A large part of Manu National Park is made up of rainforest. The key to understanding this unique environment is to look at it as layers.
At the top we have the emergent layer, this is where a small number of very tall trees, between 50 and 80m high, break out of the canopy layer. These are called emergents and are home to eagles, butterflies and bats.
Bellow that we have the canopy layer, a dense cluster of tree tops usually between 30-45m high, where the highest levels of biodiversity are found. Up to half the worlds plants and a quarter of all insect species, amongst other things, are believed to live in the rainforest canopy. The naturalist William Beebe said “another continent of life remains to be discovered, not upon the Earth, but one to two hundred feet above it, extending over thousands of square miles.”
Bellow the canopy is the understory layer, this layer can be called a shrub layer, although the shrub layer may also be considered a separate layer bellow the understory. Only around 5% of light falling on the canopy reaches this far down meaning the leaves grow much larger here. It is home to birds, snakes and lizards.
The forest floor, the bottom-most layer, receives only 2% of the sunlight. Only plants adapted to low light can grow in this region. Away from riverbanks, swamps and clearings, where dense undergrowth is found, the forest floor is relatively clear of vegetation because of the low sunlight penetration.