Why Do Leaves Change Color? 7 Fun Facts About Foliage
As fall makes its approach, everyone is reminded of what's on the horizon: Halloween, pumpkin spice everything and beautiful fall leaves. Fall foliage displays up and down the east coast give some people the urge to drive miles out of their way just to witness nature's spectacle.
Bright oranges, yellows and reds start to replace the greens that have occupied the trees since spring. It is a beautiful sight to behold and signals that an even more significant change is on the horizon. Have you ever asked yourself, “Why do leaves change color?” If it's the end of their season, why don't they just fall as the name of the season implies? Below you'll find the answer to that plus some fun and interesting facts about leaves you never knew before.
Why Do Leaves Change Color?
Leaves are the food producers for the tree. To feed the tree, they need sunlight, water, air and chlorophyll to make food. Chlorophyll is a pigment that helps trees absorb all these elements and is essential in the photosynthesis process. Without this pigment, a leaf will not be able to make food both the tree and the leaf needs to live. The pigment is present in all trees and plants. It acts as a coating over the leaves and is responsible for giving them their green sheen. However, this green color is just a topcoat and hides the actual color of the leaf. In the fall, it is the wearing away of chlorophyll that unveils a leaf's real color.
During the spring and summer, daylight hours are long, and trees soak up all the sunlight they want and need to grow and thrive. The leaves stay green because they are actively making food using the sunlight, and in the spring and summer, there is plenty of sun to go around. As the days get shorter and the sun further away from the Earth, the leaves get less and less sunlight. The first sign of the sun's waning presence is that chlorophyll starts disappearing from the leaves. Without the presence of chlorophyll, photosynthesis ceases. The leaves, therefore, have to stop food production because they can't maintain it without the pigment.
As the food-making operation of the leaf stops and the chlorophyll depletes, the stem gets weaker, and the green coating starts fading away. As the coloring lightens up, you can catch a glimpse of the leaf's true color, usually yellow, orange, red or tan. When there is no more chlorophyll left in a leaf, the color will be completely transformed and the stem totally dead. Without food, the stem will eventually snap sending the colorful leaf floating the ground.
The tree goes into a dormant state throughout the winter, surviving off the food that the leaves stockpiled and gave to the tree during the spring and summer. At this point, the tree appears dead. No growth will appear and, it may wind up buried in ice and snow for a couple of months.
The sun coming out in the spring and the thawing of the ground wakes the tree back up. The more intense the sunlight gets, the more alive it becomes. Eventually, new leaf growth emerges, and shortly after that, you may forget that the tree was bare and dead just a short time before. The photosynthesis cycle begins anew, and the food-making and storing process that is courtesy of the green leaves kicks back up into action.
Now that you know why leaves change color, you may have some other questions about them. Check out some of these fun and interesting foliage facts and use them to wow your friends and family at your next get together.
7 Fun Facts About Foliage
1. How Are Leaves And Bananas Similar?
You may not understand how a banana and a leaf could be similar, but check out this fun fact. Bananas and leaves go through the exact same process to produce food. Both contain chlorophyll to make photosynthesis happen. This means that at their peak growing time, both bananas and leaves are green. When a banana is picked, its food supply is cut off, and the chlorophyll starts to recede, much like what happens to leaves in the fall. As the chlorophyll dissipates, the actual yellow color of a banana is revealed. As the banana continues to be without food, it eventually turns brown until it rots, thereby mimicking the transformation of a leaf.
2. Why Do Leaves Have Pointed Ends?
If you look at just about any leaf, you'll notice the end is slightly pointed. Why would a leaf need a pointy end? It's called a drip edge, and it helps a leaf funnel water from rain away from the stems. If water sits too long on top of a leaf, it will oversaturate it and cause it to start rotting. If a leaf rots, it is no good to the tree, and it dies. In this way, the pointy end gives a leaf its own drainage system.
3. Why Are Leaves So Flat?
Leaves exist to feed the trees and help them store up food for the long winter. If the leaves were thick, wouldn't they be able to make more food? While that logic may make sense, it doesn't quite work that way. The number one element a leaf needs to produce food is sunlight. Only by absorbing light is photosynthesis able to create food. If a leaf were to be much thicker, it would not be able to soak in the proper amount of sunlight. Being flat allows it to produce the most area to absorb the most sunlight, and its thin form enables the sun to penetrate and get to the tiny cells where the magic of photosynthesis happens. Its size and shape help a leaf to be more productive and make more food, not less.
4. What Are Leaves To A Tree?
As the primary food source for the tree, leaves are a living, breathing and processing organ. They are considered a tree organ. It would be like you wearing your digestive system on the outside of your body. The leaf is not only the mouth for the food, but it is what changes it into the energy and nutrition the tree needs. How's that for wearing your heart, or rather your stomach, on your sleeve?
5. Does A Cactus Have Leaves?
If you've ever been to the desert or perused the succulent section of your local garden store, it does not appear that a cactus has leaves. Instead, a cactus has sharp and pointy stickers that protrude out keeping it protected from just about anything that tries to breach it. Only certain birds call a cactus home, and that's because they are keen enough to know where to stand. However, a cactus does have leaves.
For a short period of time in the spring (yes, the desert does have a spring) small leaves appear around the cactus. They don't coat it, and they don't hang around for long, but they're there. Scientists believe that cactus needles or spines are leaves that have been modified for better photosynthesis processing in the desert climate. The spines are also much stronger and can tolerate the extremely dry environment much better than a regular leaf. If a leaf were exposed to the desert climate for too long, it would dry up and die. The stem of the cactus is like the trunk of a tree, and the spines are the leaves.
6. Are There Certain Conditions That Create Better Fall Foliage Colors?
If you live in a state where the change of season begets beautiful leaf colors, you have probably experienced times when that wasn't always the case. If the summer has been unusually dry or the end of summer has been unusually cold, the colors in the leaves will not change as drastically nor will they stay around for long. A dry summer doesn't allow for as much food production for the tree, so the leaves will die and drop off more quickly without going through the full color change process. If the summer conditions were right, the leaves will change into the beautiful hues you're accustomed to.
7. What Benefits Do Leaves Provide Humans?
Can you remember your elementary school science class for the answer to this one? Aside from light, all living things need gas in order to live. The type of gas varies. Humans need oxygen while trees need carbon dioxide. When both humans and leaves use their respective gases, there is a metamorphosis that occurs transforming this gas from one type to another. After leaves take carbon dioxide in, they put out oxygen. Humans breathe in oxygen but expel carbon dioxide. Therefore, both humans and trees provide the gas the other needs to live.
Color Change Conclusions
Fall is a welcomed season ushering back cool weather at the end of what usually is a long and hot summer. Kids are returning to school and families are gearing up for the festive holidays that lie ahead. Why do leaves change color? Now you have the answer to that question and some other leafy facts. So, sit back and count down the days until you can enjoy the fall foliage with a tasty pumpkin spice latte.