A forest is made up of many layers. Starting at the bottom and working up, the main layers of all forest types are the forest floor, the understory, and the canopy. The emergent layer exists in tropical rain forests.
Forest Floor Layer
This layer is comprised of decomposing leaves, animal droppings, and dead trees and animals. All of these decay on the forest floor and create new soil and provide nutrients for the plants. Growing out of the forest floor are ferns, grasses, mushrooms, and tree seedlings.
The understory is made up of bushes, shrubs, and young trees that have adapted to living in the shade of the canopy.
The canopy is formed by the mass of intertwined branches, twigs, and leaves of the tall, mature trees. The crowns of the dominant trees receive most of the sunlight. This is where most of the tree's food is produced. The canopy forms a shady, protective “umbrella” over the rest of the forest.
The emergent layer exists in the tropical rain forest and is composed of a few scattered trees that tower over the canopy.