As discussed in the "Tree Survey", the three layers of a biotic community are based on the height of the plant. Being a tall tree is important to the community for a few other reasons. First, the height of a tree can give you an idea of its age. Second, the tallest trees don't have to compete with the other plants for sunlight. The third reason is that tall trees are important for the animals in the biotic community. The tallest trees give the biotic community a layer of leaves and branches that reaches high into the air. This top layer is called the canopy. The canopy becomes a special place in the forest where many kinds of animals find shelter and food. Each layer can now provide a home for different kinds of animals. Therefore, tall trees allow the community to become its most diverse.