Since the beginning of time, people have found many uses for trees. They have used them to build shelter, as a source of food, to provide heat and for recreation.  An increase in the earth's population has created more and more demand for products that come from trees. Fortunately, trees are a renewable resource. But even though we have many trees, they are a valuable resource, and we don't want to waste them. That's why it's important to use every part of a tree that is harvested.