Transcript mangrove forest - GE-sec2i-2014

MANGROVE
FOREST
OBJECTIVES
• Describe the distribution of mangroves.
• Describe climatic features of MG areas.
• Describe & explain the features of MG.
• Describe the adaptations of MG.
DISTRIBUTION
• along sheltered coastal regions
• Found b/w 23.5°N and S of the equator.
• areas experiencing tropical climate
STRUCTURE
• 3 distinct horizontal zones
• No vertical layers
Horizontal zonation of
Mangroves
•
http://www.mesa.edu.au/mangroves/images/mang_zones.jpg
STRUCTURE
• Coastal Zone
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• Inland Zone
Nearest to the coast
Adapted to salt water
Aerial roots
Avicennia, Sonneratia
• Middle Zone
– Prop roots
– Stilt roots
– Rhizophora
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–
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Grow inland
Least tolerant of salt
Knee-like roots
Bruguiera
CHARACTERISTICS
C1: Little Variety
• Mangrove is species poor as there are only
4 main species present: Avicennia,
Sonneratia, Rhizophora, Bruguiera
• This is because only Halophytes (salt
tolerant plants) can survive in this region.
C2: Dense & Luxuriant
• Most form a dense, continuous canopy due
to the presence of high temperatures and
high rainfall.
C3: Sparse Undergrowth
• Little sunlight filters through the dense,
continuous canopy.
• Hence there is little undergrowth present
in this layer.
C4: Evergreen leaves
• As there is high temperature and high
rainfall throughout the year, the leaves
remain evergreen.
C5: Colourful flowers
• The flowers are generally colourful to
attract insects to pollinate its flowers.
C6: Buoyant Fruits
• This enables fruits to be carried away by
waves and currents to new coastal areas.
ADAPTATIONS
A1: High rainfall
• The leaves are broad with drip tips to
enable water to flow off the leaves quickly.
A2: High Temperature
• The leaves are thick and leathery to
reduce water loss through transpiration.
A3: Salt
• Avicennia are salt secretors: They excrete
excess salt on their leaves which are then
removed by the wind or rain.
• Bruguiera, Rhizophora, Sonneratia are
ultrafiltrators: They absorb salt and store it
in the old leaves which fall off eventually.
A4: Oxygen Deprived
• Due to waterlogged conditions in the
mangrove environment, the soil is oxygendeprived.
• Avicennia and Sonneratia have aerial roots:
As these roots are exposed during low tide,
they take in oxygen.
A5: Muddy Soil
• Prop Roots
– Rhizophora: Stilt or prop roots which anchor the roots
firmly to the ground
• Keed Roots (Knee-Like)
– Bruguiera: Kneed roots that provide firm support on
the soft soil.
• Fruits with elongated structure:
– Rhizophora: enables the fruits to anchor in soft muddy
soil.
PENCIL ROOTS
PROP ROOTS
KNEED ROOTS
BUOYANT FRUITS
THE END