Underneath all of the leaves, trees and vines lies the forest floor. Very little growth occurs here--the floor is mostly covered in fallen leaves, forest turf and small ferns growing at the base of trees. Dead leaves decompose here, returning nutrients to the soil. Large and mid-sized animals live below the trees, including jaguars, gorillas and tapirs.
The herb layer may be a rain forest's plushest growth stratum. This layer rises 10 to 20 feet and receives more sunlight than the forest floor, allowing tropical grasses, wild flowers and ferns to grow in abundance. Reptiles such as turtles and snakes, along with a myriad of insects thrive in the herb layer.
Tree saplings, woody-stemmed shrubs and general growth that occurs 25 to 50 feet above the forest floor is considered the shrub layer. Depending on how much light the forest canopy emits from above, this layer may be sparsely covered, or thickly packed with small trees, vines and bushes.
Above the shrub layer and one step below the canopy lies the understory of the rain forest. Growing 55 to 100 feet from the ground, the understory is cool, moist and shady. Tree flowers and fruits emerge here, attracting bats, large insects, various monkeys and birds.
Many experts credit rain forest canopies worldwide with providing up to 45 percent of the world's species. Incredibly dense and leafy, the canopy is a thick layer of leaf and treetop growth 100 to 130 feet above the forest floor. The large leaves of this layer overlap each other, forming a tent over the entire forest that lets little sunlight through. By far the noisiest, most colorful forest layer, the canopy produces countless fruits, flowers and animals that are specifically designed to live in its unique habitat.
The canopy is not only home to countless animal species but also to plant species as well. Plants classified as epiphytes live exclusively in the canopy with no connection to the ground in order to access the direct sunlight they need to survive.
Growth that surpasses 130 feet is referred to as the overstory, or less commonly, the emergent layer. Only very large trees reach the overstory, buttressed by massive roots and thick trunks that can reach more than 15 feet in circumference. The overstory consists of the treetops that climb above the thick canopy, home to rare butterflies, insects and birds.