There is an opinion that " lungs of the planet"are forests, because it is believed that they are the main suppliers of oxygen to the atmosphere. However, in reality this is not so. The main producers of oxygen live in the ocean. These babies cannot be seen without the help of a microscope. But all living organisms on Earth depend on their vital activity.
No one argues that forests, of course, need to be preserved and protected. However, not at all due to the fact that they are these notorious “lungs”. Because in fact, their contribution to the enrichment of our atmosphere with oxygen is practically zero.
No one will deny the fact that the oxygen atmosphere of the Earth was created and continues to be maintained by plants. This happened because they learned to create organic matter from inorganic materials, using energy sunlight(as we remember from school course biology, a similar process is called photosynthesis). As a result of this process, plant leaves release free oxygen as a by-product of production. This gas we need rises into the atmosphere and is then evenly distributed throughout it.
According to various institutes, thus, about 145 billion tons of oxygen are released into the atmosphere on our planet every year. At the same time most it is spent, not surprisingly, not on the breathing of the inhabitants of our planet, but on the decomposition of dead organisms or, simply put, on decay (about 60 percent of what is used by living beings). So, as you can see, oxygen not only gives us the opportunity to breathe deeply, but also acts as a kind of stove for burning garbage.
As we know, any tree is not eternal, so when the time comes, it dies. When the trunk of a forest giant falls to the ground, its body is decomposed by thousands of fungi and bacteria over a very long period of time. All of them use oxygen, which is produced by surviving plants. According to researchers' calculations, such "cleaning up" takes about eighty percent of the "forest" oxygen.
But the remaining 20 percent of oxygen does not enter the “general atmospheric fund” at all, and is also used by forest inhabitants “on the ground” for their own purposes. After all, animals, plants, fungi and microorganisms also need to breathe (without oxygen, as we remember, many living beings would not be able to obtain energy from food). Since all forests are usually very densely populated areas, this residue is only enough to satisfy the oxygen needs of only its own inhabitants. There is nothing left for neighbors (for example, residents of cities where there is little native vegetation).
Who, then, is the main supplier of this gas necessary for breathing on our planet? On land these are, oddly enough... peat bogs. Everyone knows that when plants die in a swamp, their organisms do not decompose, since the bacteria and fungi that do this work cannot live in swamp water - there are many natural antiseptics secreted by mosses.
So, dead parts of plants, without decomposing, sink to the bottom, forming peat deposits. And if there is no decomposition, then oxygen is not wasted. Therefore, swamps contribute about 50 percent of the oxygen they produce to the general fund (the other half is used by the inhabitants of these inhospitable, but very useful places).
Nevertheless, the contribution of swamps to the total " charitable foundation oxygen" is not very large, because there are not so many of them on Earth. Microscopic ocean algae, the totality of which scientists call phytoplankton, are much more actively involved in "oxygen charity". These creatures are so small that with the naked eye they are almost impossible to see. However, their total quantity very large, the number goes into millions of billions.
The entire world's phytoplankton produces 10 times more oxygen than it needs to breathe. Enough to provide useful gas to all other inhabitants of the waters, and quite a lot ends up in the atmosphere. As for the oxygen consumption for the decomposition of corpses, in the ocean they are very low - approximately 20 percent of the total production.
This happens due to the fact that dead organisms are immediately eaten by scavengers, which sea water a great multitude live. Those, in turn, will be eaten by other scavengers after death, and so on, that is, corpses almost never lie in the water. The same remains that no one can imagine anymore special interest, fall to the bottom, where few people live, and there is simply no one to decompose them (this is how the well-known silt is formed), that is, in in this case oxygen is not consumed.
So, the ocean supplies the atmosphere with about 40 percent of the oxygen that phytoplankton produced. It is this reserve that is consumed in those areas where very little oxygen is produced. The latter, in addition to cities and villages, include deserts, steppes and meadows, as well as mountains.
So, oddly enough, the human race lives and thrives on Earth precisely due to the microscopic “oxygen factories” floating on the surface of the ocean. It is they who should be called “the lungs of the planet.” And protect in every possible way from oil pollution, heavy metal poisoning, etc., because if they suddenly stop their activities, you and I will simply have nothing to breathe.
The marked increase in free oxygen in the Earth's atmosphere 2.4 billion years ago appears to have been the result of a very quick transition from one equilibrium state to another. The first level corresponded to an extremely low concentration of O 2 - about 100,000 times lower than what is observed now. The second equilibrium level could have been achieved at a higher concentration, no less than 0.005 of the modern one. The oxygen content between these two levels is characterized by extreme instability. The presence of such “bistability” makes it possible to understand why there was so little free oxygen in the Earth’s atmosphere for at least 300 million years after cyanobacteria (blue-green “algae”) began to produce it.
Currently, the Earth's atmosphere consists of 20% free oxygen, which is nothing more than a by-product of photosynthesis by cyanobacteria, algae and higher plants. A lot of oxygen is released by tropical forests, which in popular publications are often called the lungs of the planet. At the same time, however, it is silent that during the year tropical forests consume almost as much oxygen as they produce. It is spent on the respiration of organisms that decompose finished organic matter - primarily bacteria and fungi. For that, In order for oxygen to begin to accumulate in the atmosphere, at least part of the substance formed during photosynthesis must be removed from the cycle- for example, get into bottom sediments and become inaccessible to bacteria that decompose it aerobically, that is, with the consumption of oxygen.
The total reaction of oxygenic (that is, “giving oxygen”) photosynthesis can be written as:
CO 2 + H 2 O + hν→ (CH 2 O) + O 2,
Where hν is the energy of sunlight, and (CH 2 O) is the generalized formula of organic matter. Breathing is the reverse process, which can be written as:
(CH 2 O) + O 2 → CO 2 + H 2 O.
At the same time, the energy necessary for organisms will be released. However, aerobic respiration is possible only at an O 2 concentration of no less than 0.01 of modern level(the so-called Pasteur point). Under anaerobic conditions, organic matter decomposes through fermentation, and the final stages of this process often produce methane. For example, the generalized equation for methanogenesis through acetate formation looks like:
2(CH 2 O) → CH 3 COOH → CH 4 + CO 2.
If we combine the process of photosynthesis with the subsequent decomposition of organic matter under anaerobic conditions, then the overall equation will look like:
CO 2 + H 2 O + hν→ 1/2 CH 4 + 1/2 CO 2 + O 2.
It was precisely this path of decomposition of organic matter that apparently was the main one in the ancient biosphere.
Many important details How the modern balance between the supply of oxygen to the atmosphere and its removal was established remains unclear. After all, a noticeable increase in oxygen content, the so-called “Great Oxidation of the Atmosphere,” occurred only 2.4 billion years ago, although it is known for sure that cyanobacteria carrying out oxygenic photosynthesis were already quite numerous and active 2.7 billion years ago, and they arose even earlier - perhaps 3 billion years ago. Thus, within for at least 300 million years, the activity of cyanobacteria did not lead to an increase in oxygen content in the atmosphere.
The assumption that, for some reason, there suddenly occurred a radical increase in net primary production(that is, the increase in organic matter formed during the photosynthesis of cyanobacteria) did not stand up to criticism. The fact is that during photosynthesis, the light isotope of carbon 12 C is predominantly consumed, and in the environment the relative content of the heavier isotope 13 C increases. Accordingly, bottom sediments containing organic matter must be depleted in the isotope 13 C, which accumulates in water and goes for the formation of carbonates. However, the ratio of 12 C to 13 C in carbonates and in organic matter of sediments remains unchanged despite radical changes in the concentration of oxygen in the atmosphere. This means that the whole point is not in the source of O 2, but in its, as geochemists put it, “sink” (removal from the atmosphere), which suddenly decreased significantly, which led to a significant increase in the amount of oxygen in the atmosphere.
It is usually believed that immediately before the “Great Oxidation of the Atmosphere,” all the oxygen then formed was spent on the oxidation of reduced iron compounds (and then sulfur), which were quite abundant on the Earth’s surface. In particular, then the so-called “banded iron ores" But recently Colin Goldblatt, a graduate student in the School of Environmental Sciences at the University of East Anglia (Norwich, UK), together with two colleagues from the same university, came to the conclusion that the oxygen content in earth's atmosphere could be one of two things equilibrium states: it can be either very small - about 100 thousand times less than now, or already quite a lot (although from the position of a modern observer it is small) - no less than 0.005 from the modern level.
In the proposed model, they took into account the entry into the atmosphere of both oxygen and reduced compounds, in particular paying attention to the ratio of free oxygen and methane. They noted that if the oxygen concentration exceeds 0.0002 of the current level, then some of the methane can already be oxidized by methanotroph bacteria according to the reaction:
CH 4 + 2O 2 → CO 2 + 2H 2 O.
But the rest of the methane (and there is quite a lot of it, especially at low oxygen concentrations) enters the atmosphere.
The entire system is in a nonequilibrium state from the point of view of thermodynamics. The main mechanism for restoring the disturbed equilibrium is the oxidation of methane into upper layers atmosphere by hydroxyl radical (see Fluctuations of methane in the atmosphere: man or nature - who wins, "Elements", 10/06/2006). The hydroxyl radical is known to be formed in the atmosphere under the influence of ultraviolet radiation. But if there is a lot of oxygen in the atmosphere (at least 0.005 of the current level), then an ozone screen is formed in its upper layers, which well protects the Earth from hard ultraviolet rays and at the same time interfering with the physicochemical oxidation of methane.
The authors come to the somewhat paradoxical conclusion that the mere existence of oxygenic photosynthesis is not sufficient condition neither for an oxygen-rich atmosphere to form nor for an ozone shield to arise. This circumstance should be taken into account in cases where we are trying to find signs of the existence of life on other planets based on the results of a survey of their atmosphere.
Amphipods from the genus Phronimus - one of the inhabitants of the ocean
Biologists and oceanographers have published the results of the largest and most meticulous study of a miniature sea life for the whole scientific history. The 3.5-year mission took place on the Tara ship. During this time, the researchers covered 140,000 kilometers and took 35,000 plankton samples in 210 different places in the world's oceans. One of interesting results The study identified the role of plankton in supplying the planet with oxygen. published in the journal Science. 
During the journey, they had to spend 10 days encased in Arctic ice, overcome storms in the Mediterranean Sea and the Strait of Magellan, and pass the Gulf of Aden under the protection of ships of the French fleet, which protected them from pirates. The main purpose of the study was to study the spread various types organisms, their interactions with each other and transmission genetic information. About 40 million previously unknown plankton genes were found and recorded.
Research vessel route
By studying a variety of small flora and fauna (plankton includes microscopic plants and animals, fish eggs, bacteria, viruses and other microorganisms), scientists have determined that this is not only the beginning food chain for larger animals.
Tara
“Plankton is more than just food for whales,” says Chris Bowler, director of research at the French state center scientific research. “Being tiny, these organisms are an essential part of the life support system on Earth. They are at the base of the food chain and also produce 50% of our oxygen through photosynthesis.” In addition, plankton absorb carbon dioxide and convert it into organic carbon.
And what doesn’t get into the network?
According to researchers, every sip of seawater contains about 200 million viruses, the main prey of which are the 20 million bacteria that can be found there. Scientists were also very interested in the fact that the diversity of plankton is much greater than previously thought, while the diversity of viruses turned out to be less than expected.
Various babies
It has been established that the interaction different types plankton is regulated by water temperature, and when two currents meet different temperatures Plankton colonies do not mix with each other. It was also possible to prove the previously stated hypothesis that viruses appear in a limited number of places in the ocean and are then carried by ocean currents.
Plankton catching / Reuters
Understanding the processes occurring in the plankton world will help, in particular, to refine predictive models of climate change.
Sources of oxygen on the planet and in the city of Moscow. Brief overview. August 17th, 2010
Currently, the atmosphere contains about (1.2-2.0) * 10 + 15 tons of oxygen. As a result of photosynthesis, green plants annually produce on land (0.7-1.0) * 1011 tons of this gas necessary for life. Over the same period, the world ocean produces about 4.0 * 1011 t 02. Significant amount oxygen is used in the respiration processes of heterotrophic organisms. The rate of oxygen consumption in these processes is approximately 0.22*1011 t/year.
Another source of oxygen in the atmosphere - the process of photodissociation of water molecules - has little effect on the balance of this gas, since approximately 2 * 10 + 6 tons of 02 are formed annually in this way.
The main supplier of oxygen is plants. Plants absorb 170 billion tons from the atmosphere each year through photosynthesis. carbon dioxide, releasing oxygen. The mystery of converting it into organic matter occurs in living cells with the help of chlorophyll and light. The main component of this process is photolysis of water. During it from water molecules under the influence of energy sun rays Oxygen is released, and hydrogen goes to reduce carbon dioxide.
It is believed that plants create up to 100 billion tons of organic matter annually. At the same time, they consume 130 billion tons of water, and 115 billion tons of oxygen are released from it.
Two thirds of the resulting organic mass comes from terrestrial plants and a third from plankton and algae. Of what grows on the ground, again two-thirds are forest products.
The quiet forest is a big worker. It is estimated that one hectare of good tree stand (foresters have such a term) absorbs up to six and a half tons of carbon dioxide annually and releases up to 5 tons of oxygen - as much as a large village needs to breathe clean air. In this sense, not a single man-made oxygen factory (and it would undoubtedly aggravate further pollution environment!) cannot be compared with good wood.
Performance for everyone tree species varies depending on age. Let's say, a hectare of pine forest at the age of 20 absorbs 9 tons of carbon dioxide per year, and at 60 years old - 13. This means that mid-season pine forests are the most productive green "factories" clean air, namely, they are the ones who fall under the saw and ax in the first place.
U different trees- its own productive force. Let's say, if a hectare of spruce forest is taken as 100 percent in terms of its ability to absorb carbon dioxide, then a birch, aspen and any other deciduous grove gives 120 percent, pine forest- 150, linden park - - 250, oak grove - 450 percent, etc.
But our ordinary poplar is a truly unique air orderly. In the health field, he alone can replace three linden trees or four pine trees, seven spruce trees.
Calculations carried out by scientists for the forests of the Amazon basin (and this is the largest massif tropical forests on Earth) have shown that in wetter years the production of organic matter exceeds its decomposition, so that more oxygen is released than consumed. And in drier conditions, on the contrary, decomposition proceeds more intensely than the creation of a new substance, and, accordingly, more oxygen is consumed than released. On average, over a ten-year period, these processes are balanced.
Free oxygen can accumulate in the atmosphere only if an equivalent amount of formed organic matter is removed from the cycle. In other words, it becomes inaccessible to the influence of fungi, bacteria and animals.
Reserves of coal, peat, oil - all this organic matter ended up buried in sediments, and the oxygen that was once released during its formation remained in the atmosphere. Places where it is removed from the cycle large number organic matter still exist. These are, for example, peat bogs, which Russia is so rich in.If by “lungs” we mean an organ that supplies the body with oxygen and removes carbon dioxide from it, then the “lungs of the planet” are primarily swamps.
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“There will be more greenery in Moscow,” the capital’s Department of Environmental Protection promised KP. - There is a general plan for landscaping Moscow until 2020. And in 11 years, for every Muscovite there will be 26 square meters green spaces.
The plans are impressive. 23% of the land currently occupied by industrial zones and small rivers, whose banks are washed out and littered, want to be planted with trees. Where there were fences, they plan to create parks and squares. Only... it’s hard to believe. I have seen many times how shopping complexes are built on the site of public gardens. Before my eyes they defaced the Druzhba park near the station. metro station "Rechnoy Vokzal" But I’ve never seen the new park! When a site suddenly becomes vacant in Moscow, an elite building, a store or an office is immediately installed on it. Maybe because an official can always get a considerable kickback for a construction site? What will you get for the square? Residents won’t chip in and don’t bring anything. This means there will be no harm for them...
There is an opinion that forests are the “lungs of the planet”, since it is believed that they are the main suppliers of oxygen to the atmosphere. However, in reality this is not the case. The main producers of oxygen live in the ocean. These babies cannot be seen without the help of a microscope. But all living organisms on Earth depend on their livelihoods.
No one argues that forests, of course, need to be preserved and protected. However, not at all due to the fact that they are these notorious “lungs”. Because in fact, their contribution to the enrichment of our atmosphere with oxygen is practically zero.
No one will deny the fact that the oxygen atmosphere of the Earth was created and continues to be maintained by plants. This happened because they learned to create organic substances from inorganic ones, using the energy of sunlight (as we remember from the school biology course, a similar process is called photosynthesis). As a result of this process, plant leaves release free oxygen as a by-product of production. This gas we need rises into the atmosphere and is then evenly distributed throughout it.
According to various institutes, thus, about 145 billion tons of oxygen are released into the atmosphere on our planet every year. Moreover, most of it is spent, not surprisingly, not on the respiration of the inhabitants of our planet, but on the decomposition of dead organisms or, simply put, on decay (about 60 percent of that used by living beings). So, as you can see, oxygen not only gives us the opportunity to breathe deeply, but also acts as a kind of stove for burning garbage.
Read also: The winter-summer air conditioner on Earth has broken downAs we know, any tree is not eternal, so when the time comes, it dies. When the trunk of a forest giant falls to the ground, its body is decomposed by thousands of fungi and bacteria over a very long period of time. All of them use oxygen, which is produced by surviving plants. According to researchers' calculations, such "cleaning up" takes about eighty percent of the "forest" oxygen.
But the remaining 20 percent of oxygen does not enter the “general atmospheric fund” at all, and is also used by forest inhabitants “on the ground” for their own purposes. After all, animals, plants, fungi and microorganisms also need to breathe (without oxygen, as we remember, many living beings would not be able to obtain energy from food). Since all forests are usually very densely populated areas, this residue is only enough to satisfy the oxygen needs of only its own inhabitants. There is nothing left for neighbors (for example, residents of cities where there is little native vegetation).
Who, then, is the main supplier of this gas necessary for breathing on our planet? On land these are, oddly enough... peat bogs. Everyone knows that when plants die in a swamp, their organisms do not decompose, since the bacteria and fungi that do this work cannot live in swamp water - there are many natural antiseptics secreted by mosses.
Nevertheless, the contribution of swamps to the general “charitable oxygen fund” is not very large, because there are not so many of them on Earth. Microscopic ocean algae, the totality of which scientists call phytoplankton, are much more actively involved in “oxygen charity”. These creatures are so small that it is almost impossible to see them with the naked eye. However, their total number is very large, amounting to millions of billions.So, dead parts of plants, without decomposing, sink to the bottom, forming peat deposits. And if there is no decomposition, then oxygen is not wasted. Therefore, swamps contribute about 50 percent of the oxygen they produce to the general fund (the other half is used by the inhabitants of these inhospitable, but very useful places).
The entire world's phytoplankton produces 10 times more oxygen than it needs to breathe. Enough to provide useful gas to all other inhabitants of the waters, and quite a lot ends up in the atmosphere. As for the oxygen consumption for the decomposition of corpses, in the ocean they are very low - approximately 20 percent of the total production.
This happens due to the fact that dead organisms are immediately eaten by scavengers, of which there are a great many living in sea water. Those, in turn, will be eaten by other scavengers after death, and so on, that is, corpses almost never lie in the water. The same remains, which are no longer of particular interest to anyone, fall to the bottom, where few people live, and there is simply no one to decompose them (this is how the well-known silt is formed), that is, in this case, oxygen is not consumed.
So, the ocean supplies the atmosphere with about 40 percent of the oxygen that phytoplankton produced. It is this reserve that is consumed in those areas where very little oxygen is produced. The latter, in addition to cities and villages, include deserts, steppes and meadows, as well as mountains.
So, oddly enough, the human race lives and thrives on Earth precisely due to the microscopic “oxygen factories” floating on the surface of the ocean. It is they who should be called “the lungs of the planet.” And protect in every possible way from oil pollution, heavy metal poisoning, etc., because if they suddenly stop their activities, you and I will simply have nothing to breathe.
