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Like all living things, trees need energy to grow. But trees don’t have mouths to eat with. So how do they get food?
Like most plants, trees get their energy through their green leaves. Leaves are little energy factories, and they do their work with chlorophyll, the same chemical that makes them green. The chlorophyll in leaves captures three ingredients from the tree’s environment (sunlight, carbon dioxide, and water). In a process called photosynthesis, those ingredients are turned into sugars to help the tree grow. In addition, oxygen is produced as a “waste product” of photosynthesis. Since the tree doesn’t use this oxygen, it releases it back into the air. That’s lucky for us humans, since we do use oxygen.In fact, one really big, leafy tree can put enough oxygen into the atmosphere to meet the breathing needs of two to four people.
