The Beautiful Fall Colors
What causes the change in leaves?
Have you ever wondered what caused the color of leaves to change? Living in Texas most of my life we only have a small, quick change before the leave fall to the ground. I have never witnessed the prolonged changes to the leave in the Northeast. The pictures are spectacular of the orange, red, purple and yellow hues in the leaves. I understand there is a chemical process that takes place in the trees when the temperature begins to change from warm to cold.
During the warmer months in the spring and summer, the trees take in the sunlight to make and store energy in the form of chlorophyll, resulting in the green leaves and growth of the tree. The trees turn this energy into water and CO2 or Carbon Dioxide, converts it into carbohydrates.
Also present in the new leaves are yellow and orange colors which are concealed by the color green.
How does the Chlorophyll break down?
The extent of daylight hours and temperature changes occur during the fall. The leaves do not continue their process of making the food. When the Chlorophyll production stops, the green in the leaves begins to disappear. The hidden orange and yellow color are then visible, leading to the fall colors.
At this time chemical change can occur. Different colors may develop through the anthocyanin pigments. Mixtures of these anthocyanins pigments may give us various pigments, depending on their pH. These may appear red, purple, or blue leaves and are some of the colors of autumn leaves..
Fall leaves vary in colors. These colors are caused by a mixture of remaining amounts of chlorophyll reside plus the hidden pigments of the fall leaves.
What other changes may take place?
Other changes occur during fall. As the colors change, a layer of cells develops and sever the tissue at the leaf base. The tree seals the cut and leaves behind a scar.
The Northen broadleaf trees shed their leaves in the fall. Some of the oak trees and a few other species may remain on the tree until new growth begins again. in the South where winters are milder, some of the broadleaf trees are evergreen. The leaves may keep their green color.
Some trees lose their leaves, but others do not.
Conifers are of major importance as the source of softwood, and also supply resins and turpentine. These include pines, spruces, firs, and cedar trees. These Conifers are evergreen in both the north and south.
Did you know that weather affects color intensity? Three things to consider.
Rain, sunshine, and temperature affect the degree and length of fall color. Temperatures above freezing will produce maples with bright red leaves. On the other hand, an early frost will weaken the bright colors. Overcast days with rain will increase the intensity of fall colors. The best days to enjoy bright fall colors would be clear, dry, and cool but not freezing.
Enjoy the bright colors as they will only last a short time.