What makes the leaves change?
Each tree has its own special pigment but as plants reside in their dormant stage during the spring and summer the colors are muted by the green that is produced by chlorophyll. As Fall approaches, the leaves can show their true colors in a beautiful display of reds, orange and yellow.
Plants produce a chemical called chlorophyll to make their own food (photosynthesis). They must have sunlight to produce chlorophyll. As the days grow shorter, the plants make less and less of this chemical, which is what gives leaves their green colors.
Trees such as aspen, birch and some oaks are put off a brilliant yellow color each fall with the help of a chemical called Xanthophyll. The Chestnut Oak is a beautiful example here in the Southeast.
The Southern Sugar Maple is well known here in the southeast for its original display of oranges each Autumn. Carotenes are what provide this wonderful display. As you might have guessed, it is also what gives carrots their color.
With fall fast approaching, The Red Maple will be seen in Alabama sporting a bright red flickering of leaves. Anthocyanins in these red trees have to be made each autumn season. The reason is unclear, but possible causes are that the red pigment absorbs more light or that it attracts more birds to disperse more seeds. One thing is clear, it provides an amazing visual display each year
Few trees produce a naturally brown pigment in the fall but here we have the English Oaks. Tannins are ever-present in these leaves but are more visible when the chlorophyll is limited.
The Ultimate Preppers
Deciduous trees will begin preparing for the fall and winter months as early as Spring. There is an area at the base of the leaf near the stem called the abscission zone (also known as the separation zone). The fiberless area will weaken as the reduction of chlorophyll occurs. This allows the leaf to be easily removed with an autumn breeze or a brief rain causing minimal damage to the intricate, slender branches of each limb.
Autumn Scavenger Hunt