Science Behind: Fall Leaves
By Faith W.
You step outside and take a deep breath. You can smell it. Fall. You take a look around at nature’s color palette and begin to wonder what causes the shift from green to vibrant, warm-colored leaves. It just so happens that science has an explanation!
Chlorophyll is the green pigment found in the majority of plants. Carotenoids, responsible for yellow, orange, and brown colors in some food and plants, and chlorophyll are present in the chloroplasts of leaf cells all year long, but the green pigment tends to mask the other colors. Autumn’s nights as they increase in length, slow down chlorophyll production until it is all destroyed allowing the carotenoids and anthocyanin, the pigment of cranberries, red apples, etc., to show off their vibrant colors. Different trees produce different colors—oak leaves are red or brown, beech leaves are light tan and red maples are scarlet. Other factors affecting leaf color are temperature and moisture. Sugars are produced on warm days, and cool nights prevent the sugars from leaving. Different levels of soil moisture result in varying leaf colors from year to year. Delayed color change and lowered color intensity come from summer drought and warm fall, respectively.
With its unpredictability comes beauty. Arguably, the best season is fall, or at least, I believe it is. The best part is, of course, the leaves. There’s nothing better than trudging through piles of colorful, crunchy fall leaves. The mystery of their colors is uncovered. Science—there’s an explanation for everything
