No, plants cannot live without oxygen. Plants are categorized as living things. Similar to how humans cannot survive without oxygen, it’s the same case for plants.
This may sound a little odd, considering that we are well aware that plants are the main sources of oxygen in the atmosphere.
True enough, plants do release oxygen through the process of photosynthesis.
They absorb carbon dioxide from the air and when this is combined with water from the ground and energy from sunlight, they turn it into oxygen and sugar.
But in reality, plants take up and absorb more oxygen than they release, being that it is crucial for their survival.
Why Do Plants Need Oxygen?
Plants are constantly making use of oxygen to survive and to successfully complete the process of photosynthesis.
They need oxygen because of respiration, which is the process that plants and animals use to produce energy. During respiration, oxygen is absorbed and converted into energy that plants use in their cells to generate sugar and oxygen.
The respiration process in plants and animals differ. In plants, the process is more accurately called aerobic respiration.
While animals take in carbohydrates through food and release energy through respiration, plant cells generate their own carbohydrates during photosynthesis. They then use those same self-produced carbohydrates during respiration.
It is true that plants can photosynthesize using the energy they absorb from the sun. This is why in the morning, plants absorb carbon dioxide and release oxygen. But at night, it works the other way around — they absorb oxygen and release carbon dioxide.
Without oxygen, plants are unable to respirate. The respiration process happens more often than photosynthesis, which is why plants absorb more oxygen from the atmosphere than they release.
But there can be species and situations where plants photosynthesize more than they respire. And in these instances, it is possible for plants to live solely on the oxygen that they produce.
For example, you can put a plant in a vacuum with no oxygen intake at all. They can still survive for a limited duration because they are able to use up the oxygen that they themselves produce through photosynthesis.
How Do Plants Absorb Oxygen?
Plants absorb oxygen through the cells in their roots. This is why a plant’s roots can develop and foster to give the plant more avenues to absorb oxygen.
Root cells do not undergo photosynthesis along with the rest of the plant. They are mainly in charge of absorbing oxygen from spaces in the soil and the air.
This is the reason why overwatering a plant can kill it. With too much water, the roots are drowned and have no source of oxygen.
At this point, you might be wondering about plants in low-oxygen areas like mangroves or those underwater. These are able to survive in water because they have developed special types of roots that can obtain oxygen despite their habitat.
There are also plants whose roots grow very deep into the soil. They absorb oxygen through growing root hairs on their stems so that they can access the oxygen from the air.
When Do Plants Absorb the Most Oxygen?
Plants absorb more oxygen when there is an absence of sunlight from where they can absorb energy to use for photosynthesis.
As mentioned, plants generally respire more than they photosynthesize, which means they are using up more air than they can make. But this can also depend on the light source that they have.
In bright sunlight, plants can absorb more energy, carbon dioxide, and water. In this scenario, they are more active in the photosynthesis process. Hence, they can produce more oxygen and require less respiration.
In dim sunlight, the photosynthesis and respiration rates are equal. This means that the exact amount of oxygen a plant emits is also the amount it needs to respire.
In the dark, photosynthesis does not take place because of the absence of light and energy sources. This is why at night, plants retire to respiring, consuming oxygen and releasing carbon dioxide.
Do Plants Breathe?
We now know that during the process of respiration, plants take in oxygen. And then they release it into the air through photosynthesis.
This may sound familiar because it’s similar to how we humans inhale and exhale air.
But it’s not scientifically correct to say that plants breathe. It’s more accurate to refer to their process as respiration.
To breathe is to inhale oxygen from the air into the lungs and then exhaling the air out after a short period. This is a physical process that humans and animals are capable of doing.
But plants do not literally “breathe” air into the lungs. Instead, they respire through the use of their root cells or pores, which are called stomata.
Via diffusion, which is the movement of molecules from high concentration to low concentration areas, oxygen and carbon dioxide are absorbed and released through the stomata.
Although the process of respiration is significantly different from the act of breathing, the purpose behind the two actions is similar.
Like how humans inhale oxygen to help the body carry out specific functions, plants also absorb oxygen for cellular respiration. Both are necessary means of survival.
Animals, humans, and plants are all living things that have oxygen at the top tier of their basic needs. Without it, no living thing can survive.
But it is amusing how the process of taking in oxygen is different for every type of living thing. While humans and animals breathe, plants respire and absorb energy and oxygen through their cells.
Plants have their own way of survival and are able to adapt to different situations to survive. They can evolve and find ways to meet their basic needs.
An example would be plant species that have evolved to bring their roots up to their stems so that they can absorb oxygen in the air and survive underwater.
There are also remarkable plants that can live in uber dry areas by storing the water they need and managing their use of it so that they can survive until the next rainfall.
It is truly remarkable how plants are able to adapt to their environments. And our job as human beings is to respect and preserve them. After all, without plants, we won’t have oxygen to breathe in the first place.