Tree branches look stark and bare against the gray winter sky. In order to understand why leaves die, one must study how they live. The leaf is an efficient factory designed by God to meet the nutritional needs of a growing plant, and in turn provide food for man and animals. Man is dependent upon plants for his food. God's design has equipped plants with a unique solar-powered factory that provides the healthy environment we enjoy.
Plants are dependent on light in order to carry out the function known as photosynthesis .
The top and bottom surface of a leaf are covered with a single layer of cells known as the epidermis . A thin waxy film known as a cuticle often covers the leaf epidermis in order to slow down the escape of water vapor from the leaf. Surrounding each stoma is a pair of guard cells that open and close to allow the exchange of gases and water vapor. Sandwiched between the two layers of epidermis is the mesophyll . Chloroplasts are found in the mesophyll section of the leaf.