MARYLAND — Lots of us wait all year for autumn to enjoy the cooler air, warm drinks, and the picturesque views of the leaves changing colors.
The vibrant reds, yellows, and oranges showing off in the fall air.
But have you ever wondered why do the trees end up changing colors?
Julie Conway, a State Forester with the Maryland Department of Natural Resources, explains that it's their way of preparing for the winter.
“As the days get cooler and shorter and the nights get longer, we experience less overall sunlight the trees begin to prepare to lose their leaves for the dormant season,” says Conway.
As they start to prepare for the winter, trees begin to slowly block off the veins to the leaves restricting the flow of water and nutrients.
This results in less chlorophyll to be produced and leading to less of it being replaced in the leaves, allowing certain colors to become more visible.
“During the growing season there is also another pigment called carotenoids which are your yellows and oranges and they’re present throughout the summer but there’s typically enough chlorophyll to kind of overshadow the carotenoids, so we still see leaves as green. As chlorophyll diminishes then you’ll end up with those carotenoids, the yellows and oranges, showing through.”
So, while the yellow and orange pigments are already in the leaf, the reds that we see in certain trees come through in a slightly different process.
“There’s no longer as much of an ability for those nutrients to be shuttled to from the leaf to the tree because those veins are getting closed off. So, you end up with a buildup of something called anthocyanins in the leaf and that’s where your reds come from.”
Which means that the red pigments can vary from season to season as they are wholly dependent their buildup during warm sunny days and cool nights early in the fall.
As you are out leaf peeping you may encounter a pink colored tree but Conway explains to us that those trees, sugar maples and sassafras, are a mixture of yellow and orange and not really pink.
To see where the colors are close to peak or when they will get closer to their peak, click here.
