The Emergents
The few trees that grow above beyond the canopy layer 
make up the emergent layer. They get the full force of drying winds, hot sun, and soaking rain. In order to better retain water, emergent trees have developed small leathery leaves. The height of the trees also makes them a prime nesting site for birds of prey. With the tallest trees ranging in height from 75 to 250 feet (22 to 76 meters), they provide a clear view of the surrounding forest.
The Canopy
The trees of the canopy are approximately 40-70 feet (11 - 20 meters) tall. The canopy layer, like the emergent layer, also gets the full force of wind, rain, and sun. This ample supply of sunlight explains why 90% of the rainforests photosynthesis occurs in the canopy. Monkeys, sloths, opossums, anteaters, rats, and birds also makes their home in the canopy layer, making the canopy the most active of the 4 layers. In order to better protect themselves, some of the trees have developed poisons to deter leaf eating animals. The crowns of the trees of the canopy are also shaped like open umbrellas.
The Understory
Less than 1% of the light 
that the canopy receives reaches the understory. Trees in the understory have thin trunks and their crowns are shaped like closed umbrellas. The trees in the understory have developed larger leaves to better absorb light in the dark forest understory. Leaf eating animals are often found in this layer, because the leaves are less poisonous and larger than those in the canopy.
The Forest Floor
The forest floor is dark, and very little plant life besides ferns and 
small broad-leafed plants grow here. Branches, rotten leaves and fruit, animal dropping, and other debris that falls from above is quickly removed by fungi, termites, bacteria, and tiny tree roots. In areas where trees are not as close together and sunlight reaches the forest floor, shrubs, grasses, and other forest plants grow.
