The main cause of the destruction of the ozone layer. The ozone layer, the causes and consequences of its destruction, acid rain, toxic fogs

F and in and i o b o l o h to a h e m l and

Everywhere on Earth, wherever you look, life dominates. Plants and animals can be found everywhere. And how many more organisms that are not visible to the naked eye! The simplest unicellular animals and microscopic algae, numerous fungi, bacteria, viruses...

In our time, up to 500 thousand plant species and about 1.5 million animal species are known. But far from all species have been discovered and described. And if you imagine how many individuals each species has! .. Try to count the number of firs in the taiga, or dandelions in a meadow, or ears of corn in one wheat field ... How many ants live in one anthill, how many crustaceans of cyclops or daphnia in one puddle, how many squirrels are in the forest, how many pikes, perches or roaches are in one lake?.. And truly fabulous numbers are obtained when trying to count microorganisms.

Yes, in1 gram forest soil, on average, there are:

bacteria -400,000,000,

mushrooms - 2,000,000,

algae - 100,000,

protozoa - 10,000.

Microbiologists at the University of Georgia believe that on Earth there are only 5,000,000,000,000,000,000,000,000,000,000 (5 nonillion) bacteria . This amounts to 70% of the mass of all life on the planet.

All this innumerable multitude of living beings is placed not chaotically and randomly, but strictly naturally, in a certain order, according to the laws of life historically established on Earth. Here is what the American biologist K. Willy writes about this: “At first glance, it may seem that the world of living beings consists of an unimaginable multitude of plants and animals that are different from each other and each go their own way. However, a more detailed study shows that all organisms, both plant and animal, have the same basic vital needs, they face the same problems: obtaining food as a source of energy, conquering living space, reproduction, etc. In the course of solving these problems, plants and animals have formed a huge variety of different forms, each of which is adapted to life in given environmental conditions. Each form has adapted not only to the physical conditions of the environment - it has acquired resistance to fluctuations within certain limits of humidity, wind, lighting, temperature, gravity, etc., but also to the biotic environment - to all plants and animals living in the same zone.

Regularly distributed on Earth, the totality of organisms forms a living shell of our planet - the biosphere. The merit in developing the concept of "biosphere" and clarifying its planetary role belongs to the Russian academician V. I. Vernadsky, although the term itself was used at the end of the last century. What is the biosphere and why is it so important?

The surface parts of the Earth consist of three mineral, inorganic shells: the lithosphere is the hard stone shell of the Earth; hydrosphere - a liquid, non-continuous shell, including all the seas, oceans and inland waters - the World Ocean; atmosphere is a gaseous shell.

The entire hydrosphere, the upper parts of the lithosphere and the lower layers of the atmosphere are inhabited by animals and plants. The modern biosphere was formed in the process of origin and further historical development of living matter. From the time of the origin of life on Earth, according to various estimates, from 1.5-2.5 to 4.2 billion years have passed. V. I. Vernadsky came to the conclusion that during this time all the outer layers of the earth's crust were processed by the vital activity of organisms by 99 percent. Therefore, the Earth as we perceive it, on which we live, is largely a product of the activity of organisms.

Life, having arisen on Earth as a result of the natural development of matter, over the course of many millions of years of its existence in the form of various organisms has changed the face of our planet.

All organisms in the biosphere together form a biomass, or "living matter", with powerful energy that changes the earth's crust and atmosphere. The total weight of the plant mass is about 10,000 billion, and the animal mass is about 10 billion tons, which is approximately 0.01 percent of the weight of the entire biosphere with its solid, liquid and gaseous habitats. It is estimated that the biomass of all living creatures that inhabited the Earth, about a billion years after the appearance of life, would have to be many times greater than the mass of our planet. But that did not happen.

Why doesn't biomass accumulate significantly? Why is it kept at a certain level? After all, biomass as a living matter tends to continuous development, improvement and constant accumulation in the process of this development, in the process of reproduction and growth of living beings.

And this does not happen because each element from which the body of an organism is built is perceived from the environment, and then through a number of other organisms again returns to the surrounding, inorganic environment, from which it again enters the composition of living matter, biomass. Consequently, each element that is part of living matter is used by it many times.

However, this should not be taken in an absolute sense. On the one hand, some part of the elements leaves the circulation of substances, since the Earth itself accumulates organic compounds in the form of deposits of coal, oil, peat, oil shale, etc. On the other hand, a person can ensure a more intensive process of biomass accumulation, which is manifested in a continuous increase in crop yields and productivity of domestic animals.

But all this by no means rejects the general rule. Essentially, the biomass on Earth still does not accumulate, but is constantly kept at a certain level, although this level is not absolute and constant. This happens because the biomass is continuously destroyed and re-created from the same building material, within its boundaries there is an uninterrupted circulation of substances. V. I. Vernadsky writes: “Life captures a significant part of the atoms that make up the matter of the earth's surface. Under its influence, these atoms are in continuous intensive motion. Of these, millions of diverse compounds are being created all the time. And this process continues without interruption for tens of millions of years, from the most ancient Archeozoic eras to our time. There is no chemical force on the earth's surface that is more constantly active, and therefore more powerful in its final consequences, than living organisms taken as a whole.

This cycle, which takes place as a result of the vital activity of organisms, is called the biological cycle of substances. It took on a modern character with the advent of green plants that carry out the process of photosynthesis. Since that time, the conditions for the evolution of living matter on Earth have acquired a completely different character.

The course of the circulation of substances can be briefly considered using the example of carbon, the atoms of which are part of a complex protein molecule. It is with the protein molecule that life and metabolism are connected.

Over each hectare of the Earth contains up to 2.5 tons of carbon in the composition of carbon dioxide (CO2). Calculations have shown that, for example, sugarcane crops per hectare absorb up to 8 tons of carbon, which is used to build the body of these plants. As a result, green plants have used

Would be the whole stock of carbon. But this does not happen, because organisms release significant amounts of carbon dioxide during respiration. And even more carbon is released by putrefactive bacteria and fungi, destroying carbon compounds contained in the dead bodies of animals and plants. Some part of the carbon nevertheless leaves the sphere of "circulation", being deposited in the form of deposits of oil, coal, peat, etc., into which dead plants and animals turn. But this loss of carbon is compensated by the destruction of rock carbonates, and in modern conditions also by the burning of a huge amount of extracted fuel. As a result, carbon seems to be constantly flowing from the atmosphere through green plants, animals, micro organisms back into the atmosphere. Thus, the total carbon stocks in the biosphere remain approximately constant. It can be assumed with a high degree of certainty that almost every carbon atom in the biosphere since the emergence of life on Earth has repeatedly been part of living matter, passed into atmospheric carbon dioxide and again returned to the composition of living matter, biomass.

In modern conditions, carbon in the process of the biological cycle of substances goes through the following stages: 1) green plants, creators of organic matter, absorb carbon from the atmosphere and introduce it into their bodies; 2) animals, or consumers, feeding on plants, build carbon compounds of their body from their carbon compounds; 3) bacteria, as well as some other organisms, or destroyers, destroy the organic matter of dead plants and animals and release carbon, which again escapes into the atmosphere as carbon dioxide.

Nitrogen is another important constituent of amino acids and biomass proteins. The source of nitrogen on Earth is nitrate, which is absorbed by plants from soil and water. Animals, eating plants, synthesize their protoplasm from the amino acids of plant proteins. Putrefactive bacteria convert the nitrogen compounds of the dead bodies of these organisms into ammonia. Nitrifying bacteria then convert the ammonia into nitrites and nitrates. Part of the nitrogen is returned to the atmosphere by denitrifying bacteria. But on Earth, in the process of evolution of living matter, organisms appeared capable of binding free nitrogen and converting it into organic compounds. These are some blue-green algae, soil, as well as nodule bacteria, along with legume root cells. When these organisms die, the nitrogen of their body is converted by nitrifying bacteria into salts of nitric acid.

A similar cycle is carried out by water, phosphorus, and many other substances that are part of living matter and the mineral shells of the biosphere. As a result, all elements, with rare exceptions, are involved in the activity of the living substance of the biosphere in the most grandiose in scale, continuously moving flow - the biological cycle of substances . "The cessation of life would inevitably be associated with the cessation of chemical changes, if not the entire earth's crust, then at least its surface - the face of the Earth, the biosphere," writes Academician V. I. Vernadsky.

Vernadsky's idea is especially vividly confirmed by the role played by oxygen, a product of plant photosynthesis, in the process of its circulation. Almost all the oxygen in the earth's atmosphere originated and is maintained at a certain level by the activity of green plants. In large quantities, it is consumed by organisms in the process of respiration. But, in addition, having a huge chemical activity, oxygen continuously enters into compounds with almost all other elements.

If green plants did not emit such a huge amount of oxygen, then it would completely disappear from the atmosphere in about 2000 years. The whole appearance of the Earth would be transformed, almost all organisms would disappear, all oxidizing processes in the physical part of the biosphere would stop ... The Earth would become a lifeless planet. It is the presence of free oxygen in the atmosphere of the planet that indicates that there is life on it, living matter, there is a biosphere. And since there is a biosphere, almost all elements of the environment are involved by it in a grandiose, endless cycle of substances.

It has been calculated that in the modern era all the oxygen contained in the atmosphere is circulated through organisms (bound by respiration and released by photosynthesis) in 2000 years, that all the carbon dioxide of the atmosphere cycles in the opposite direction every 300 years, and that all the waters on Earth decompose and recreated by photosynthesis and respiration in 2,000,000 years.

The study of the biosphere is based on geochemical studies, primarily studied by V. I. Vernadsky, the cycles of oxygen and carbon. He was the first to suggest that the oxygen contained in the modern atmosphere was formed as a result of the photosynthetic activity of plants.

The outstanding naturalist V. I. Vernadsky possessed an amazing ability to cover almost all areas of modern natural science with his sharp and brilliant thought. In his thoughts and concepts, he was far ahead of his contemporary level of knowledge and foresaw their development for decades to come. Back in 1922, Vernadsky wrote about man's imminent mastery of vast reserves of nuclear energy, and at the end of the 1930s he predicted the coming era of man's spacewalk. He stood at the origins of many sciences about the Earth - genetic mineralogy, geochemistry, biogeochemistry, radiogeology and created the doctrine of the Earth's biosphere, which became the pinnacle of his work.

The scientific searches of V. I. Vernadsky were constantly connected with a huge organizational work. He was the initiator of the creation of the Commission for the Study of the Natural Productive Forces of Russia, one of the organizers of the Ukrainian Academy of Sciences and its first president. On the initiative of Vernadsky, the Institute of Geography, the M. V. Lomonosov Institute of Mineralogy and Geochemistry, the Radium, Ceramic and Optical Institutes, the Biogeochemical Laboratory, which has now become the V. I. Vernadsky Institute of Geochemistry and Analytical Chemistry, the Commission for the Study of permafrost, then transformed into the V. A. Obruchev Institute of Permafrost Science, the Commission on the History of Knowledge, now the Institute of the History of Natural Science and Technology, the Committee on Meteorites, the Commission on Isotopes, Uranium and many others. Finally, he came up with the idea of ​​creating the International Commission for Determining the Geological Age of the Earth.

ENERGY FLOW IN THE BIOSPHERE

The cycles of all substances are closed, they repeatedly use the same atoms. Therefore, no new substance is required for the cycle to take place. The law of conservation of matter, according to which matter never arises or disappears, is evident here. But for the transformation of substances within the biogenic cycle, energy is needed. Due to what kind of energy is this grandiose process carried out?


The main source of energy necessary for life on Earth, and hence for the implementation of the biological cycle of substances, is sunlight, that is, the energy that occurs in the bowels of the Sun during nuclear reactions at a temperature of approximately 10,000,000 degrees. (The temperature on the surface of the Sun is much lower, only 6000 degrees.) Up to 30 percent of the energy is dissipated in the atmosphere or reflected by clouds and the Earth's surface, up to 20 percent is absorbed in the upper layers of clouds, about 50 percent reaches the land or ocean surface and is absorbed in the form of heat. Only an insignificant amount of energy, only about 0.1-0.2 percent, is captured by green plants; it provides the entire biological cycle of substances on Earth.

Green plants accumulate the energy of the sun's beam, accumulate it in their body. Animals, eating plants, exist due to the energy that entered their body along with food, with eaten plants. Predators also ultimately exist on the energy stored by green plants, because they feed on herbivorous animals.

Thus, the energy of the Sun, originally used by green plants in the process of photosynthesis, is converted into the potential energy of the chemical bonds of those organic compounds from which the very body of plants is built. In the body of an animal that has eaten a plant, these organic compounds are oxidized with the release of such an amount of energy that was spent on the synthesis of organic matter by the plant. Part of this energy is used for the life of the animal, and part, according to the second law of thermodynamics, turns into heat and dissipates in space.

Ultimately, the energy received from the Sun by a green plant passes from one organism to another. With each such transition, energy is transformed from one form (life energy of a plant) into another (life energy of an animal, microorganism, etc.). With each such transformation, a decrease in the amount of useful energy occurs. Therefore, unlike the circulation of substances, which flows in a vicious circle, energy moves from organism to organism in a certain direction. There is a one-way flow of energy, not a cycle.

It is not difficult to imagine that as soon as the Sun goes out, all the energy accumulated by the Earth will gradually turn into heat after a certain and relatively short period of time and will be dissipated in space. The circulation of substances in the biosphere will stop, all animals and plants will die. Pretty grim picture... The end of life on Earth...

However, we should not be embarrassed by this conclusion. After all, the Sun will shine for several billion more years, that is, at least as long as life already exists on Earth, which has developed from primitive lumps of living matter to modern man. Moreover, man himself appeared on Earth only about a million years ago. During this period, he went from a stone ax to the most complex electronic computers, penetrated into the depths of the atom and the universe,

Any transition of energy from one form to another is accompanied by a decrease in the amount of useful energy that has gone beyond the boundaries of the Earth and is successfully mastering outer space.

The emergence of man and such a highly organized matter as his brain was and is of exceptional importance for the evolution of living mothers and the entire biosphere. Since its inception, humanity, as part of the biomass, has been completely dependent on the environment for a significant time. But as the brain and thinking develop, man more and more conquers nature, rises above it, subordinates it to his own interests. Back in 1929, A.P. Pavlov, emphasizing the ever-increasing role of man in the development of the organic world on Earth, proposed calling the Quaternary period "anthropogen", and then V.I. Vernadsky, believing that humanity creates a new, intelligent shell of the Earth, or sphere mind, proposed the name "noosphere".

Human activity significantly changes the circulation of substances in the biosphere. About 50 billion tons of coal have been mined and burned; billions of tons of iron and other metals, oil, peat are mined. Man has mastered various forms of energy, including atomic energy. As a result, completely new chemical elements appeared on Earth and it became possible to transform some elements into others, and a large amount of radioactive radiation was included in the biosphere. Man has become the magnitude of the cosmic order and by the power of his mind in the near future he will be able to master such forms of energy that we now do not even suspect.

Biomass of the Earth. On land of the Earth, starting from the poles to the equator, the biomass gradually increases. At the same time, the number of plant species is also increasing. Tundra with lichens and mosses gives way to coniferous and broad-leaved forests, then steppes and subtropical vegetation. The greatest concentration and diversity of plants takes place in tropical rainforests. The height of the trees reaches 110-120m. Plants grow in several tiers, epiphytes cover the trees. The number and variety of animal species depend on plant mass and also increase towards the equator. In the forests, animals are settled in different tiers. The highest density of life is observed in biogeocenoses, where species are connected by food chains. Food chains, intertwined, form a complex network of transfer of chemical elements and energy from one link to another. Between organisms there is a fierce competition for the possession of space, food, light, oxygen. Man has a great influence on land biomass. Under its influence, the areas producing biomass are reduced.

soil biomass. Soil is the environment necessary for plant life and biogeocenosis with a variety of tiny living organisms. This is a loose surface layer of the earth's crust, modified by the atmosphere and organisms and constantly replenished with organic remains. The formation of living organic matter occurs on the earth's surface; decomposition of organic substances, their mineralization are carried out mainly in the soil. The soil was formed under the influence of organisms and physico-chemical factors. The thickness of the soil, along with the surface biomass and under its influence, increases from the poles to the equator. In northern latitudes, humus is of particular importance.

Distribution of biomass on the land surface.

The soil is densely populated with living organisms. Water from rains, melting snow enriches it with oxygen and dissolves mineral salts. Part of the solutions is retained in the soil, part is carried out into the rivers and the ocean. The soil evaporates the groundwater rising through the capillaries. There is a movement of solutions and precipitation of salts in different soil horizons.

Gas exchange also takes place in the soil. At night, when cooling and compressing gases, a certain amount of air penetrates into it. Air oxygen is absorbed by animals and plants and is part of chemical compounds. Nitrogen that has penetrated into the soil with air is captured by some bacteria. During the day, when the soil is heated, gases are released: carbon dioxide, hydrogen sulfide, ammonia. All processes occurring in the soil are included in the cycle of substances in the biosphere.

Some types of human economic activity (chemicalization of agricultural production, processing of petroleum products, etc.) cause mass death of soil organisms that play an important role in the biosphere.

Biomass of the oceans. The Earth's hydrosphere, or the World Ocean, occupies more than 2/3 of the planet's surface. Water has a high heat capacity, makes the temperature of the oceans and seas more uniform, mitigating extreme temperature changes in winter and summer. The ocean freezes only at the poles, but there are living organisms under the ice.

Water is a good solvent. The composition of ocean water includes mineral salts containing about 60 chemical elements; oxygen and carbon dioxide coming from the air are dissolved in it. Aquatic animals also release carbon dioxide when they breathe, and algae enrich the water with oxygen during photosynthesis.

The physical properties and chemical composition of the ocean waters are very constant and create an environment conducive to life. Photosynthesis of algae occurs mainly in the upper layer of water - up to 100 m. The surface of the ocean in this thickness is filled with microscopic unicellular algae that form microplankton.

Plankton plays a major role in the nutrition of ocean animals. Copepods feed on algae and protozoa. The crustaceans are eaten by herring and other fish. Herrings are eaten by predatory fish and gulls. Baleen whales feed exclusively on plankton. In the ocean, in addition to plankton and free-swimming animals, there are many organisms attached to the bottom and crawling along it. The population of the bottom is called benthos. Condensations of organisms are observed in the ocean: planktonic, coastal, bottom. Living clusters also include coral colonies that form reefs and islands. In the ocean, especially at the bottom of it, bacteria are common that convert organic residues into inorganic substances. Dead organisms slowly settle to the bottom of the ocean. Many of them are covered with flint or calcareous shells, as well as calcareous shells. At the bottom of the ocean, they form sedimentary rocks.

At present, a number of countries are solving the problem of extracting fresh water and metals from the ocean and making fuller use of its food resources while protecting the most valuable animals.

The hydrosphere has a powerful influence on the entire biosphere. Daily and seasonal fluctuations in the heating of the land and ocean surfaces cause the circulation of heat and moisture in the atmosphere and affect the climate and cycles of substances throughout the biosphere.

Oil production in the seas, its transportation in tankers and other human activities lead to pollution of the World Ocean and a reduction in its biomass.

Biologists have conducted a quantitative analysis of the global distribution of biomass on Earth, which totaled 550 billion tons of carbon. It turned out that more than 80 percent of this number falls on plants, the total biomass of terrestrial organisms is approximately two orders of magnitude greater than that of marine organisms, and the proportion of humans is about 0.01 percent, scientists write in Proceedings of the National Academy of Sciences.

Quantitative data on the total biomass of all living organisms on Earth and its distribution among individual species is important information for modern biology and ecology: they can be used to study the general dynamics and development of the entire biosphere, its reaction to the climatic processes taking place on the planet. Both the spatial distribution of biomass (geographically, by depth and species habitats) and its distribution among different species of living organisms can be an important indicator in assessing carbon and other elemental transport pathways, as well as ecological interactions or food chains. However, to date, quantitative estimates of the distribution of biomass have been made either for individual taxa or within some ecosystems, and reliable estimates of the entire biosphere have not yet been made.

To obtain such data, a group of scientists from Israel and the United States, led by Ron Milo (Ron Milo) from the Weizmann Institute of Science, conducted a kind of census of all animal species with an assessment of their biomass and geographical distribution. Scientists collected all the data from several hundred relevant scientific articles, after which they processed this information using the developed integration scheme, taking into account the geographical distribution of species. As a quantitative indicator of the biomass attributable to different species, scientists used information about the mass of carbon that falls on different taxa (that is, the consideration did not take into account, for example, the mass of water). Now all the results obtained, as well as the programs used for the analysis, are in the public domain, and they can be found on github.

Schematic diagram of the derivation of data on the global distribution of biomass from the available incomplete data, taking into account the geographical distribution of environmental parameters

Y. M. Bar-On et al./ Proceedings of the National Academy of Sciences, 2018

An analysis of the data obtained showed that the total biomass of all living organisms on Earth is approximately 550 billion tons of carbon. At the same time, the overwhelming majority of it is contained by representatives of the plant kingdom: 450 gigatonnes of carbon is more than 80 percent of the total. Bacteria are in second place with approximately 70 billion tons of carbon, while animals (2 billion tons) are also behind fungi (12 billion tons), archaea (7 billion tons) and protozoa (4 billion tons). Among animals, arthropods have the largest biomass (1 billion tons), and, for example, the total biomass of the species Homo sapiens is 0.06 billion tons of carbon - this is approximately 0.01 percent of all biomass on Earth.

Distribution of biomass between representatives of different kingdoms (left) and within the animal kingdom (right)

Y. M. Bar-On et al./ Proceedings of the National Academy of Sciences, 2018

Distribution of biomass between different habitats: total for all living organisms (left) and separately for representatives of various kingdoms (right)

Y. M. Bar-On et al./ Proceedings of the National Academy of Sciences, 2018

Interestingly, the maximum proportion of representatives of the main kingdoms in terms of biomass lives in various habitats. So, most of the plants are terrestrial species. The maximum biomass of animals lives in the seas and oceans, and, for example, most bacteria and archaea are located deep underground. At the same time, the total biomass of terrestrial organisms is about two orders of magnitude greater than that of marine organisms, which, according to the authors of the study, account for only 6 billion tons of carbon.

Scientists note that due to the lack of accurate information, the data obtained are calculated with a very large uncertainty. Thus, only the biomass of plants on Earth can be estimated with sufficient confidence, while for bacteria and archaea, the obtained data may differ from the actual data by a factor of 10. However, the uncertainty in the data on the total biomass of all living organisms on Earth does not exceed 70 percent.

According to the authors of the work, the results they obtained are based on data from current scientific studies, therefore they can be used for modern ecological and biological assessments, even despite a rather large error. The scientists also note that when analyzing the data, they were able to identify those geographic areas for which there is currently very little data and additional research is needed. The researchers hope that in the future, data refinement will allow not only to conduct such an analysis with sufficient geographic resolution, but also to monitor the dynamics of changes in such distributions over time.

More recently, scientists have distributed biomass in smaller systems by looking at large forests across the Earth. It turned out that more than half of the total biomass of the forest is accounted for by only one percent of the largest trees, most of which exceed 60 centimeters in diameter. At the same time, dynamic analysis can already be carried out for some animal species in certain geographical areas. For example, last year European ecologists studied the biomass of flying insects in German national parks and that in 27 years it has decreased by 76 percent at once.

Alexander Dubov