When you enter the rainforest you are struck by the sounds and sights of life all around you, the swinging orangutans, the towering trees, and the cooing birds. What many people don’t know is that the rainforest actually has four distinct zones of life.
The four layers of the rainforest are the ground layer, understory, canopy and emergent layer. At the bottom of the rainforest the ground layer is the the forest floor. Now if you look up a little bit, to the trunks of the trees, you will find the understory. Above the understory comes the third layer, the canopy. Here are the leaves and the crowns of the trees. Finally you come the the fourth layer, the emergent layer. This layer is the highest layer of them all. Each of these has an interesting story.
Only two percent of the sunlight hits the forest floor. Therefore some small plants have adapted to growing basically without light or root systems. Many of the common plants you find here are bryophytes and some fungus like mushrooms. Covering the forest floor is the humus layer. It is made up of dead organic matter like leaves and fallen trees. Lots of bacteria live in this humus and decompose dead things so that the plants can use the nutrients to grow. The seeds from the canopy and emergent trees fall and wait on the ground for years for a patch of sunlight, created from fallen trees, to grow. Only then they take root and grow as fast as they can first making it to the understory.
Only five percent of the sunlight finds it’s way to the understory layer, and because of this some larger plants can grow. Some of these plants are shrubs, small trees, vines, and a variety of small medicinal plants and herbs. You will also find the trunks of large trees here. Many animals live here to, these include birds, reptiles, and small mammals. This is the layer that we experience as we walk through.
When we look up, we see the canopy. Most of the sunlight is found in the canopy layer. This is the densest area of the rainforest, it contains crowns of the largest trees. Other flora from this area of the forest are a range of moss’s, and ferns. These plants hold water necessary for animal life in the canopy. Some animals that live in this area are monkeys, orangutang, Hornbills, and tons of insects. In some rainforests the average population of arthropods can be up to 20 million.
The last and highest layer of the rainforest is the my favourite, the emergent layer. It is at the top of the rainforest so if receives 100% of the sunlight. It is very hot and windy so only certain species of trees can survive here. Few animals live up there, for example, the flying fox and eagle.
These four zones of the rainforest are essential to life thriving in the forest. As you walk through the forest now with this new knowledge you can look around with a new view. The ground layer with its distinct decay, the understory with vines and trunks, the canopy layer with its lush crowns and orangutangs, or the emergent layer with so few trees poking through, they are all equally impressive.
Written by Roxana McDonald