Biospheric level of life organization. Fundamentals of V.I.Vernadsky's teachings about the biosphere. Organization of the biosphere The biosphere is a natural part of the cosmic organization
The biosphere is a thermodynamically complex open system on the surface of the Earth, acting due to the energy of the Sun and the vital activity of living organisms, accumulating and redistributing huge flows of matter and energy. This process is possible only due to the chemical properties of cyclic, or organogenic elements, so named by V. I. Vernadsky in his geochemical classification of elements for their ability to numerous chemical reversible processes, and the history of all these elements can be expressed in cycles.
The concept of " living matter” and the whole complex of ideas about its geochemical activity were introduced into science by V. I. Vernadsky. In 1919, he wrote: “Under the name of living matter, I will mean the totality of all organisms, and animals, including man. From a geochemical point of view, this set of organisms is significant only by the mass of matter that composes it, its chemical composition and the energy associated with it. Obviously, it is only from this point of view that living matter is important for the soil, since, since we are dealing with soil chemistry, we are dealing with a particular manifestation of general geochemical processes. The living matter that has become part of the soil causes the most diverse changes in its properties, which are usually not taken into account in soil science. In the first place, I will dwell here on its effect on the fine-grainedness of the soil, because this property of the soil is its most basic and sharp difference from all other products of the earth's surface. It also determines the course of all chemical reactions in the soil and makes the soil the most active area from a chemical point of view in the biosphere.
At the same time, the scientist for the first time expressed the idea of \u200b\u200bthe joint finding chemical elements in living matter, which is determined by the biological properties of organisms, and not chemical properties elements.
To build living organisms from 105 chemical elements, six are required - carbon, nitrogen, hydrogen, oxygen, phosphorus, sulfur. They are characterized by low atomic weight, ease of return and attachment of electrons. The main element among them is carbon. Due to the ability of atoms to combine in a chain, carbon can form an infinite number of compounds. The remaining five elements also extremely easily form common electron pairs with atoms of other elements, including with each other.
As for the amount of accumulated elements, 99.9% of the live weight of organisms are the elements of the "initial dozen": H, C, N, O, Na, Mg, P, S, C1, K, Ca, Fe. All of them belong to the first 26 elements of the periodic system, which D. I. Mendeleev drew attention to. The live weight is 99% formed by only four elements - H, C, N, O, which are highly reactive, have highly soluble compounds and actively interact with carbon.
In the biosphere, the cycle of an element will be fast and stable only if this element is not only soluble, but also volatile, i.e. if one of its compounds can, like water, return to land through.
There are at least three such elements in the biosphere: carbon, nitrogen and sulfur. Among their "air" compounds are carbon dioxide (CO2), methane (CH4), free nitrogen (N2), ammonia (NH3), hydrogen sulfide (H2OS) and sulfur dioxide (SO2). Interestingly, in the process of cycling, carbon, nitrogen and sulfur change their valency. All of them are in the biosphere in a more reduced form than in the surrounding world.
In the exchange of substances between animate and inanimate nature, the most important is the redistribution of gases. Plants, synthesizing organic matter, absorb carbon dioxide from the atmosphere and release oxygen. The binding of 1 g of carbon in organic matter is accompanied by the release of 2.7 g of oxygen. From 1 hectare of meadow, 10-12 thousand m3 of oxygen is released into the atmosphere per year.
The most important stage of the cycle is the reduction of carbon dioxide. Essentially, it is a hydrogen addition reaction resulting in formaldehyde. The source of hydrogen is the dehydrogenation of water (removal of hydrogen from it), while oxygen is released along the way. This way of storing energy chemical bonds is characteristic only of green plants, but the accumulated energy becomes suitable for other vital reactions and for the functioning of trophic () chains. Carbon fixed by plants and then used not only by them, but also by animals, returns to the external environment, where it can be included in any of the geochemical cycles. Recall that the biosphere is characterized not only by the presence of living matter. It contains significant amounts of liquid water, takes on a powerful flow of energy from sunlight, in the biosphere there are interfaces between substances that are in one of three phases - solid, liquid and gaseous. Due to this, the biosphere is characterized by a continuous circulation of matter and energy, in which living organisms play the most active role.
The biosphere is characterized not only by the presence of living matter. It also has the following three features: it contains a significant amount of liquid water; a powerful stream of energy from the sun's rays rushes to it; it contains interfaces between substances in three phases - solid, liquid and gaseous. In this regard, within the biosphere, there is a continuous circulation of matter and energy, in which living organisms play the most active role.
The biosphere accumulates and redistributes huge flows of matter and energy. This process is possible only due to the chemical properties cyclic, or "organogenic" elements named so by V. I. Vernadsky in the geochemical classification of elements for their ability to numerous chemically reversible processes.
The cyclic nature of chemical reactions was first foreseen by scientists of the 18th century for atmospheric gases, especially for oxygen. In a clear form, the ideas of chemical cycles were expressed by the Scottish scientist J. Pringle in 1773, when he discussed the balance of plant and animal life in relation to free oxygen and carbon dioxide, and then by A. Lavoisier. The French scientists J. B. Dumas and J. Bussingault in 1842 gave a vivid picture of chemical cycles, and somewhat later C. Bischof and J. Liebig transferred these ideas to ash elements earth's crust. It was this biotic cycle that was named by V. I. Vernadsky "organization of the biosphere". The most important point here is the geochemical activity of living matter.
In 1919 Vernadsky wrote: "By the name of living matter, I will mean the totality of all organisms, plant
and animals, including humans. From a geochemical point of view, this collection of organisms is significant only by the mass of matter that composes it, its chemical composition and the energy associated with it. At the same time, the scientist for the first time expressed the idea of organogenic paragenesis as a factor of geochemical transformations - the joint presence of chemical elements in living matter, which is determined by the biological properties of organisms, and not by the chemical properties of the elements.
V. I. Vernadsky attributed C, O, H, N, S, P, C1, K, Mg, Ca, Na, Fe to the main elements of organogenic paragenesis, to which Si, Mn, F, I, Co, B, Sr, Pb, Zn, Ag, Br, V. Living organisms always contain at least 20 - 25 chemical elements.
Chemical elements consumed by organisms contribute to the flow of biochemical processes in them: respiration, photosynthesis, protein synthesis, protein, carbohydrate and fat metabolism, maintaining homeostasis of the internal environment, its water-salt balance. These physiological processes determine the needs of living organisms for certain elements in a biologically accessible form and the course of biogeochemical processes in the environment.
Of the 105 chemical elements, six are required for the construction of living organisms: C, N, H, O, P, S. These elements are characterized by a low atomic mass, the ease of giving off and attaching electrons. The main element among them is carbon. Due to the electrical neutrality of the atom, the ability of atoms to combine in a chain, carbon can form an infinite number of compounds. The remaining five elements also extremely easily form common electron pairs with atoms of other elements, including with each other.
As for the amount of accumulated elements, 99.9% of the live weight of organisms are elements "original dozen": H, C, N, O, Na, Mg, P, S, C1, K, Ca, Fe. All of them belong to the first 26 lightest elements. Periodic system, to which D.I. Mendeleev drew attention. 99% of the live weight is formed by only four elements: H, C, N, O, which are highly reactive, have highly soluble compounds and actively interact with carbon.
It must be remembered that no bio chemical reactions people on Earth do not go without water, and the presence of free water is as important a feature of the biosphere as the activity "living matter". Even the limits of active life in the biosphere are due to the possibility of finding water here in a liquid state. A large amount of water is so characteristic of any living organisms that, as the famous German physiologist E. Dubois-Reymond wrote,
the organism is animated water. For a living organism, bound water that does not lose its basic properties is an indispensable component. Its quantity in living organisms, with the exception of spores and inert seeds, ranges from 60 to 99.7%.
In the biosphere, the circulation of an element will be fast and stable only if the substances are not only soluble, but also volatile, i.e. if one of the compounds of the element can, like water, return to land through the atmosphere. There are at least three such elements in the biosphere: C, N and S. Among their "air" compounds are carbon dioxide (CO 2), methane (CH 4), free nitrogen (N 2), ammonia (NH 3), hydrogen sulfide (H 2 S) and sulfur dioxide (SO 2). Interestingly, in the process of cycling, carbon, nitrogen and sulfur change their valencies. It is clearly no coincidence that all of them are found in the biosphere in a more reduced form than in the environment.
Modern biochemistry believes that three main chemical reactions ensure the formation of biomass and the biogenic cycle:
carbon fixation in the process of photosynthesis or chemosynthesis, in other words, carboxylation;
sulfur recovery by microbes - obligate anaerobes;
reduction of nitrogen by adding hydrogen, i.e. hydrogenation.
Of these reactions, only carbon fixation necessarily occurs in a green plant under the action of sunlight. The other two reactions are carried out by microbes under anaerobic conditions. Water, in principle, is able to circulate on its own, without the help of the biosphere. But, being a source of hydrogen, which gives energy to the biosphere, water cannot but be involved in the reactions taking place in living matter.
In the exchange of substances between animate and inanimate nature, the most important is the redistribution of gases. Plants, synthesizing organic matter, absorb carbon dioxide from the atmosphere and release oxygen. The binding of 1 g of carbon in organic matter is accompanied by the release of 2.7 g of oxygen. From each hectare of meadow, 10-12 thousand m 3 of this gas is released into the atmosphere per year. Annually, the supply of oxygen is replenished by (7-10) · 10 10 tons due to the photosynthesis of green plants.
The most important stage of this cycle is the photosynthetic reduction of carbon dioxide. It is essentially a hydrogenation reaction resulting in formaldehyde. The source of hydrogen is the dehydrogenation of water (removal of hydrogen from it); while simultaneously freeing oxygen. This method of accumulating the energy of chemical bonds is characteristic only of green plants, but the accumulated energy becomes suitable for use inside the body for other life forms.
reactions, and in the ecosystem for the functioning of trophic (food) chains. Carbon fixed by plants and then used not only by them, but also by animals, is returned again oxidized to dioxide into the external environment, where it can be included in any geochemical cycle.
The chemical reduction of nitrogen, one of the most important hydrogenation reactions, cannot be carried out by green plants, although its result is by no means indifferent to them: the cycles of carbon and nitrogen are closely dependent on each other. Without microorganisms that absorb nitrogen from the air and hydrogenate nitrogen (the source of carbon for them is its dioxide), all the nitrogen of the biosphere would soon pass into the atmosphere and remain there in a stable oxidized form.
biospheric level- the highest form of organization of life on Earth. At this level, all the cycles of matter are combined and energy is transformed into a single cycle. Living things are organized according to the type of hierarchical systems: the transition from one level to another is associated with the preservation of the functional mechanisms that acted on previous level, and with the advent of new structures and functions, new qualities. The level is represented by the biosphere - the area of active life. She covers aerosphere(lower atmosphere) hydrobiosphere(hydrosphere), terrabiosphere(land surface) and lithobiosphere(upper part of the lithosphere). The biosphere is a rather thin layer: microbial life is distributed up to 22 km above the surface, and in the oceans the presence of life has been found at depths up to 10-11 km below sea level. Life penetrates less into the earth's crust, microorganisms are found when drilling to depths of 2 - 3 km. By chance, living matter also falls into the layers lying next to "above" and "below", they are called pair- And metabiosphere respectively. But the "film of life" covers the entire Earth, even in the deserts and ice traces of the living have been found. The distribution of life is extremely uneven. In the soil (upper layers of the lithosphere), hydrosphere and lower layers of the atmosphere - the largest amount of living matter.
The development of the doctrine of the biosphere has its own history. One of the first naturalists who looked at the Earth as a whole was M.V. Lomonosov. He wrote in his work “On the Layers of the Earth” that “chernozem is not primitive and not primordial matter, but came from the decay of animals and growing bodies over time”, that brown coal, coal and chernozem are the results of the influence of organisms on the soil. Lomonosov gave a general outline of the Earth's geology and proved its antiquity as a planet. At that time, even fossils - the fossil remains of organisms - were far from being perceived by everyone as traces of the once former life. In 1802, Lamarck, in Hydrogeology, pointed out the role of living organisms in geological processes. A. Humboldt's book "Cosmos" contains a lot of material about the influence of living things on geological structures.
The origin of the domestic agrochemistry associated with D.I. Mendeleev. He researched the problems of plant nutrition and increasing yields.
crops. The efficiency of mineral and organic fertilizers was studied by A.N. Engelgardt and D.N. Pryanishnikov. Emerged at the beginning of the 20th century. geochemistry proceeded from the principles of evolution. Soil forest formation studied V. A. Obruchev, initiating permafrost, he studied tectonics and geology. V.V. Dokuchaev, with his work "Russian Chernozem", opened soil science as a scientific discipline at the intersection of geology, biology and chemistry. He has soil - a special natural body, which is of great importance for Agriculture. He gave the world's first classification of soils, outlined the doctrine of landscape-geographical zones, developed plans to combat drought, providing for a number of agronomic and forest reclamation measures. M. M. Sibirtsev and P. A. Kostychev worked with him. Sibirtsev participated in many expeditions to the southern steppes of Russia, wrote the first textbook "Soil Science" (1889). Kostychev showed the relationship between soil properties and the vital activity of plants and microorganisms, and the role of man in changing these relationships. He established (1886) the decisive role of lower organisms in the formation of humus (humus). The German scientist G. Gelriger showed experimentally the symbiosis of legumes with nodule bacteria (1888), which turned out to be important in agronomy.
The Russian scientist V. R. Williams proved the role of biological factors (natural communities of higher green plants and microorganisms) in the formation of soil fertility. He was the first to emphasize the importance of the biological cycle of elements in the formation of not only the organic, but also the mineral part of soils, and developed the scientific foundations of the grass-field system of agriculture (1914). Dokuchaev, who taught mineralogy, determined the vital interests of V. I. Vernadsky as early as his student years. Vernadsky studied the evolution of the minerals of the earth's crust (1908), created a geochemical classification of chemical elements, developed the doctrine of the migration of atoms in the earth's crust, laid the foundations of the genetic direction in mineralogy, and it was the general problems of mineralogy and geology that led him to the concept of biogeochemistry (1917). "Biosphere" by Vernadsky gives a complete picture of the mechanism of formation of the earth's crust, taking into account the determining influence of life.
V.I.Vernadsky created the doctrine of the biosphere as an active shell of the Earth, in which the total activity of living organisms - geochemical factor planetary scale and significance. The term "biosphere", introduced (1875) by E. Suess, referred to the totality of organisms living on the surface of the Earth. Vernadsky also included man in the concept of living organisms. He singled out in the biosphere inert(solar energy, rocks, minerals, etc.) and bio-inert(soils, surface waters and organic matter). Although living matter in terms of mass and volume makes up an insignificant part of the biosphere, it plays a major role in the geological processes associated with the change of our planet.
According to Vernadsky, the biosphere is the living substance of the planet and the inert substance transformed by it. The concept of "biosphere" is a fundamental concept of biogeochemistry, and not biological or geological. The biosphere organizes processes on the Earth and near the Earth, bioenergetic processes and metabolism occur in it as a result of vital activity. A living organism is an integral part of the earth's crust that can change it. Living matter - a set of organisms involved in geochemical processes. Organisms take chemical elements from the environment, build bodies from them, return them to the same environment both in the process of life and after their death. Therefore, living matter binds the biosphere together, is a system-forming factor. Changes in living matter occur much faster than in inert matter, therefore they use the concept of historical time in it, and geological time in inert matter. In the course of geological times, the power of living matter and its impact on inert matter grows, and only in living matter during these times do qualitative changes occur. And living matter, perhaps, has its own process of evolution, regardless of changes in the environment.
If the "life cycle" of an individual organism is finite and its existence is not unlimited, then the living as a whole can be considered geologically immortal. Geologically, life is eternal, so if an individual eventually loses the ability to do work and ceases to exist, then the process of life itself is distinguished by the continuous growth of the ability to do external work. He expressed this idea in three principles, which he called biogeochemical:
1 - free (biogeochemical) energy tends to the maximum manifestation in the biosphere;
2 - during the evolution of species, those organisms survive that increase their free energy with their lives;
3 - the settlement of the Earth should be the maximum possible during geological time.
These principles express the law of living nature only and do not contradict the laws of thermodynamics. The entire flow of living matter from the simplest to the most advanced forms, including the human mind and social labor, is that form of matter movement where the law of entropy decreases, while it grows for inorganic matter. And these two types of matter are connected into a single whole. Vernadsky successfully applied the entropy increase law to explain the cosmic evolution of the Earth. And he considered the birth of the biosphere as a planetary-cosmic "special point" - a qualitative leap, up to which processes of inanimate nature prevailed on the surface of our planet, and after which processes in living nature began to predominate.
kind. Under the action of radiant energy, organic life arises and irreversibly develops.
Vernadsky believed that life on Earth arose simultaneously with the formation of the planet: "The creatures of the Earth are the creation of a cosmic process, a necessary and natural part of a harmonious cosmic mechanism." Among the many patterns that take place in biology, geology, biochemistry and geochemistry, Vernadsky singled out the main empirical principles.
1. The principle of integrity of the biosphere is ensured by the self-consistency of all processes in the biosphere. Life is limited by narrow limits - physical constants, radiation levels, etc. Gravitational constant determines the size of stars, temperature and pressure in them. If it becomes smaller, the stars will have smaller masses, their temperature will become insufficient for nuclear reactions to occur; if a little more, the stars will pass their "critical mass", leave the general circulation and turn into black holes. Electromagnetic interaction constant determines chemical transformations, is responsible for electron shell atoms and the strength of bonds in molecules. Weak interaction constant, responsible for transformation elementary particles, when it changes, it will “undermine” our whole world. The strong interaction constant, responsible for the stability of the nuclei of atoms, should also not change, otherwise the reactions in stars will go differently, carbon and nitrogen may not be formed. And it is not clear whether life of our type will be possible at all.
2. The principle of harmony of the biosphere and its organization related to the previous one. The laws of energy transformation on Earth, the laws of the movement of atoms are a reflection of the harmony of the Cosmos, the rhythm of movement celestial bodies. The basis for the existence of the biosphere is the position of the Earth in Space, the tilt of the earth's axis to the ecliptic, which determines the climate and life cycles of all organisms. The sun is the main energy source of the biosphere and the regulator of biological processes. As Yu. R. Mayer noted, "life is the creation of a sunbeam."
3. Space role of the biosphere in energy transformation- this part of living nature can be considered as a further development of the same process of converting solar light energy into effective energy of the Earth. The biosphere is one and the same spacecraft from the most ancient geological times. Life has remained constant all this time, only its form has changed. Living matter itself is not a random creation. Sources of energy of geological phenomena - cosmic, mainly solar; planetary, associated with the structure and cosmic history of the Earth; the internal energy of matter is radioactivity. Living matter actively transforms solar energy into chemical molecular motion and into the complexity of biological structures.
4. The spread of life- manifestation of its geochemical energy, analogue of the law of inertia inanimate matter. Small organisms reproduce faster than large ones. The rate of transmission of life depends on the density of living matter.
5. autotrophic organisms take everything they need for life from the inert matter surrounding them and do not require ready-made compounds of another organism to build their body. The field of existence of green autotrophic organisms is determined primarily by the area of penetration of sunlight.
6. space energy causes the pressure of life, which is achieved by reproduction. The reproduction of organisms decreases as their number increases.
7. Forms of finding chemical elements: rocks and minerals, magmas, trace elements, living matter. The earth's crust is a complex mechanism where atoms and molecules are constantly moving, various geochemical cycles occur, determined to a large extent by the activity of living matter. The law of frugality in the use of simple chemical bodies by living matter: once an element enters, it goes through a long series of states, and the organism introduces into itself only the required number of elements.
8. Life on Earth is completely determined by the field sustainability of green vegetation. The limits of life are determined by the physicochemical properties of the compounds that build the body, their indestructibility under certain environmental conditions. The maximum field of life is determined by the extreme limits of the survival of organisms. The upper limit of life is due to radiant energy, the presence of which excludes life and from which the ozone layer protects. The lower limit is associated with reaching a high temperature. The interval of 432 °С (from -252 to +180 °С) is the maximum thermal shield.
9. The principle of constancy of the amount of living matter in the biosphere. The amount of free oxygen in the atmosphere is of the same order as the amount of living matter (1.5-10 18 kg and 10 17 -10 18 kg). The rate of transmission of life cannot exceed limits that violate the properties of gases. There is a struggle for the necessary gas.
10. Every system reaches a position of stable equilibrium
this, when its free energy is equal to zero or approaches
to it, i.e., when all the work possible under the conditions of the system
exhausted. The concept of stable equilibrium is extremely important.
anthropic principle, put forward by G. M. Idlis (1958), is associated with the first of the principles of Vernadsky listed here and consists in the exact correspondence of the values of world constants with the possibilities of the existence of life. The amazing consistency of a number of quantities gives the impression that there may be a hidden principle ordering the entire Universe. To that
In fact, many people applied. Now it is formulated in two versions - weak and strong. As the famous American physicist J. Dyson put it: “If we look at the Universe and see how many accidents have served us well, it almost seems that the Universe knew that we would appear.” This is one of the formulations of the weak principle, in English literature - WAP. But it does not answer many questions, such as why the universe is such that it allowed the origin of life. Or maybe it is not necessary to create theories that do not allow the existence of an observer? A strong principle is that the emergence of life is natural in the Universe, but perhaps the appearance of an observer is the goal of the evolution of the Universe?
The geological role of the living Vernadsky classified into five categories: energy, concentration, destructive, environment-forming, transport. Living organisms create the migration of chemical elements in the biosphere through their respiration, nutrition, metabolism, continuous change of generations. The biogeochemical energy of the living is the source of energy for the transformation of the geospheres.
Living organisms enrich the environment with oxygen, regulate the amount of carbon dioxide, salts of various metals and a number of other compounds - in a word, they maintain the composition of the atmosphere, hydrosphere and soil necessary for life. Largely due to living organisms, the biosphere has the property of self-regulation - the ability to maintain the conditions on the planet created by the Creator.
The huge environmental role of living organisms allowed scientists to put forward a hypothesis that the atmospheric air and soil were created by living organisms themselves over hundreds of millions of years of evolution. According to Scripture, both soil and air were already present on Earth on the day the first living creatures were created.
Academician Vernadsky, based on the similarity of the structure of geological rocks lying deeper than the Cambrian, with later ones, suggested that life in the form of simple organisms was present on the planet "almost from the beginning." The fallacy of these scientific constructions later became apparent to geologists.
The undoubted merit of V.I. Vernadsky is the firm conviction that life appears only from living organisms, but the scientist, rejecting the biblical doctrine of the creation of the world, believed that "life is eternal, as the cosmos is eternal", and came to Earth from other planets . Vernadsky's fantastic idea was not confirmed. The hypothesis of the evolutionary origin of the planet's organisms from the simplest forms is even more controversial today than at the time of Vernadsky.
The energy basis for the existence of life on Earth is the Sun, so the biosphere can be defined as a shell of the Earth permeated with life, the composition and structure of which is formed by the joint activity of living organisms and is determined by the constant influx of solar energy.
Vernadsky pointed out the main difference between the biosphere and other shells of the planet - the manifestation in it of the geological activity of living beings. According to the scientist, "the entire existence of the earth's crust, at least in terms of the weight of the mass of its substance, in its essential, from a geochemical point of view, features, is conditioned by life." Vernadsky considered living organisms as a system for converting the energy of sunlight into the energy of geochemical processes.
The composition of the biosphere distinguishes between living and non-living matter - living organisms and inert matter. The bulk of living matter is concentrated in the intersection zone of the three geological shells of the planet: the atmosphere, hydrosphere (oceans, seas, rivers, etc.) and lithosphere (surface layer of rocks). The inanimate matter of the biosphere includes a component of these shells, connected with the living matter by the circulation of matter and energy.
In the non-living component of the biosphere, there are: biogenic substance, which is the result of the vital activity of organisms (oil, coal, peat, natural gas, biogenic limestones, etc.); bioinert substance, formed jointly by organisms and non-biological processes (soils, silts, natural water of rivers, lakes, etc.); an inert substance that is not a product of the vital activity of organisms, but is included in the biological cycle (water, atmospheric nitrogen, metal salts, etc.).
The boundaries of the biosphere can only be determined approximately. Although the facts of detection of bacteria and spores at an altitude of up to 85 km are known, the concentration of living matter at high altitudes is so negligible that the biosphere is considered limited at an altitude of 20-25 km. ozone layer, protecting living beings from the destructive effects of hard radiation.
In the hydrosphere, life is ubiquitous. In the Mariana Trench at a depth of 11 km, where the pressure is 1100 atm and the temperature is 2.4°C, the French scientist J. Picard observed holothurians, other invertebrates and even fish through the window. Bacteria, diatoms and blue-green algae, foraminifera, and crustaceans live under a thickness of more than 400 m of Antarctic ice. The bacterium is found under a layer of sea silt at a depth of 1 km, in oil wells at a depth of up to 1.7 km, in groundwater at a depth of 3.5 km. Depths of 2-3 km are considered the lower boundary of the biosphere. The total thickness of the biosphere, therefore, in different parts of the planet varies from 12-15 to 30-35 km.
The atmosphere is mainly composed of nitrogen and oxygen. Small amounts include argon (1%), carbon dioxide (0.03%) and ozone. The state of the atmosphere depends on the vital activity of both terrestrial organisms and aquatic creatures. Oxygen is used mainly for respiration and mineralization (oxidation) of dying organic matter. Carbon dioxide is essential for photosynthesis.
Hydrosphere. Water is one of the most essential components of the biosphere. About 90% of the water is in the world ocean, which occupies 70% of the surface of our planet and contains 1.3 billion km3 of water. Rivers and lakes include only 0.2 million km3 of water, and living organisms - about 0.001 million km3. The concentration of oxygen and carbon dioxide in water is essential for the life of organisms. The content of carbon dioxide in water is 660 times greater than in air. In the seas and oceans, five types of condensations of life are distinguished:
1. Offshore coastal. This zone is rich in oxygen, organics and other nutrients coming from the land (for example, with river water). Here, at a depth of up to 100 m, plankton and its bottom "partner" benthos flourishes, processing dying plankton organisms.
Oceanic plankton is made up of two communities:
a) phytoplankton - algae (70% of them are microscopic diatoms) and bacteria;
b) zooplankton - the primary consumers of phytoplankton (mollusks, crustaceans, protozoa, tunicates, various invertebrates).
The life of zooplankton proceeds in constant motion, it either rises or falls to a depth of 1 km, avoiding its eaters (hence the name: Greek plankton wandering). Zooplankton is the main food of baleen whales. Phytoplankton make up only 8% of the mass of zooplankton, but, multiplying rapidly, produce 10 times more biomass than the rest of ocean life. Phytoplankton provide 50% of oxygen (the remaining 50% is produced by forests).
Benthic organisms - crabs, cephalopods and bivalves, worms, sea stars and hedgehogs, holothurians ("sea cucumbers" or another name - trepangs), foraminifera (sea rhizomes), algae and bacteria are adapted to life with almost no light. Processing organic matter and turning it into minerals, which are delivered to the upper layers by ascending flows, benthos feeds plankton. The richer the benthos, the richer the plankton, and vice versa. Outside the shelf, the number of both drops sharply.
Plankton and benthos form a thick layer of calcareous and silica silts in the ocean, which form sedimentary rocks. Carbonate sediments can turn into stone in just a few decades.
2. Upwelling thickenings are formed at the sites of ascending flows carrying benthos products to the surface. Californian, Somali, Bengal, Canarian and especially Peruvian upwelling are known, which gives about 20% of the world fishery.
3. Reef - known to all coral reefs, abundant in algae and molluscs, echinoderms, blue-greens, corals and fish. Reefs grow unusually fast (up to 20-30 cm per year) not only due to coral polyps, but also due to the vital activity of mollusks and echinoderms, which concentrate calcium, as well as green and red algae with a calcareous skeleton.
The main producer of reef ecosystems is microscopic phototrophic algae, therefore reefs are located at depths of no more than 50 m, they require clear warm water with a certain salinity. Reefs are one of the most productive systems in the biosphere, producing annually up to 2 t/ha of biomass.
4. Sargas thickening - fields of brown and purple algae floating on the surface with many air bubbles. Distributed in the Sargas and Black Seas.
5. Abyssal rift near-bottom concentrations are formed at a depth of up to 3 km around hot springs on faults in the oceanic crust (rifts). In these places, hydrogen sulfide, iron and manganese ions, nitrogen compounds (ammonia, oxides) are removed from the earth's interior, feeding chemotrophic bacteria - producers consumed by more complex organisms - mollusks, crabs, crayfish, fish and huge sessile worm-like animal rifts. These organisms do not need sunshine. In rift zones, creatures grow about 500 times faster and reach impressive sizes. Bivalves grow up to 30 cm in diameter, bacteria - up to 0.11 mm! Galapagos rift clusters are known, as well as near Easter Island.
In the sea, a variety of animals prevails, and on land - plants. Only angiosperms make up 50% of the species, and seaweeds only 5%. The total biomass on land is represented by 92% green plants, and in the ocean 94% are animals and microorganisms.
The biomass of the planet is updated on average every 8 years, land plants - in 14 years, ocean - in 33 days (phytoplankton - daily). All water passes through living organisms in 3 thousand years, oxygen in 2-5 thousand years, and atmospheric carbon dioxide in just 6 years. Cycles of carbon, nitrogen and phosphorus are much longer. Biological cycle is not closed, about 10% of the substance goes in the form of sedimentary deposits and burials into the lithosphere.
The mass of the biosphere is only 0.05% of the mass of the Earth, and its volume is about 0.4%. The total mass of living matter is 0.01-0.02% of the inert matter of the biosphere, but the role of living organisms in geochemical processes is very significant. The annual production of living matter is about 200 billion tons of dry weight of organic matter, in the process of photosynthesis 70 billion tons of water reacts with 170 billion tons of carbon dioxide. Every year, the vital activity of organisms involves 6 billion tons of nitrogen, 2 billion tons of phosphorus, iron, sulfur, magnesium, calcium, potassium, and other elements in the biogenic cycle. Mankind, using numerous techniques, extracts about 100 billion tons of minerals per year.
The vital activity of organisms makes a significant contribution to the planetary circulation of substances, carrying out its regulation, life serves as a powerful geological factor that stabilizes and transforms the biosphere.
