Sec 1 geog unit 3 lesson 1
Transcript of Sec 1 geog unit 3 lesson 1
Chong Boon Secondary School Geography Unit Lower
SecondarySec 1 Unit 3 Lesson 1Tropical Rainforest
At the end of the lesson you will be able to : 1.Identify a tropical rainforest 2.List the characteristics of a
tropical rainforest3.Label and describe the layers
of a tropical rainforest.
Lesson Objectives
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?
Investigation Question
Take 2 minutes, read the poem Lets listen to a rainforest.
Turn to Pg 74
Earth’s oldest ecosystem.High rainfall and high temperatures throughout the year.
Thick, luxuriant evergreen forests.◦Evergreen = no distinct shedding season.
Characteristics of tropical rainforests
1. Diversity of types2. Structure of rainforest3. Plant Adaptations
3 Key characteristics
Highest plant diversity in all forest types.
Warm temperatures and constant rainfall encourages plant growth.
Over 300 species in 0.01sq kmSource of common local food
◦Bananas, mangoes, pepper, cinnamon, corn, pandan, walnuts
Diversity of plant species
Plants grown to different heights
Three-layered structure found in tropical rainforests
Structure of a tropical rainforest
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.
Emergent layer 50m
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.
Canopy layer 30m
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.
Undergrowth
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
Epiphytes and Lianas
Monkey ladder vine
Ferns, Moss
50m /30m (a) 20m (B) Emergent layer (c) Canopy layer (D) Epiphytes (H) Lianas (G) Buttress Roots (F) Ferns (H) Vines (F)
Helping words
Plants adapt to the climatic conditions with special features.
Without adaptations, they will not survive the high temperatures and heavy rainfall.
Adaptations of plants
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.
Bark and branches
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
Leaves
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.
Fruit and flowers
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.
Buttress roots
Skill builder - Sketching
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.
Homework
Complete the test in the time allocated.
Remember to write in black ink. If you are drawing diagrams, you can use pencil.
Unit Test