sec 1 geog unit 3 lesson 1
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Sec 1 Unit 3
Lesson 1
Tropical Rainforest
At the end of the lesson you will be able to :
1.Identify a tropical rainforest 2.List the characteristics of a
tropical rainforest
3.Label and describe the layers of a tropical rainforest.
How can we save tropical rainforest?◦ What are tropical rainforests?
◦ What is deforestation?
◦ Where are tropical rainforests found?
◦ Which areas have been deforested?
◦ Why do we deforest?
◦ How should we manage deforestation?
Take 2 minutes, read the poem
Lets listen to a rainforest.
Earth’s oldest ecosystem.
High rainfall and high temperatures throughout the year.
Thick, luxuriant evergreen forests.◦ Evergreen = no distinct shedding season.
1. Diversity of types
2. Structure of rainforest
3. Plant Adaptations
Highest plant diversity in all forest types.
Warm temperatures and constant rainfall encourages plant growth.
Over 300 species in 0.01sq km
Source of common local food◦ Bananas, mangoes, pepper, cinnamon, corn, pandan, walnuts
Plants grown to different heights
Three-layered structure found in tropical rainforests
Trees up to 50m talls.Clearly visible from above Trees that rise above the even canopy below.
Trees tend to have tall, straight and smooth trunks.
Tualang, Kapok tree.
Layer of trees that grow to between 20 – 30m
The crowns form an interlocking layer.
Blocks 90% of sunlight from the forest floor.
Deflects most rainfall.
Dark most of the day as sun rays are blocked by canopy.Plants tend to be small and widely-spaced apart.Vegetation is sparse on forest floor, mostly decomposing leaves.
Epiphytes grow on trees to receive more sunlight.◦Ferns, orchids, mosses
Lianas are woody vines that twine up trees for more sunlight.◦Monkey ladder vine
50m
20m
Emergent layer
Canopy layer
Epiphytes
Lianas
Buttress Roots
Ferns
Plants adapt to the climatic conditions with special features.
Without adaptations, they will not survive the high temperatures and heavy rainfall.
PG 78
Tall straight trunks
Branches spread out near the top to reach for sunlight.
Smooth bark to allow rainwater to flow easily down to the roots.
Broad leaves to capture more sunlight
Waxy, leathery or hairy surfaces to minimise water loss.
Drip tips to allow water to runoff.◦ Reduces the growth of fungi and bacteria
Drip tip
Waxy surface
Hairy surface
Still air and lack of wind is bad for seed dispersal.
Strong smelling flowers and fruit encourage animal and insect pollination.
Large spread roots that grow up to 5m above the ground.◦ Help to support the tall emergent and
canopy trees
Shallow roots that reach for the nutrients in the topsoil and decomposing foliage.
Constant presence of water, no need for deep roots that search for ground water.
By the next lesson, pick a leaf that you think is from a rainforest tree and sketch it on a piece of blank paper.
Submit both the leaf and the paper as your homework.
Complete the test in the time allocated.
Remember to write in black ink.
If you are drawing diagrams, you can use pencil.
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