There are four layers in the rain forests:
The tallest trees are in the emergent layer, they receive the most amount of sunlight but have to endure low winds, very little humidity, etc.
The broad, irregular crowns of these trees form a tight, continuous canopy 60 to 90 feet above the ground.
Receiving only 2 to 15 percent of the sunlight that falls on the canopy, the understory is a dark place. It is relatively open and contains young trees.
The forest floor receives less than 2 percent of the sunlight and consequently, little grows here except plants adapted to very low light.