What do we call the lungs of the planet. Forests, lungs of the planet? Why green color

Instruction

Trees and other plant species that are abundant in forests form organic matter through photosynthesis. For this purpose, plants use carbon absorbed from the atmosphere. After processing, carbon dioxide is absorbed by trees, and oxygen is released into the atmosphere. The carbon bound in the process of photosynthesis goes to the building of plant organisms, and is also returned to the environment along with dying parts - branches, foliage and bark.

Throughout its life, a plant uses a certain amount of carbon, commensurate with the amount of oxygen released into the atmosphere. In other words, how many carbon molecules are assimilated by an adult plant, the planet received the same amount of oxygen. Part of the carbon bound by trees goes to other parts of the forest ecosystem - to the soil, fallen leaves and needles, dried branches and rhizomes.

When a tree dies, the reverse process starts: decomposing wood takes oxygen from the atmosphere, releasing carbon dioxide back. The same phenomena are observed during forest fires or when wood is burned as fuel. It is for this reason that it is so important to protect green spaces from premature death and from the destructive effects of fire.

The role of forest ecosystems in the life of the planet is determined by the rate of accumulation. If this process proceeds at a rapid pace, oxygen accumulates in the atmosphere and the amount of carbon dioxide decreases. If the balance shifts in the opposite direction, the “green lungs of the planet” perform their function of oxygen saturation of the atmosphere worse.

It would be a mistake to assume that only young forests serve as a source of oxygen on the planet, the trees in which grow intensively, absorbing carbon dioxide. Of course, any ecosystem at some point reaches a period of maturity, when it creates a balance between the interrelated processes of carbon dioxide uptake and oxygen release. But even a very mature forest, where the percentage of old trees is high, continues its invisible work of providing the atmosphere with oxygen, although not so intensively.

Living trees are the main, but far from the only component of the forest ecosystem where it can accumulate. Soil with its organic matter, as well as the forest floor, which is formed from parts of dying plants, are essential for the processes of oxygen production. Such a variety of components of the ecological system allows you to maintain a stable balance in the metabolic processes occurring in the "green lungs", which are so necessary to sustain life on the planet.

"Planets of the solar system" - Venus. Venus is the third brightest object in the Earth's sky after the Sun and Moon. Take care of our planet!!! Plan. The second planet in the solar system. Earth. Over time, water and an atmosphere appeared on planet Earth, but one thing was missing - life. A new star is born - our SUN. Saturn is the second largest planet in the solar system after Jupiter.

"Lesson of the Planet of the Solar System" - Foster camaraderie, the ability to work in a group. Information card of the lesson. Fizkultminutka. Earth. Mars. Photoforum. The role of the Sun for life on Earth. star or planet. Lesson plan. Complete the tasks: Complete the test. Develop cognitive processes, computer literacy skills. Planets of the solar system.

"Small planets" - The figure of Venus. The surface of the moon. The distance from Venus to the Earth varies from 38 to 258 million km. There is every reason to believe that there is a lot of water on Mars. Atmosphere and water on Mars. The volume of Mercury is 17.8 times less than that of the Earth. The composition and internal structure of Mars. Physical fields of the Moon. The density at the center of the Earth is about 12.5 g/cm3.

"Planets in the Solar System" - Astronomical models of Ptolemy and Copernicus. Mars is the fourth planet from the Sun. The planet that was discovered "at the tip of the pen." Neptune has a magnetic field. Sun. Uranus has 18 moons. Mars. Neptune is the eighth planet from the Sun. A planet where life exists. Uranus. Neptune. The sun is a hot ball - the closest star to the Earth.

"Ecology of the planet" - Formation of ecology into an independent branch of knowledge. Stages of interaction between human society and nature. Abiotic factors of the aquatic environment. Biological capacity of the medium. Age structure. Categories of living matter in the biosphere. Abiotic factors of the terrestrial environment. System laws of ecology. Laws of ecology B. Commoner.

"Planets and their satellites" - Inner 10 moons - small in size. A huge number of craters have been discovered on the surface of Titania. Iapetus. Pluto is rightly called a double planet. The crater Eratosthenes with a diameter of 61 km was formed relatively recently. Therefore, the Moon either does not have, or has a very insignificant iron core. From one upper climax to the next, 130 hours pass - more than five days.

The world of flora is diverse. We are surrounded by flowers, shrubs, trees, herbs of many shades, but green is predominant in the color scheme. But why are plants green?

Causes of green color

Plants are rightly called the lungs of the planet. By processing harmful carbon dioxide, they give oxygen to humanity and the environment. This process is called photosynthesis, and the pigment responsible for it is chlorophyll.

It is thanks to chlorophyll molecules that inorganic substances turn into organic ones. The most important of them is oxygen, but at the same time, in the process of photosynthesis, plants produce proteins, sugar, carbohydrates, fats, and starch.

It is known from the school curriculum that the beginning of a chemical reaction is the exposure of a plant to sunlight or artificial light. Chlorophyll absorbs not all light waves, but only a certain wavelength. This happens most quickly from red to blue-violet.

Green is not absorbed by plants, but reflected. This is what is visible to the eyes of a person, therefore, the representatives of the flora around us are green.

Why the green color?

For quite a long time, scientists struggled with the question: why is the green spectrum reflected? As a result, it turned out that nature simply does not waste energy in vain, because this smallest particle of light - photos of this color do not have any outstanding qualities, while blue photons are sources of useful energy, red ones contain the largest amount. How can one not remember that nothing in nature is done just like that.

Where do the bright colors come from in plants?

Biologists say with confidence that plants originated from something similar to algae, and chlorophyll appeared under the influence of evolutionary processes.

In nature, other colors change under the influence of light. When it becomes smaller, the leaves and stems begin to die off. Chlorophyll, responsible for the bright green color, breaks down. It is replaced by other pigments responsible for bright colors. Red and yellow leaves indicate that carotene has become predominant. The pigment xanthosine is also responsible for the yellow color. If it is impossible to find a green color in a plant, that is the “fault” of anthocyanins.

Works of scientists about photosynthesis and chlorophyll

How was photosynthesis discovered?

The discovery of the process of converting carbon dioxide into oxygen happened by accident and was made by the English chemist Joseph Priestley. The scientist was looking for a way to clean the "spoiled air" (as carbon dioxide was called at that time). And during the experiments, under a glass cap, instead of a mouse and a candle, a plant was sent, which, contrary to expectations, survived. The next step was to plant a mouse in a flower pot. And a miracle happened - the animal did not die from suffocation. So it was concluded that it is possible to convert carbon dioxide into oxygen.

Much attention and much time was devoted to the role of chlorophyll and the process of photosynthesis by the Russian naturalist Kliment Arkadyevich Timiryazev. His main scientific achievements:

• proof of the extension of the law of conservation of energy to the process of photosynthesis, which was denied by Western researchers;
• establishing the fact that only light rays absorbed by the plant participate in photosynthesis.

Works by K.A. Timiryazev laid a solid foundation for the study of the transformation of water and carbon dioxide into organic useful substances under the influence of light. Now science has stepped far forward, some studies have undergone changes (for example, the fact that a light beam decomposes not carbon dioxide, but water), but it is safe to say that it was he who studied the basics. The book “Plant Life” will allow you to get acquainted with the work of a scientist - these are fascinating and informative facts about the nutrition, growth, development and reproduction of green plants.

Photosynthesis and chlorophyll are closely related when it comes to why plants are green. A light beam has several spectra, some of which are absorbed and participate in the chemical process of converting carbon dioxide into oxygen. Green is reflected and gives its color to the leaves and stems - and this is visible to the human eye.

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There is a journalistic stamp that the forest is the lungs of planet Earth. But then what about the data of science, which suggests that the oxygen atmosphere arose on our planet long before photosynthesis?

In fact, plants on both land and oceans produce about as much oxygen during photosynthesis as they then consume themselves in the process of respiration.

Initially, the Earth's atmosphere had a generally reducing character: methane + ammonia + water + carbon dioxide.

The earth's crust should also have had a restorative character, since it was in equilibrium with the atmosphere.

And today we have that the atmosphere contains 20% free oxygen, and most of the rocks are completely oxidized and the system is in a state of equilibrium (the composition of the atmosphere has not changed significantly for several hundred million years).

In order to oxidize the entire primary atmosphere and lithosphere, a huge amount of free oxygen is needed.

The balances don't match

According to the generally accepted hypothesis, it is believed that living organisms are responsible for the release of oxygen.

But they are not suitable for this role, because despite the fact that plants emit a significant amount of oxygen per unit time, but in general the biosphere is quite stable - the circulation of substances takes place in it. The release of free oxygen can only be achieved through the accumulation of undecomposed residues (mainly in the form of coal). In other words:
H2O + CO2 = biomass(C + O + H) + O2 + C + CH4.

Given that the current biomass is small compared to the mass of even free oxygen in the atmosphere (it is approximately a hundred times less), we get that in order to form all atmospheric and lithospheric (for the oxidation of the primary lithosphere) oxygen, it is necessary that somewhere in the Earth are stored would be similar in mass reserves of coal and hydrocarbons - and this is a layer of several meters only for atmospheric oxygen, and for lithospheric oxygen it is orders of magnitude larger. No such reserves are observed (inferred reserves of coal and other hydrocarbons approximate the total biomass).
So, we obviously don't have balances.

In the bright sun

Note that another source of oxygen is the dissociation of water molecules under the action of solar radiation.

As is known, the velocity of molecules in a gas obeys the Maxwell distribution. According to this distribution, there is always a certain fraction of molecules whose speed exceeds the second cosmic one. And such molecules can freely leave the Earth. Moreover, light gases, hydrogen and helium, escape first of all from the atmosphere. Calculations show that the time of complete volatilization of hydrogen from the earth's atmosphere is only a few years. However, hydrogen is still present in the atmosphere. Why? For oxygen and other gases, this time exceeds the lifetime of the Earth. million years. In the earth's atmosphere, hydrogen and helium are constantly renewed due to the supply from the earth's interior and a number of atmospheric processes. Hydrogen, which forms a "corona" around the Earth, is a product of the dissociation of water molecules under the influence of ultraviolet and X-ray radiation from the Sun.

Calculations show that over a period of about ten million years, an amount of oxygen equal to the current value arises in the atmosphere due to photodissociation.

So we get:
1) Initially, the atmosphere, lithosphere and the entire mantle of the Earth are of a restorative nature.
2) Due to photodissociation, water (which, by the way, came from the mantle as a result of volcanic activity) decomposes into oxygen and hydrogen. The last one leaves the Earth.
3) The remaining oxygen oxidizes the primary lithosphere and atmosphere to the current state.
4) Why doesn’t oxygen accumulate, because it is constantly supplied as a result of photodissociation (the current amount accumulates over 10 million years, and the age of the Earth is 4.5 billion)? It goes to the oxidation of the mantle. As a result of the movement of continents in subduction zones, a new crust is formed from the mantle. The rocks of this crust are oxidized under the action of the atmosphere and hydrosphere. These oxidized rocks from oceanic plates in subduction zones are then fed back into the mantle.

Extras of the universe

But what about living organisms, you ask? They actually play the role of extras - there was no free oxygen, they lived without it - at a primitive unicellular level. Appeared - adapted and began to live with him - but already in the form of advanced multicellular organisms.

So whether there will be forests on Earth or not, this will not affect the oxygen content in the planet's atmosphere. Another thing is that the forest cleans the air of dust, saturates it with phytoncides, gives shelter and food to many animals and birds, gives people aesthetic pleasure ... But calling the forest “green lungs” is at least illiterate.

There is a misconception that has even entered textbooks, that forests are the lungs of the planet. Forests actually produce oxygen, while lungs consume it. So it's more like an "oxygen cushion". So why is this statement false? In fact, oxygen is produced not only by those plants that grow in the forest. All plant organisms, including the inhabitants of water bodies, and the inhabitants of the steppes, deserts constantly produce oxygen. Plants, unlike animals, fungi and other living organisms, can themselves synthesize organic substances using light energy for this. This process is called photosynthesis. As a result of photosynthesis, oxygen is released. It is a by-product of photosynthesis. Oxygen is released very, very much, in fact, 99% of the oxygen that is present in the Earth's atmosphere of plant origin. And only 1% comes from the mantle, the underlying layer of the Earth.

Of course, trees produce oxygen, but no one thinks about the fact that they also spend it. And not only them, all other inhabitants of the forest cannot be without oxygen. First of all, plants breathe on their own, this happens in the dark when photosynthesis does not occur. And you need to somehow dispose of the stocks of organic matter that they created during the day. That is, to eat. And in order to eat, you need to spend oxygen. Another thing is that plants spend much less oxygen than they produce. And this is ten times less. However, do not forget that there are still animals in the forest, as well as fungi, as well as various bacteria that do not produce oxygen themselves, but nevertheless breathe it. A significant amount of oxygen that the forest produced during the daylight hours will be used by the living organisms of the forest to support life. However, something will remain. And this is something about 60% of what the forest produces. This oxygen enters the atmosphere, but does not remain there for very long. Further, the forest itself withdraws oxygen, again for its own needs. Namely, the decomposition of the remains of dead organisms. In the end, the forest often spends 1.5 times more oxygen on the disposal of its own waste than it produces. It is impossible to call it the oxygen factory of the planet after that. True, there are forest communities that work on a zero oxygen balance. These are famous tropical forests.

The rainforest is generally a unique ecosystem, it is very stable, because the consumption of matter is equal to production. But again, there is no surplus left. So even tropical forests can hardly be called oxygen factories.

So why, then, after the city it seems to us that the forest has clean, fresh air, that there is a lot of oxygen there? The thing is that the production of oxygen is a very fast process, but the consumption is a very slow process.

So what then are the planet's oxygen factories? In fact, these are two ecosystems. Among the "terrestrial" are peat bogs. As we know, in a swamp, the process of decomposition of dead matter is very, very slow, as a result of which the dead parts of plants fall down, accumulate, and peat deposits are formed. Peat does not decompose, it is compressed and remains in the form of a huge organic brick. That is, during peat formation, a lot of oxygen is not wasted. Thus, marsh vegetation produces oxygen, but oxygen itself consumes very little. As a result, it is the swamps that give exactly the increase that remains in the atmosphere. However, there are not so many real peat bogs on land, and of course it is almost impossible for them alone to maintain the oxygen balance in the atmosphere. And here another ecosystem, which is called the world ocean, helps.

There are no trees in the oceans, grasses in the form of algae are observed only near the coast. However, vegetation in the ocean still exists. And most of it is made up of microscopic photosynthetic algae, which scientists call phytoplankton. These algae are so small that it is often impossible to see each of them with the naked eye. But the accumulation of them is visible to all. When bright red or bright green spots are visible on the sea. This is what phytoplankton is.

Each of these little algae produces huge amounts of oxygen. She consumes very little. Due to the fact that they are intensively dividing, the amount of oxygen produced by them is growing. One phytoplankton community produces 100 times more per day than a forest occupying such a volume. But at the same time they spend very little oxygen. Because when the algae die, they immediately fall to the bottom, where they are immediately eaten. After that, those who ate them are eaten by other, third organisms. And so few remains reach the bottom that they quickly decompose. There is simply no such long decomposition as in the forest, in the ocean. There, recycling is very fast, as a result of which oxygen is actually not wasted. And so there is a "big profit", and that's it stays in the atmosphere. So the "lungs of the planet" should not be considered forests at all, but the oceans. It is he who makes sure that we have something to breathe.