Plants are nature's food factories; which means that they make their own 'food'! For this, they take water from the soil using their roots and carbon dioxide gas from the air. Using sunlight, they break them into 'oxygen' and 'glucose'.
Oxygen is the gas that people need to breathe, while glucose is a type of sugar that gives energy and helps in growth. The whole process is known as photosynthesis, meaning 'putting together with light'. And for this process, plants need a chemical known as 'chlorophyll' that is found in the leaves and is green.
As summer ends and autumn begins, the day becomes shorter and shorter. Therefore, the plants and trees start preparing for winter. When there is not enough light and water, the plants begin to shut down their food-making factories and the green chlorophyll begins to disappear from the leaves.
This is why we see the leaves change colors into beautiful shades of yellow, orange, and red. Small amounts of these colors are present in the leaves all along; we just can't see them because of the overwhelming green chlorophyll.
In the autumn, trees put on a beautiful fashion show. Leaves that are green all over summer long start to turn bright orange, yellow and red. But where do these colors come from?
It all starts inside the leaf, color of leaves based on chemicals called pigments, and there are four main types of pigment in each leaf:
Chlorophyll (greens)
Chlorophyll is also called white birch and is responsible for helping trees and plants turn into food with the help of sunlight. For most months, it is the dominant color seen in most leaves until it fades away. As many trees shut down the production of their food, they turn to stored sugars to survive the winter.
Xanthophylls (yellows)
Xanthophyll is also called aspen, which can be seen throughout the fall including beeches, ashes, birches, aspens, and some oaks. It also contributes its bright yellow color to autumn squash and corn.
Carotenoids (oranges)
Carotenoids are also called sugar maples, they may be one of the best examples of carotene in action. Their bright signature orange fills many hills and country roads throughout the northern us. Sassafras leaves also turn a slightly more muted orange. As its name implies, carotene is also the chemical responsible for giving carrots their unique coloring.
Anthocyanins (reds)
Anthocyanins are also called swamp chestnut oak, these are unlike other leaf colors that always exist in the leaf, anthocyanins are produced as the chlorophyll is broken down. The anthocyanins are often seen in leaves named for their autumn splash of red, including red maples, scarlet oaks, and red sumac.
The summer sunlight triggers the leaves to keep making more chlorophyll. But trees are very sensitive to changes in their environment.
As summer fades into fall, the days start getting shorter and there is less sunlight. This is a signal for the leaf to prepare for winter and to stop making chlorophyll. Once this happens, the green color starts to fade and the reds, oranges, and yellows become visible photographs of the silhouette of a tree in the sunset Shorter days in the fall are a signal for trees to start preparing for winter.
Weather is also an important part of the color change. In the fall, the temperatures get colder and there is also more rain and snow. Changes in these weather conditions can play a role in how early the leaves change and how long they keep their beautiful colors.
Extreme weather changes can also have an effect on the leaves. For example, a drought or an early frost could make the leaves fall off of the trees before they’ve had time to change colors.
So if you want to know how long the colors will last this fall, be sure to keep an eye on the weather!
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