Tropical rainforests and mangroves have distinct characteristics based on their environments. Tropical rainforests have three layers - an emergent layer with very tall trees over 50 meters, a canopy layer between 20-30 meters that blocks most sunlight, and an undergrowth layer under 20 meters with sparse vegetation due to lack of sunlight. Mangroves have zonation based on plant tolerance to salinity and flooding. Species closest to the low tide level tolerate high salinity and long floods, while species further inland are less tolerant and closer to the high tide level. Tropical rainforest species are generally not found in coastal mangrove areas due to environmental differences.

1. Tropical Rainforests and
Mangroves
What are the characteristics of TRFs and Mangroves?

2. At the end of this lesson, I will be
able to…
1. Describe the characteristics of
TRFs and mangroves
2. Compare the differences in
terms of the characteristics of
TRFs and mangroves
OBJECTIVES

3. • Study the worksheet page 1.
• In pairs, brainstorm and write
down your points based on
what you know.
5 minutes

8. Characteristics of
Tropical Rainforests

9. Emergent
> 50 m
The Emergent
• Up to 50 metres tall
• Very tall, straight and
smooth trunks
• Very few branches
Examples:
• Kapok Tree
• Tualang Tree
• Rise through the canopy
and tower above other
trees.

10. Emergent
The tallest trees in the
forest. They rise several
meters above the canopy.

11. Key Feature 3:
Large buttress roots to
support the tree
Emergent
The tallest trees in the
forest. They rise several
meters above the canopy.
Key Feature 1:
Tall straight trunks that
can grow > 50m to
compete for sunlight
Key Feature 2:
Smooth bark
allows water to
drain off easily

13. Canopy
20 – 30 m

15. The Canopy
• Grow to heights of 20 –
30 metres tall.
• Crowns of the trees
interlock to form a thick
and near continuous
mass of branches and
leaves
• blocks up to 90% of
sun’s rays reaching the
forest floor.
Canopy
20 – 30 m

17. The Canopy Layer
Viewed from inside

18. Undergrowth
< 20 m

19. Undergrowth
< 20 m
The Undergrowth
• Does not receive much
sunlight as it is blocked by
canopy above.
• Larger leaves to catch sun’s
rays.
• Plants in this layer are small,
thin and widely-spaced due
to lack of sunlight.
• Vegetation is sparse.

20. Canopy
20 – 30 m
Undergrowth
< 20 m
Emergent layer –
grow 30m or more.

21. Do you think that the
plant species in the
tropical rainforests
can be found in the
coastal areas?

22. Characteristics of Mangroves

23. Why are there different mangrove plant species at different parts of the coast?
Different mangrove plant species have different tolerance level to salinity of water and ability
to withstand flooding. This results in a horizontal zonation, whereby there are different
distribution of plants in specific areas of the coast due to certain parameters. The zonation is
largely determined by high and low tide level.
Zonation

24. • Mangroves plant species in
this zone are able to
tolerate higher salinity levels
and longer period of
flooding as they are closest
to the low tide level.
• E.g. Sonneratia, Avicennia

25. • Mangroves plant species in
this zone are not tolerant to
the high salinity levels, so
they are found further
inland and closer to high
tide level.
• E.g. Rhizophora, Bruguiera

26. Compare the differences in
terms of the characteristics
of TRFs and mangroves