What are tropical rainforests?

A forest is an area with many trees growing closely together. Tropical rainforests are forests which are found near the equator, in places which receive a lot of rainfall every year. The picture below shows part of a rainforest.

Rainforests are very important ecosystems. Many different types of trees and other plants can be found growing in a tropical rainforest. There may be hundreds of different types of plants growing in just one square mile of rainforest. 

The layers of a rainforest

Plants in a rainforest grow to different heights. This makes a rainforest look like it has different levels. These levels are called the layers of the rainforest. These layers can be seen in the diagram below.

^{Diagram by Vzb83, modified and used under this creative commons licence.}

Emergents: The tallest trees in the forest grow much higher than the canopy. These very tall trees are called emergents and they may be over 60 meters (200 feet) tall.

The canopy: The tops of tall trees in the rainforest are so close together that they form a layer  called the canopy. If you look at a rainforest from above you would only be able to see the canopy. You can think of it as the roof of a rainforest.

The understory: The trees in this layer are shorter than the trees in the canopy. They do not get a lot of sunlight because much of it is blocked by the canopy.

The forest floor: The ground in the rainforest is covered in leaves. Because it is warm and wet in the rainforest, these leaves and other organic matter decay quickly. Their nutrients return to the soil, making it rich. Small plants like ferns and shrubs are found on the forest floor. They get very little sunlight as most of it is blocked by the layers above them.