Although there are many types of leaves and many types of trees that inhabit the Earth, the life cycle is much the same for all of them. The life cycle of a leaf is cyclic, with its life and death dictated by the seasons. Most leaves are born in the spring, live throughout the summer and die in the fall.
The leaf begins life in the spring, as the tree pushes out the new leaf buds along the branches. The buds begin to make a substance known as sugar sap that nourishes the tree. This substance will be made throughout the life of the leaf.
In exchange for the food, the tree delivers water and nutrients that it absorbs from the soil, through the roots, to the leaves so that they can make the sugar sap. This exchange process continues until late September or October, when the change in daylight hours triggers the leaves to stop producing sap.
Preparation for Death
The tree seals off the attachment point on the branch so that no water or minerals can be delivered to the leaf and no sugar sap can be delivered to the tree. This seal is sometimes known as a scab.
The leaf begins to die from lack of nutrients. The leaves will turn colors, from red to yellow to purple, and then to brown. The skin and stem of the leaf becomes brittle and the leaf will then fall from the tree.
Circle of Life
The dead leaves will begin to break down in the elements, returning nutrients back into the soil for the next generation of leaves.