Coat the tops of two other leaves. Let the rest of the leaves remain uncoated. Observe the leaves daily for a week. Overview From the oxygen we breathe to the food we eat, we owe our lives to plants. Plant variety is essential to life, and rain forests shelter more than half of all plant and animal species on earth.
Rain forests straddle the equator in a belt called the tropics.
The tropics receive more direct sun than the rest of the earth. That means more solar energy for photosynthesis - the process plants use to make food. This supports more plants, which in turn support more animals in the food chain. Rain forest plants compete with one another for scarce nutrients and for light and space to grow. Many develop buttresses - roots that grow above ground from the trunk to create a wide, stable base for the tree.