Zusammenfassung der Ressource
GQ 1: What are Tropical Rainforests?
- Characteristics of Tropical
Rainforests
- Diversity of Plant Species
- Variety of plants and animals.
Large Biodiversity. 0.01 km
contains about 300 different
species of animals
- Structure of the tropical rainforest
- Emergent Layer
- From 50m to 80m. Trees rise
above the canopy layer
- Formed by the crown of trees.
Very tall and straight with
smooth trunks
- Examples: Tualang Tree and
Kapok Tree
- Canopy Layer
- 20m to 50m. Crowns of trees grow in a
continuous canopy layer like and umbrella
blocking 90% of sunlight
- Lianas and Epiphytes can be
found in this layer. They grow to get
as much sunlight as it can.
- Undergrowth Layer
- 20m and below. It is generally darker
because sun's rays are blocked by the
canopy. Plants have larger leaves to capture
sunlight
- Plants widely spaced and sparse due to lack on
sunlight. Forest floor hot and wet encouraging
decomposition leaving layer of leaf litter
- Adaptation of Plants
- Bark and Branches
- Tall and straight trunks with
branches near top of trees. Helps
trees get most sunlight
- Smooth bark allows rainwater
to flow easily from crown to
roots of trees
- Leaves
- Broad leaves to capture sunlight
- Waxy, Hairy and leathery surface to minimise
loss of moisture through transpiration
- Drip tips to allow water to run off easily.
This is to prevent fungal growth on leaves
- Fruits and Flowers
- Fruits and flowers are bright and colourful and strong smelling.
This attracts insects and other animals for dispersal of seeds or
pollination
- Roots
- Buttress roots: Large roots that grow 1 to
5 m above ground. This is to support the
heavy weight of trees which are very tall
- Roots are shallow as nutrients
are mostly in the top layer of soil
- Water available
throughout the year, so
no need for deep roots
- Uses of Tropical
Rainforests
- Water Catchment
- Refers to an area drained by a river
and the smaller rivers that flow into it
- Water drips from trees and seeps into
the ground. This is stored as groundwater
- Impurities in the water is trapped by the soil
before it flows into the reservoir
- Example: Central Catchment
Nature Reserve Singapore
- Green Lungs of the Earth
- Trees in the forests absorb carbon dioxide from
atmosphere and release oxygen through the
process of photosynthesis
- Trees also act as the earth's natural air
purifier as they absorb tonnes of CO2 every
year
- Dense vegetation also
keeps the earth cool!
- Habitat to Flora and
Fauna
- Home to more than 2 million species
which represents over half of the world's
species of flora and fauna
- Ample sunlight allows plants to convert it into
energy and food. Animals will in turn eat the
food provided.
- Canopy is a habitat where other plants
can grow and animals can live.
- Examples: Trilobite Beetle, Macaque
- Habitat to Indigenous
people
- Many indigenous people live in
Rainforests for thousands of years. It
provides them with basic necessities such
as food and water
- Known as hunter gatherers, they
gather and grow food that is only
just enough for their needs
- Shifting cultivators grow their own plants and
medicine by burning vegetation to provide
nutrients for soil.
- Example - Penan of Sarawak
- Source of timber
- Forests trees can be cut down
as timber. This can be made into
furniture and other uses
- Examples: Meranti, Teak wood, Mahogany
- Medical
Application
- Rainforests contain plants that can
contain medicinal properties and cures
for diseases. 3000 plants have been
identified in the Amazon Rainforest
- Example: Cinchona Tree used to treat
malaria. Madagascar Periwinkle trests
childhood leukemia