Trees grow as a result of the formation and division of cells in meristems and by conducting photosynthesis and absorbing nutrients and water through their root systems. Cells in the cambium layer divide and grow to form bark cells, contributing to the tree's outward and upward growth.
Each tree has three growing parts: the buds, root tips and cambium layer. Apical meristems, located on the tips of the branches, help the tree grow in height. During the summer, buds form in preparation for the next year. The buds form new branches, and chlorophyll is created in the leaves. Photosynthesis allows the tree to form sugars for food through the conversion of carbon dioxide, water and energy from the sun.
The cambium layer is located below the outer bark. It contributes to trunk, branches and root growth by producing new xylem and phloem every year. The xylem help move water and nutrients from the roots to the rest of the tree. The leaves depend on the water that the xylem transports. The phloem moves sugars from the leaves to the rest of the tree. The roots take up water and minerals from the soil for the xylem. Roots also contribute to the tree's growth by taking up oxygen from the soil.