The Big Dipper and the Colors of Autumn
Every autumn a change washes over the area. The greens of summer begin to dwindle and are replaced by brilliant oranges and reds and yellows. It is as if some mysterious painter, tired of summer's green, uses his entire palette to create a world of colors.
Deciduous trees do this leafy color change act every year just before the leaves fall to decorate our lawns and cover up that fading green too. Interestingly, the word "deciduous" comes from a Latin root meaning "to fall off.
The Algonquin Native Americans of this area had a legend which explained just why the leaves changes color. The legend tells of a mighty bear which roamed the countryside wreaking havoc among the Native Villages. The bear obviously had an attitude. He would charge into their village, eat all their food, destroy their homes, chase away their animals and like as not munch on a few women and children while he was at it.
Not surprisingly, the natives decided they had to do something about the bear. They had a meeting and selected the bravest hunters from each village to put an end to the bear. The hunters set out with their dogs and soon found the bear.
Now the bear was no fool, and when he saw the entourage sent after him, he decided on a change of residence, quickly. The bear began to run and the hunters and their dogs gave chase. On and on the bear ran and the hunters followed. Sometimes they would gain a little and then they would shoot some arrows. On one of these occasions an arrow nicked the bear. It was not a very big injury, but the bear howled with rage and fear and ran so fast he went up into the sky. The hunters, so bent on their pursuit, ran up into the sky after the bear.
The bear is represented by the 4 stars in the bowl of the Big Dipper. The three stars in the handle of the dipper represent the hunters chasing the bear. And the dimmer stars around the three hunters are their dogs. The hunters and bear go round and round in the north sky. But every fall, the Big Dipper comes low to the horizon. It is then, according to the legend, that the bear's wound leaks a few drops of blood, and this blood changes the colors of the leaves on the trees. It is a fanciful story, and if you look in the north sky you will indeed see that at this time of year the Big Dipper is almost touching the horizon.
Those beautiful orange and yellow colors we look forward to in fall have been in tree leaves since last spring. Leaves contain carotenoids - the substance that makes carrots orange -- and xanthophylls, which make egg yolks yellow. In spring or summer, these colors are masked by the green pigment chlorophyll -- needed for photosynthesis -- the chemical reaction that works with water, air and sunlight to make food for a tree.
Photosynthesis takes place in the leaves of trees. And the leaves also let excess moisture evaporate from the tree. But during the winter, when the ground is frozen, a tree can't absorb water through its roots. If it kept losing moisture through its leaves, the tree would die of thirst.
So the leaves have
to go. When the tree senses the shorter days, less intense sun, and cooler
temperatures of autumn, it begins to form a layer of new cells at the place
where leaves attach to their stems. These cell layers ultimately completely
plug up the tubes that carry water and minerals to the leaves. No water
-- no photosynthesis -- so the green pigment chlorophyll in the leaf is
longer needed. When it goes, you see the other colors that were hidden in the leaves all along.
Copyright © 2001 Kathy A. Miles and Charles F. Peters II