Adaptations Of Australian Plants Flashcards
What are 4 factors associated with the Australian environment?
Harsh
Extremes temperature
Lack of water
Xerophytes
What are 8 adaptations of Australian land plants to live in the harsh Australian environment?
–Thick waxy cuticle –Small thin leaves –Sunken, closed or few Stomata –Curled leaves –Leaves covered in hairs –Leaves hang vertically, -shedding of leaves –Long extensive roots
How is the cuticle adapted in the Australian environment?
4
•Thick, shiny surface on upper epidermis of plant leaves.
Reflects light which prevents overheating and water loss from the plant.
Physical impermeable barrier.
Stops uncontrolled evaporation through leaves
What are 5 adaptations of leaf structure in Australian plants to minimise heat and water loss?
Small, thin leaves to reduce surface area for water loss.
Curled leaves e.g. spinifex.
Leaves covered in small hairs
Leaves hang vertically
Shedding of leaves
Why do small, thin leaves reduce water loss?
Reduce surface area for water loss
How do curled leaves reduce water loss?
Curled leaves reduce water loss by increasing the humidity around the inner leaf surface where the stomata are located.
How do small hairs covering leaves reduce water loss?
Leaves covered in small hairs called tomentum.
Protective covering against water loss and abrasion by wind.
Hairs trap humid air next to the leaf surface and reduce water loss.
Why do leaves hanging vertically to reduce water loss?
–To shade the rest of the plant
–Allow rain to run towards the ground.
–Reduce the incidence of light on the leaf surface during the hottest part of the day.
How does shedding leaves during the dry season reduce water loss?
Reduces surface area of the leaves and water loss.
How are stomata adapted to the Australian environment?
Mainly on the lower surface of the leaf.
Are sunken or Few in number or Closed during the hottest parts of the day so little water is lost through transpiration.
How do long extensive root system help roots adapt to the Australian environment?
To penetrate all parts of the soil in search of water.
Maximise water uptake
How does the adaptation of a low stomata density help plants reduce water loss?
Smaller surface area for diffusion
How does the adaptation of a sunken stomata help reduce water loss?
Maintains humid air around the stomata
