|Picture not taken in So. Cal.|
As you all know, those of us from Southern California don’t have 4 seasons. We just get hot, warm, dry and (occasionally) rainy. My experience with leaf color change is based on the sycamore trees we had in Redlands. Sometime in November they started changing color and occasionally would show reds, oranges and yellows. The few other trees that dropped their leaves just turned brown. The rest stayed green all year. The oaks dropped their leaves on an ongoing basis and were replaced by new leaves. In my entire life I have never seen what we are classically taught is "autumn". So this year, with plans to visit New England, we decided to stay through the fall to watch the leaves change colors. And boy, were we rewarded.
I decided we should stay at least for 2 weeks in the “far north” in order to actually watch the colors change. Since we stayed for a week in northern New Hampshire during mid-summer I thought that returning to that area would give us a good comparison. The campground owners at Timberland, near Gorham, NH, were helpful in that they
|Balsams Grand Resort Hotel in July and in September. A good comparison.|
gave me the dates during the end of September when the leaves usually change colors and provided maps of drives we could take to go leaf peeping. Leaf peepers, at least in Vermont and New Hampshire, is apparently what the locals (somewhat derisively) call the tourists who go driving all over creation gaping slack jawed at tree activity that they take entirely for granted.
|How do they know when to do this?|
So, this experience being new to us, I wanted to know how the trees know when to change their colors so I could predict where we should go. Obviously, when the days get shorter the leaves begin to turn. But from my reading and planning I discovered that I couldn’t know exactly where we should be at a given time. Where and when the best colors can be seen varies from year to year. In some years the colors are better than others. Usually the leaf changing begins in the north and proceeds to the south and the higher elevations show the changes before lower elevations, but it isn’t that simple. There are obviously other factors involved.
As far as the scientists know, the other factors include temperature, rainfall, and nutrient supply. Also the timing of the color change can depend on the species of tree. The vividness of the colors can depend upon the temperature and moisture. As autumn approaches a succession of warm, sunny days and crisp but not freezing nights may result in the most spectacular color displays.
|Surprise... the colors were there all along.|
The US Forest Service discussion states, “As days grow shorter, and nights grow longer and cooler, biochemical processes in the leaf begin to paint the landscape with Nature's autumn palette.” As night length increases and the temperature drops in the fall, the production of chlorophyll slows and then stops and eventually all the chlorophyll is destroyed. The carotenoids (yellow, orange and brown colors) and anthocyanins (reds & purples) that are present in the leaf are then unmasked and show their colors. “Certain colors are characteristic of particular species. Oaks turn red, brown, or russet; hickories, golden bronze; aspen and yellow-poplar, golden yellow; dogwood, purplish red; beech, light tan; and sourwood and black tupelo, crimson. Maples differ species by species-red maple turns brilliant scarlet; sugar maple, orange-red; and black maple, glowing yellow.”
So as you can see our experience in New England was grand, but as we traveled south, the changes were less spectacular. By the time we hit Gettysburg, some trees hadn’t changed yet and some leaves had quickly turned brown and dropped. This trend continued on south through Shenandoah National Park. We spent a few days visiting Roger's former receptionist in Tennessee and the colors around Johnson City were quite nice but as we moved south into the Carolinas there was less and less Autumn change.
Still, we were quite pleased overall with our experience of the Fall foliage. I always thought someone was kidding me as I cut out brightly colored construction paper leaves in school. I could clearly see outside that the only realistic color choices were green and brown. Now, after only 60 years, I finally know what people are talking about when they gush about the Fall colors.
Autumn in New Hampshire