Why Do Plants Need Oxygen? – “Wait, Do They Breathe Too?”

It’s a well-known fact that plants take in carbon dioxide and release oxygen. That’s how we get oxygen for survival. So one reason people keep indoor plants is to have more oxygen in the indoor atmosphere for easier breathing.

But are we the only ones who breathe? Believe me or not but quite like animals and humans, plants also breathe! During respiration, plants absorb oxygen and release carbon dioxide into the environment.

But why do plants need oxygen, and can they survive without oxygen? Continue reading this post to learn how vital oxygen is for plants and how you can help by making sure they’re getting an ample supply.

Do Plants Need Oxygen?

Yes. Plants need oxygen for their survival! So plant cells consume oxygen all the time. The process is called respiration, which you’ll learn about further in this article. Also, sometimes the consumption rate is higher than what they’re producing during photosynthesis.

But, in any 24-hour interval, plants will produce more oxygen than they consume and take in more carbon dioxide than they give out. So, plants give oxygen, and we need them for our survival.

What Is Meant By Plant Respiration?

So we know that oxygen is necessary for plants. But why do plants need oxygen? What do they use it for? To answer this question, we’ll need to look deeper into a vital plant process: respiration. Think of respiration as the opposite of photosynthesis.

How Does Photosynthesis Work?

Carbon dioxide is absorbed through stomatal openings and used with water and light energy to create glucose and oxygen during photosynthesis. Oxygen is a byproduct of the process and is released into the environment through stomata.

Light Energy + Carbon Dioxide + Water Oxygen + Glucose

How Does Plant Respiration Work?

During cellular respiration, plant cells use oxygen to break glucose created during photosynthesis to release heat energy for a series of cellular activities. As a result, respiration continuously consumes the carbohydrates that plants make to produce energy, releasing carbon dioxide as a byproduct. Here’s what the equation looks like:

Oxygen + Glucose → Heat Energy + Carbon Dioxide + Water

So you see, it’s precisely the reverse of what you see during photosynthesis!

What Is The Difference Between Animal Respiration And Plant Respiration?

Animals also respire since that gives us the energy for different activities within our body. But, we use the carbohydrates from the food we eat to carry out respiration and release energy. In contrast, plants use the carbohydrates they create to release energy for their processes.

Do Plants Breathe Yes Or No?

Though we mentioned that plants breathe, cellular respiration isn’t strictly “breathing.” In its real sense, breathing is inhaling and exhaling air through the lungs to facilitate the exchange of gases between the internal and external environment. Breathing brings in the oxygen needed for cellular respiration. So in animals, breathing is carried out in addition to cellular respiration.

Respiration in plants is a bit different. During respiration (and photosynthesis), gases are exchanged between the plants and the external environment through stomata, using diffusion rather than breathing. But, since gases are exchanged with the external environment, people often label it as “breathing.” Although plants don’t use lungs, the process is quite similar.

Can Plants Survive Without Oxygen?

So now you understand why plants need oxygen. They need oxygen to carry out respiration and release energy for several activities. But can they survive without oxygen? No. Oxygen is a necessity for plants, just like it is for us.

But, since they also create oxygen during photosynthesis, shouldn’t it be enough to carry out respiration? Do they need more oxygen than they produce? It depends on the rate of photosynthesis and respiration. In conditions where the rate of photosynthesis is faster than the speed of respiration, they may be able to live on just the oxygen they produce.

But, if photosynthesis is slower than respiration and plants aren’t getting enough oxygen from the surroundings, they will suffer. In any case, plants will enjoy from ample oxygen in the environment to carry out respiration effectively. This is because aerobic respiration relies on oxygen to produce energy.

Further in this article, you’ll see how the exchange rate of gases changes with the environmental conditions.

Do Plant Roots Take In Oxygen?

The green parts of the plant, including stems and leaves, carry out photosynthesis and produce oxygen. So the cells in these parts have all the oxygen they need to carry out respiration and release energy. But what about the roots? The cells in the roots don’t have access to light, so they’re not carrying out photosynthesis.

Oxygen from the surroundings is even more critical for these cells since they’re not producing any. Most plants get oxygen from the air spaces between the soil particles. No wonder gardeners don’t like heavy clay soils!

One of the reasons why clayey soils aren’t the best for plants is that it gets compacted, with much fewer air spaces between the clay particles. Waterlogged soil isn’t good either since that inhibits the roots’ air supply. You can practically “drown” plants by overwatering them!

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Rate Of Gaseous Exchange

The rate of giving out and taking in carbon dioxide and oxygen differs with the amount of sunlight present. Though respiration is carried out all the time, photosynthesis depends on sunlight.

  • In the dark, when there’s no light, only respiration is carried out. Oxygen is absorbed, and carbon dioxide is released.
  • In the dim light, the rate of photosynthesis equals the rate of respiration. No gases are released into the environment.
  • In bright sunlight, photosynthesis is faster than respiration. Carbon dioxide is taken in, and oxygen is released into the environment.

What Happens When Plants Don’t Have Oxygen?

Oxygen is among the 16 essential plants’ “nutrients.” It’s a basic need for the plants. You’ve already seen why plants need oxygen. In the absence of enough oxygen for respiration, deficiency symptoms will appear. Let’s see how lack of oxygen affects crops along with the solutions:

What Would Happen If A Plant Has A Deficiency Of Oxygen?

Under normal conditions, plant roots are firm and white. In an oxygen-deprived plant, they’ll turn mushy and brown. The leaves will droop and will turn paler in color.

What Can Cause Oxygen Deficiency In Plants

The most common cause for oxygen deficiency in plants is stagnant water around plant roots. The lack of oxygen around the roots will eventually develop root rot if the condition isn’t resolved promptly.

How To Fix / Prevent Oxygen Deficiency?

Correct watering is often the best treatment for plants suffering from oxygen deficiency. Give the soil a chance to dry out before watering the plants. Then, water just enough so that the plants can absorb in the next couple of hours. Avoid soggy conditions at all costs. Make sure the soil drains well so that the roots won’t “drown.” Organic mulch can also help improve the drainage around your plants.

For hydroponic systems, make sure there’s an air pump installed to oxygenate the nutrient solution delivered to the plant roots.

Once the plants develop root rot, it is challenging to revive them, so ensure you treat the problem before it turns into anything serious.

Plants Defense Mechanism Against Oxygen Deficiency

While you should do your part as a gardener to save the plants from oxygen deficiency and root rot, plants also fight for survival! Different species have developed their mechanisms to sustain life in low-oxygen conditions.

Some plants develop aerial roots from the part of the stem that’s just above the root crown if the soil isn’t well-aerated. This helps them take in the required oxygen through the air.

Wetland plants are often oxygen-deprived. They have developed a tolerance to low-oxygen environments, though they still need some oxygen to survive. Most of them have shallow roots to adapt to the environment, stretching horizontally and keeping themselves as close to the above-ground air as possible.

Tips To Prevent Oxygen Deficiency

Help your plants receive all the oxygen they need to create energy. Here are some tips you can follow to make sure the plant roots are getting plenty of oxygen to grow:

  • Let the soil dry out between waterings.
  • Adding earthworms to the ground naturally aerates it.
  • Aerate the soil using a shovel or aerator before planting crops in it.
  • Use a growing medium with high porosity when gardening in containers.
  • Water until it filters out of the drainage holes, leaving space for fresh oxygen to come in.
  • Choose deep boxes as they drain well, leaving plenty of air pockets for the roots to absorb oxygen from.
  • Make sure the soil temperatures aren’t too high. As temperatures increase, the concentration of oxygen in water drops.

Final Words

Why do plants need oxygen? In short, plants need oxygen to produce energy. Without oxygen, you won’t see the lush green growth, those beautiful flowers, and juicy fruits typical of a healthy garden. So let your plants have a tiny share of the oxygen in the atmosphere. Don’t worry. They’ll still be producing plenty for you to breathe!

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