Leaves change color because of the breakdown of chlorophyll, the green pigment responsible for photosynthesis during the growing season. As days get shorter and temperatures cool in autumn, trees stop producing chlorophyll, causing it to fade and reveal other pigments in the leaves.
Process of Color Change
- Chlorophyll, which absorbs sunlight to help make food for the tree, breaks down due to less sunlight and cooler temperatures in fall.
- As the green fades, yellow and orange pigments called carotenoids and xanthophylls that were always present but masked by chlorophyll become visible.
- In some trees and under certain conditions, red pigments called anthocyanins are produced in response to high sugar concentrations and light, adding reds and purples to the mix.
Factors Influencing Color
- The length of daylight is the primary trigger for chlorophyll breakdown.
- Weather conditions such as temperature, light, and moisture affect the intensity and duration of leaf colors.
- Cool nights and sunny days promote the formation of anthocyanins and vibrant reds.
- Soil moisture and environmental stresses can influence the timing and brilliance of colors.
Thus, the beautiful autumn colors arise from the chemical process of chlorophyll fading and other pigments becoming visible or being produced anew as the tree prepares for winter.