Chapter 375

Zhang Yuan carefully observed the so-called tree core, with some hollow sieve tubes in the middle, and the overall density was much lower than that of steel.

Yamamoto said amazingly, "these tree cores are very good materials for Riley civilization, providing shelter and food But it's also a big crisis to destroy the whole ecological chain! "

He used a knife to hang a bit of wood debris and ignited it with a lighter.

Suddenly, the whole burning phenomenon produced a faint smoke.

Zhang Yuan covered his nose and smelled the burning smell of plastic. He felt thoughtful.

Everyone smelled it.

"It's really like plastic."

"What is plastic?"

Zhang Yuan explained: "it's a kind of polymer material from oil. It's very cheap. The earth civilization used to use it widely, but after the oil is exhausted, it's useless. It can only use a lot of renewable materials."

Yamamoto pressed the button again. "Do you smell it? This kind of tree core is a natural polymer material, and its chemical composition is a bit similar to the plastics widely used on our earth, that is, very stable chemical substances. "

The screen shows an image of a human geographer looking for a fossil vein in a plain area: a large organic mine with a reserve of 300 million tons!

"The composition of this organic mineral is almost all the core of the world tree. Because it was buried underground for a long time, it became something similar to coal. It's even better than coal and has a higher calorific value. "

Some quick witted biologists have come to understand why Professor Yamamoto thinks there will be a mass extinction on this planet!

Why?

"Because of these tree hearts It can't be broken down by native microbes! That's why they're piling up a lot. "

Zhang Yuan was surprised that he could not speak. Human beings could actually witness A mass extinction!

The so-called "World Tree" of the Riley people is undoubtedly an excellent species on this planet, providing food and living space for the Riley people.

Because of its strong ability to adapt to the environment, the "World Tree" can be found in almost every corner of the planet.

But also because the "tree heart" of the world tree evolved too far ahead of time, the indigenous microorganisms could not decompose this highly stable substance.

A large number of organic mineral veins discovered by human beings in the plain were formed when other fibers rotted in the original forest and only accumulated in the tree core and precipitated underground.

Why do we say that this will cause mass extinction?

It's very simple, because the carbon cycle of the native planet has been destroyed.

The general situation of aerobic respiration is that consumers inhale oxygen and carbon dioxide, while producers inhale carbon dioxide and produce oxygen to form a carbon cycle.

But now, a large amount of carbon has become the tree heart sinking underground, which leads to the gradual decrease of carbon dioxide concentration in the atmosphere. Plants do not have enough carbon dioxide, and then a large number of animals die.

The concentration of carbon dioxide on this planet is about five thousandths, millions of years, tens of millions of years later, the carbon dioxide may be reduced by 60% - 80%. At this time, it is difficult for plants to reproduce, so that they can produce real lethality.

A biologist sitting at the bottom asked, "is there anything that indigenous microbes can't break down? Professor Yamamoto, are you sure your scientific research is correct? "

The problem was explained by an expert who was in charge of geographical research: "we found the active ingredients of tree heart in soil all over the world Although these substances are high molecular organic compounds, they will become some small fragments due to physical action, but even the decomposition rate of these fragments is very slow, and they can be stable for thousands of years, even tens of thousands of years. It shows that the disintegrators of this planet can't effectively disintegrate the heart of the world tree. "

"How to say, it's just like plastic. Although small plastic particles are not poisonous, they will not be decomposed if they are buried underground for a long time. And the active ingredients in the heart of a tree are even more stable than plastic and can last longer. "

Zhang Yuan nodded.

This is the origin of the great crisis.

The expert continued, "ladies and gentlemen. This kind of environmental mutation caused by plant evolution has not happened on earth... "

"2.4 billion years ago, there was a" big oxygen event "on the earth, which changed the composition of minerals on the earth and made it possible for animals to appear in the future."

"That is to say, the oxygen content of the whole planet has soared, mainly because of the rapid evolution of plants, and the formation of wood fibers, while the fungi that decompose plant fibers have not yet appeared. This leads to a sharp drop in the concentration of carbon dioxide in the air. "

"A large number of carbon elements were solidified and deposited underground with the life cycle of plants, so that high-quality coal was formed in the Later Carboniferous period, which benefited the later human beings."

"At the beginning, the decomposing ability of the earth was not strong enough, the proportion of carbon dioxide in the atmosphere decreased, and the oxygen ratio increased significantly. In the Late Carboniferous, the proportion of oxygen in the atmosphere reached the highest level in the history of the earth. The sudden change of the environment led to the big bang of life after the mass extinction. "All of you here understand that.

"And Riley star is also in such a special stage. With the accumulation of time, there are more and more dead world trees, and more and more accumulated tree hearts."

"This planet has been formed for a long time. The concentration of carbon dioxide in the atmosphere is not too high, so where does carbon come from? After the consumption of carbon dioxide in the atmosphere, of course, it is the carbon element in organisms As long as there are more dead creatures than those born, with the destruction of the whole world's carbon cycle, more and more carbon elements will be buried underground! "

"Without carbon dioxide in the atmosphere, there will be fewer and fewer plants and fewer and fewer animals. Instead, the concentration of oxygen will rise.

"Mass extinction, that's it. It's starting!"

"Or the extinction has begun, but these Rileys don't know it. After thousands of years, animals and plants are rare, and a lot of carbon has become the same material as this plastic That's the theory. "

Everyone was sitting quietly, thinking, thinking.

The extinction of this kind of creature was exposed naked, serious and full of heavy killing intention.

It comes from the killing intention of the planet itself.

This kind of killing has always been slow and firm.

Even human beings, as interstellar civilization, are hard to stop this power from the planet itself.

……

(PS: without the comments of silly loser online game, I feel that it's not exciting to write!

Especially in recent days, it is still being pushed by the strong wind. As a result, it is covered by the big red flag, which leads to the unsatisfactory increase in the collection Ah, bad luck, but let's celebrate in the third shift

(the National Day parade is still quite spectacular. I don't want to publish my speech. I like the nuclear bomb df41 best. Although it can't be used in war, it means real safety!)