||Monday, January 1, 2001
||Why leaves change colors
||"Why leaves change colors" - Source: Good Housekeeping, October 1995
The leave of deciduous trees contain three types of pigment:
Chlorophyll, which gives them their basic green color and is essential for photosynthesis, the chemical reaction that
enables plants to use sunlight to manufacture sugars for their food.
Carotenoids, which produce yellow, orange, and brown colors in such things as corn, carrots, daffodils,
rutabagas, buttercups, and bananas.
Anthocyanins, which produce reds in cranberries, red apples, concord grapes, blueberries, cherries,
strawberries, and plums.
During the growing season, the leaves appear green. As the amount of daylight decreases in autumn,
chlorophyll production slows down and then stops altogether, enabling the carotenoids and
anthocyanins to appear.
Certain colors are characteristic of particular species: Oak turns red, brown, or russet;
hickory, golden bronze; aspen and yellow-poplar, golden yellow; dogwood, purplish red;
beech, light tan; and sourwood and black tupelo, crimson. As for the maple family, red maple
turns brilliant scarlet; sugar maple, orange-red; black maple, glowing yellow; and striped maple
becomes almost colorless.