The Amazon is the world’s largest tropical rainforest. It covers an area of nearly 2.8 million square miles, which is about the size of the continent of Australia. The Amazon rainforest gets its life from the majestic Amazon river, the world’s second largest river, which runs directly through the heart of the region. The rainforest itself is simply the drainage basin for the river and its many tributaries. The vast forest itself consists of four layers, each featuring its own ecosystem and specially adapted plants and animals.The forest floor is the lowest region. Since only two per cent of the sunlight filters through the top layers to the under storey, very few plants grow here. The forest floor, however, is rich with rotting vegetation and the bodies of dead organisms, which are quickly broken down into nutrients and integrated into the soil. Tree roots stay close to these available nutrients and decomposers such as millipedes and earthworms use nutrients for food.
The under storey is the layer above the forest floor. Much like the forest floor, only about 2-5 per cent of the sunlight reaches this shadowy realm. Many of the plants in the under storey have large, broad leaves to collect as much sunlight as possible. The under storey is so thick that there is very little air movement. As a result, plants rely on insects and animals to pollinate their flowers.

How important is the Amazon river for the Amazon rainforest?