Physical Factors (TRFs)

• What’s the distribution of tropical rainforests across the world?

  They are centred along the equator between the tropics of Cancer and Capricorn
• What are the four layers of the rainforest?

  Emergent: Highest layer of trees reaching over 50m in height.

  Canopy: Most life is found here as it receives 70% - 80% of the light, 30m in height.

  Under Canopy: Consists of trees that reach 20m high.

  Forest Floor: The lowest layer of the tropical rainforests, small trees and shrubs have adapted to live here.
• What is the climate like in the tropical rainforest?

  Due the the presence of clouds, temperatures rarely rise about 32C but it is very humid.
• Describe the Rainforest nutrient cycle:

  The warm, damp conditions on the forest floor and the abundance of insects enables the rapid decay of dead leaves and plant material that then are re-absorbed by the biomass.
• Describe the richness of the ground in tropical rainforests:

  Leaf Litter: A thin layer of dead leaves that rapidly decompose due to the heat and microorganisms.

  Top Soil: A mixture of decomposed organic matter and materials - usually red.

  Sub-soil: Deep due to weathering of rocks below, not a lot of nutrients.

  Rock: Underlying rocks weather quickly due to high temperature and becomes sub-soil.
• What is convectional rainfall and how does it occur?

  1. The roots of plants absorb water from the ground and intercept rain as it falls.
  2. As the rainforest heats up, the water evaporates into the atmosphere.
  3. The water condenses and it rains.
• There is no dry season in TRF's so there is constant growth of vegetation.
• The climate is hot and humid in TRF's with high levels of precipitation.
• Trees grow tall because they compete with other trees for sunlight in TRF's.
• Temperatures range between 18°C and 40°C in TRF's.