Are fall leaves changing colors or revealing colors? Leaf Chromatography Science

October 07, 2019

Are fall leaves changing colors or revealing colors? Leaf Chromatography Science

Many areas of the world experience plant leaves changing color and falling off during Fall or Autumn. This happens because the daylight becomes shorter and the days get colder. The plants stop producing food, so they don't need their leaves in the wintertime. They go dormant and use stored food over the winter, making fall a beautiful time of year. Many refer to the leaves as changing colors, but are the colors really changing?

Are they Really Changing Colors?

Plants need sunlight to perform photosynthesis, which involves using water, sunlight, and carbon dioxide to make food.

The leaves contain brightly colored pigments that are essential in light absorption. The pigment chlorophyll is the most important in light absorption. Chlorophyll A is bluish-green, and chlorophyll B is yellowish-green. Other pigments are xanthophyll, carotenoids, and anthocyanin. Xanthophyll is yellow. Carotenoids are orange. Anthocyanin is red.

During the peak growing season, plants contain mostly chlorophyll, which is why most plants appear green. The other pigments are still present but masked by the chlorophyll.

When fall approaches, the leaves begin to break down the chlorophyll. This allows the other pigments in the leaves to be revealed. The pigments were always there but hidden by the amount of chlorophyll.

The only exception is anthocyanin. This pigment is produced when chlorophyll begins to break down. A burning bush is a great example. It is a beautiful red color in the fall.