1. MANGROVE FOREST

2. OBJECTIVES Describe the distribution of mangroves.
Describe climatic features of MG areas.
Describe & explain the features of MG.
Describe the adaptations of MG.

3. DISTRIBUTION along sheltered coastal regions
Found b/w 23.5°N and S of the equator.
areas experiencing tropical climate

4. STRUCTURE
3 distinct horizontal zones
No vertical layers

5. Horizontal zonation of Mangroves

6. STRUCTURE Coastal Zone Inland Zone Middle Zone Nearest to the coast
Adapted to salt water
Aerial roots
Avicennia, Sonneratia
Inland Zone
Grow inland
Least tolerant of salt
Knee-like roots
Bruguiera
Middle Zone
Prop roots
Stilt roots
Rhizophora

7. CHARACTERISTICS

8. 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.

9. C2: Dense & Luxuriant
Most form a dense, continuous canopy due to the presence of high temperatures and high rainfall.

10. C3: Sparse Undergrowth
Little sunlight filters through the dense, continuous canopy.
Hence there is little undergrowth present in this layer.

11. C4: Evergreen leaves
As there is high temperature and high rainfall throughout the year, the leaves remain evergreen.

12. C5: Colourful flowers
The flowers are generally colourful to attract insects to pollinate its flowers.

13. C6: Buoyant Fruits
This enables fruits to be carried away by waves and currents to new coastal areas.

14. ADAPTATIONS

15. A1: High rainfall
The leaves are broad with drip tips to enable water to flow off the leaves quickly.

16. A2: High Temperature
The leaves are thick and leathery to reduce water loss through transpiration.

17. 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.

18. A4: Oxygen Deprived
Due to waterlogged conditions in the mangrove environment, the soil is oxygen-deprived.
Avicennia and Sonneratia have aerial roots: As these roots are exposed during low tide, they take in oxygen.

19. A5: Muddy Soil Prop Roots Keed Roots (Knee-Like)
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.

20. PENCIL ROOTS

21. PROP ROOTS

22. KNEED ROOTS

23. BUOYANT FRUITS

24. THE END