It may seem like magic, but each leaf’s new look comes from chemical changes happening within.
It may seem like magic, but each leaf’s new look comes from chemical changes happening within.
What’s Behind Those Colorful Leaves?
ByCara GiaimoSept. 25, 2020
What’s Behind Those Colorful Leaves?
What’s Behind Those Colorful Leaves?
Fall is marked by the vibrant leaves that carpet our lawns and line our highways.
It may seem like magic, but each leaf’s new look comes from chemical changes happening within. Here’s what’s going on →
What’s Behind Those Colorful Leaves?
In the spring and summer, leaves produce a lot of chlorophyll, a chemical that helps plants get energy from sunlight.
The chlorophyll absorbs red and blue wavelengths of light and reflects the rest, making the leaf appear green.
What’s Behind Those Colorful Leaves?
As the days get shorter, trees pull the nutritious chlorophyll from their leaves and distribute it to their trunks and roots.
This lets other pigments shine through. Some, called xanthopylls, make leaves appear yellow.
What’s Behind Those Colorful Leaves?
Others, called carotenoids, have an orange hue.
Both xanthophylls and carotenoids help the plant make energy by absorbing wavelengths of light that chlorophyll can’t.
What’s Behind Those Colorful Leaves?
Some trees make special pigments in the fall called anthocyanins that turn leaves red.
Scientists aren’t quite sure what these pigments do, although they might have a protective quality.
What’s Behind Those Colorful Leaves?
As fall progresses, leaves are gradually cut off from the water and nutrients from the rest of the tree. They turn brown and soon fall to the ground.
Their work for their tree may be done,but they’re still great for crunching underfoot.
Learn more aboutthe science of our world.