A Palette Of Color. We’ve all seen it. The spectacle has been around since the beginning of time. There has been many a story to explain it. Let’s explore.
A Native American legend has it that there was once a great bear who roamed around terrorizing people. The bear was far too powerful for any one person to kill, so the bravest and strongest warriors from several tribes banded together to hunt it.
When the bear saw the hunters coming he took off running. The warriors chased the bear for many months, over all the earth while firing their arrows. Though they never caught him, they got close enough for their arrows to reach him.
One arrow pieced the bear’s side deep enough to draw blood. In his pain and rage, the bear reared up and took to the sky, running from his pursuers through the heavens. To this day, says the legend, those warriors continue to chase the bear in circles around and under the earth. In the fall, when he is rising above the horizon, the bear’s blood drips down onto the trees below, turning the leaves scarlet.
The bear is said to be the pan of the Big Dipper part of the constellation Ursa Major, or the Great Bear. The handle of the Dipper, known as the bear’s tail, is said to be that band of warriors, still diligently chasing the bear after so many years. Another legend states that Jack Frost nips leaves with his fingers, painting them various hues as he moves through the forest.
For years, scientists have worked to understand the changes that occur in autumn. The basics to help you enjoy nature’s multicolored display include 3 factors that influence autumn leaf color: leaf pigments, length of night, and surprise – the weather.
You noticed that some years the fall leaf display is absolutely magnificent while other years the leaves are positively blah. So really, why do we see different hues each year and why are some more vibrant?
So to start – as the days get shorter, the tree does not have enough sunlight to make food so it shuts down. It stops producing chlorophyll and allows its fall leaves to die. When the tree stops producing chlorophyll, the green color leaves the foliage and you are left with the “true color” of the leaves. Leaves are naturally orange and yellow. The green just normally covers this up.
As the chlorophyll stops flowing, the tree starts to produce anthocyanins. This replaces the chlorophyll and is red colored. So, depending at which point in the fall leaf life cycle the tree is in, the tree will have green, yellow, or orange leaves then red autumn leaf color. If you have a bright, sunny fall, your tree will be a little blah because the pigments are breaking down quickly.
Some trees produce anthocyanins faster than others, meaning that some trees skip right over the yellow and orange color stage and go straight into the red leaf stage. How bright the red is depends on what species the leaf belongs to, its inherent genetics and the environment around it — including the forest, the tree, and individual leaves. Either way, you end up with a brilliant display of leaves changing color in the fall.
There is some truth to the old wives’ tale that rainy days wash the color from leaves. Cloudy, rainy days or warm nights really do reduce the intensity of fall colors.
Some have found that cooler temperatures in late summer and plenty of sunshine, often leads to brighter colors sooner. Cool is good, but too cold kills leaves early (as in freezing). So ideal for fall color would be a moist growing season early, dry late summer and early fall, with sunny warm days and cool nights during the latter.
The calendar needs an August footnote to remind us to watch the weather during that month for fall color later. Too many clouds, too much rain, or too much heat here can make for a duller fall. September, though generally cooler, follows suit. Drought is the other enemy of a good fall. The trees have to be in a healthy state —not water-stressed—heading into the season.
Certain colors are characteristic of particular species: Oaks: red, brown, or russet; Hickories: golden bronze; Aspen and yellow-poplar: golden yellow; Dogwood: purplish red; Beech: light tan; Sourwood and black tupelo: crimson. The color of maples leaves differ species by species.
The timing of the color change also varies by species. For example, sourwood in southern forests can become vividly colorful in late summer while all other species are still vigorously green. Oaks put on their colors long after other species have already shed their leaves.
These differences in timing among species seem to be genetically inherited; for a particular species at the same latitude will show the same coloration in the cool temperatures of high mountain elevations at about the same time as it does in warmer lowlands.
The amount of moisture in the soil also affects autumn colors. Like the weather, soil moisture varies greatly from year to year. The countless combinations of these two highly variable factors assure that no two autumns can be exactly alike. A late spring, or a severe summer drought, can delay the onset of fall color by a few weeks. A warm period during fall will also lower the intensity of autumn colors. A warm wet spring, favorable summer weather, and warm sunny fall days with cool nights should produce the most brilliant autumn colors.
There appears to be some difference between European colors and elsewhere. In Europe autumn leaves are mostly yellow, while the United States and East Asia boast lustrous red foliage. But why? One theory proposes we look back 35 million years back to solve the color mystery.
It proposes that the strong autumn colors result from a long evolutionary war between the trees and the insects that use them as hosts. According to the theory large areas of the globe were covered with evergreen jungles or forests composed of tropical trees until 35 million years ago. During this phase, a series of ice ages and dry spells transpired and many tree species evolved to become deciduous. Many also began an evolutionary process of producing red deciduous leaves in order to ward off insects. In North America, as in East Asia, north-to-south mountain chains enabled plant and animal ‘migration’ to the south or north with the advance and retreat of the ice according to the climatic fluctuations. And the tree’s insect ‘enemies’ migrated too. Thus the war for survival continued there uninterrupted, so the need for red.
In Europe the mountains – the Alps and their lateral branches – reach from east to west and therefore no migration for better climate. Many tree species did not survive the severe cold and died, and with them the insects that depended on them for survival. At the end of the repeated ice ages, most tree species that had survived in Europe had no need to cope with many of the insects that had become extinct, and therefore no longer had to expend efforts on producing red warning leaves.
According to the scientists, evidence supporting this theory can be found in the dwarf shrubs that grow in Scandinavia, which still color their leaves red in autumn. Unlike trees, dwarf shrubs have managed to survive the ice ages under a layer of snow that covered them and protected them from the extreme condition above. Under the blanket of snow, the insects that fed off the shrubs were also protected – so the battle with insects continued in these plants, making it necessary for them to color their leaves red.
Since man first noticed a rhythm in the changing seasons and the weather that comes with each new season, we’ve looked for a reliable means to know the weather ahead of us. We tried to see predictions in the natural world.
Here are several bits of weather folklore focused on trees, leaves, and more in the fall: The brighter the leaf colors in fall, the colder and snowier will be the winter. The earlier fall color peaks, the milder will be the winter. Leaves that drop early portend a mild winter. Leaves that cling to their trees later into autumn foreshadow a severe winter.
A Native American legend tells how trees like oaks and maples came to drop their leaves in fall while trees like pines hold onto their needles throughout the winter. According to the legend, a sparrow sought refuge in the leaves of an oak, but the oak turned it way. The sparrow then sought refuge in the leaves of a maple, but the maple also turned it away. Finally, the sparrow sought refuge in the needles of a pine and, although its needles were much less substantial than the leaves of the other trees, the pine granted refuge to the sparrow. When the creator learned of the trees’ behavior, he caused the deciduous trees to drop their leaves but allowed the pine to keep its needles.
So whatever the reason. Whatever the color. Enjoy, because it sure beats white!!