Fall is a season of transformation, and one of the most iconic symbols of autumn is the changing color of the leaves. But why do leaves fall in autumn, and what causes their stunning colors?
As the days grow shorter and temperatures cool, trees prepare for winter by halting the production of chlorophyll, the green pigment responsible for photosynthesis. Without chlorophyll, the vibrant colors underneath, such as yellows and oranges, become visible. These colors are due to pigments called carotenoids, which are also found in carrots and corn. Red and purple hues in some leaves come from anthocyanins, pigments also found in cranberries and grapes.
As the tree shifts its energy to survive the winter, the cells at the base of each leaf begin to break down. This weakens the leaf’s attachment to the tree, eventually causing it to fall off. This process helps trees conserve water and energy during the cold months.
Interestingly, not all trees shed their leaves. Evergreens like pines and cedars retain their needles, which are coated in a waxy substance to resist freezing. This enables them to continue producing energy, even in harsh winter conditions.
The brilliance of fall colors can vary year by year, depending on factors like temperature, moisture, and sunlight. Ideal conditions—such as warm, sunny fall days and cool nights—can result in a dazzling display of colors. In contrast, drought conditions can cause leaves to turn brown and fall prematurely.
Whether you live in a region known for fall foliage or just admire it from afar, the vibrant colors of autumn are a reminder of the beauty of nature’s cycles.