Outdoors Journal: Fall foliage colors
- Article by: JIM GILBERT
- September 24, 2009 - 7:25 PM
FALL FOLIAGE COLORS
There are some beautiful fall colors now being seen on the leaves of deciduous woody plants. Nowhere in the world are the fall colors more rich and varied than in the climax woodlands of the United States east of the Rocky Mountains. Each September and October we marvel at the color of the many woody plants, sadly acknowledging that it is only a brief pleasure.
The fall coloring is the result of chemical processes in the leaves as the season changes from summer to winter, with many leaves turning before the first frost. Because of the decreasing amount of daylight and lowering of average daily temperatures, leaves stop their food- making process. As they do, the chlorophyll breaks down, the green color disappears, and the yellow pigment that was covered up becomes visible, giving the leaves part of their fall splendor. At the same time, other chemical changes occur and cause the formation of additional pigments that vary from yellow to red to blue.
Some pigments give rise to the red and purple fall colors of the sumacs and dogwoods, but others give the sugar maple its brilliant orange and fiery red. The quaking aspen, birch, green ash and basswood show yellow and golden-yellow. Familiar trees with red or scarlet leaves are red maple, Amur maple and red oak. Within the same species, the degree of color might vary from tree to tree or branch to branch.
© 2013 Star Tribune