As you look around outside this time of year, you'll see fall leaves in various shades of brown, orange, red and yellow. The season has changed and the leaves are following suit. But have you ever wondered why the foliage turn so many colors during the fall?
The obvious response to that question is that they're dying. But the process is so much more interesting than that! (Insert dream sequence back to your grade-school science class here.)
The chemical responsible for giving leaves their green coloring is chlorophyll, but all leaves actually start out yellow in composition. When the seasons change, bringing along rain and shorter daylight hours, the chlorophyll breaks down. During this process is when you'll see the yellow or orange carotenoids (or pigments) that were there all along.
However, when leaves change to red, it's because they produce a chemical called anthocyanins. This chemical creates a red coloring that often times combines with what's left of the green, thus giving us different shades of red.
The most interesting fact in this process is that the brightness of the red is dependant upon what tree species the leaf belongs to. According to the New York Times, the colors can also signal other evolutionary factors, like attracting birds and bugs to spread their seeds. They might also be warning others about poisons or bad chemicals.
Whatever the signal the leaf is sending to the ecosystem, we're glad to see the vibrant colors change. Peeper season is in full swing right now, so go out and enjoy the beautiful fall leaves while you can!