A canopy is the uppermost layer of a forest, consisting of the crowns of the trees and occasional trees with heights that extend above the canopy.
Canopies are complex both structurally and ecologically, and they are important components of forest ecosystems, with critical functions including serving as a buffer for external light, wind, and temperature fluctuations and playing a major role in the recycling of nutrients and energy. For example, the branches and leaves in a canopy can intercept as much as 95 percent of the light reaching them, thus making the understory of the forest deeply shaded.
Canopies also provide habitat for a wide range of plants and animals and serve as home to the great majority of the animal species that live in rainforests, some of which spend their entire lives there rarely or never venturing down to the ground.