Characteristics of tropical rainforests

Tropical rainforests have distinct characteristics that support a wide variety of different species. This means that they have a high biodiversity. The biotic or living components of the ecosystem and the abiotic or non-living components of the ecosystem depend on one another - a change in one leads to a change in the other.


  • Very wet with over 2,000 mm of rainfall per year.
  • Very warm with an average daily temperature of 28°C. The temperature never drops below 20°C and rarely exceeds 35°C.
  • The atmosphere is hot and humid.
  • The climate is consistent all year round. There are no seasons.


  • Most of the soil is not very fertile.
  • A thin layer of fertile soil is found at the surface where the dead leaves decompose.
  • It is red in colour because it is rich in iron.
  • Due to heavy rainfall the nutrients are quickly washed out of the soil.

Plants and animals

  • The warm and very wet climate provides perfect conditions for plant growth.
  • The wide range of plant species supports many different animals, birds and insects.
  • Species have adapted to the conditions of the rainforest, eg trees and plants have shallow-reaching roots to absorb nutrients from the thin fertile layer in the soil.

Structure of a tropical rainforest

A tropical rainforest is made up of the following layers:

  • ground level
  • shrub layer
  • under canopy
  • (main) canopy
  • emergents
Emergents at the top receive most light. Beneath is the canopy, then the under canopy, and lastly the shrub level, receiving the least light.