Why leaves change color in the autumn
Did you know the vivid colors of autumn leaves are there throughout spring and summer, but hidden? Here's why leaves change color in the fall. The post Why leaves change color in the autumn first appeared on EarthSky .
Autumn brings a stunning transformation in the colors of trees' leaves in the Northern Hemisphere. The deep green hue of chlorophyll, which helps plants absorb sunlight, fades, revealing other pigments that were once hidden. As leaves shed their chlorophyll, dormant yellow and orange hues become visible. Analyses by chemists reveal that reds are actively produced in leaves by sunlight and cold nights in the fall.
Different factors like sunlight exposure, temperature, and tree species determine the mix of autumn colors. While some trees may have mostly brown leaves, indicating loss of all pigments, others display vibrant reds or yellows. Scientists believe that the colors serve various purposes, such as acting as a natural sunscreen to protect against excessive sunlight, warding off pests, or even attracting pollinators.
However, these vibrant autumn hues are remnants of an ancient evolutionary relationship between plants and insects, now preserved as a "fossil memory" despite having no current function.
Written by urgent.news from EarthSky's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
