Why exactly do leaves fall

Why exactly do leaves fall

Rains are over. There is a slight chill in the atmosphere. Winter is just around the corner. Soon, sweaters, scarves, blankets will come out of the wardrobe, after a long break. It is a healthy season. Eat and be happy. Ideal one to go for a jog in the morning, were sun is yet to come up, slight mist in the air.

Everything is happy and dandy.

And suddenly, in blissful morning air, there is acrid smoke. The smoke is coming from dry leaves getting burnt.

Come winter, and leaf fall starts. In a city, it is a major challenge. What to do with all those leaves?

Burning them off seems convenient, easy, isn’t it?

Oh, it is not so. Why burning is not a good strategy, we will discuss in later blogs.

Today let’s discuss, why leaves fall, in the first place.

Leaf fall

Ready for some botany? Don’t worry, nothing too complicated 😊. Let’s simplify and understand.

Trees that shed leaves for some time in a year are called “deciduous” trees.

Deciduous word comes from the Latin word, Decidere. It means “to fall off” or “to fall down”.

Water absorbed by the roots of the plant is distributed to all parts of the plant and gets evaporated through leaves. It is called transpiration. Leaves have pores on them called stomata. Stomata open and water is let out.

Opening of stomata allows Carbon Dioxide to enter through the leaves. Carbon Dioxide is essential for trees for photosynthesis. In simple words, plants prepare their food through this process.

Also, letting out water helps trees to cool off.

After winter, there is summer, the dry season. In the summer heat, soil dries off, water table drops. This is the time when it is necessary to save water. For us and for plants as well 😊

So how to hold in water, as much as possible? By not letting it go out, right?

But if leaves are present, plant will keep losing water.

What could be the solution?

To get rid of the leaves!!

Yes, that’s what they do.

They shed leaves.

Deciduous trees shed all the leaves. For some duration, there is not a single leaf present on these trees.

Now tree is ready to face summer and the summer heat.

There are trees like Mango, Jamun, Jackfruit, that are never completely leaf-less. They shed leaves but not all at once. They keep shedding them all throughout the year. They are called ever-green or semi evergreen trees.

Okkay, back to deciduous trees.

Shedding leaves not only helps trees, but also helps the soil.

Leaves that fall off from the tree, cover the soil around the tree. Leaves form a layer over soil. Because of this leaf cover, sun light cannot reach the soil. Even soil can retain moisture.

Fallen leaves make a protective layer over the soil. It helps soil retain moisture

Nature’s design is simply brilliant, isn’t it?

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