Y2 Geography Unit 2: Tropical Rainforests (2.1 - 2.2 only)

[2.1]: What are tropical rainforests?

Thick and luxuriant evergreen forests found in areas with high rainfall and high temperatures throughout the year.

[2.1]: What are the three layers in a tropical rainforests? From top to bottom

Emergent, Canopy, Undergrowth

[2.1]: Describe the emergent layer

• trees have tall, straight trunks

• 50m - 80m tall

• above the canopy layer

[2.1]: Describe the canopy layer

• crowns of canopy trees form an almost continuous cover by spreading their branches horizontally

• extremely thick

• 25m - 35m tall

[2.1]: Describe the undergrowth layer

• fungi and mosses live here

• sparse vegetation

[2.2]: What are lianas? Where are they found?

• thick, woody vines that twine up trees to get closer to the sun to absorb more sunlight

• found in mainly the canopy layer, with some in the undergrowth

[2.2]: What are epiphytes? Where are they found?

• plants that perch themselves on trees to get closer to the sun to absorb more sunlight

• found mainly in the canopy layer, with some in the undergrowth

[2.2]: What are buttress roots? Where are they found? What are they used for?

• large roots that grow 1m - 5m above the ground

• found on large, tall trees

• supports the tree and gathers more nutrients

[2.2]: What are shallow roots? Why are they grown differently from other roots?

• roots that are grown close to the topsoil

• growing down deep into the soil is unnecessary, as nutrients and water (due to high rainfall annually) can be found near the topsoil

[2.2]: What do drip tips do?

Allows water to run off easily, preventing the growth of bacteria and fungi on leaves

[2.2]: What do waxy / hairy / leathery leaves do?

Prevents the loss of moisture through transpiration due to high temperatures.

[2.2]: What do broad leaves do?

Captures more sunlight for photosynthesis

[2.2]: What is leaf angling? What is the purpose of it?

• leaves on the same plant that are arranged at different angles

• avoids shading its own leaves to capture as much sunlight as possible

[2.2]: What do holes in leaves do?

• enables rainwater to run off more easily, preventing the growth of bacteria and fungi on leaves

• allows sunlight to reach the leaves below it