Reason for Color Change of Leaves in the Fall
Even if you live in the most tropical climate, where summer is your only season, you still can not help but admire the splendor of a colorful autumn view. So what’s behind this annual event? Why do the leaves change every autumn, and why are some years brighter than others?
In order to understand what is involved in turning a sea of fresh greenery into a kaleidoscope of red, orange, yellow and all shades in between every autumn, it is useful to know two important points. The timing of the color change of the leaves is mainly influenced by the calendar, and the intensity is the product of three main factors: color pigments, the duration of the night and the weather.
The first are the pigments. There are three more responsible for the color of the leaves. Most of us know the first one, chlorophyll. You know that it has something to do with the basic green color in leaves and grass. It is necessary for photosynthesis, the chemical process that allows plants of all sizes to use sunlight to produce food.
In the warmer months, when the plants are actively growing, the pigment chlorophyll dominates the color that we see in the leaves. However, another pigment is also present in this period, carotenoids. They produce yellow, orange and brown. But because chlorophyll is so dominant as a pigment, carotenoid pigments begin to appear only in the fall, when the process of photosynthesis stops. After all, the process of photosynthesis stops, and all chlorophyll is depleted, as a result of which the green color of some leaves is completely removed, and the carotenoid pigments can come to the fore.
A third pigment, anthocyanins are not in the leaves before autumn. Warm and bright autumn days produce a lot of sugar in the leaf. But as the days get shorter and the nights get cooler, those excess sugars get trapped in the leaf as the ribs that enter and exit the leaves gradually close. The combination of bright light and trapped sugars stimulates the production of anthocyanin pigments. They create the bright shades of red and violet and the many shades in between.
The next factor contributing to the color of the autumn leaves is the longer nights. The days are getting shorter, which reduces the amount of sunlight available for the photosynthesis of plants. Thus, nature signals to plants that winter is on its way. Energy begins to move from food and energy production to storage and reserves. As the photosynthesis process slows down in response to shorter days, chlorophyll production also decreases. In the absence of the dominant green pigment, carotenoid and anthocyanin pigments illuminate the autumn landscape.
The third and responsible factor for the intensity of the autumn color is the weather. The brightest autumn exhibitions are the result of a warm and humid spring, a mild summer, sunny and bright autumn days and cool nights, but above freezing. When this combination comes together, the result is the brightest color exposure.
So, looking back at the color representation this season, I hope you were rewarded with extraordinary views. And next spring, when it gets warm and humid, be happy. Maybe it’s the stuff of a spectacular matter !