.
  • Roots protect the mud and sand from being washed away by waves. Here burrowing animals can settle down.
Many of our favourite seafood come from mangroves and the seagrass areas near mangroves

Question: What is YOUR favourite seafood?
Stay in mangroves all their lives: Mud crab, mussels, clams
Stay in mangroves when they are young: big prawns, baby fishes of grouper and other fishes. These go into deeper waters when they grow up.
Found in seagrass areas: flower crab, sting ray, baby fishes

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