home › Salon › The role of living organisms in the biosphere. The role of living matter in the biosphere The main attention in the doctrine of the biosphere

The role of living organisms in the biosphere. The role of living matter in the biosphere The main attention in the doctrine of the biosphere

Question 1. What is the impact of living organisms on the biosphere?
Living beings contribute to the transfer and circulation of substances in nature. Thanks to the activity of photosynthetics, the amount of carbon dioxide in the atmosphere decreased, oxygen appeared and a protective ozone layer formed. The activity of living organisms determines the composition and structure of the soil (processing of organic residues by decomposers), protects it from erosion. To a large extent, animals and plants also determine the content of various substances in the hydrosphere (especially in small water bodies). Some organisms are able to selectively absorb and accumulate certain chemical elements - silicon, calcium, iodine, sulfur, etc. The result of the activity of living beings are deposits of limestone, iron and manganese ores, reserves of oil, coal, gas.

Question 2. Tell us about the water cycle in nature.
Under the influence of solar energy, water evaporates from the surface of reservoirs and is transported by air currents over long distances. Falling on the surface of the land in the form of precipitation, it contributes to the destruction of rocks and makes their constituent minerals available to plants, microorganisms and animals. It erodes the upper soil layer and leaves along with the substances dissolved in it. chemical compounds and suspended organic and inorganic particles into the seas and oceans. The circulation of water between the ocean and land is the most important link in maintaining life on Earth.
Plants participate in the water cycle in two ways: they extract it from the soil and evaporate it into the atmosphere; Part of the water in plant cells is broken down during photosynthesis. In this case, hydrogen is fixed in the form of organic compounds, and oxygen enters the atmosphere.
Animals consume water to maintain osmotic and salt balance in the body and excrete it into external environment along with metabolic products.

Question 3. What organisms absorb carbon dioxide from the atmosphere?
Carbon dioxide from the atmosphere is absorbed by photosynthetic organisms, which assimilate it and store it in the form of organic compounds (primarily glucose). Carbon dioxide from the atmosphere is absorbed by photosynthetic organisms, which assimilate it and store it in the form of organic compounds (primarily glucose). In addition, part of atmospheric carbon dioxide dissolves in the water of the seas and oceans, and then in the form of carbonic acid ions can be captured by animals - mollusks, corals, sponges, which use carbonates to build shells and skeletons. The result of their activity may be the formation of sedimentary rocks (limestone, chalk, etc.).

Question 4. Describe the way fixed carbon is returned to the atmosphere.
Carbon enters the biosphere as a result of its fixation in the process of photosynthesis. The amount of carbon bound by plants annually is estimated at 46 billion tons. Part of it enters the body of animals and is released as a result of respiration in the form of CO 2, which again enters the atmosphere. In addition, carbon reserves in the atmosphere are replenished by volcanic activity and human combustion of fossil fuels. Although most of the carbon dioxide entering the atmosphere is absorbed by the ocean and deposited as carbonates, CO 2 in the air is slowly but steadily increasing.

Question 5. What factors, in addition to the activities of living organisms, affect the state of our planet?
In addition to the activity of living organisms, abiotic factors influence the state of our planet: the movement of lithospheric plates, volcanic activity, rivers and sea surf, climatic phenomena, droughts, floods and other natural processes. Some of them act very slowly; others are able to almost instantly change the state of a large number of ecosystems (large-scale volcanic eruption; a strong earthquake accompanied by a tsunami; forest fires; the fall of a large meteorite).

Question 6. Who first introduced the term "noosphere" into science?
Noosphere (from the Greek noos - mind) is a concept that denotes the sphere of interaction between nature and man; this is an evolutionary new state of the biosphere, in which the rational activity of man becomes the decisive factor in its development. The term "noosphere" was first introduced into science in 1927 by French scientists Edouard Leroy (1870-1954) and Pierre Teilhard de Chardin (1881-1955).

Abstract on the topic:

Introduction

The biological cycle is a phenomenon of a continuous nature, cyclic, regular, but not uniform in time and space, the redistribution of substances, energy and information within ecological systems of various hierarchical levels of organization - from biogeocenosis to the biosphere. The circulation of substances on the scale of the entire biosphere is called a large circle, and within a specific biogeocenosis - a small circle of biotic exchange.

Academician V.I. Vernadsky was the first to postulate the thesis about the most important role of living organisms in the formation and maintenance of the basic physical and chemical properties of the Earth's shells. In his concept, the biosphere is considered not just as a space occupied by life, but as an integral functional system, at the level of which the inseparable connection of geological and biological processes is realized. The main properties of life that ensure this connection are the high chemical activity of living organisms, their mobility and the ability to self-reproduce and evolve. In maintaining life as a planetary phenomenon, the diversity of its forms, which differ in the set of consumed substances and waste products released into the environment, is of paramount importance. Biological diversity is the basis for the formation of stable biogeochemical cycles of matter and energy in the Earth's biosphere.

Questions about the role of living organisms in the small circulation were considered by such scientists, teachers as Nikolaikin N.I., Shilov I.A., Melekhova O.P. and etc.

1. The role of living organisms in the biological cycle

A specific property of life is the exchange of substances with the environment. Any organism must receive certain substances from the external environment as sources of energy and material for building its own body. Metabolic products that are no longer suitable for further use are brought out. Thus, each organism or a set of identical organisms in the course of its life activity worsens the conditions of its habitat. The possibility of the reverse process - maintaining living conditions or even improving them - is determined by the fact that the biosphere is inhabited by different organisms with different types of metabolism.

In its simplest form, a set of qualitative life forms is represented by producers, consumers and decomposers, whose joint activity ensures the extraction of certain substances from the environment, their transformation at different levels of trophic chains and the mineralization of organic matter to components available for the next inclusion in the cycle (basic elements migrating along the chains of the biological cycle - carbon, hydrogen, oxygen, potassium, phosphorus, sulfur, etc.).

Producers are living organisms that are able to synthesize organic matter from inorganic components using external energy sources. (Note that obtaining energy from the outside is a general condition for the life of all organisms; in terms of energy, all biological systems are open) they are also called autotrophs, since they themselves supply themselves with organic matter. In natural communities, producers perform the function of producers of organic matter accumulated in the tissues of these organisms. Organic matter also serves as a source of energy for life processes; external energy is used only for primary synthesis.

All producers, according to the nature of the energy source for the synthesis of organic substances, are divided into photoautotrophs and chemoautotrophs. The former use the energy of solar radiation for synthesis in the part of the spectrum with a wavelength of 380-710 nm. This is mainly green plants, but representatives of some other kingdoms of the organic world are also capable of photosynthesis. Among them, cyanobacteria (blue-green "algae"), which, apparently, were the first photosynthetics in the evolution of life on Earth, are of particular importance. Many bacteria are also capable of photosynthesis, which, however, use a special pigment - bacteriochlorin - and do not emit oxygen during photosynthesis. The main starting materials used for photosynthesis are carbon dioxide and water (the basis for the synthesis of carbohydrates), as well as nitrogen, phosphorus, potassium and other elements of mineral nutrition.

By creating organic substances based on photosynthesis, photoautotrophs thus bind the used solar energy, as if storing it. The subsequent destruction of chemical bonds leads to the release of such "stored" energy. This applies not only to the use of fossil fuels; The energy “stored” in plant tissues is transferred in the form of food along trophic chains and serves as the basis for energy flows that accompany the biogenic cycle of substances.

Chemoautotrophs use the energy of chemical bonds in the processes of organic matter synthesis. This group includes only prokaryotes: bacteria, archaebacteria and partly blue-green. Chemical energy is released in the processes of oxidation of mineral substances. Exothermic oxidative processes are used by nitrifying bacteria (oxidize ammonia to nitrites and then to nitrates), iron bacteria (oxidation of ferrous iron to oxide), sulfur bacteria (hydrogen sulfide to sulfates). Methane, CO and some other substances are also used as a substrate for oxidation.

With all the variety of specific forms of autotrophic producers, their general biospheric function is one and consists in involving elements of inanimate nature into the composition of body tissues and thus into the general biological cycle. The total mass of autotrophic producers is more than 95% of the mass of all living organisms in the biosphere.

Consumers. Living beings that are not able to build their body on the basis of the use of inorganic substances, requiring the intake of organic matter from the outside, as part of food, belong to the group of heterotrophic organisms that live off products synthesized by photo- or chemosynthetics. Food extracted in one way or another from the external environment is used by heterotrophs to build their own body and as a source of energy for various forms of life. Thus, heterotrophs use the energy stored by autotrophs in the form of chemical bonds of organic substances synthesized by them. In the flow of substances in the course of the cycle, they occupy the level of consumers obligately associated with autotrophic organisms (consumers of the 1st order) or with other heterotrophs that they feed on (consumers of the 2nd order).

The general significance of consumers in the circulation of substances is peculiar and ambiguous. They are not necessary in the direct process of circulation: artificial closed model systems, composed of green plants and soil microorganisms, in the presence of moisture and mineral salts, can exist indefinitely. for a long time due to photosynthesis, destruction of plant residues and involvement of released elements in a new cycle. But this is only possible under stable laboratory conditions. In a natural environment, the probability of the death of such simple systems from many causes increases. The “guarantors” of the stability of the cycle are, first of all, the consumers.

In the process of their own metabolism, heterotrophs decompose the organic substances obtained in the composition of food and, on this basis, build the substances of their own body. The transformation of substances primarily produced by autotrophs in consumer organisms leads to an increase in the diversity of living matter. Diversity is a necessary condition for the stability of any cybernetic system against the background of external and internal disturbances. Living systems - from the organism to the biosphere as a whole - operate according to the cybernetic principle. feedback.

Animals, which make up the bulk of consumer organisms, are characterized by mobility, the ability to actively move in space. By this, they effectively participate in the migration of living matter, its dispersion over the surface of the planet, which, on the one hand, stimulates the spatial settlement of life, and on the other hand, serves as a kind of “guarantee Mechanism” in case of destruction of life in any place due to various reasons. .

An example of such a “spatial guarantee” is the well-known catastrophe on about. Krakatoa: as a result of the volcanic eruption in 1883, life on the island was completely destroyed, but it recovered within just 50 years - about 1200 species were recorded. The settlement proceeded mainly at the expense of Java, Sumatra and neighboring islands, which were not affected by the eruption, from where, in different ways, plants and animals repopulated the island covered with ash and frozen lava flows. At the same time, films of cyanobacteria appeared first (after 3 years) on volcanic tuff and ash. The process of establishing sustainable communities on the island continues; forest cenoses are still in the early stages of succession and are greatly simplified in structure.

Finally, the role of consumers, primarily animals, is extremely important as regulators of the intensity of matter and energy flows along trophic chains. The ability to actively autoregulate biomass and the rate of its change at the level of ecosystems and populations certain types is ultimately realized in the form of maintaining the correspondence between the rates of creation and destruction of organic matter in the global cycle systems. Not only consumers participate in such a regulatory system, but the latter (especially animals) are distinguished by the most active and rapid reaction to any disturbances in the biomass balance of adjacent trophic levels.

In principle, the system for regulating the flow of matter in the biogenic cycle, based on the complementarity of the ecological categories of living organisms that make up this system, operates on the principle of waste-free production. However, ideally, this principle cannot be observed due to the great complexity of the interacting processes and the factors influencing them. The result of the violation of the completeness of the cycle was the deposits of oil, coal, peat, sapropels. All these substances carry the energy originally stored in the process of photosynthesis. Their use by a person is, as it were, the completion of the cycles of the biological cycle “delayed in time”.

Reducers. This ecological category includes heterotrophic organisms, which, using dead organic matter (corpses, feces, plant litter, etc.) as food, decompose it into inorganic components in the process of metabolism.

Partial mineralization of organic substances occurs in all living organisms. So, in the process of breathing, CO2 is released, water, mineral salts, ammonia, etc. are excreted from the body. True decomposers, which complete the cycle of destruction of organic substances, should therefore be considered only those organisms that release into the external environment only inorganic substances that are ready to be involved in a new cycle.

The category of decomposers includes many types of bacteria and fungi. By the nature of their metabolism, they are reducing organisms. Thus, devitrifying bacteria reduce nitrogen to its elemental state, while sulfate-reducing bacteria reduce sulfur to hydrogen sulfide. The end products of decomposition of organic substances are carbon dioxide, water, ammonia, mineral salts. Under anaerobic conditions, decomposition goes further - to hydrogen; hydrocarbons are also formed.

The full cycle of organic matter reduction is more complex and involves a larger number of participants. It consists of a series of successive links, in a series of which various destroying organisms gradually convert organic substances, first into simpler forms, and only after that into inorganic components by the action of bacteria and fungi.

Levels of organization of living matter. The joint activity of producers, consumers and decomposers determines the continuous maintenance of the global biological cycle of substances in the Earth's biosphere. This process is supported by the regular relationships of the spatial and functional parts that make up the biosphere and is provided by a special system of connections that act as a mechanism for homeostasis of the biosphere - maintaining its stable functioning against the background of changing external and internal factors. Therefore, the biosphere can be considered as a global ecological system that ensures the sustainable maintenance of life in its planetary manifestation.

Any biological (including ecological) system is characterized by a specific function, ordered relationships of the parts (subsystems) that make up the system, and regulatory mechanisms based on these interactions that determine the integrity and stability of the system against the background of fluctuating external conditions. From what has been said above, it is clear that the biosphere in its structure and function corresponds to the concept of a biological (ecological) system.

At the level of the biosphere as a whole, a universal functional connection of living matter with inanimate nature is carried out. Its structural and functional components (subsystems), at the level of which specific cycles of the biological cycle are carried out, are biogeocenoses (ecosystems).

2. Small circulation of substances in the biosphere

Biological (biogeochemical) cycle (small cycle of substances in the biosphere) - the cycle of substances, the driving force of which is the activity of living organisms. The biogeochemical cycle of substances takes place within the biosphere. The main energy source of the cycle is solar radiation, which generates photosynthesis. In an ecosystem, organic substances are synthesized by autotrophs from inorganic substances. It is then consumed by heterotrophs. As a result of excretion during life activity or after the death of organisms, organic substances undergo mineralization, i.e. transformation into inorganic substances. These inorganic substances can be reused for the synthesis of organic substances by autotrophs.

In biogeochemical cycles, two parts should be distinguished:

1. a reserve fund is a part of a substance that is not associated with living organisms;

2. exchange fund - a much smaller part of a substance that is connected by direct exchange between organisms and their immediate environment.

Depending on the location of the reserve fund, biogeochemical cycles can be divided into two types:

1. gas-type cycles with a reserve fund of substances in the atmosphere and hydrosphere (cycles of carbon, oxygen, nitrogen);

2. sedimentary cycles with a reserve fund in the earth's crust (circulations of phosphorus, calcium, iron, etc.).

Cycles of the gas type are perfect, because have a large exchange fund, and therefore ways to rapid self-regulation. Sedimentary cycles are less perfect, they are more inert, because the bulk of the substance is contained in the reserve fund of the earth's crust in a form "inaccessible" to living organisms. Such cycles are easily disturbed by various kinds of influences, and part of the exchanged material leaves the cycle. It can return again to the circulation only as a result of geological processes or by extraction by living matter. However, to extract the substances necessary for living organisms from earth's crust much more difficult than from the atmosphere.

The intensity of the biological cycle is primarily determined by the ambient temperature and the amount of water. So, for example, the biological cycle proceeds more intensively in humid tropical forests than in the tundra. In addition, biological processes in the tundra occur only in the warm season.

Producers, consumers, detritophages and decomposers of the ecosystem, absorbing and releasing various substances, interact with each other clearly and in a coordinated manner. Organic matter and oxygen produced by photosynthetic plants are the most important foodstuffs for food and respiration of consumers. At the same time, carbon dioxide and mineral substances of manure and urine emitted by consumers are biogens, much-needed producers. Therefore, substances in ecosystems make an almost complete cycle, getting first into living organisms, then into the abiotic environment and again returning to the living. Here is one of the basic principles of the functioning of ecosystems: the receipt of resources and the processing of waste occur in the process of the cycle of all elements.

Consider the cycles of the most significant substances and elements for living organisms. The small biogeochemical cycle of biogenic elements includes: carbon, nitrogen, phosphorus, sulfur, etc.

2.1 The carbon cycle

Carbon exists in nature in many forms, including in organic compounds. The inorganic substance underlying the biogenic cycle of this element is carbon dioxide (CO2). In nature, CO2 is part of the atmosphere, and is also dissolved in the hydrosphere. The inclusion of carbon in the composition of organic substances occurs in the process of photosynthesis, as a result of which sugars are formed on the basis of CO2 and H2O. Subsequently, other biosynthetic processes convert these carbons into more complex ones, as well as into proteins, lipids. All these compounds not only form the tissues of photosynthetic organisms, but also serve as a source of organic matter for animals and non-green plants.

In the process of respiration, all organisms oxidize complex organic substances; the end product of this process, CO2, is released into the environment, where it can again be involved in the process of photosynthesis.

Under certain conditions in the soil, the decomposition of accumulated dead residues proceeds at a slow pace - through the formation of humus by saprophages, the mineralization of which by the action of fungi and bacteria can proceed at different, including low, rates. In some cases, the decomposition chain of organic matter is incomplete. In particular, the activity of saprophages can be inhibited by a lack of oxygen or increased acidity. In this case, organic residues accumulate in the form of peat; carbon is not released and the cycle stops. Similar situations arose in past geological epochs, as evidenced by deposits of coal and oil.

In the hydrosphere, the suspension of the carbon cycle is associated with the incorporation of CO2 into CaCO3 in the form of limestone, chalk, and corals. In this case, carbon is excluded from the cycle for entire geological epochs. Only the rise of organogenic rocks above sea level leads to the renewal of the circulation through the leaching of limestone by atmospheric precipitation. And also in a biogenic way - by the action of lichens, plant roots.

Forests are the main reservoir of biologically bound carbon; they contain up to 500 billion tons of this element, which is 2/3 of its reserve in the atmosphere. Human intervention in the carbon cycle leads to an increase in the content of CO2 in the atmosphere and the development of the greenhouse effect.

CO2 cycle rate, i.e. the time it takes for all the carbon dioxide in the atmosphere to pass through living matter is about 300 years.

2.2 The nitrogen cycle

Main source nitrogen of organic compounds - molecular nitrogen in the composition of the atmosphere. Its transition to compounds accessible to living organisms can be carried out in different ways. Thus, electrical discharges during thunderstorms are synthesized from nitrogen and oxygen in the air, nitric oxide, which, with rainwater, enters the soil in the form of nitrate or nitric acid. There is also photochemical nitrogen fixation.

A more important form of nitrogen assimilation is the activity of nitrogen-fixing microorganisms synthesizing complex proteins. When they die, they enrich the soil with organic nitrogen, which quickly mineralizes. In this way, about 25 kg of nitrogen per 1 ha annually enters the soil.

The most efficient nitrogen fixation is carried out by bacteria that form symbiotic bonds with leguminous plants. The organic nitrogen formed by them diffuses into the rhizosphere and is also included in the ground organs of the host plant. In this way, 150-400 kg of nitrogen is accumulated per year in the ground and underground plant organs per 1 hectare.

There are nitrogen-fixing microorganisms that form symbiosis with other plants. IN aquatic environment and on very wet soil, cyanobacteria directly fix atmospheric nitrogen. In all these cases, nitrogen enters the plants in the form of nitrates. These compounds are transported through roots and pathways to leaves, where they are used for protein synthesis; the latter serve as the basis for the nitrogen nutrition of animals.

Excrements and dead organisms form the basis of the food chains of saprophage organisms, decomposing organic compounds with the gradual transformation of organic nitrogen-containing substances into inorganic ones. The final link in this reduction chain is ammonifying organisms that form ammonia, which can then enter the nitrification cycle. In this way the nitrogen cycle can be continued.

At the same time, there is a constant return of nitrogen to the atmosphere by the action of denitrifying bacteria, which decompose nitrates to N2. These bacteria are active in soils rich in nitrogen and carbon. Thanks to their activities, up to 50-60 kg of nitrogen are volatilized annually from 1 ha of soil.

Nitrogen can be excluded from the cycle by accumulating in deep ocean sediments. To a certain extent, this is compensated by the release of molecular N2 in the composition of volcanic gases.

2.3 Phosphorus cycle

Of all the macronutrients (elements needed for all life in large quantities), phosphorus is one of the rarest available reservoirs on the surface of the Earth. In nature, phosphorus is found in large quantities in a number of rocks. In the process of destruction of these rocks, it enters terrestrial ecosystems or is leached by precipitation and eventually ends up in the hydrosphere. In both cases, this element enters the food chain. In most cases, decomposer organisms mineralize organic substances containing phosphorus into inorganic phosphates, which can again be used by plants and thus are again involved in the cycle.

In the ocean, part of the phosphates with dead organic residues enters deep sediments and accumulates there, being excluded from the cycle. The process of the natural cycle of phosphorus in modern conditions is intensified by the use of phosphate fertilizers in agriculture, the source of which are deposits of mineral phosphates. This may be a cause for concern, since phosphorus salts are rapidly leached from such use, and the scale of exploitation mineral resources are growing all the time. Currently amounting to about 2 million tons per year.

2.4 Sulfur cycle

The main reserve fund of sulfur is in sediment and soil, but unlike phosphorus, there is a reserve fund in the atmosphere. The main role in the involvement of sulfur in the biogeochemical cycle belongs to microorganisms. Some of them are reducing agents, others are oxidizing agents.

Sulfur occurs in rocks in the form of sulfides, in solutions - in the form of an ion, in the gaseous phase in the form of hydrogen sulfide or sulfur dioxide. In some organisms, sulfur accumulates in its pure form (S) and, when they die, deposits of native sulfur are formed on the bottom of the seas.

In terrestrial ecosystems, sulfur enters plants from the soil mainly in the form of sulfates. In living organisms, sulfur is found in proteins, in the form of ions, etc. After the death of living organisms, part of the sulfur is reduced in the soil by microorganisms to HS, the other part is oxidized to sulfates and is again included in the cycle. The resulting hydrogen sulfide escapes into the atmosphere, oxidizes there and returns to the soil with precipitation.

Human combustion of fossil fuels, as well as emissions chemical industry, leads to the accumulation of sulfur dioxide (SO) in the atmosphere, which, reacting with water vapor, falls to the ground in the form of acid rain.

Biogeochemical cycles are largely influenced by humans. Economic activity violates their isolation, they become acyclic.

Conclusion

Complex relationships that support a stable circulation of substances, and with it the existence of life as a global phenomenon of our planet, have been formed over the long history of the Earth.

The joint activity of various living organisms determines the regular circulation of individual elements and chemical compounds, including their introduction into the composition of living cells, transformations chemical substances in metabolic processes, release into the environment and destruction of organic substances, as a result of which mineral substances are released, which are again included in biological cycles.

Thus, the cycle processes occur in specific ecosystems, but biogeochemical cycles are realized in full only at the level of the biosphere as a whole. And the joint activity of high-quality life forms ensures the extraction of certain substances from the external environment, their transformation at different levels of trophic chains and the mineralization of organic matter to components available for the next inclusion in the cycle (the main elements migrating along the chains of the biological cycle are carbon, hydrogen, nitrogen , potassium, calcium, etc.).

Bibliography

1. Kolesnikov S.I. Ecology. - Rostov-on-Don: "Phoenix", 2003.

2. Petrov K.M. General ecology: Interaction between society and nature: Uchebn. allowance. 2nd ed. - St. Petersburg; Chemistry, 1998.

3. Nikolaikin N.I. Ecology.: Proc. for universities / Nikolaykin N.N., Nikolaykina N.E., Melekhina O.P. - 2nd ed., revised. and additional - M .: Bustard, 2003.

4. Khotuntsev Yu.L. Ecology and environmental safety: Proc. allowance for students. higher ped. textbook establishments. - M .: Publishing Center "Academy", 2002.

5. Shilov I.A. Ecology: Proc. for biol. and honey. specialist. universities I.A. Shilov. - 4th ed., Rev. - M .: Higher School, 2003.

Question 2. Tell us about the water cycle in nature.
Under the influence of solar energy, water evaporates from the surface of reservoirs and is transported by air currents over long distances. Falling on the surface of the land in the form of precipitation, it contributes to the destruction of rocks and makes their constituent minerals available to plants, microorganisms and animals. It erodes the upper soil layer and goes along with the chemical compounds dissolved in it and suspended organic and inorganic particles into the seas and oceans. The circulation of water between the ocean and land is the most important link in maintaining life on Earth.
Plants participate in the water cycle in two ways: they extract it from the soil and evaporate it into the atmosphere; Part of the water in plant cells is broken down during photosynthesis. In this case, hydrogen is fixed in the form of organic compounds, and oxygen enters the atmosphere.
Animals consume water to maintain osmotic and salt balance in the body and release it into the external environment along with metabolic products.

Nature protection is commonly understood as a system of measures aimed at maintaining a rational interaction between human activities and the natural environment. This system of measures should ensure the conservation and restoration of natural resources, rational use natural resources as well as to prevent direct and indirect harmful effects industrial production on nature and human health. At the same time, the task is set to maintain a balance between the development of production and the sustainability of the natural environment in the interests of mankind. This requires a comprehensive study of the processes occurring in the natural environment, and the organization of all types of production, taking into account the identified patterns. The scientific basis for the study of natural objects and an integrated approach to the organization of modern production is the doctrine of the Earth's biosphere.

The term "biosphere" was introduced in 1875 by the Austrian geologist E. Suess; the founder of the modern theory of the biosphere is the Russian scientist V. I. Vernadsky. In the view of V. I. Vernadsky, the biosphere covers the space in which living matter acts as a geological force that forms the face of the Earth;

IN modern view The biosphere is a complex dynamic large system consisting of many components of animate and inanimate nature, the integrity of which is maintained as a result of the constantly acting biological cycle of substances.

The teachings of V. I. Vernadsky are based on the ideas of the planetary geochemical role of living matter in the formation of the biosphere, as a product of a long-term transformation of matter and energy in the course of the geological development of the Earth. Living Substance is a set of living organisms that existed or exist in a certain period of time and are a powerful geological factor. Unlike living beings studied by biology, living matter as a biogeochemical factor is characterized by elemental composition, mass and energy. It accumulates and transforms solar energy and involves inorganic matter in a continuous cycle. Atoms of almost all chemical elements have repeatedly passed through living matter. Ultimately, the living matter determined the composition of the atmosphere, hydrosphere, soils and, to a large extent, the sedimentary rocks of our planet.

IN AND. Vernadsky pointed out that living matter accumulates the energy of the cosmos, transforms it into the energy of terrestrial processes (chemical, mechanical, thermal, electrical, etc.) and, in a continuous exchange of substances with the inert matter of the planet, ensures the formation of living matter, which not only replaces its dying masses, but also introduces new qualities, thereby determining the process of evolution of the organic world.

In the views of V. I. Vernadsky, the biosphere includes four main components:

living matter - the totality of all living organisms;

biogenic matter, i.e., products formed as a result of the vital activity of various organisms (coal, bitumen, peat, forest litter, soil humus and ip.);

bioinert matter - inorganic matter transformed by organisms (for example, the surface atmosphere, some sedimentary rocks, etc.);

inert matter - rocks of mainly igneous, inorganic origin that make up the earth's crust.

Any species of plants, animals and microorganisms, interacting with the environment, ensure their existence not as a sum of individuals, but as a single functional whole, which is a population (populations of pine, mosquito, etc.).

According to S.S. Schwartz, a population is an elementary grouping of organisms of a certain species, which has all the necessary conditions to maintain its numbers indefinitely. long time and in constantly changing environmental conditions. In other words, a population is a form of existence of a species, that supraorganismal system that makes a species potentially (but not really) immortal. This indicates that the adaptive capacity of the population is much higher than that of the individual organisms that make it up.

A population as an elementary ecological unit has a certain structure, which is characterized by its constituent individuals and their distribution in space. Populations are characterized by growth, development, and the ability to maintain existence in constantly changing conditions.

In nature, populations of plants, animals and microorganisms constitute systems of a higher rank - communities of living organisms, or, as they are commonly called, biocenoses. Biocenosis is organized group populations of plants, animals and microorganisms living in interaction under the same environmental conditions. The concept of "biocenosis" was proposed in 1877 by the German zoologist K-Mobius, who found that all members of one community of living organisms are in close and constant relationship. Biocenosis is a product natural selection, when its stable existence in time and space depends on the nature of the interaction of populations and is possible only with the obligatory supply of radiant energy from the Sun and the presence of a constant circulation of substances.

Sometimes, to simplify the study of biocenosis, it is conditionally divided into separate components: phytocenosis - vegetation, zoocenosis - animal world, microbiocenosis - microorganisms. Such a division leads to the artificial separation of separate groups of living organisms that cannot exist independently. There can be no stable system that would consist only of plants or only of animals. Communities and their components must be considered as a biological unity different types living organisms.

The biocenosis cannot develop on its own, outside and independently of the environment of the inorganic world. As a result, certain relatively stable complexes, sets of living and non-living components, are formed in nature. A space with homogeneous conditions inhabited by a community of organisms (biocenosis) is called a biotope, i.e. a biotope is a place of existence, a habitat for a biocenosis. Therefore, the biocenosis can be considered as a historically established complex of organisms, characteristic of this particular biotope.

The biocenosis forms a dialectical unity with the biotope, a biological macrosystem of an even higher rank - the biogeocenosis. The term "biogeocenosis", denoting the totality of the biocenosis and its habitat, was proposed in 1940 by V.N. Sukachev. The term is practically identical to the term "ecosystem", which belongs to A. Tensley.

An ecological system is a system consisting of living and non-living elements of the environment, between which there is an exchange of matter, energy and information. Ecological systems of different ranks may include a limited or very large number of components and occupy small or very large areas and volumes; the ecological system of Europe, the ecological system of the country, the ecological system of the region, district, area of operation of the enterprise, etc.

Biogeocenosis is understood as an element of the biosphere, where, for a certain extent, the biocenosis (community of living organisms) and the biotope corresponding to it (parts of the atmosphere, lithosphere and hydrosphere) remain homogeneous and closely interconnected into a single complex. That is, biogeocenosis is understood as a natural natural complex through which no significant biocenotic, geomorphological, hydrological, microclimatic, nocturnal-geochemical or any other boundary passes. This is a region of the biosphere that is homogeneous in terms of topographic, microclimatic, hydrological, and biotic conditions. The concept of "ecological system" does not carry this limitation and can combine different natural complexes (forest, meadow, river, etc.). Biogeocenosis itself is an elementary ecological system.

The elementary structural unit of the biosphere - biogeocenosis - consists of two interrelated components (Fig. 3.1):

abiotic (biotope), including abiotic elements of the environment that are in relationship with living organisms;

biotic (biocenosis), a community of living organisms living within a selected biotope (selected ecological system).

The abiotic component includes the following components: lithosphere, hydrosphere and atmosphere.

In the lithosphere, a section of an array of rocks, the earth's surface, which are the habitat of living organisms and are part of the selected biocenosis, are distinguished. An important characteristic biotope is a section of the earth's surface with a special structure and material composition of soils (pedosphere) within the selected area.

The hydrosphere includes surface and ground waters located within the biotope and directly or indirectly providing the vital activity of living organisms, as well as water that falls in the form of precipitation in the territory of a selected area.

The atmosphere (gas component) includes: atmospheric air; gases dissolved in surface and underground waters; the gas component of soils, as well as gases released from the mountain range, which directly or indirectly affect the vital activity of living organisms.

The biotic component of the natural environment (biocenosis) includes three components: phytocenosis-producers (producers) of primary production, accumulating solar energy; eocenosis - consumers, producers of secondary products, using for their life the energy contained in the organic matter of the phytocenosis; microbocenosis-reducers (disruptors), organisms that live off the energy of dead organic matter and ensure its destruction (mineralization) with the production of initial mineral elements in a form convenient for use by plants for the reproduction of primary organic products.

All components of the natural environment (biogeocenosis), its biotic and abiotic components are in constant relationship and ensure the evolutionary development of each other. The composition and properties of the lithosphere, hydrosphere and atmosphere largely determine living organisms. At the same time, living organisms themselves, providing the vital activity of each other, depend on changes in environmental conditions. The external environment provides them with energy and essential nutrients.

Thus, in general, the biosphere includes the following levels of life: population, biocenosis, biogeocenosis. Each of these levels is relatively independent, which ensures the evolution of the macrosystem as a whole, where the evolving unit is the population. At the same time, the elementary structural unit of the biosphere is the biogeocenosis, that is, the community of organisms in conjunction with the inorganic habitat (see Fig. 3.1).

In modern conditions, human activity transforms natural resources(forests, steppes, lakes). They are replaced by sowing and planting of cultivated plants. This is how new ecological systems are formed - agrobiogeocenoses or agrocenoses. Agrocenoses are not only agricultural fields, but also field-protective forest plantations, pastures, forest plantations, ponds and reservoirs, canals and drained swamps. In most cases, agrobiocenoses in their structure are characterized by a small number of species of living organisms, but their high abundance. Although there are many specific features in the structure and energy of natural and artificial biocenoses, there are no fundamental differences between them.

The situation is much more complicated with ecological systems that arise in the zones of influence of industrial enterprises, cities, dams and other large engineering structures. Here, as a result of the active impact of people on the environment, qualitatively new ecological systems are formed, the functioning of which is ensured as a result of natural processes and the constant impact of an industrial enterprise on the abiotic (non-living) and biotic (living) components of nature.

5. Biotic cycle of substances in the biosphere

The existence of the biosphere as a whole and its individual parts ensures the circulation of substances and the conversion of energy:

The circulation of substances in the biosphere is carried out in the first place on the basis of the vital activity of a wide variety of organisms. Each organism extracts from the environment the substances necessary for its vital activity and returns unused ones. Moreover, some types of living organisms consume the substances they need Directly from the environment, others use products processed and isolated first, still others second, and so on until the substance returns to the natural1 environment in its original state. Hence the need arises for the coexistence of various organisms (species diversity) capable of using the products of each other's life activity, i.e., it operates practically without waste; new production of biological products.

The total number of living organisms and the rate of their development in the biocenosis depend on the amount of energy entering the ecological system, the rate of its transfer through the individual elements of the system and the intensity of the circulation of mineral substances. A feature of these processes is that nutrients (carbon, nitrogen, water, phosphorus, etc.) circulate between the biotope and biocenosis constantly, that is, they are used countless times, and the energy entering the ecological system in the form of a stream of solar radiation, is spent ^ Xia Completely. According to the law of conservation and transformation, the energy entering the ecological system can change from one form to another. The second fundamental principle is that any action associated with the transformation of energy cannot take place without its loss in the form of Heat dissipated in space. That is, part of the energy entering the ecological system is lost and cannot do work.

Any ecological system In the process of its evolution tends to its equilibrium state, when all its fn=eic parameters take on a constant value, & the coefficient of efficiency reaches its maximum value»

The vital activity of any organism is ensured as a result of the many-sided biotic relationships it enters into with other organisms. All organisms can be classified according to the mode of feeding and the trophic level at which they are found in the general food chain. According to the method of nutrition, two groups are distinguished: autotrophic and heterotrophic.

Autotrophs have the ability to create organic substances from inorganic substances using the energy of the Sun or the energy released during chemical reactions.

Heterotrophic organisms use organic matter as food. In this case, living plants or their fruits, dead remains of plants and animals can be used as food. Moreover, each organism in nature in one form or another serves as a source of nutrition for a number of other organisms.

As a result of the successive transition of organic matter from one trophic level to another, the cycle of matter and the transfer of energy in nature occur (Fig. 3.2). At the same time, organic substances, moving from one trophic level to another, are partially excluded from the cycle. As a result, organic compounds accumulate on Earth in the form of mineral deposits (peat, coal, oil, gas, oil shale, etc.). However, essentially the biomass on Earth does not accumulate, but is kept at a certain level, since it is constantly destroyed and re-created from the same building material, i.e. within its limits, an uninterrupted circulation of substances takes place. In table. 3.1 provides data on the rate of biomass reproduction for some natural ecological systems.

In the process of vital activity of organisms, the inanimate part of the biosphere was also radically transformed. Free oxygen appeared in the atmosphere, and an ozone screen appeared in its upper layers; carbon dioxide, extracted by organisms from air and water, was preserved in deposits of coal and calcium carbonate.

As a result of geological processes, deformations and destruction of the upper part of the lithosphere occur. Previously buried sedimentary rocks are again on the surface. In the future, their weathering occurs, in which living organisms also take an active part.

By releasing carbon dioxide, organic and mineral acids, they contribute to the destruction of rocks and thereby participate in the process of migration of chemical elements.

The total amount of solar energy annually received by the Earth is approximately 2-1024 J. In the process of photosynthesis, about 100 billion tons of organic substances are formed per year and 1.9-1021 J of solar energy is accumulated. For photosynthesis processes, 170 billion tons of carbon dioxide are annually involved from the atmosphere, about 130 billion tons of water are decomposed by photochemical means, and 115 billion tons of oxygen are released into the environment. In addition, 2 billion tons of nitrogen, silicon, ammonium, iron, calcium and many other substances are involved in the circulation of substances. In total, more than 60 elements are involved in the biological cycle.

The synthesis phase of organic matter is replaced at the next stage of the biological cycle by the phase of its destruction with simultaneous dissipation of potential chemical energy (in the form of thermal energy) in space. As a result, organic matter passes into gas, liquid and solid forms (mineral and other compounds). In the process of these three phases, the biological cycle is renewed, which is supported by solar energy and in which practically the same masses of substances and chemical elements are involved.

In the process of the geological circulation of substances, mineral compounds are transferred from one place to another on a planetary scale, and there is also a transfer and change in the state of aggregation of water (liquid, solid - snow, ice; gaseous - lares). Water circulates most intensively in the vapor state.

The water cycle in the biosphere is based on the fact that total evaporation is compensated by precipitation. At the same time, more water evaporates from the ocean than returns with precipitation. On land, on the contrary, more precipitation falls, but the excess flows into lakes and rivers, and from there again into the ocean.

With the advent of living matter based on the water cycle and mineral compounds dissolved in it, i.e. on the basis of the abiotic, geological, the cycle of organic matter, or the small biological cycle, arose.

In the biological cycle, the most important process is transpiration. When soil moisture is absorbed by the roots of a plant, mineral and organic substances dissolved in water enter it with water. The process of transpiration is also important for regulating the temperature of the plant, preventing it from overheating. Due to the heat loss that occurs during the evaporation of water, the temperature of the plant decreases. At the same time, this process is regulated by the plant itself - in hot weather, the stomata located on the leaves open wider and this contributes to an increase in evaporation and a decrease in temperature, and at a lower temperature, the stomata are covered, the intensity of evaporation decreases. Thus, transpiration is both a physiological and physical process, since it differs from ordinary evaporation from inanimate matter in the ability to regulate the plant itself.

The transpiration capacity of a plant is often estimated by the transpiration coefficient, which characterizes the volume of water that must be spent to form a unit mass of dry matter of the plant. For example, for the formation of 1 ton of ground plant mass of wheat, i.e. grain and straw, 300-500 m3 of water is consumed Water consumption for travepiration depends on a large number of factors: the nature of the plant itself, weather conditions, and the presence of moisture in the soil. In dry, hot weather, the plant needs to spend a large amount of water for transpiration.

Plant roots absorb soil moisture from different depths. The root system of wheat extends to a depth of 2.0-2.5 m, oak roots sometimes penetrate to a depth of 20 m. Due to this, plants are able to use moisture located at great depths and are less dependent on fluctuations in the moisture content of the surface soil layer.

Evaporation from the soil cannot be considered in isolation from transpiration. For example, under a forest canopy, little water evaporates from the soil surface, regardless of its presence. This is because solar radiation weakly penetrates through the crowns of trees. In addition, under the canopy of the forest, the speed of air movement slows down, and it is more saturated with moisture. Under these conditions, the main part of the moisture evaporates due to transpiration.

In the water cycle, the most important phases are those that occur within individual river and lake basins. Vegetation performs an important screening function, retaining part of the water that falls in precipitation. This interception, which, of course, is maximum during light rains, can reach up to 25% of the total precipitation in temperate latitudes.

Part of the water is retained in the soil, and the stronger, the more significant the soil colloidal complex (humus and clay). That part of the water that penetrates the soil to a depth of 20-30 cm can again rise to its surface through capillaries and evaporate. Thus, the transition of water from the surface to the atmosphere is carried out as a result of physical evaporation and the process of transpiration. At the same time, the amount of water transpired by the plants increases with the improvement of their water supply. So, one birch evaporates 0.075 m3 of water per day; beech - 0.1 m; linden - 0.2, and 1 ha of forest - 20-50 m3. 1 hectare of birch forest, whose foliage weight is 4940 kg, evaporates 47 m - "of water per day, and 1 hectare of spruce forest, whose needle weight is 31 thousand kg. Transpires 43 m:< воды в день. 1 га пшеницы за период развития использует 375 мм осадков, а продуцирует 12,5 т (сухая масса) растительного вещества.

The biological cycle, in contrast to the geological cycle, requires less energy. Only 0.!-0.2% of the solar energy incident on the Earth is spent on the creation of organic matter (up to 50% on the geological cycle) - Despite this. the energy involved in the biological cycle does a great job of creating primary production on the planet.

The circulation of substances is usually called biogeochemical cycles. The main biogeochemical cycles are the circulation of oxygen, carbon, water, nitrogen, phosphorus and a number of other elements.

In general, each circulation of any chemical element is part of the general grandiose circulation of substances on Earth, that is, they are all closely interconnected by various forms of interaction. The main links of biogeochemical cycles are living organisms, which determine the intensity of all cycles and the involvement of almost all elements of the earth's crust in them.

Almost all the molecular oxygen in the earth's atmosphere originated and is maintained at a certain level thanks to the activity of green plants. In large quantities, it is consumed by organisms in the process of respiration. But, in addition, having a high chemical activity, oxygen will certainly enter into compounds with almost all elements of the earth's crust. It is estimated that all the oxygen contained in the atmosphere passes through living organisms (binding during respiration and released during photosynthesis) in 200 years, carbon dioxide cycles in the opposite direction in 300 years, and all the waters on Earth are decomposed and recreated through photosynthesis and respiration in 2 million years.

The cycle and migration of substances in biochemical cycles can be considered using the carbon cycle as an example (Fig. 3.3). On land, it begins with the fixation of carbon dioxide by plants during photosynthesis. The carbon dioxide contained in the atmosphere is taken up by plants, and as a result of photosynthesis, hydrocarbons are formed and oxygen is released.

In turn, carbohydrates are the starting material for the formation of plants.

The carbon fixed in the plant is largely consumed by animals. Animals also release carbon dioxide when they breathe. The obsolete plants and animals are decomposed by microorganisms, as a result of which the carbon of the dead organic matter is oxidized to carbon dioxide and re-enters the atmosphere. A similar cycle of carbon occurs in the ocean.

Part of the carbon dioxide from the atmosphere enters the ocean, where it is in dissolved form. That is, the ocean ensures the maintenance of carbon dioxide in the atmosphere within certain limits. In turn, the carbon content in the ocean at a certain level is provided by the accumulated reserves of calcium carbonate in bottom sediments. The presence of this permanent natural process to a certain extent regulates the content of carbon dioxide in the atmosphere and in the waters of the ocean.

The nitrogen cycle, like other biogeochemical cycles, covers all areas of the biosphere (Fig. 3.4). Nitrogen, which is very abundant in the atmosphere, is absorbed by plants only after it is combined with hydrogen or oxygen. In modern conditions, man intervened in the nitrogen cycle. He grows nitrogen-fixing legumes over vast areas or artificially fixes natural nitrogen. It is believed that Agriculture and industry provide almost 60% more fixed nitrogen than it is produced naturally.

The cycle of phosphorus, which is one of the main elements required by living organisms, is relatively simple. The main sources of phosphorus are igneous (apatites) and sedimentary (phosphorites) rocks. Inorganic phosphorus is involved in the cycle as a result of natural leaching processes. Phosphorus is assimilated by living organisms, which, with its participation, synthesize a number of organic compounds and transfer it to different trophic levels. Having finished their journey through the trophic chains, organic phosphates are decomposed by microbes and turn into mineral orthophosphates available to green plants. Phosphates enter water bodies as a result of river runoff, which contributes to the development of phytoplankton and living organisms located at different levels of the trophic chain of freshwater or marine water bodies. The return of mineral phosphates to water is also carried out as a result of the activity of microorganisms. However, it should be noted that phosphates deposited at great depths are excluded from the cycle, which must be taken into account when compiling the balance of this biogeochemical cycle. Thus, there is only a partial return of phosphorus that has fallen into the ocean back to land. This process occurs as a result of the life of birds that feed on fish.

Part of the phosphorus comes to the continent as a result of human fishing. However, the amount of phosphorus annually supplied with fish products is much lower than its removal to the hydrosphere, which reaches many millions of tons per year. In addition, by applying phosphate fertilizers to the fields, a person significantly accelerates the process of phosphorus removal into watercourses and the ocean. At the same time, environmental damage is caused to water bodies, as the natural processes of vital activity of organisms living in the water are disturbed.

Since phosphorus reserves are very limited, its uncontrolled consumption can lead to a number of negative consequences. It is the main limiting factor for autotrophic organisms of both aquatic and terrestrial environments, the main regulator of a number of other biogeochemical cycles. For example, the content of nitrates in water or oxygen in the atmosphere largely depends on the intensity of the phosphorus cycle in the biosphere.

6. natural ecological systems

Structure and dynamics of populations. The study of the structure and dynamics of populations is of great practical importance.

Not knowing the patterns of population life. It is impossible to ensure the development of scientifically based environmental, engineering and organizational measures for the rational use and protection of natural resources.

The population approach to the study of the vital activity of organisms is based on their ability to regulate their abundance and density under the influence of various abiotic and biotic environmental factors.

The main parameters of a population are its abundance and density. Population size is the total number of individuals in a given area or in a given volume. It is never constant and, as a rule, depends on the ratio of the intensity of reproduction and mortality.

Population density is determined by the number of individuals or biomass per unit area or volume. For example, 106 birch plants per 1 ha. or 1.5 perch per 1 m3 of water characterizes the population density of these species. With an increase in abundance, the He density increases only if the population can be dispersed over a larger area or in a larger volume.

The size of the distribution area, the number and density of populations are not constant and can vary within significant limits. Often these changes are associated with human activities. But the main reasons for such dynamics are changes in the conditions of existence, the availability of food (ie energy resources) and other reasons.

It has been established that the number of populations can fluctuate without limit. Keeping the population within certain limits is ensured by its ability to self-regulate. Any population always has lower AND upper density limits, beyond which it cannot go (Fig. 3.5). With a favorable combination of factors, the population density is kept at some optimal level, slightly deviating from it. Such fluctuations in density are usually correct, regular in nature and clearly reflect the reaction of the Population to specific changes in environmental conditions. In nature, seasonal fluctuations in laziness can take place, especially in small animals (mouse-like rodents. Insects, some birds). Thus, the number of mouse-like rodents during one season sometimes increases by 300-100 times, and of some insects by 1300-1500 times.

A drop in density below the optimum causes a deterioration in the protective properties of the population, a decrease in its fertility and a number of other negative phenomena. Populations with a minimum number of individuals cannot exist for a long time. There are known cases of extinction of animals with a low number even in reserves with very favorable living conditions. Increasing the density above the optimum also adversely affects the population, since this destroys the food supply and reduces the living space.

Populations regulate their numbers and adapt to changing environmental conditions by updating individuals. Individuals appear in the population through birth and immigration, and disappear as a result of death and emigration. With a balanced intensity of births and deaths, a stable population is formed. In such a population, mortality is compensated by growth, i.e. population size to its range is kept at a certain level.

However, population equilibrium does not exist in nature. Each population is endowed with both static and dynamic properties, so their density is constantly fluctuating. But under stable external conditions, these fluctuations occur around some average value. As a result, populations do not decrease or increase, do not expand or narrow their range.

Self-regulation of population density is carried out by two mutually balancing forces acting in Nature. This, on the one hand, is the ability of organisms to reproduce, on the other hand, processes that depend on population density and limit reproduction. Autoregulation of population density is a necessary adaptation for maintaining life in constantly changing conditions.

A population is the smallest evolving unit. It does not exist in isolation, but in connection with populations of other species. Therefore, non-population mechanisms of automatic regulation, more precisely, inter-population mechanisms, are also widespread in nature at the same time. At the same time, the population is a regulated object, and the natural system, which consists of many populations of different species, acts as a regulator. This system as a whole and the populations of other species included in it affect this particular population, and each separately, for its part, affects the entire system of which it is a part.

Functioning and structure of biogeocenoses. In biocenoses between various types living organisms have certain connections. The main form of these connections is nutritional relationships, on the basis of which complex chains and cycles of nutrition and spatial relationships are formed. It is through food and spatial relationships (trophic and topical) that various biotic complexes are built that unite the species of living organisms into a single whole, i.e. into the biological macrosystem - biogeocenosis.

Natural biogeocenoses usually represent multispecies communities. And the more diverse in species composition the biocenosis, the more opportunities it has for a more complete and economical development of material and energy resources.

All links in the food chain are interconnected and dependent on each other. Between them, from the first to the last link, the transfer of matter and energy is carried out (Fig. 3.6, a). When energy is transferred from one trophic level to another, energy is lost. As a result, the supply chain cannot be long. Most often, it consists of 4-6 links on land and 5-8 in the ocean. In any food chain, not all food is used for the growth of an individual, i.e. for the accumulation of biomass. Part of it is spent on meeting the body's energy costs: for respiration, movement, reproduction, maintaining body temperature, etc. At the same time, the biomass of one link cannot be completely processed by the next link. In each subsequent link in the food chain, there is a decrease in biomass compared to the previous one. This applies not only to biomass, but also to the number of individuals and energy flow.

This phenomenon was studied by C. Elton and called the pyramid of numbers, or Elton's pyramid (Fig. 3.6.6). The base of the pyramid is formed by plants - producers, Phytophages are located above them. The next link is represented by consumers of the second order. And so on to the top of the pyramid, which is made up of the largest predators. The number of floors of the pyramid usually corresponds to the number of links in the food chain.

Ecological pyramids express the trophic structure of an ecological system in geometric form. They can be built from separate rectangles of the same height, the length of which on a certain scale reflects the value of the measured Parameter. In this way, pyramids of numbers, biomass and energy can be built.

The source of energy for the biological cycle of substances is solar radiation accumulated by green plants - autotrophs. Of all the solar radiation reaching the Earth, only about 0.1-0.2% of the energy is captured by green plants and provides the entire biological cycle of substances in the biosphere. At the same time, more than half of the energy associated with photosynthesis is consumed by the plants themselves, while the rest is accumulated in the body of the plant and subsequently serves as an energy source for the whole variety of organisms of subsequent trophic levels.

The functions of living matter in the biosphere are diverse, but they all serve the same purpose - the movement of chemical elements. Why is this movement necessary, and how did it occur 3.5 billion years ago, that is, before life appeared on Earth? Since its inception, the role of living matter in the biosphere has become key. Despite its insignificant mass, approximately 10 -6 masses of other shells of the Earth, it is the carrier of energy due to which this movement occurs.

The concept of "living matter of the biosphere" includes all living organisms on the planet. Regardless of which class, species, genus, and so on they belong. These are not only organic substances, but also inorganic, as well as minerals. It "lives" in all layers of the biosphere - in the lithosphere, hydrosphere and atmosphere. If the conditions of existence are unsuitable, it either falls into a state of suspended animation, that is, it slows down all its processes so much that visible manifestations of life are practically absent, or it dies.

Distinctive features and role

How to distinguish the living matter of the biosphere from the non-living?

Fifth, it exists in all phase states. Sixth, it is an individual organism and, with a change of generations, is characterized by continuity or heredity.

The living matter of the biosphere ensures the migration of chemical elements both from one organism to another, and between the organism and the environment. Movement occurs when living organisms digest food, develop and grow, and also move in the process of life. The first such movement of elements is called chemical or biochemical, and the second - mechanical. Moreover, the activity of living organisms strives to ensure that this migration proceeds as quickly as possible, and the energy received from the Sun is used most efficiently. To do this, they constantly and continuously adapt, adapt and develop.

Functions

The role of living organisms in the biosphere is to perform several functions. The main ones are: energy, destructive, concentration and environment-forming.

Energy function. It is associated with the ability of green chlorophyll organisms to photosynthesis. With the help of the solar energy they receive, they transform the simplest compounds such as water, carbon dioxide and minerals into complex organic substances, which, in turn, are necessary for the existence of other living beings. Plants have this ability. For the process of photosynthesis, they use only 1% of the solar energy that falls on Earth. They annually produce about 145 billion tons of oxygen, for which they consume about 200 billion tons of carbon dioxide. In this case, more than 100 billion tons of organic matter are produced. This is how plants replenish the atmosphere with free oxygen. If plants did not do this permanently, then oxygen, as an active chemical element, would enter into reactions and form various compounds, and as a result, it would completely disappear from the Earth's atmosphere. And with it, life would cease to exist. In addition to plants, organic matter in a very small amount - no more than 0.5% of the total, is produced by some bacteria. This process is called chemosynthesis. It does not involve solar energy, but the energy released during the oxidation reactions of sulfur and nitrogen compounds.

Organic compounds synthesized in this way - protein, sugar, and so on - together with the energy contained in them, are food and are distributed along the trophic chain. In addition, the energy synthesized by plants is dissipated as heat or accumulated in dead organic matter, turning into a fossil state. And in this the next function is destructive.

This role of living organisms in the biosphere is also called the mineralization of organic substances. As a result of decomposition, dead organic matter is converted into simple inorganic compounds. This process involves living organisms that perform a destructive or destructive function. In the trophic chain, they are called "reducers". These are fungi, bacteria, worms and microorganisms. The result of decomposition are: carbon dioxide, water, hydrogen sulfide, methane, ammonia and so on. Which, in turn, are "food" for plants. And the process starts again.

An important role is played by the decomposition process taking place in the lithosphere. Thanks to him, elements such as silicon, aluminum, magnesium and iron are released from rocks.

Reducers, with the help of the acids at their disposal, “extract” and “send” such important chemical elements as calcium, potassium, sodium, phosphorus, silicon and various trace elements into the biotic circulation. Thanks to the destructors, the soil acquires its fertility.

Another function of living organisms is concentration. It refers to the process in which some of their species extract and then accumulate certain chemical elements in themselves. In this case, the concentration of elements such as carbon, hydrogen, nitrogen, sodium, magnesium, silicon, sulfur, chlorine, potassium, calcium and oxygen can be hundreds and thousands of times higher than in the environment. For example, manganese by 1,200,000 times, silver by 240,000, and iron by 65,000. Shells, shells and skeletons can be striking examples of such an accumulation. With elements "suitable" for accumulation, some species accumulate poisonous, poisonous and radioactive substances in themselves. And getting them into the food chain is clearly not positive.

The opposite of the concentration function is the scattering function. It manifests itself with various secretions, movements, and the like. For example, there is a dispersion of iron from the blood, with the bites of various insects or blood-sucking.

The biosphere is not only the interaction between living organisms and the exchange of energy between them. The essential role of living organisms in the biosphere is its transformation. Living organisms change the physicochemical parameters of their environment, and this function is called "environment-forming". It is, as a result of all the previously considered functions in the aggregate. The extraction of chemical elements, their accumulation, and then, with the help of the energy received, "dispatch" on the way through the biological cycle, led to significant changes in the natural environment. Over billions of years, the gas composition of the atmosphere has changed, the chemical composition of water has changed, sedimentary rocks and bottom sediments have appeared, and a fertile soil cover has arisen. And we are currently facing this influence.

By transforming the external environment, organisms create an optimal balance of energy and "nutrient" for their existence and the entire biosphere as a whole. This balance, as a result of numerous internal and external influences, is always under threat of destruction. And the substance, due to its listed qualities, resists such influence, restores the broken and brings the system to a stable state.

The considered functions of living organisms in the biosphere concerned two stages of the transformation of organic matter into inorganic and vice versa. At these stages, plants play their role as producers, and bacteria, fungi and microorganisms as decomposers. What is the role of consumers or consumers, the main types of which are animals?

Animals

The most saturated, in terms of the number of transitions from one organism to another, is the stage between how the plants produced oxygen and ends when the dead organism hit the "table" of the destroyers.

The next level uses no more than 1% of the energy of the previous one. With the death of phytophages and zoophages, their bodies fall into the hands of saprophages and bacteria. Saprophages are the same destroyers, decomposers or gravediggers. On their "table" organic matter completes its journey. The circle is closed. During this cycle, the amount of matter or chemical elements remained the same. As it was millions of years ago. Only energy is wasted. It is believed that the role of animals in the biosphere is that they contribute to the movement of chemicals, participate in their distribution and in the exchange of energy. But their role seems to be somewhat broader. As a living self-organizing system, the biosphere seeks to balance and maintain its internal balance. The mass of its living matter must be maintained in a certain volume, and this function is performed by animals. An example would be those biosystems where the animal world has disappeared or is on the verge of it. As a result, the volume of matter falls, which inevitably leads to the destruction of the balance and the death of the system.