Diary entry Aug. 28, 2012: "Seems that the leaves are changing color much earlier this year."
When I checked diaries from previous years, I wrote on Sept. 24, 2010, "In some areas, the leaves on the hillsides are about three-quarters changed, and a few asters are in bloom." And, on Sept. 2, 2009, I wrote, "The mountainsides are showing a tinge of color and I saw some asters in bloom."
In reality, the leaves seem to change approximately the same time each year whether drought or wet conditions persist during the summer. As I make diary entries during late August and September, I find nature preparing for the harsh winter ahead. Keeping a diary can be very useful, especially when writing about nature.
American Indians believed that the leaves changed colors when the Spirit Bear, in the star constellation Ursa Major, was slain by three Spirit Indian hunters. The star group that we know as the Big Dipper was called the Great Bear by the American Indians.
The four stars in the cup of the Big Dipper made up the body of the bear and the three stars in the handle represented the three Indians. A dog, by the name of Alcor, was traveling with them. To find Alcor, look at the second Indian (star) in the handle, and you will see a faint star close by, which is the star that represented the dog.
Throughout the summer, the star constellations have been moving across the sky. The American Indians believed this occurred because the three Spirit Indians were in pursuit of the Spirit Bear and, every fall, the bear was slain, with the blood dripping from the sky and falling on the leaves, turning them red. As the bear's meat cooked, fat splattered out of the pot, staining some of the leaves either a yellow or brown color.
Because the spirit bear never died, the hunt has been repeated year after year.
Credit also had been given to Jack Frost for changing the color of leaves. On cold fall nights, it was believed that Jack Frost dashed from tree to tree, painting the leaves brilliant orange, yellow and red colors.
Jack Frost is a sprite-like character with roots in Viking lore. There he is known as Jokul Frosti (icicle frost). In Britain and the U.S., Jack is a variant of old man winter and is held responsible for frosty weather, for nipping the nose and toes in such weather, coloring the foliage in autumn and leaving fernlike patterns on cold windows in winter.
Today, botanists, using no imagination at all, are saying that shorter days signal the tree to cut off the water supply to the leaves. A special layer of cork cells is grown at the base of each leafstalk, which eventually blocks and weakens the connection of the leaf, causing it to fall from the tree due to either its own weight or from the wind and rain.
The carotenoid in the leaf causes the change of color. Actually, the color was there all the time but hidden by chlorophyll.
With clear, sunny days and temperatures dropping to 45 degrees at night, the chlorophyll disappears and the leaves show their real color. At this time, three other chemicals begin to show their colors: xanthophyll (a chemical present in egg yolks) makes the leaves yellow; carotene produces the orange color in leaves; and anthocyanin gives the red and purple leaves their colors (these two colors appear as stains on the leaves and are water soluble).
Many sunny days and cool nights are essential to produce brightly colored leaves. These conditions cause sugar to be trapped inside the leaf and when this happens, the red pigment anthocyanin is produced.
Sometimes a combination of colors are seen on one tree. For example, a sugar maple tree can have red, yellow and orange leaves. Bright sunlight produces the red leaves; the yellow leaves appear on the shaded side of the tree and the orange is a combination of the yellow and the red showing through the leaves.
Just as the birds and animals know it is time to prepare for winter, so do the trees.
Bower retired after 34 years as a wildlife conservation officer for the state Game Commission. He has published several books about his experiences. Questions and comments may be sent to him at 153 Redington Ave., Troy PA 16947.