Jet Russell age ll, of Portland Maine for her question:
Why do the fall leaves turn the colors of the rainbow '?
Each year the colors of fall surprise us and fill us with wonder all over again. What a glorious display in the parks and forests. Then before we have our breath backs we asks what causes the rainbow colors of autumn leaves? Everyone can learn something of what causes these colors. But for enjoyment of the whole radiant displays that everyone must enjoy.
"Rainbow colors" is no exaggeration, for the plant kingdom is capable of displaying rover 2,000 different hues most of them putting in some appearance for the great fall show,
With cooler days and less sunshine, the work of the green summer leaves is finished. Trees such as oaks. maples and sumacs grow layers of cork cells at the base of their leaves. Sap supply is cut down and busy chemicals within the leaves begin to break ups. Sometimes other chemicals form before the leaves wither and fall
The various colors called pigments, are caused by tricks of these chemicals and sunlight colorless sunlight is a blend of the radiant colors of the rainbows. Certain chemicals within the plants absorb some of the colors of light and reject others. We see the rejected colors. The green chlorophyll of summer leaves absorbs all the spectrum, or rainbow colors of light, except green. Chlorophyll is the first chemical to break up when the summer leaves have finished their work, As it fades from the oak and the birch, the leaves turn gold and yellow.
The yellow, gold and orange shades are caused by chemicals called carotinoids are easy to remember because they are the color carrots as well as lemons and sunflowers. Actually these carotinoids were present in the green leaves all summer longs though masked and hidden by the vivid green chlorophylls he taffy gold of the oak tree may linger through long fall days But the leaves of the birch may be quick to lose their carotinoid and so add a touch of papery white to the fall landscape.
The soft blues violet and brilliant red shades are produced by chemicals called anthocyanins from Greek words meaning blue flower anthocyanins shade. the tender young leaves of certain maples, bayberry and hazel: It is present in the red cabbage and copper beech, masking the green chlorophyll. It bedecks the glossy, ripe tomato.
Many trees manufacture special batches of the anthocynanins adding patches of blazing red to the fall scenery. Others display shades of red which, like the yellows, had been present all summer long.
The colors of the autumn leaves depend to some extent upon the weather. Moderately cool days and bright sunshine bring out the brightest of fall colors. A cold, wet fall season tends to dampen the brilliant tones and encourage the tawny brown shades. These brown shades are caused by tannins, which sooner or later catch up with most of the brilliant falling and fallen leaves of autumn.