If you live in the general vicinity of the American Northeast, you can feel the wind beginning to change. It’s no longer heavy and hot, instead bringing a pleasant chill that signals the beginning of fall.
For many, this is a favorite time of year. Reds, oranges, purples, and yellows suddenly burst into the trees. The color change is a result of chemical processes that take place as trees react to the weather shift from summer to winter.
Why Do the Leaves Change?
During the spring and summer, tree leaves serve as production facilities that manufacture the food necessary to feed the tree. This process, photosynthesis, takes place in cells containing chlorophyll, which is characteristically green. This special chemical can absorb sunlight like a solar panel and convert it into energy. For the tree, this energy is in the form of sugars and starch. There are other pigments present too, but for most of the year they are hidden by the chlorophyll that populates the cell.
In the fall, as the weather shifts, the leaves react. They stop the food-making processes that require chlorophyll to prepare for their dormancy in the winter and, as a result, the chemical breaks down. The other pigments in the leaves can now shine with chlorophyll departing: dogwoods and maplewoods show reds and purples, while sugar maples display a brilliant orange.
Other changes are taking place as the colors shift. Falling leaves, for example, happen because a special layer of cells severs the tissues that support the leaf against the tree. Then, the tree seals the cut, so that when the leaf finally drops, a leaf scar is left in its stead.
Evergreens are different: conifers– like pines, spruces, firs, hemlocks, and cedars– remain greenish all year round so that individual leaves may stay on for two to four years.
Don't Miss It
There are only a few weeks where this color is at its most vibrant and pronounced, so make sure to get outside as much as possible so you don’t miss it. As we know, being outside and among nature boosts our endorphins and helps to calm the anxieties that come about from daily life. If you aren’t an outdoor person, use the color change of fall as a motivator to get out into a wooded space and enjoy the fresh air.