Grid
• The concept of the biosphere, its boundaries, following parts and functions.
• Distribution of biomass in the biosphere, the nature and significance of periodic circulation of substances and energy.
• The main groups involved in biogenic migration - producers, consumers, reducers.
• The main stages of biosphere evolution, the differences between the stages of biogenesis and noogenesis, the essence of the noosphere concept.
• Man's effects on the biosphere (beneficial and harmful) Harmful effects on the biosphere in the conditions of Uzbekistan.
• You should study the significance of the biosphere for humanity and its proper use.
The concept of biosphere (derived from the Greek bios - life, sphere - water sphere) was introduced to science for the first time by the Austrian geologist E. Zuss with the purpose of defining the earth's crust inhabited by living organisms. The doctrine of biosphere khaki was created and developed by the Russian academician VI Vernadsky.
The biosphere is a part of the earth's crust that is inhabited by living organisms and constantly changes under their influence. The sum of all biogeocenoses on the earth forms a general ecological system - the biosphere. Thus, the elementary (smallest) unit of the biosphere is biogeocenoses.
The biosphere consists of living and dead components. The totality of all living organisms living on our planet constitutes the living substance of the biosphere. Living organisms are mainly found in the Earth's gaseous (atmosphere), liquid (hydrosphere) and solid (lithosphere) geological spheres. According to further data, the upper limit of the biosphere is 22 km above sea level, and the lower layer of the atmosphere is in the troposphere.
Life is found in all parts of the hydrosphere, even in the deepest places - up to 11 km. Life is spread to a depth of 3-4 km in the upper layers of the lithosphere. The boundary of the biosphere extends to the deepest parts of the oceans and parts of the lithosphere where there is petroleum and where anaerobic bacteria live. The basic composition of the biosphere includes the parts of the atmosphere, hydrosphere and lithosphere that interact in the process of exchange of substances and energy.
The limits of life on the planet determine the limits of the biosphere. The biosphere is a part of the Earth's geological sphere inhabited by living organisms.
The peculiarity of the biosphere is the periodic cycle of substances produced by the activity of organisms. The biosphere is considered an open system because it receives energy from the outside - from the sun. Living organisms are a powerful geological factor that changes the surface of the planet by changing the periodic cycle of substances.
Functions of living matter. There are main biochemical functions in the tune of living matter:
• 1) gas exchange;
• 2) oxidation reduction;
• 3) concentration, accumulation;
• 4) biochemical.
The function of gas exchange depends on the processes of photosynthesis and respiration. In the process of synthesis of organic substances by autotrophic organisms, carbon dioxide contained in the old atmosphere is consumed in large quantities. As the green plants grow more and more, the gas content of the atmosphere also begins to change. The amount of carbon dioxide decreases, and oxygen begins to increase. All of the oxygen in the atmosphere is produced as a result of the activity of living organisms. In the process of breathing, oxygen is used up, carbon dioxide is produced and released into the atmosphere again. Thus, the atmosphere created as a result of the activity of living organisms is preserved in the present period due to their activity.
The concentration function is the accumulation of chemical elements observed in the environment by living organisms. In the process of photosynthesis, plants take chemical elements from the soil, potassium, phosphorus, nitrogen, hydrogen and others, carbon from the air and add them to the organic substances of the cell. Due to the functions of accumulation, living organisms produce a large amount of sedimentary rocks, for example, limestone.
Oxidation-reduction function - ensures the circulation of chemical elements with variable valence, iron, sulfur, manganese, nitrogen and others. For example: chemosynthesizing bacteria in soil carry out these processes. As a result, N2S, some types of iron ore, various nitrogen oxides are formed.
Biochemical functions provide biochemical processes during the life activity of living organisms and after their death. Biochemical function is related to nutrition, respiration, reproduction of organisms, decomposition and decay of mature organisms.
Biomass, land surface and ocean biomass.
The total mass of living matter in the biosphere is called biomass. Currently, about 500 species of plants and 1,5 million species of animals have been identified. 93% of them live in swamps, and 7% live in water.
In the table below, the dry mass of organisms living in water and in the soil is expressed in tons.
Biomass of terrestrial organisms
Dry matter Oceans Oceans
green plant
Animals
and micro-organisms Total Green plant-
Animals
and microorganisms Total Total Total
Tons 2,4 x1012 0,02 x 1012 2,42 -1012 0,0002 x 1012 0,003 x 1012 0,0032 x1012 2,4232 x 1012
Percent 99,2 0,8 100 6,3 93,7 100
As can be seen from the table, the oceans occupy 70% of the Earth's surface and produce 0,13% of the Earth's biomass. Plants make up 21% of known species of organisms and 99% of Earth's biomass. Although animal species cover 79% of all organisms, their contribution to biomass is less than 1%. Among animals, 96% are invertebrates and 4% are vertebrates. Only 10% of vertebrates are mammals. The given data indicate that most of the organisms living on Earth have not yet reached a high level of evolution. Even if living matter makes up only 0,001-0,02 percent of carbonaceous matter in its mass, it plays the most important role in the implementation of the main functions of the biosphere. Living matter is the most important component of the biosphere, and as a result of geochemical processes, it has a great impact on other parts of the Earth.
Curician biomass. The amount of biomass in different parts of the surface of Kuriklik is not the same. From the poles to the equator, the amount of biomass and the number of species of organisms increases. Especially in tropical forests, there are many types of plants, they grow densely and in several layers. Animals are placed on different levels. In equatorial biogeocenoses, the density of life is very high. There is a strong competition between organisms for habitat, food, light, and oxygen. In Kktbs, we do the opposite. Areas where biomass is produced can change dramatically due to human influence. Therefore, it is necessary to use the natural resources wisely for industrial and agricultural purposes. The main part of the surface of the aridity is occupied by soil biogeocenoses. Soil formation is a very complex process, and rocks are of primary importance in its composition. The soil layer of the Earth is gradually formed due to the action of microorganisms, plants and animals on the rocks. Organisms accumulate biogenic elements in its composition. After plants and animals die and decompose, their elements are absorbed into the soil, and biogenic elements accumulate. Also, organic substances that have not yet decomposed to the end accumulate in the soil. Living organisms are densely located in the soil. For example, the number of microorganisms can reach 1×25 in 108 t of soil, it has been determined that about 1 million earthworms can live in 2,5 ha of soil. The exchange of gases in the soil continues continuously. Oxygen in the air is absorbed by plants and becomes part of chemical compounds. Nitrogen is fixed by some bacteria. Carbon dioxide, hydrogen sulphide, and ammonia are released from the soil during the day. Thus, the soil is produced in a biogenic way. It consists of inorganic and organic substances and living organisms. Soil cannot be formed outside the biosphere. Soil is the habitat of living organisms, from which plants take water and nutrients. The processes taking place in the soil are a component of the circulation of substances in the biosphere. Human economic activities can often lead to a gradual change in soil composition and the death of microorganisms in it. Therefore, it is necessary to develop measures for the rational use of soil.
Ocean biomass. Water is one of the most important components of the biosphere, and it is considered one of the most necessary factors for the survival of living organisms. The main part of water is in the ocean, seas, and the composition of ocean and sea water includes mineral salts consisting of about 60 chemical elements. Oxygen and carbon dioxide gases, which are very necessary for the life of organisms, dissolve well in water. Aquatic animals release carbon dioxide during respiration. As a result of photosynthesis of plants, water is enriched with oxygen. In the bottom layer of ocean waters up to 200 m, there are a lot of single-celled algae, which produce microplankton (derived from the Greek "planktos" - mobile, moving water). About 30 percent of the photosynthesis process on our planet takes place in water. Water jets accept the energy of the sun and convert it into the energy of chemical reactions. Plankton has the main importance in the nutrition of animals living in water. Organisms that cling to the bottom of the water are called benthos (derived from the Greek word "benthos" meaning water in the deep). At the bottom of the ocean, there are many bacteria that convert organic matter into inorganic matter. The hydrosphere also has a strong influence on the biosphere. The hydrosphere plays an important role in the distribution of heat and moisture on the planet, and in the circulation of substances.
Periodic circulation of substances and change of energy in the biosphere.
One of the main functions of the biosphere is to ensure the periodic cycle of chemical elements. Biotic circulation in the biosphere takes place with the participation of all living organisms living on Earth. Chemical elements from one compound to another, from the composition of the earth's crust to living organisms, and then their disintegration into inorganic compounds and chemical elements and entering the composition of the earth's crust again, is called the periodic cycle of substances and energy. This cycle is a continuous process. As a result of the biotic cycle, the amount of chemical elements is limited, and life is assumed to exist and develop for many years. In fact, the amount of chemical elements necessary for organisms on Earth is not infinite. If these elements were only consumed, sooner or later they would run out and life could stop. According to academic VR Williams, the only way to approximate the infinity of a small quantity is to force it to rotate through a closed loop. Life has chosen the same way. Green plants use solar energy to create organic substances from inorganic substances. Heterotrophs consume other living organisms, and decomposers break down these substances. New plants synthesize new organic substances from mineral substances formed as a result of decomposition of organic substances. The only source that predicts the periodic cycle of substances on Earth is solar energy. The amount of solar energy falling on the earth during one year is 10,5X1020 kJ. 42% of this energy is returned from the Earth to space, 58% is absorbed by the atmosphere and soil, and 20% is returned by the Earth. 10% of the heat energy absorbed by the earth is spent on evaporation of water and water from the soil. About 1 billion tons of water evaporates from the earth's surface every minute. The constant circulation of water between reservoirs and aridity is one of the main factors predicting life on Earth, as well as the inanimate nature and behavior of plants and animals. Green plants use 0,1-0,2% of the solar energy that reaches the earth in the process of photosynthesis. Although this energy is very small compared to the energy used to evaporate water and heat the earth's surface, it plays a very important role in ensuring the circulation of chemical elements.
Biogenic migration of atoms. The continuous periodic circulation of substances, the biogenic migration of atoms and the flow of energy are carried out due to the nutrition, respiration, reproduction, synthesis, accumulation and decomposition of organic substances of living organisms. In the periodic exchange of substances, the chemical elements that are part of living organisms are carbon, hydrogen, nitrogen, oxygen, phosphorus and others. There are many isotopes of chemical elements, and only certain isotopes can enter living organisms. For example, among the 1N, 2N, 3N isotopes of hydrogen, 1N is the most active, but only this isotope is characteristic of organisms. Organic substances include the 12S isotope, and inorganic chemical compounds include the 13S isotope. Among oxygen isotopes 16O, 17O, 18O, only 16O isotope is included in water and carbon dioxide gas and has high biological activity.
Chemical elements are constantly absorbed from one organism to another, from the soil, atmosphere, hydrosphere to living organisms, and from them to the environment, filling the composition of inanimate substances of the biosphere. These processes continue endlessly. For example, all the oxygen in the atmosphere is consumed by living matter for 2000 years, carbon dioxide gas for 200-300 years, and all the water in the biosphere for 2 million years. Living organisms have the ability to accumulate not only chemical elements that are widely distributed in nature, but also elements that are found in very small quantities. The concentration of chemical elements in plants and animals is much higher than in the external environment. The concentration of carbon in plants is 200 times higher than in the soil, and nitrogen is 30 times higher. As a result of biogenic migration, the valency of some chemical elements changes under the influence of living organisms. As a result, new chemical compounds are formed. About 40 known chemical elements are actively involved in biogenic migration.
Autotrophic organisms absorb the energy of sunlight and produce primary plant substances from inorganic substances and organic substances. Heterotrophs feed on plants and turn plant products into secondary animal products. Bacteria and fungi break down the organic products of plants and animals into mineral salts, which can be consumed by autotrophic plants. There are two types of biogenic migration: the first type is carried out by microorganisms, and the second by multicellular organisms. The first type of migration prevails over the second type. Currently, the role of humanity in the biogenic migration of atoms is increasing. Below we will get to know more about the periodic cycle of some biogenic elements. Carbon dioxide is absorbed by plants and turns into carbohydrates, lipids, oxygens and other organic substances during photosynthesis. These substances. are consumed by other animals. All living organisms release carbon dioxide gas in the atmosphere during respiration. Dead plants and animals, their wastes are decomposed and mineralized by microorganisms. The final product of mineralization is carbon dioxide, which is released into the atmosphere from soil and water bodies. Part of the carbon is stored in the soil as organic compounds. Carbon accumulates in seawater in the form of sulfuric acid and its water-soluble salts or in the form of SaSO3 bur, limestone, corals. A part of the carbon accumulates in the seabed as sediments and limestones and does not participate in biogenic migration for a long time. With the passage of time, as a result of the processes of mountain formation, igneous rocks are pushed up again, and as a result of chemical changes, they again undergo cyclical rotation. Carbon also enters the atmosphere from smoke emitted from cars, factories and factories. As a result of the carbon cycle in the biosphere, energy resources - oil, coal, natural gas, peat, wood - are produced, which are widely used in human practical activities. All the substances listed above are products of photosynthetic plants. Wood and peat are renewable natural resources, while oil, gas and coal are non-renewable natural resources. The limited and non-replenishment of organic resources poses complex problems for mankind, such as the use of new sources of energy - geothermal energy, ocean and sea currents, and solar energy.
Nitrogen is one of the most important elements. It is a part of nucleic acids. Nitrogen is released from the atmosphere during lightning as a result of the combination of nitrogen and oxygen to form nitrogen IV oxide. But the main mass of nitrogen is absorbed into water and soil as a result of fixation of nitrogen contained in the air by living organisms (rayem 173).
Nitrogen-fixing bacteria and algae live in water and soil. As a result of the mineralization of these bacteria and algae, they enrich the soil with nitrogen. As a result, each hectare of soil absorbs about 25 kg of nitrogen in a year. Nodule bacteria living in the roots of leguminous plants are considered the most effective nitrogen fixers. Nitrogen is absorbed from various sources into plant roots, stems and leaves, and oxygen is biosynthesized in these places. Plant oxides are the main source of nitrogen for animals. After the organisms die, under the action of bacteria and fungi, oxygen is broken down and ammonia is released. The released ammonia is partly absorbed by plants and partly by bacteria. As a result of the activity of some bacteria, ammonia turns into nitrates. Nitrates, like ammonium salts, are consumed by plants and microorganisms. Some of the nitrates are reduced to elemental nitrogen by some bacteria and released into the atmosphere. This process is called denitrification. Meanwhile, the periodic exchange of nitrogen in nature continues. Thus, as a result of the interaction of living (biotic) and non-living (abiotic) nature, inorganic matter absorbs living organisms, changes and returns to an abiotic state again.
Organisms involved in biological migration can be divided into three large groups.
1. Producers - producers of living substances from dead substances. These are mainly photosynthetic complex and bottom green plants.
2. Consumers or consumers. Producers consume organic matter produced. They include animals, parasitic plants and microorganisms.
3. Reductants - mineralizers of organic substances, returning them to their previous state. They include bacteria, fungi, and saprophytic plants. In other words, the relay of life is passed from green plants to animals, bacteria take it to the finish line, and then pass it back to green plants. This relay continues unceasingly from the beginning of the new era.
Evolution of the biosphere
The evolution of the biosphere can be divided into 3 main stages.
1. Creation of the primary biosphere with biotic cycle. This phase began about 3 billion years ago and ended in the Cambrian period of the Paleozoic era.
2. In the 2nd stage, multicellular organisms appear and develop, and the evolution of the biosphere continues. This period begins with the Cambrian period 0,5 billion years ago and ends with the appearance of modern humans.
3. In the 3rd stage, the biosphere is developing under the influence of modern people, starting 40-50 thousand years ago and continuing until the present time. In the main part of the history of the biosphere, it develops under the influence of two different factors: 1. Natural geological and climatic changes on the planet. 2. Changes in the number and amount of species of living organisms as a result of biological evolution are the main factors. At present, the third factor, human activity, has a great influence on the evolution of the biosphere. The evolution of the first and second stages of the biosphere takes place only on the basis of biological conditions, therefore these two periods are called the period of biogenesis. Hayet appeared and developed during this period. The third period is connected with the emergence of personal society. Let's get acquainted with the period of biogenesis.
Stage of biogenesis. On Earth, the biosphere appeared at the same time as the first living organisms. Since then, along with the evolution of living organisms, the biosphere has evolved. The first living organisms to appear were unicellular heterotrophs, anaerobes. They appeared about 3 billion years ago, receiving energy from the processes of digestion. They fed on ready-made organic matter produced abiogenically and accumulated biomass. In the biosphere that had just appeared, there was a lack of organic matter, primary organisms could not reproduce quickly. As a result of natural selection, autotrophic organisms that can independently synthesize organic substances from inorganic substances have appeared. The first chemosynthesizing bacteria, photosynthesizing and green algae appeared. The first photosynthetic organisms absorbed carbon dioxide and released oxygen, changing the composition of the atmosphere. As a result, the amount of carbon dioxide in the atmosphere decreased and the amount of oxygen increased. In the upper layer of the atmosphere, oxygen forms an ozone screen. The ozone screen protects living organisms on earth from the harmful effects of ultraviolet rays and cosmic rays. In such conditions, the living organisms on the surface of the sea increased. The presence of free oxygen in the atmosphere caused the emergence of aerobic oxygen-breathing organisms and multicellular organisms on the Earth's surface. The ozone screen allowed living organisms to spread from water to land. The first multicellular organisms are thought to have appeared 3 million years ago, at the beginning of the Cambrian period, when the concentration of oxygen in the atmosphere reached about 500 percent. Excess oxygen was produced by photosynthetic organisms living in the sea. This led to an increase in the number of organisms that breathe aerobically. In the process of aerobic respiration, a lot of energy is released due to the breakdown of substances. Morphological and functional structure has become increasingly complex in organisms with high energy.
In a short time, they spread to different habitats. In the Paleozoic era, the hyaet was not only widespread in water, but also on dry land. The widespread development of green plants enriched the atmosphere with oxygen, which made it possible to further improve the structure of organisms. During the Paleozoic period, there was a balance between the production and consumption of oxygen, the amount of oxygen in the atmosphere reached about 20 percent, and this balance has not been disturbed until now.
Noogenesis stage. With the emergence of human society, the period of noogenesis of the biosphere begins. During this period, the evolution of the biosphere continues under the influence of the conscious cocktail activity of a person. The concept of noosphere was introduced by the French scientist E. Leroy in 1927 (derived from the Greek words "noos" - mind, "sphere" - sphere). According to VI Vernadsky, the noosphere is the biosphere that has changed under the influence of human labor and scientific activity.
The appearance of man caused strong changes in the biosphere. The rapid development of science, technology and industry accelerated the biogenic migration of elements. Throughout history, humanity has been as close as possible to the environment with its labor activities; and tried to get the background quickly. He did not think about the consequences of human intervention in natural phenomena. Since the earliest stages of human existence, some species of animals have become extinct (in excess of what is needed for nutrition). Stone Age humans caused the extinction of large mammals such as mammoths. Man is also a component of the biosphere. Man takes everything he needs from the biosphere, and only industrial waste is released into the biosphere. For a long time, human activity did not cause a disturbance in the balance of the biosphere, because the natural products taken by humans are returned to the biosphere. But in the next century, the influence of man on the biosphere increased greatly and caused acute problems. Natural resources are getting less and less. Many species of plants and animals have disappeared. The environment is not polluted and poisoned by industry, household waste, toxic chemicals. If natural ecosystems, ash, forests are not destroyed. Such unusual changes in the biosphere have a strong impact on the world of plants and animals, as well as on humans.
A person's lack of understanding of the conditions of biosphere change can lead to very unfortunate changes in the external environment.
Increasing human impact on the hydrosphere and atmosphere is causing climate change within the biosphere. In particular, the amount of carbon dioxide in the atmosphere has been increasing in recent years. The use of organic fuels causes the burning of oxygen to decrease, and carbon dioxide to increase. The increase of carbon dioxide in the atmosphere leads to the "greenhouse effect", which causes the temperature of the Earth's surface to rise. During the next 100 years, the average temperature of the Earth's surface is expected to increase by 0,6°C. Climate change leads to an increase in the area of deserts, melting of glaciers in the mountains, and a decrease in the level of ocean and sea waters. As we mentioned above, there is an ozone layer in the atmosphere, and its maximum concentration is 20-25 km above the Earth's surface. As a result of nitrogen II oxide and freon entering the atmosphere, the ozone layer has been thinning for several years. Freon is widely used as a spray agent for varnishes and paints, and as a refrigerant in refrigerators and air conditioners. In recent years, as a result of ozone depletion in the atmosphere of Antarctica, there have been sad and dangerous phenomena such as the formation of "ozone holes". In 1987, in Montreal, Canada, representatives of 50 countries signed an international agreement to reduce the production of freons by 50% in order to prevent this phenomenon and the destruction of the ozone layer. Atmospheric pollution continues unceasingly and increases year by year. Atmospheric pollution is increasing due to the waste of industrial enterprises, compounds emitted by vehicles, especially N2S carbon and particles of heavy metals such as lead, copper, cadmium, nickel and other metals. Hundreds of millions of tons of pollutants are released into the atmosphere every year. An increase in N2S in the air is thought to be the reason for the increase in acid rain. One of the main reasons for the decrease in the productivity of fruit trees in Uzbekistan, and the fact that vineyards become diseased and yield less year after year is the increase in acid rains.
The tailings of the aluminum plant built around the city of M. Tursunzoda, Tajikistan, led to a sharp decrease in the yield of the famous pomegranate orchards in the Surkhandarya region, to the shriveling of the fruits, and to the increase of diseases among animals and people. Waste from the chemical factory in Navoi city also plays a big role in environmental damage. Wasteful use of water for irrigation and industrial enterprises leads to the drying up of small rivers and the sharp decrease of water in large rivers. A typical example of such unfortunate events is the problem of the Aral Sea. Excessive expansion of irrigated cotton areas poses the risk of drying up of this sea. As a result of uncontrolled and excessive use of water, large rivers such as Amudarya and Syrdarya cannot reach the Aral Sea. This is the reason for the destruction of the natural ecological systems around the island, and the worsening of the health of the people living in this region. The dumping of mineral fertilizers, livestock waste and sewage into water bodies leads to the increase of nitrogen and phosphorus in the water, the evaporation of water, and as a result of the reduction of oxygen reserves, animals in the water, especially fish, enter. In recent times, the cutting down of forests has led to very sad results. As a result of increasing pollution of water bodies, water bodies, and soil, the trees in the forests are dying. The loss of forests leads to a sharp change in climate, a decrease in water resources, and the deterioration of the condition of the soil. Currently, many hydroelectric and nuclear power plants are being built to supply the economy with energy. Because thermal power plants use natural resources, they pollute the atmosphere, and water power plants require the construction of large-scale reservoirs, as a result of which fertile lands and soils are submerged under water. Nuclear power plants, which were previously considered the cleanest and safest from an environmental point of view, have become known to pose a great danger. The disaster of the Chernobyl nuclear power plant in Ukraine led to an ecological crisis in a large area, causing great damage to flora and fauna. It caused various diseases to spread among the population. Thus, the strong influence of man on ecological systems can lead to unexpected tragic events. As a result, there is a chain of ecological changes. At present, humanity is under the threat of ecological crisis. If the necessary measures are not taken, many areas of the biosphere may become unfit for human habitation. Protecting nature is becoming one of the most pressing issues today.
