If the Amazon rainforest disappeared, would it affect the oxygen content on Earth?

The Amazon rainforest burns several times almost every few years.

This is not a rumor. As a natural forest with such a large area (about 5.5 million square kilometers), it is normal for a few forest fires to occur occasionally.

But the news every year is very boring. They even show photos of big fires that have been used in previous years. And it’s always the same few old places that are on fire. But if these places were on fire every year, the trees there wouldn’t be able to grow so fast.

What’s even more interesting is that these news reports all mention one thing in common: the Amazon rainforest is the “lungs of the earth” and can provide 20% of the world’s oxygen. If the fires cause the forest area to decrease, then the oxygen available for us to breathe will also decrease.

First, let’s look at the title “Lungs of the Earth”. Lungs are an organ found in mammals, birds, amphibians and other organisms.

The main function of the lungs is simply to help the internal organism exchange gases with the outside world. For example, in the human body, we inhale oxygen, which exchanges with carbon dioxide in the human body in the alveoli, and then expel carbon dioxide through the respiratory tract.

Similarly, but not identically, plants can produce oxygen and absorb carbon dioxide from the air through photosynthesis.

As the largest rainforest on Earth, the photosynthesis carried out by the Amazon rainforest accounts for about 20% of the total photosynthesis on land in the world. Does it look familiar?

That’s right, some news reports claiming that “the Amazon rainforest can provide 20% of the world’s oxygen” is actually a misinterpretation of the concept.

And! Most of the oxygen produced by the Amazon rainforest is not actually for you to breathe. It is almost all "absorbed" by the rainforest itself.

Simply put, in the vast ecosystem of the Amazon rainforest, there live millions of species of insects, plants, birds and mammals, all of which need to consume oxygen.

Not only the Amazon rainforest, but most other ecosystems on Earth consume almost as much oxygen as they produce.

Besides, you don’t think that plants only need to absorb carbon dioxide, right?

Of course, plants also need oxygen for aerobic respiration. In fact, in the Amazon rainforest, nearly 60% of the oxygen produced by these plants is consumed by themselves, and the rest is divided up by other organisms and microorganisms in the rainforest.

So, overall, the Amazon and most other ecosystems on Earth contribute almost zero net oxygen to their supply.

So where does the oxygen come from for so many creatures on Earth to breathe?

The first is the oxygen contained in the atmosphere. The oxygen that exists naturally on Earth accounts for about 21% of the atmosphere.

Another source of the greatest contribution to the Earth's oxygen is our oceans. To be more precise, it is the phytoplankton (mainly referring to phytoplankton, including eight phyla: Cyanobacteria, Chlorophyta, Bacillariophyta, Chrysophyta, Xanthophyta, Dinophyta, Cryptophyta and Euglena). About half of the oxygen on Earth is produced through photosynthesis by phytoplankton.

Phytoplankton can also absorb carbon dioxide, and then add water to produce C6H12O6 (glucose) through solar energy, and produce oxygen, but there is a prerequisite, these phytoplankton must have chloroplasts.

Due to the huge base of phytoplankton in the ocean, the amount of oxygen they produce is also very huge.

Therefore, if the Amazon rainforest really disappears, it will not have much impact on the overall oxygen content of the earth, and the overall oxygen concentration in the atmosphere will only drop by about one percent.

But then again, we certainly don't want the Amazon rainforest to disappear, because among all the ecosystems in the world, the Amazon rainforest is of paramount importance.

First, rainforests can regulate regional rainfall and thus regulate the global climate.

Plants in the rainforest can absorb water from the ground through their deep roots, and then transport the water to the xylem of the stems or leaves through their own conducting tissues. Then, the water enters the evaporation site of the cell wall of the mesophyll cells near the substomatal cavity from the terminal cells of the leaf xylem. Finally, the water vapor evaporates through the stomata.

This water vapor enters the atmosphere and becomes the basis for clouds and precipitation.

More importantly, the Amazon rainforest is also a giant storage site for fixed carbon. Photosynthesis not only absorbs carbon dioxide, but also fixes carbon through dark reactions.

The fossil fuels we mine now, such as coal, were slowly formed billions of years ago when large amounts of plants accumulated underground through biochemical and physicochemical reactions.

It can be imagined that in billions of years, this Amazon rainforest will become a coal field with huge reserves.

So, if we lose this rainforest, although it will not have much impact on the oxygen content in the atmosphere, the concentration of carbon dioxide in the atmosphere will increase by 10%, and the rich biodiversity of the tropical rainforest will decrease or even disappear.

This will be a disaster that the earth cannot bear at present.