Tropical rainforest
The canopy is like a huge green roof over the forest. The trees grow up thin and straight, like pillars seeking the sun. They do not put out branches until they are very tall. Then, they spread out like an umbrella in the sunlight. The trees are so close together that very little light penetrates through to the lower layers. Many kinds of monkeys, birds, and insects live in the layer. Other mammals, like cats, also live there. Many animals that call this layer home often never touch the ground throughout their entire lives. They find everything they need in the canopy. Water can be got from the boles of trees, if not, the leaves and epiphytes which grow in the canopy can supply that need. The animals eat the leaves and fruit of the trees, insects, or other animals. The tall canopy trees must be able to reach the sunlight high in the air and still get nutrients from the thin soil on the forest floor. Their roots do not go deep into the soil because there is nothing there for the plants to reach. Instead, the roots spread out in all directions along or just under the ground. That way they can quickly make use of the nutrients from the recycled plants and animals that have fallen to the floor.