Why Do Leaves Fall? Some Interesting Science Facts For You

When you spot falling leaves in your yard, you know that it's time to bid farewell to summer.

Yellow, orange, red, brown, and occasionally green leaves are seen detaching themselves from trees. All these leaves make the autumn season look a lot more aesthetic and beautiful.

We have all learned in biology about the important role leaves play in a plant or a tree. Leaves assist plants in producing food by the process of photosynthesis. They are the primary organ that interacts with the environment and looks after the plant's basic requirements. We know that plants do not eat food directly; instead, they make food by absorbing water from the soil, taking in the carbon dioxide from the atmosphere, and also using the energy from light (or the Sun) to produce sugars. If they play such an important role, then why do trees lose their leaves?

The answer is pretty simple. Leaves are shed because they are no longer involved in the production of sugars for the tree. Thus, it would simply be inefficient to hold on to the leaves on the branches. It helps the trees in saving up necessary nutrients during cold temperatures. Thus, the leaves of most of the beautiful trees of the world fall down during autumn. You can notice each leaf change its color as autumn approaches.

Continue reading to find more answers to interesting questions. You can also read other fun information, such as why cells divide and why your ears pop!

Why do leaves change color in the fall season?

Yes, every leaf acts as an important part of a plant. However, leaves do not always have the same function. Their importance change, just like their colors. They lose their chlorophyll and become unimportant to a plant, so they are shed by trees. But why do leaves change color? Why can't a leaf have a constant color?

When the leaves present on plants are green, they work as vital organs. The color green comes from the presence of a chemical called chlorophyll. This chlorophyll processes the available sunlight, which falls on the leaves, to sugars. This helps trees feed themselves. As the cold temperatures of the winter season come by, the days begin getting darker. With little sunlight available, the remaining parts of the tree begin absorbing the essential parts of each leaf. These absorbed nutrients are stored in the roots in the soil during the winter season. Hence, the chlorophyll pigment is withdrawn from the cells, and thus we see a change of color in leaves. At first, the greens slowly transform to yellow, followed by the transition to orange, red, and brown during the peak fall months.

What does it mean when a tree is shedding leaves?

Spring is undoubtedly the most vibrant season, with flowers and lush trees lightening the mood. However, the dry autumn days slowly creep in, and we see leaves dropping all around us. If trees require leaves to survive, why do they shed and lose their leaves?

It is as simple as it can be. When the chlorophyll is withdrawn, the leaves are basically of no use as they cannot process sunlight and produce sugars. Thus, the trees shed their leaves. This also ensures a longer life for these trees. Had this not been done, the water present in the leaves' cells would be freezing to ice, thus damaging and rupturing them. By the onset of the hot weather, the trees would technically have no leaves efficiently working for them. Hence, the production of food fails, and the tree can no longer survive. As the hot summer ends, most of the leaves will either be decaying or be eaten by bugs.

Why do Christmas trees stay green throughout the year?

Christmas is one of the most fun festivals for kids and adults. Fairy lights, Christmas carols, and of course, the Christmas tree are what sets the mood of this festival. But have you ever thought about why Christmas trees remain green in every weather? Why do they not shed their leaves even when it is winter?

This is because certain trees, like Christmas trees, are called 'evergreens'. It would only make sense to give them such a name as the leaves remain green all year round. Evergreens such as pine and fir trees contain waxy layers over the leaves called resin, which save them during the winter months. Thus, they do not succumb to freezing temperatures or decay, and they remain intact for a long time. Hence, they become useful for trees throughout the year. If the leaves create nutrients continually, why would they be shed?

Why do trees shed leaves in autumn?

You know you are close to the autumn season as you notice red, orange, and yellow leaves drop down on the ground. As the weeks pass by, more and more leaves fall down, and it is time for you to pull out your scarf and grab a warm cup of pumpkin latte. But what is the reason for leaves falling in the autumn season? Well, we have the answer for you!

Buds and stems of trees can withstand cold, freezing temperatures. However, leaves cannot handle the low drop in temperature. This can affect the health of the entire tree. Thus, plants and trees simply shed any damaged, diseased, or dead tissues, such as a leaf or flower. At the same time, it seals off the point where the leaf (or flower) connects to the main branch. Also referred to as the abscission layer, it is this region that houses many cells that, based on physiological situations, are capable of separating from one another. With the change in the amount of sunlight received and the weather conditions, the hormones contained in trees experience changes too. One notable hormone in trees is auxin, which is mainly produced in the body as well as leaves of trees. The overall balance of auxin between the branches of trees and the leaves determines when a leaf would fall off to the ground.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our article on why leaves fall, then why not take a look at our facts about why boats float or why people dance?