Leaves and Photosynthesis

• Chlorophyll, the green -- or occasionally red -- pigment in a tree's leaves absorbs energy from sunlight during photosynthesis. The foliage also draws carbon dioxide from the air through tiny pores, or stomata. When the stomata open to take in carbon dioxide, oxygen and water vapor escape from the leaves. The tree uses the energy and carbon dioxide to create sugar. The leaves must strike a balance between taking in carbon dioxide and releasing water.