By now, many trees in the area already have leafed out. Some trees leaf out before flowers appear, while other trees will flower first and then leaf out.
A late frost is harder on a tree that produces its leaves first than on a tree that produces its flowers first. Although failing to flower one year will reduce the seed production, the tree will not be harmed as much as if the leaves are lost. However, if you have an orchard or grove, this is disastrous.
Some trees, such as the dogwood and elm, have separate buds for the flowers and the leaves, while other trees, such as apple, cherry and Juneberry, will have both leaves and flowers in the same bud.
PHOTO COURTESY OF BILL BOWER
The forsythia flowers before leafing out.
PHOTO COURTESY OF BILL BOWER
The ornamental cherry tree in the photographer’s backyard leafs out before it flowers.
All buds - both leaf and flower - are packed with nutrition that wildlife, such as grouse, deer and some birds, feed on during the winter months. When checking the buds on a tree you will find that the larger buds usually are the flower buds, and the smaller buds are the leaf buds.
The buds are an amazing part of a tree; however, the leaves of a tree are even more amazing. There are two basic types of leaves:
A simple leaf in which the leaf blade is all in one piece (an apple leaf) and
A compound leaf, which is composed of a number of small leaflets attached to the main leaf stalk (a walnut leaf).
Leaves usually are green because of the chlorophyll; however, some trees such as Japanese maples have a dark red coloring. In these cases, the chlorophyll color is present but not visible because it is overlaid by stronger darker coloring elements.
Plants and trees appear to do nothing but stay in one place and grow slowly; however, trees are busy working with a complex process that fuels the whole planet.
This complex process is known as photosynthesis, a Greek word meaning "putting together with light."
We humans have been trying to harness the sun's energy to power our homes and vehicles; however, the green leaf has been using the sun's solar energy to combine the food from water and carbon dioxide to make carbohydrates. The process is the beginning of the food chain.
Plants, along with some bacteria and algae, are our only producers of food; all other living things are consumers, feeding directly or indirectly on the food produced in photosynthesis.
The chlorophyll in leaves contains chloroplasts, which capture the sun's energy and combine it with carbon dioxide from the air and water that contains mineral salts sent up from the roots.
This complex process, which produces sugar and starch, is the start of a long chain reaction that becomes life-energy for the plant, enabling it to grow and create still more leaves, flowers, wood and roots.
All creatures, including humans, use these plant products. This photosynthesis also is the main source of oxygen that most living creatures need to survive. In fact, there is no living thing that could exist in the world as we know it without green leaves to capture the sun's energy.
Here is a simplified explanation on how the leaf works: carbon dioxide enters the leaf through pores, or stomata, which are on the underside of the leaf. The small openings also allow air to escape, air that contains a little excess oxygen from the leaves using carbon dioxide and water to make food.
The openings also allow the moisture out of the leaf. The pores will close at night when no photosynthesis is taking place and also during the heat of the day when the plant is in danger of losing too much water to evaporation from its leaves.
The water that is absorbed by the roots is sent up to the leaves. Sunlight provides the energy that makes the process work.
Since the trees and plants produce more glucose than is needed immediately, the extra glucose is stored as either a more complex sugar or a starch until needed by a plant for growth or food when it is too dark to perform photosynthesis. Many times this storage becomes food for us. For example, potatoes are made of extra stored starch.
Perhaps leaves do not seem all that important, especially when raking them in the fall; however, leaves are one of the foundations of life. Without leaves performing photosynthesis, we wouldn't have oxygen or food to eat.
Even after dying and falling to the ground, leaves continue to nurture life. With the aid of bacteria, fungi, insects and moisture, leaves decompose into nutrient humus, enriching the soil for future generations of plants, which, in turn, will do the same, thus endlessly renewing the earth.
Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.