The biosphere is like any ecosystem. The biosphere as a global ecosystem. Living matter of the biosphere
1. The concept of the biosphere.
2. Living matter of the biosphere.
3. Geochemical work of living matter.
The concept of the biosphere.
The concept of the biosphere as a planetary envelope covering the troposphere, hydrosphere, sedimentary (and possibly granite) rocks of the lithosphere throughout the entire geological history of the Earth; as a global unified system of the Earth, where the entire basic course of geochemical and energy transformations is determined by life, was developed in the works of V.I. Vernadsky. Vernadsky was the first to point out the active transforming activity of ancient and modern organisms in changing the appearance of our planet. The enormous scale of this process allowed him to develop the doctrine of the cosmic role of life in the geological history of the Earth, which undoubtedly gives the right to consider him the founder of the doctrine of the biosphere.
Vernadsky called the biosphere that area of our planet in which life exists or has ever existed and which is constantly exposed or exposed to the influence of living organisms.
The participation of each individual organism in the geological history of the Earth is negligible. However, there are infinitely many living beings on Earth, they have a high potential for reproduction, actively interact with the habitat and ultimately represent in their totality a special, global factor that transforms the upper shells of the Earth. The importance of organisms is due to their great diversity, ubiquitous distribution, the duration of existence in the history of the Earth, the selective nature of biochemical activity and extremely high chemical activity in comparison with other components of nature. Thus, the biosphere is the area of the Earth that is covered by the influence of living matter. From modern positions, the biosphere is considered as the largest ecosystem on the planet that supports the global circulation of substances.
Modern life is widespread in the upper part of the earth's crust (lithosphere), in the lower layers of the Earth's air shell (atmosphere) and in the Earth's water shell (hydrosphere). To designate the totality of all life on Earth, together with its immediate environment and resources, we will introduce the term "modern biosphere" or "ecosphere".
The ecosphere covers the globe with a continuous shell, and its vertical length varies from fractions of a meter - in areas of extremely poor life (Arctic and Antarctic deserts) - to thousands of meters. The lower boundary of the ecosphere is limited primarily by the temperature of rocks and groundwater, which gradually increases with depth and already exceeds 100 ° C at a level of 1.5-15 km. Therefore, living organisms penetrate deep into the Earth a short distance. The deepest depth at which bacteria have been found in the rocks of the earth's crust is 4 km. In oil fields at a depth of 2 - 2.5 km, bacteria are recorded in significant numbers. In the ocean, life is widespread to greater depths and is found even at the bottom of oceanic trenches 10-11 km from the surface, since the temperature there is about 0 ° C. However, along Vernadsky, the lower boundary of the biosphere should be drawn even deeper. Giant strata of sedimentary rocks gradually accumulating in the ocean, the origin of which is associated with the activities of living beings, is also part of the biosphere. In accordance with the dynamic processes in the earth's crust, sedimentary rocks are gradually drawn deep into it, metamorphosing under the influence of high temperature and pressure. Metamorphic rocks of the earth's crust, originating from sedimentary, are ultimately also derivatives of life.
The upper limit of life in the atmosphere is determined by the increase in ultraviolet radiation with height. At an altitude of 25 - 27 km, most of the sun's ultraviolet radiation is absorbed by a thin layer of ozone located here - the ozone screen. All living things that rise above the protective layer of ozone die. The atmosphere above the Earth's surface is saturated with diverse living organisms. Spores of bacteria and fungi are found up to an altitude of 20-22 km, but the bulk of air plankton is concentrated in a layer up to 1-1.5 km. Although the vital processes of modern organisms are concentrated only in the ecosphere, the influence of living matter (modern or existing in the past) is felt far beyond its borders. That is why the Vernadsky biosphere (as the area of existence of all former ecospheres) extends far beyond the modern ecosphere, covering a layer 40-50 km thick vertically.
The approximate mass of the biosphere is 0.05% of the mass of the Earth, and its volume is 0.4% of the volume of the planet.
The structure of the biosphere is a complex multicomponent system - a combination of gaseous, liquid, solid and biological organizations. It is characterized by strict organization, biological balance of numbers and mutual adaptation of its constituent organisms. Vernadsky emphasized that the biosphere should be considered as an integral geological shell of the Earth, a very complex self-regulating system consisting of living matter and inanimate matter. Vernadsky called the entire set of organisms on the planet living matter. Inert matter, according to Vernadsky, is a set of those substances in the biosphere, in the formation of which living organisms do not participate - i.e. rocks of magmatic, inorganic origin, substances of cosmic origin modified by living organisms, cosmic dust, meteorites. A biogenic substance is created and processed by life, by the aggregates of living organisms. It is a source of extremely powerful potential energy (coal, soil humus, oil, bitumen, peat, etc.). After the formation of a biogenic substance, living organisms in it are inactive. Bioinert substance is a special category. Vernadsky defined that it "is created in the biosphere simultaneously by living organisms and inert processes, representing the systems of dynamic equilibrium of both". Organisms play a leading role in bio-inert matter. The planet's bioinert substance is soil, weathering crust, all natural waters, the properties of which depend on the activity of living matter on Earth.
Ecosystem Is a system consisting of living beings and their habitat combined into a single functional whole.
Basic properties:
1) the ability to carry out the circulation of substances
2) resist external influences
3) produce biological products
Types of ecosystems:
1) microecosystems (a tree trunk in the breeding stage, an aquarium, a small body of water, a drop of water, etc.)
2) mesoecosystem (forest, pond, steppe, river)
3) macroecosystem (ocean, continent, natural zone)
4) global ecosystem (biosphere as a whole)
Y. Odum proposed a classification of an ecosystem based on biomes. These are large natural ecosystems corresponding to physical and geographical zones. It is characterized by some basic type of vegetation or other characteristic feature of the landscape.
Biome types
1) terrestrial (tundra, taiga, steppes, deserts)
2) freshwater (flowing waters: rivers, streams, stagnant waters: lakes, ponds, swampy waters: swamps)
3) marine (open ocean, shelf waters, deep-sea zones)
Concept biogeocenosis and ecosystem are close, but there are differences. Any biogeocenosis is a system. An ecosystem can include several biogeocenoses, but not every ecosystem is a biogeocenosis, since it does not have all its features.
The ecosystem can be distinguished two components - biotic and abiotic . Biotic It is divided into autotrophic (organisms that receive primary energy for existence from photo- and chemosynthesis or producers) and heterotrophic (organisms that receive energy from the oxidation of organic matter - consumers and reducers) components that form the trophic structure of the ecosystem.
The only source of energy for the existence of an ecosystem and the maintenance of various processes in it are producers who assimilate the energy of the sun (heat, chemical bonds) with an efficiency of 0.1-1%, rarely 3-4.5% of the initial amount. Autotrophs represent the first trophic level of the ecosystem. Subsequent trophic levels of the ecosystem are formed at the expense of consumers (2nd, 3rd, 4th and subsequent levels) and are closed by reducers, which convert nonliving organic matter into a mineral form (abiotic component), which can be assimilated by an autotrophic element.
The main components of the ecosystem
From the point of view of the structure in the ecosystem, there are:
1.climatic regime, which determines temperature, humidity, lighting regime and other physical characteristics of the environment;
2.inorganic substances included in the circulation;
3.organic compounds that bind biotic and abiotic parts in the cycle of matter and energy:
Producers - organisms that create primary products;
Macroconsumptions, or phagotrophs, are heterotrophs that eat other organisms or large particles of organic matter;
Microconsumptions (saprotrophs) are heterotrophs, mainly fungi and bacteria that destroy dead organic matter, mineralizing it, thereby returning it to the circulation.
The last three components form biomass ecosystems.
From the point of view of the functioning of the ecosystem, the following functional blocks of organisms (in addition to autotrophs) are distinguished:
biophages - organisms that eat other living organisms,
saprophages are organisms that eat dead organic matter.
This division shows the temporal-functional relationship in the ecosystem, focusing on the division in time of the formation of organic matter and its redistribution within the ecosystem (biophages) and processing by saprophages. A significant period of time can elapse between the dying off of organic matter and the re-inclusion of its constituents in the cycle of matter in the ecosystem, for example, in the case of a pine log, 100 years or more.
All these components are interconnected in space and time and form a single structural and functional system.
Term biosphere was introduced by Jean-Baptiste Lamarck at the beginning of the 19th century, and proposed in geology by the Austrian geologist Eduard Suess in 1875. However, the creation of a holistic theory of the biosphere belongs to the Russian scientist Vladimir Ivanovich Vernadsky.
Biosphere - an ecosystem of a higher order that unites all other ecosystems and ensures the existence of life on Earth. The biosphere includes the following "spheres":
The atmosphere is the lightest of the Earth's shells, bordering on outer space; through the atmosphere there is an exchange of matter and energy with space (outer space).
The hydrosphere is the watery shell of the Earth. Almost as mobile as the atmosphere, it practically permeates everywhere. Water is a compound with unique properties, one of the foundations of life, a universal solvent.
The lithosphere - the outer solid shell of the Earth, consists of sedimentary and igneous rocks. At the moment, the earth's crust is understood as the upper layer of the solid body of the planet, located above the border of Mohorovichich.
The biosphere is also not a closed system, it is actually completely provided by the energy of the Sun, a small part is the heat of the Earth itself. Every year, the Earth receives about 1.31024 calories from the Sun. 40% of this energy is emitted back into space, about 15% goes to heating the atmosphere, soil and water, all the rest of the energy is visible light, which is the source of photosynthesis.
V.I.Vernadsky was the first to clearly formulate the understanding that all life on the planet is inextricably linked with the biosphere and owes its existence to it:
V. I. Vernadsky
Living matter (the totality of all organisms on Earth) constitutes an insignificant part of the mass of the Earth, however, the influence of living matter on the processes of transformation of the Earth is enormous. The entire appearance of the Earth, which is observed now, would not have been possible without billions of years of vital activity of living matter.
At the moment, man himself, as a part of living matter, is a significant geological force and significantly changes the direction of the processes taking place in the biosphere, thereby endangering his existence:
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In a vivid way, the economist L. Brentano illustrated the planetary significance of this phenomenon. He calculated that if each person were given one square meter and all people were put side by side, they would not even occupy the entire area of the small Lake Constance on the border of Bavaria and Switzerland. The rest of the Earth's surface would remain empty of man. Thus, all of humanity, taken together, represents an insignificant mass of the planet's substance. His power is connected not with his matter, but with his brain, with his mind and his labor directed by this mind. In the thick, in the intensity and complexity of modern life, a person practically forgets that he himself and all of humanity, from which he cannot be separated, are inextricably linked with the biosphere - with a certain part of the planet on which they live. They are geologically naturally related to its material and energy structure. Humanity, as a living substance, is inextricably linked with the material and energy processes of a certain geological shell of the Earth - with its biosphere. It cannot physically be independent from her for a single minute. The face of the planet - the biosphere - chemically changes sharply by man consciously and mainly unconsciously. Man changes physically and chemically the air shell of the land, all of its natural waters. |
V.I. Vernadsky.
Artificial ecosystems
Arable land is a typical artificial ecosystem, inseparably adjacent to a natural meadow
Artificial ecosystems are ecosystems created by man, for example, agrocenoses, natural-economic systems or Biosphere 2.
Artificial ecosystems have the same set of components as natural ones: producers, consumers and decomposers, but there are significant differences in the redistribution of matter and energy flows. In particular, human-created ecosystems differ from natural ones in the following:
a smaller number of species and a predominance of organisms of one or more species (low uniformity of species);
low stability and strong dependence on the energy introduced into the system by a person;
short power circuits due to the small number of species;
unclosed circulation of substances due to the withdrawal of the crop (production of the community) by a person, while natural processes, on the contrary, tend to include in the circulation as much of the crop as possible
Without the maintenance of energy flows on the part of a person in artificial systems, natural processes are restored at one rate or another, and the natural structure of ecosystem components and material-energy flows between them is formed.
Lecture number 2
Biosphere. Ecosystems: types and components.
1. Boundaries and structure of the biosphere.
2. Functions of living matter.
3. The structure and types of ecosystems.
4. Biotic components of the ecosystem.
5. Interaction of species in ecosystems.
1. According to modern data, the mass of the Earth is 5.976 10 24 kg, the volume is 1.08 1012 km3, and the surface area is 510.2 million km 2. The size, and therefore all the natural resources of our planet, are limited. Therefore, the main task of man is to maintain the ecological balance on the planet.
Our planet has a heterogeneous structure and consists of concentric shells (geospheres) - internal and external. The inner ones include the core, the mantle, and the outer ones - the lithosphere (earth's crust), the hydrosphere, the atmosphere and the complex shell of the Earth - the biosphere.
Biosphere - the shell of the Earth, inhabited by living organisms, under their influence and occupied by the products of their vital activity (transformed by them); global ecological system of the Earth. It began to form with the appearance of the first organisms on Earth. In Greenland, researchers found a rock sample with a tiny blotch of carbon. The sample is over 8 billion years old. The source of carbon, most likely, was some kind of organic matter - during this time it completely lost its structure. Scientists believe this lump of carbon may be the oldest trace of life on Earth.
French natural scientist Jean Baptiste Lamarck at the beginning of the 19th century. first proposed the concept of the biosphere, without even introducing the term itself. The term "biosphere" was proposed by the Austrian geologist and paleontologist Eduard Suess in 1875. The biogeochemist and philosopher V.I. Vernadsky. He for the first time assigned living organisms the role of the main transforming force of the planet Earth, taking into account their activity not only at the present time, but also in the past.
As already mentioned, the biosphere is the totality of all living organisms. It is home to more than 3 million species of plants, animals, fungi and bacteria. Man is also a part of the biosphere, his activity surpasses many natural processes, as V.I. Vernadsky: "Man becomes a mighty geological force."
The biosphere penetrates into the entire hydrosphere, the upper part of the lithosphere and the lower part of the atmosphere, i.e. inhabits the ecosphere.
Ecosphere - a set of ecosystems; properties of the Earth as a planet, creating conditions for the development of biological systems. Spatially includes all layers of the atmosphere, hydrosphere and part of the lithosphere where life is possible. For the first time proposed to use the term L. Kol (1958), the term is also found in the works of B. Commoner (1973).
The environmental laws of B. Commoner were formulated in the early 70s of the XX century.
First law. Everything is connected to everything. This is the law on ecosystems and the biosphere, which draws attention to the universal connection between processes and phenomena in nature. It is designed to warn a person against rash impact on certain parts of ecosystems, which may lead to unforeseen consequences. (for example, drainage of bogs leads to shallowing of rivers).
Second law. Everything has to go somewhere. This is a law on human economic activity, waste from which is inevitable, and therefore it is necessary to think about both reducing their number and their subsequent use.
Third law. Nature "knows" best. This is the law of a reasonable, conscientious use of natural resources. We must not forget that man is also a biological species, that he is a part of nature, and not its ruler. This means that you cannot try to conquer nature, but you need to cooperate with it. So far we do not have complete information about the mechanisms and functions of nature, and without an accurate knowledge of the consequences of the transformation of nature, no "improvements" are allowed.
Fourth law. Nothing is given for free. This is the law of rational use of natural resources. "... The global ecosystem is a single whole, within which nothing can be gained or lost, and which cannot be the object of overall improvement." You need to pay with energy for additional waste treatment, fertilizer - for increasing the yield, sanatoriums and medicines - for the deterioration of human health, etc.
In contrast to the biosphere, the concept of ecosphere includes a characteristic of the state of the environment in which biological systems are located, as well as areas where living organisms can be located (including those outside the natural habitat).
The boundaries of the biosphere:
■ upper limit in the atmosphere: 15-20 km. It is determined by the ozone layer, which traps short-wave ultraviolet radiation, which is harmful to living organisms;
■ lower boundary in the lithosphere: 3.5-7.5 km. It is determined by the temperature of transition of water into steam and the temperature of denaturation of proteins, however, in general, the spread of living organisms is limited to a depth of several meters;
■ boundary between the atmosphere and the lithosphere in the hydrosphere: 10-11 km. Determined by the bottom of the World Ocean, including bottom sediments.
Living matter - the whole set of bodies of living organisms inhabiting the Earth. Living matter makes up about 0.01% of the total mass of the biosphere, but due to its high chemical and geological activity, it is this substance that is the basis of the biosphere, the composition of which is determined by the combined activity of living organisms in the present and the past (Table 2.1). But this is one of the most powerful geochemical forces of the Earth, since living organisms not only inhabit the earth's crust, but transform the appearance of the planet.
Table 2.1
Living organisms inhabit the earth's surface very unevenly. Their distribution depends on the geographic latitude.
Biogenic substance- a substance created and processed by a living organism. Throughout organic evolution, living organisms have passed through their organs, tissues, cells, blood a thousandfold through most of the atmosphere, the entire volume of the world's oceans, a huge mass of mineral substances. This geological role of living matter can be imagined from the deposits of coal, oil, carbonate rocks, etc.
Inert substance- products formed without the participation of living organisms. These include non-biogenic minerals and rocks formed mainly or deeper than the biosphere (outside the area of life) or within the biosphere at a depth of several kilometers without the participation of living matter. Examples of inert matter are igneous rocks. Dead (inert) non-biogenic rocks and minerals by mass are many times greater than the mass of all living matter (see Table 2.1).
Bioinert substance- a substance that is created simultaneously by living organisms and inert processes, representing dynamically equilibrium systems of both. Such are the soil, silt, weathering crust, etc. Organisms play a leading role in them.
Substance in radioactive decay.
Scattered atoms continuously created from all kinds of terrestrial matter under the influence of cosmic radiation.
A substance of cosmic origin. Living matter is inseparable from the biosphere. It is both a function of the biosphere and one of the most powerful geological forces on the planet, performing various functions.
2. According to A.V. Lapo, the classification of the functions of living matter identifies ten main functions.
1. Energy the function is associated with storing energy in the process of photosynthesis, transferring it along food chains, and dissipating it. The energetic function of living matter is reflected in two biogeochemical principles formulated by V.I. Vernadsky. In accordance with the first of them, geochemical biogenic energy tends to be maximized in the biosphere. The second principle says that in the process of evolution those organisms survive that increase their geochemical energy with their lives.
2. Gas the function is manifested in the ability to change and maintain a certain gas composition of the habitat and the atmosphere as a whole. In particular, the inclusion of carbon in the processes of photosynthesis, and then in the food chain, caused its accumulation in biogenic matter (organic residues, limestones, etc.) As a result, there was a gradual decrease in the content of carbon and its compounds, primarily dioxide (C 02) in the atmosphere from tens of percent to modern 0.03%. The same applies to the accumulation of oxygen in the atmosphere, the synthesis of ozone and other processes.
3. Redox the function is expressed in the acceleration under the influence of living matter of the processes of oxidation (in the presence of oxygen) and reduction (decomposition of organic substances in the presence of oxygen deficiency). Reduction processes are usually accompanied by the formation and accumulation of hydrogen sulfide and methane. This, in particular, makes the deep layers of bogs practically lifeless, as well as significant bottom water layers (for example, in the Black Sea). This process is progressing in connection with human activity.
4. Concentration the function is the ability of living organisms to concentrate in their body scattered chemical elements absorbed from the environment. For some metals, for example, for manganese, concentration reaches 106. The result of concentration activity is deposits of fossil fuels, limestone, ore deposits, etc. This function of living matter is comprehensively studied by the science of biomineralogy. Concentrating organisms are used to solve specific applied problems, for example, to enrich ores with chemical elements or compounds of interest to humans.
5. Opposite results scattering the function is manifested through the nutritional and transport activities of organisms. For example, the dispersion of a substance when excrement is excreted by organisms, the death of organisms, a change in integument, etc.
6. Destructive the function consists in the destruction by organisms and products of their vital activity, including after their death, of both dead organic matter and inert substances. The mechanism is associated with the circulation of substances.
7. Transport function is expressed in the transfer of matter as a result of the active form of movement. Such transfer is often carried out over colossal distances, for example, during migrations and migrations of animals.
8. Environment-forming the function consists in the ability of living matter to change the chemical parameters of the environment in more favorable living conditions for living organisms. It is aimed at ensuring the living conditions of all its members, including humans; carried out by changing the gas composition of the atmosphere and the chemical composition of the hydrosphere, the formation of soil and sedimentary rocks, the balance of substances and energy in the biosphere, the restoration of human-disturbed living conditions, etc.
9. Medium-regulating function - biotic regulation of the environment. Biota (any spatial set of living organisms) is capable of maintaining important environmental parameters at a constant level with great accuracy and for a long time, despite the complexity of the regulated system. For example, ocean biota regulates and stabilizes the concentration of carbon monoxide (II) CO 2 in the atmosphere. The mechanism of this regulation is as follows. The atmospheric concentration of CO 2 is in equilibrium with its concentration in the surface layer of the ocean. The ocean biota, by regulating the concentration in the surface layer of the ocean, actually stabilizes the concentration in the atmosphere.
10. Information function of the living matter of the biosphere. It was with the appearance of the first primitive living beings on the planet that active ("living") information appeared, which differs from that "dead" information, which is a simple reflection of the structure. Organisms have proven to be capable of receiving information by combining the flow of energy with an active molecular structure that plays the role of a program. The ability to perceive, store and process molecular information has made advanced evolution in nature and has become the most important ecological system-forming factor.
Thus, the structure and functions of the biosphere are quite complex. But the main thing should be noted: none of the shells that make up the biosphere can develop in isolation from the others. Any qualitative change in one of them adequately affects the other.
The general law of biosphere balance is the basic principle of direction in the development of the entire organic and inorganic world. An imbalance in this process is introduced not only (and not so much) by any natural catastrophic changes occurring on the earth, but also by human economic activity, which can not only be commensurate with the catastrophic developing natural factors, but even exceed the level of their impact.
3. Objects of ecology are mainly systems above the level of organisms (Fig. 2.1), i.e. study of the organization and functioning of supraorganism systems: populations, biocenoses (communities), biogeocenoses (ecosystems) and the biosphere as a whole. In other words, the main object of study in ecology is ecosystems, i.e. unified natural complexes formed by living organisms and habitat:
Fig 2.1 The structure of biological systems in the biosphere
(after I.A.Shilov, 1988)
Living organism - this is any form of life. In the course of school biology, a classification is most often used, in which four kingdoms are distinguished: bacteria, fungi, plants and animals. A more complex classification includes additionally viruses and the simplest organic compounds (humus). Plant sizes range from microscopic single-celled floating plants known as phytoplankton to the largest of all living organisms, the sequoia trees found in western North America. Animals can range in size from the smallest floating zooplankton to a 4-meter African elephant and a 30-meter blue whale.
Bacteria do not have a formalized cell nucleus, therefore they are united in a super-kingdom, called the super-kingdom of prokaryotes. Plants, fungi and animals have a formed cellular nucleus, which is why they are also united into one super-kingdom, called the super-kingdom of eukaryotes.
Population - a group of organisms of the same species living in a certain area. Examples of populations are all perches in a pond, squirrels or white oaks in forests, a population in a particular country, or the entire population of the Earth. Populations are dynamic groups of organisms that adapt to changes in environmental conditions by changing their size, distribution of age groups (age structure), and genetic composition.
View - a set of populations of individuals, representatives of which actually or potentially interbreed with each other in natural conditions. It is estimated that there are from 3 to 30 million species of living organisms in the world.
Each organism or population has its own habitat (range): the locality or type of locality where they live. The totality of species of plants, animals and microorganisms, united by a common area of distribution, is called biota. Examples are all plants, animals, fungi, viruses that grow and live in a forest, pond, desert, or aquarium.
Ecosystem - the relationship of communities (biocenosis) with chemical and physical factors that create an inanimate environment (biotope). It is an ever-changing (dynamic) network of biological, chemical and physical interactions that maintain the vitality of communities and help them adapt to changing environmental conditions. An example is a deciduous forest in central Russia with a certain composition of forest litter, soil characteristic of this type of forests and a stable plant community, and, as a consequence, with strictly defined microclimate indicators (temperature, humidity, illumination) and a complex of animals corresponding to such environmental conditions. organisms.
Ecosystem = Biotope + Biocenosis
The scale or size of ecosystems in nature is extremely diverse. Microecosystems are distinguished (a puddle, a rotting tree trunk, a corpse of an animal with organisms inhabiting it, an aquarium, as long as there are living organisms in it that are capable of cycling), mesoecosystems (forest, pond, etc.), macroecosystems (ocean, continent, etc.). NS.). The global ecosystem is one - it is the biosphere. Thus, larger ecosystems include ecosystems of lower rank.
According to Yu. Odum (1986), there are three groups of natural ecosystems: terrestrial (biomes), freshwater and marine (Fig. 2.2).
Figure 2.2 Main types of natural ecosystems
The classification is based on certain characteristics: for terrestrial - the type of vegetation, for freshwater - the physical properties of water, etc.
Ecosystems large and small do not usually have clear boundaries. The transition zone between two adjacent ecosystems is called an ecotone. The ecotone includes representatives of plant and animal species and destructors of both adjacent ecosystems.
The inanimate, or abiotic, components of an ecosystem include a variety of physical and chemical factors. Important physical factors, as you already know, include sunlight, shade, evaporation, wind, temperature, and water currents. The main chemical factors are nutrients and their compounds in the atmosphere, hydrosphere and earth's crust, which are necessary in large or small quantities for the existence, growth, reproduction of organisms.
4. Biotic components ecosystems are the main types of organisms that form the living components of an ecosystem. First of all, all organisms are divided according to the way of feeding into autotrophs and heterotrophs.
1. Autotrophic organisms use inorganic sources for their existence, thereby creating organic matter from inorganic. These organisms include photosynthetic green plants of land and aquatic environment, blue-green algae, some chemosynthetic bacteria, etc. These are wonderful chemical factories.
Using the energy of light, they synthesize glucose from carbon dioxide and water, releasing oxygen as a by-product. By oxidizing part of glucose to obtain additional chemical energy from the rest of the glucose and nutrients extracted from the soil, they form other complex organic molecules and all plant tissues, due to which they grow.
Heterotrophs, in turn, are divided into:
■ saprophytes (for example, fungi, microorganisms) that consume dead organic matter,
As you can see, the main difference between heterotrophs and autotrophs is the chemical nature of the nutrients they need. The essence of their nutritional processes is also different. Autotrophic organisms expend energy when converting inorganic substances into organic ones, heterotrophs do not expend energy when feeding.
Since organisms are quite diverse in types and forms of nutrition, they enter into complex trophic (food) interactions with each other, thereby performing the most important ecological functions in biotic communities. Some of them manufacture products, others consume, and still others transform it into inorganic form. It is customary to subdivide them into producers, consumers andreducents. This division is based on the predominant way in which organisms are fed.
Producers("Self-feeding") produce food for themselves and provide food for all others - both consumers and decomposers; They are terrestrial green plants that produce organic matter from inorganic matter.
Consumptions- consumers of organic substances. Consumers are divided into three main classes depending on the power source:
■ phytophages (herbivores) are first-order consumers that feed exclusively on living plants (either in whole or on their individual organs). For example, birds eat seeds, buds, and foliage. Deer and hares feed on branches and leaves. Grasshoppers and many other insect species consume all plant parts;
■ carnivores (carnivores) are second-order consumers who feed exclusively on herbivorous animals (phytophages), as well as third-order consumers who eat only carnivores. Spiders and birds that feed on predatory insects and tuna that feed on herring are secondary consumers. A hawk or falcon that preys on snakes and ermines, as well as a shark that feeds on other fish, are tertiary consumers;
■ euryphages (omnivores), which can eat both plant and animal food. Examples are pigs, rats, foxes, cockroaches as well as humans.
Reducers (reducing agents) return substances from dead organisms back to inanimate nature, decomposing organic matter to simple inorganic compounds and elements (CO 2, NO 2, H 2 O). By returning biogenic elements to the soil or aquatic environment, they thereby complete the biochemical cycle. There are two main classes of decomposers: detritus feeders and destructors.
Detritus feeders directly consume dead organisms or organic debris. These include, for example, crabs, jackals, termites, earthworms, worms, millipedes, ants, and vultures.
Most of the dead matter in the ecosystem, especially dead trees and leaves, goes through stages of decomposition and decay, as a result of which complex organic molecules are divided into simpler inorganic compounds. This process, which is also part of the food chain, is produced by a separate type of decomposers - destructors. Destructors include two types of organisms - fungi and microscopic unicellular bacteria. In turn, fungi and bacteria are an important food source for living organisms such as worms and insects in soil and water. Reducers are the final link in the cycle of substances.
5. Ecological niche Is a complex of all physical, chemical and biological environmental factors that are necessary for a particular biological species for life, growth and reproduction in a given ecosystem. The concept of a niche also includes the role of an organism in an ecosystem. A well-known analogy states that the habitat of an organism is its “address” in the ecosystem, while the ecological niche is its “occupation” and “lifestyle”.
Knowledge of the ecological niche allows you to answer the questions of how, where and what the species feeds on, whose prey it is, how and where it rests and reproduces.
As long as the ecosystem has a sufficient amount of common resources, different species consume them together. However, if two or more species in the same ecosystem begin to consume the same scarce resource, they will find themselves in a relationship of interspecific competition. Their ecological niches, at least in part, overlap. Scarce resources can be food, water, carbon dioxide, sunlight, soil nutrients, living space, hiding places, or any other vital environmental factor. An example of interspecies competition is the struggle between gray and black rats, as a result of which gray rats ousted black rats from a larger territory, since they are better adapted to existence.
Intraspecific interactions mean combining animals of the same species into groups of two or more individuals. Intraspecific competition is manifested mainly in the territorial behavior of animals that protect their places; nesting sites and a known area in the area. These are the interactions of many birds and fish.
Interspecies relationships are much more diverse. Two species living next to each other may not influence each other at all, may influence favorably or unfavorably.
Neutralism- both types are independent and do not have any effect on each other. In this case, the species are not directly related to each other and do not even contact each other. For example, owls and foxes, snakes and tigers.
Amensalism- these are biotic relationships in which the growth of one species (amensal) is inhibited by the excretion products of another. They are best studied in plants and microorganisms, which use various toxic substances in the fight against competitors for resources, and this phenomenon is called allelopathy. For example, mold fungi, being in the same habitat with E. coli, secrete a substance that causes the death of the latter.
Predation- this is when an individual of one species, called a predator, feeds on organisms (or parts of organisms) of another species, called a prey, and the predator lives separately from the prey. In such cases, the two organisms are said to be involved in a predator-prey relationship. In the oceans, one of the most dangerous predators is the shark. Prey species use a variety of defense mechanisms to prevent predators from becoming easy prey. Some of them can run or fly fast. Others have thick skin or shells. Still others have a protective coloration or are able to change color, masking in the environment. Still others emit chemicals with a smell or taste that scare away or even poison a predator.
Predators also have several ways to prey. Carnivores, unlike herbivores, are usually forced to chase and catch up with their food. Some predators, in order to feed themselves, are forced to run fast, like, for example, a cheetah. Others, such as spotted hyenas, lions, and wolves, achieve the same goal by hunting in packs. In natural conditions, such species are usually more numerous than leopards, tigers and panthers, which hunt alone.
The third way of getting food by predators is catching mostly sick, wounded and other defective individuals as victims. Such natural selection of individuals of a particular species is beneficial for the species as a whole, since it inhibits the spread of diseases in the population and leaves stronger and healthier individuals for reproduction.
The fourth way of providing oneself with animal food is the way that Homo sapiens went, the way of inventing hunting tools and traps, as well as the domestication of animals.
Commensalism(from the Latin "companion") is characterized by the fact that one of the two types (commensal) benefits from such interaction, while the other is practically not reflected (neither positively nor negatively). For example, in the open ocean, some barnacle species live directly on the jaw bones of whales. As a result of this cohabitation, crustaceans acquire a safe refuge and a stable food source. For the whale, such a neighborhood, obviously, is not of any benefit, but it does not bring harm either.
Protocooperation- both organisms benefit from combining, although their coexistence is not necessary for their survival. For example, crabs and coelenterates: the crab "puts" on its back a coelenterate, which disguises and protects it (has stinging cells), but, in turn, it receives pieces of food from the crab and uses it as a vehicle.
Mutualism(from Lat. "mutual") - a form of symbiosis in which each of the cohabitants receives relatively equal benefits, while they cannot exist without each other. This form of coexistence is favorable for their growth and survival. A mutualistic relationship can be traced between conifers and some species of fungi growing on their roots. Mushrooms absorb the nutrient-rich solutions they need from the roots and at the same time help the tree roots extract water and minerals from the soil. Lichens are a classic example - the close cohabitation of fungi and algae. The fungus protects the algae, and the latter feeds it.
? Questions for self-control
1. Give the definition of the biosphere.
2. What is the difference between the biosphere and the ecosphere?
3. List the structural elements of the biosphere.
4. What is the role of “living matter” on Earth?
5. Give the classification to living organisms.
6. What types of ecosystems exist?
7. What two groups are all living organisms divided into according to the type of nutrition?
8. How producers and consumers are interconnected. and reducers?
9. What is interspecific and intraspecific competition? Illustrate the answer with examples.
10. Explain the difference between such types of interaction of species as neutralism, amensalism, predation.
Biosphere, being a global ecosystem (ecosphere), like any ecosystem, it consists of abiotic and biotic parts.
Abiotic part presented by:
1) soil and underlying rocks to a depth where they still contain living organisms that exchange with the substance of these rocks and the physical environment of the pore space;
2) atmospheric air to the heights at which the manifestations of life are still possible;
3) aquatic environment oceans, rivers, lakes, etc.
Biotic part consists of living organisms of all taxa, performing the most important function of the biosphere, without which life itself cannot exist: biogenic current of atoms ... Living organisms carry out this current of atoms due to their respiration, nutrition and reproduction, ensuring the exchange of matter between all parts of the biosphere (Fig. 6.2).
Rice. 6.2. The relationship of living organisms with components of the biosphere
Biogenic migration in the biosphere is based on two biochemical principle:
¨ strive for maximum manifestation, for the "ubiquity" of life;
¨ to ensure the survival of organisms, which increases the biogenic migration itself.
These patterns are manifested primarily in the desire of living organisms to "capture" all the spaces that are more or less adapted to their life, creating an ecosystem or a part of it. But any ecosystem has boundaries, has its boundaries on a planetary scale and the biosphere. One of the options for the boundaries of the biosphere is shown in Fig. 6.5.
With a general consideration of the biosphere as a planetary ecosystem, the idea of its living matter as a certain total living mass of the planet acquires special significance.
Under living matter VI Vernadsky understands the entire number of living organisms on the planet as a single whole. Its chemical composition confirms the unity of nature ¾ it consists of the same elements as inanimate nature (Fig. 6.3), only the ratio of these elements is different and the structure of the molecules is different (Fig. 6.4).
Rice. 6.3. Participation of various chemical elements of the atmosphere, hydrosphere and lithosphere
in the construction of living matter (relative numbers of atoms) (according to V. Larher, 1978).
Highlighted the most common elements
Rice. 6.4. Structural formulas of some organic compounds
living cell
Living matter forms an insignificantly thin layer in the total mass of the Earth's geospheres.
According to scientists, its mass is 2420 billion tons, which is more than two thousand times less than the mass of the lightest shell of the Earth ¾ the atmosphere. But this insignificant mass of living matter is found almost everywhere ¾ currently, living things are absent only in the area of extensive glaciations and in the craters of active volcanoes.
The "omnipresence of life" in the biosphere is due to the potential and the scale of adaptability of organisms, which gradually, capturing seas and oceans, came out onto land and captured it. VI Vernadsky believes that this seizure continues.
In fig. 6.5 clearly shows the boundaries of the biosphere ¾ from the heights of the atmosphere, where cold and low pressure reign, to the depths of the ocean, where the pressure reaches 12 thousand atm. This became possible because the limits of temperature tolerance in various organisms are practically from absolute zero to plus 180 ° C, and some bacteria can exist in a vacuum. The range of chemical environmental conditions for a number of organisms is wide - from life in vinegar to life under the influence of ionizing radiation (bacteria in the boilers of nuclear reactors). Moreover, the endurance of some living beings in relation to individual factors goes even beyond the limits of the biosphere, that is, they still have a certain "margin of safety" and potential for spreading.
Rice. 6.5. Distribution of living organisms in the biosphere:
1
¾ ozone layer; 2¾ snow border; 3¾ the soil; 4¾ animals living in caves;
5
¾ bacteria in oil waters (height and depth are given in meters)
However, all organisms survive also because wherever their habitat is, there is a biogenic current of atoms. This current could not have taken place, at least in terrestrial conditions, if there were no soils.
Soil¾ the most important component of the biosphere, which, along with the World Ocean, has a decisive impact on the entire global ecosystem as a whole. It is the soils that provide nutrients for the plant that feed the entire world of heterotrophs. Soils on Earth are diverse and their fertility is also different.
Fertility depends on the amount of humus in the soil, and its accumulation, like the thickness of the soil horizons, depends on climatic conditions and terrain. The richest in humus are steppe soils, where humification is fast and mineralization is slow. Forest soils are the least rich in humus, where mineralization is faster than humification.
Many types of soils are distinguished according to various characteristics. Under type of soil is understood as a large group of soils, which is also formed under homogeneous conditions, characterized by a certain soil profile and direction of soil formation.
Since the most important soil-forming factor is the climate, then, to a large extent, the genetic types of soils coincide with the geographic zoning: arctic and tundra soils, podzolic soils, chernozems, chestnut, gray-brown soils and sierozem, red soil and yellow soils... The distribution of the main soil types on the globe is shown in Fig. 6.6.
Rice. 6.6. Schematic map of zonal soil types of the world:
1
¾ tundra; 2¾ podzols; 3¾ gray-brown podzolic soils, brown forest soils, etc .;
4
¾ lateritic soils; 5¾ prairie soils and degraded chernozems; 6¾ black soil;
7
¾ chestnut and brown soils; eight¾ gray soils and desert soils;
9
¾ soils of mountains and mountain valleys (complex); ten¾ ice sheet
The time of soil formation depends on the intensity of humification. The rate of humus accumulation in soils can be determined in units that measure the thickness (thickness) of the humus layer in relation to the time of their formation, for example, in mm / year. Such figures are given in table. 6.4.
Table 6.4
The rate of formation of the humus horizon of the soils of the Russian Plain
(according to A.N. Gennadiev et al., 1987)
Knowing the rate of humus accumulation and the thickness of the humus horizon, it is possible to calculate the age of different types of soils (Gennadiev, 1987). On the Russian Plain, chernozems were formed in 2500-3000 years, gray and brown forest soils in 800-1000 years, podzolic, in about 1500 years. The rate of soil formation also depends on the type of parent rock - on granites in humid tropical climates, it takes 20,000 years for a real soil to form.
These data make it possible to quantify the permissible washout under intense anthropogenic impact. At the same time, they show how easy it is to destroy this thin "brown film" and how long it takes, not counting the costs, to restore what was lost.
The soil cover, being an integral component of the biosphere, performs a number of biospheric, i.e., global from an ecological point of view, functions (Table 6.5). V.F.Valkov, K. Sh. Kazeev, S.I.
1) soil is a habitat, accumulator and source of matter and energy for land organisms;
2) soil regulates the composition of the atmosphere and hydrosphere;
3) soil ¾ a protective barrier of the biosphere (neutralizes a significant part of substances polluting the biosphere, thereby preventing their entry into living matter);
4) the soil provides a small biogeochemical cycle of substances on land and its conjugation with a large geological cycle of substances and, thus,
5) ensures the existence of life on Earth.
Table 6.5
Global functions of soils (pedosphere)
(Dobrovolsky, Nikitin, 1986)
Soil is the boundary layer between the atmosphere and the biospheric part of the lithosphere. It is observed not only a mixture of living and nonliving components of nature, but also their interaction within the soil ecosystem. The main purpose of this ecosystem is to ensure the circulation of substances in the biosphere.
Introduction
Biosphere
Structural levels of the biosphere
Living matter of the biosphere
The history of the development of the biosphere
The doctrine of the biosphere
History of the study of the biosphere
Vernadsky's teachings
Ecosystem
Ecosystem concept
Ecosystem classification
Ecosystem components
The cycle of matter
Biosphere - a global ecosystem
Conclusion
INTRODUCTION
The biosphere plays a key role in the existence of life on Earth. Thanks to the interaction of the biotic and abiotic parts, a unique environment is formed - an ecosystem in which the circulation of matter takes place, which ensures the maintenance of the balance of biocenoses.
Man is directly related to the biosphere. He cannot leave this shell, requiring a constant supply of energy from the products produced by the producers of ecosystems, protection from cosmic radiation and a suitable microclimate for life. Therefore, the vital task of modern mankind is to preserve their habitat in a state of equilibrium (the transition from the technosphere to the noosphere - a reasonably controlled sphere). A holistic understanding of the mechanism of operation of the components that make up the biosphere gives an understanding of the importance of preserving each component, which is especially important now, when the irrational use of the resources of the biosphere upsets the balance, leading to irreversible processes of destruction of the thin "shell of life".
The purpose of the course work is to show and substantiate the statement that the biosphere is a global ecosystem, which will give an understanding that the biosphere, like any system, exists due to the mutually beneficial interaction of its components, and imprudent removal or change of any component entails a change in the rest, which can have negative consequences for the biosphere, including for humanity.
To achieve this goal, it is necessary to complete a number of tasks, consisting in a step-by-step description of the biosphere from the point of view of it as an ecosystem:
Show the significance of the topic: a narrow range of conditions for the existence of organisms, their distribution within the biosphere.
The history of the study of the biosphere, the emergence of new views on its essence.
Tell about the biosphere as a system of interaction between living and nonliving.
Describe the biosphere as a system of interaction between organisms: energy flows, trophic connections in the biosphere.
Make a conclusion based on the study of the properties of the biosphere.
BIOSPHERE
The biosphere in the modern sense is the shell of the Earth, containing living matter and that part of the abiotic environment, in continuous exchange with which bio-matter is. Living matter here means the totality of all organisms that inhabit the Earth. The biosphere extends to the lower atmosphere, the hydrosphere and the thin upper strip of the lithosphere and the soil surface. However, this division is somewhat arbitrary, since individual "islands of life" due to technogenesis can occur outside the layer of life, for example, spacecraft, boreholes.
Structural levels of the biosphere
The following structural levels are distinguished in the biosphere (Fig. 1):
Rice. 1. Structural levels of the biosphere
Aerobiosphere. Located within the atmosphere (the gas envelope of the planet). The substance in the atmosphere is unevenly distributed, which is caused by a decrease in air density with distance from the surface. Usually the atmosphere is divided into three large sets of layers: the troposphere (from the surface to an altitude of 8-10 km), the stratosphere (8-10 km to the ozone layer) and the ionosphere (above the ozone layer). In more detail, it is subdivided into tropobiosphere (corresponds to the troposphere - 8-10 km.), in which almost all aerobionts are concentrated (organisms that constantly live in the air layer, needing moisture and suspended particles - aerosols; mainly bacteria), and altobiosphere (from 8-10 km. To the ozone layer, after which hard ultraviolet radiation does not allow the existence of life forms.
Nowadays, it is sometimes also distinguished parabiosphere (above the ozone layer, where some organisms can accidentally fall, but cannot exist normally), apobiosphere (a layer above 60-80 km., where living organisms never rise, but bio-matter can be introduced in very small quantities) and arbiosphere (outer space in which biological beings exist in limited spaces created by man, i.e. space satellites, space stations, etc.).
Hydrobiosphere. The aquatic envelope of the planet, represented by oceans, seas, and land waters (hydrosphere). It extends from the surface of water bodies to a depth of 11 km. (Mariana Trench). Subdivided intomarianobiosphere(or ocean-biosphere), and aquabiosphere , which in turn is divided by some scientists intolimnoaquabiosphere(biosphere of lakes; includinghalolimnobiosphere- biosphere of salt lakes) and re-biosphere (rivers).
Geobiosphere. The shell most populated by organisms, extending from the soil surface at the border with the atmosphere and hydrosphere to a depth of several kilometers (the upper part of the lithosphere). The geobiosphere is subdivided into the surface part - terrabiosphere , and the underground part - lithobiosphere (see fig. 2). The latter does not have definitively established lower boundaries and theoretically can extend up to 20-25 km., On which, due to temperatures of about 450 O With any pressure, water turns into steam, making the existence of any organisms impossible. Today, the depths of the spread of microorganisms, confirmed experimentally, are about 2 km.
Rice. 2. The ratio of the layers of the biosphere with the heights of their distribution
Abiotic components of the biosphere
To abiotic (inanimate, inert ) the components include a substance in the creation of which living matter did not take part: the earth's crust (except for the uppermost layer - soil, as well as fossilization products, i.e. burial of organic matter), minerals and substances entering the biosphere from outside of it (space, depths of the planet). It is rather difficult to isolate an absolutely "pure" inert substance, since all inanimate substances experience the effect of living organisms in the biosphere. Therefore, the inert substance formed and processed by living organisms is called bioinert (for example: soil, silt).
Biogenic substance is a substance created and processed by living matter. Throughout organic evolution, living organisms have passed through their organs, tissues, cells, blood thousands of times the entire atmosphere, the entire volume of the world's oceans, a huge mass of mineral substances (for example, this is how coal, oil, mineral rocks, oxygen were formed).
Living matter of the biosphere
Living matter, or biomass - the totality of all living organisms on Earth capable of reproduction, spreading around the planet, fighting for food, water, territory, etc. Living matter is associated with inert matter - the atmosphere (up to the level of the ozone screen), completely with the hydrosphere and lithosphere, mainly within the boundaries of the soil, but not only.
The living matter of the biosphere is heterogeneous and has three types of trophic interactions: autotrophy, heterotrophy, mixotrophy.
Trophic ecological interactions contribute to the transformation of inorganic (inert) matter into organic and reverse transformation of organic matter into mineral.
Living matter is characterized by certain properties: it is a huge free energy; chemical reactions that occur thousands and even millions of times faster than in other substances on the planet; specific chemical compounds - proteins, enzymes and other compounds that are stable in the composition of living things; the possibility of arbitrary movement - growth or active movement; the desire to fill the entire surrounding space; a variety of shapes, sizes, chemical variants, etc., significantly exceeding many contrasts in inanimate, inert substance.
The amount of living matter in the biosphere within a separately considered geological period is constant. According to the law of biogenic migration of atoms, living matter turns out to be an energetic and chemical mediator between the Sun and the Earth's surface.
The history of the development of the biosphere
The biosphere did not develop uniformly throughout the history of the Earth. Its greatest influence on the formation of the external appearance of the planet became noticeable only in the last 600-700 million years, when the role of photosynthesis increased sharply with the settlement of continents, which led to a manifold increase in the proportion of oxygen in the ancient atmosphere.
In the development of the biosphere, it is conditionally possible to distinguish several stages, each of which is marked by an important progressive advance; which in the end led to the formation of the current state of the biosphere (Fig. 3).
Fig. 3. The main stages of the development of the biosphere
Chemogenesis (chemical evolution).Most hypotheses about the origin of life on Earth assume that for a long time after the formation of a temperature environment suitable for the survival of living organisms, the planet was lifeless. At this time, a slow abiogenic synthesis of organic compounds (methane, hydrogen, ammonia, water vapor), which led to the formation of the first, most primitive organisms, took place on its surface, in the atmosphere and ocean under the influence of short-wave solar studies. The duration of the stage is estimated to be at least 1 billion years.
Biogenesis. The key factor that caused the emergence of complex organisms from simple ones was the saturation of the atmosphere with oxygen, which, as the concentration in the upper layers of the atmosphere increased, under the action of ultraviolet radiation, it formed ozone gas, which had the ability to trap short-wave radiation, which is detrimental to life forms. At the initial stages of biogenesis, the oxygen concentration was no more than 0.1% of the present; the change in the atmosphere began about 2 billion years ago, when the first photosynthetic organisms appeared (apparently, they were blue-green algae - prokaryotes). A significant increase in the proportion of oxygen began about 1.5 billion years ago, together with the appearance of chlorophyll cells, which absorb carbon dioxide and emit oxygen in large volumes. About 600 million years ago, there was another sharp increase in the proportion of oxygen in the atmosphere (from 3% of the present value 700 million years ago to 50% in the Cretaceous period 140 million years ago). The reason for this was the emergence and resettlement across the continents, first of the lower, then of the higher autotrophs.
Sociogenesis. The emergence of man and his dispersal across the planet (1.5 - 3 million years ago).
Technogenesis. The biosphere has undergone significant changes during the period of active formation of the technical envelope - man-made and natural-technical complexes (the results of production activities), which man has surrounded himself with. The beginning of this stage is associated with the appearance of urban settlements 10-15 thousand years ago.
Noogenesis. The last, highest stage in the development of the biosphere, associated primarily with the transformation of the unilateral use of natural resources (characteristic of technogenesis) into a reasonably controlled social-natural system (noosphere). Its feature is the mutually beneficial interaction of nature and the human community, where human activity becomes a determining factor in global development, in particular the external appearance of its environment. At the same time, since humanity can exist only in a layer favorable for life - the biosphere, the main goal of building the noosphere is to preserve the type of biosphere that ensures the survival and development of man and his interaction with the environment. The term was first introduced and described by the Soviet scientist V. Vernadsky.
THE TEACHING ABOUT THE BIOSPHERE
The modern understanding of the term "biosphere" and its isolation as the area of distribution of living matter is possible thanks to the works of J.-B. Lamarck, E. Suess, V. Vernadsky and other scientists, thanks to whom the biosphere became the central object of study of a new science - ecology. The study of the biosphere and planning of its future development cannot be separated from the study of the history of its formation.
History of the study of the biosphere
"Biosphere" as a concept reflecting the area of distribution of living organisms was first introduced in his works by the French naturalist J.-B. Lamarck (1802). He emphasized that all substances located on the surface of the globe and forming its crust were formed due to the activity of living organisms.
The facts and statements about the biosphere were accumulated gradually in connection with the development of botany, soil science, plant geography and other predominantly biological sciences, as well as geological disciplines. However, at that time, the rapid stratification of the natural sciences resulted in the term not catching on. Only more than 70 years later, in 1875, the Austrian geologist E. Suess again mentioned this term. Initially, "biosphere" meant only the totality of living organisms inhabiting our planet, although sometimes their connection with geographical, geological and cosmic processes was indicated, but at the same time attention was rather paid to the dependence of living nature on forces and substances of inorganic nature. Even the author of the term "biosphere" E. Suess in his book "Face of the Earth", published thirty years after the introduction of the term (1909), did not notice the reverse effect of the biosphere and defined it as "a set of organisms, limited in space and time and living on the surface of the Earth. "
And the third and final revival of the concept became possible thanks to the Soviet geologist V.I. Vernadsky, who created the modern doctrine of the biosphere in the 1920s (1926). At first, due attention was not paid to the scientific work of Vernadsky, but after the Second World War, the consequences of radioactive and chemical pollution of air, water and soil forced scientists to return to Vernadsky's research.
Vernadsky's teachings
According to the views of Vernadsky, the entire appearance of the Earth, all its landscapes, atmosphere, chemical composition of waters, and sedimentary rocks owe their origin to living matter. Life is a connecting link between Space and Earth, which, using the energy coming from space, transforms inert matter, creates new forms of the material world. Thus, living organisms created the soil, filled the atmosphere with oxygen, left behind kilometer strata of sedimentary rocks and the fuel wealth of the bowels, repeatedly passed the entire volume of the World Ocean through themselves. Vernadsky did not deal with the problem of the origin of life, he understood it as a natural stage in the self-organization of matter in any part of the cosmos, leading to the emergence of ever new forms of its existence.
In the structure of the biosphere, Vernadsky distinguished seven types of matter:
Alive.
Biogenic (arising from living or processed).
Inert (abiotic, formed outside of life).
Bioinert (which arose at the junction of living and nonliving; soil, according to Vernadsky, belongs to bioinert).
Substance in the stage of radioactive decay.
Scattered atoms.
A substance of cosmic origin.
Vernadsky was a supporterhypothesis of panspermia (bringing life to Earth from space). Methods and approaches of crystallography Vernadsky extended to the substance of living organisms. He believed that living matter develops in real space, which has a certain structure, symmetry and dissymmetry. The structure of matter corresponds to a certain space, and their diversity testifies to the diversity of spaces. Thus, the living and the inert cannot have a common origin, they come from different spaces that are eternally close to each other in the Cosmos. For some time, Vernadsky connected the features of the space of living matter with its supposed non-Euclidean nature, but for unclear reasons, he abandoned this interpretation and began to explain the space of living matter as a unity of space-time.
An important stage in the irreversible evolution of the biosphere Vernadsky considered its transition to the stage of the noosphere .
The biosphere as a global ecosystem
The concept of "ecosystem"
Ecosystem - a system consisting of a community of living organisms (biocenosis), their habitat (biotope), a system of connections that exchange matter and energy between them.
A distinctive feature of an ecosystem is the presence of relatively closed, stable in space and time flows of matter and energy between the biotic and abiotic parts of the ecosystem, therefore not every system of relationships, natural or artificial, can be called an ecosystem.
Ecosystem classification
Since ecosystems are complex systems, they are classified according to several characteristics.
By size, there are:
Microecosystems... Ecosystems of the lowest rank, similar in size to small components of the environment: a small body of water, a rotting trunk of a fallen tree, etc.
Mesoecosystems ... Examples include a forest, a river, etc.
Macroecosystems... They are very widespread (within the seas, oceans, continents), for example, the Andes mountains, mainland Australia.
The global ecosystem, which is analogous to the biosphere.
The stability of ecosystems increases with the breadth of coverage of the territory.
According to the degree of anthropogenic impact, ecosystems are divided into three types:
Natural (or natural) - ecosystems not disturbed by human influence. For example, remote from human settlements jungles in the Amazon, nature reserves, oceanic trenches.
Socio-natural - natural systems modified by man (park, reservoir)
Anthropogenic - man-made systems for gaining benefits. They are divided into technogenic and agroecosystems.
Ecosystems can also be classified according to many other characteristics: structure (terrestrial, freshwater, marine, coastal, etc.); energy sources (the main source is the Sun, but there are also other subsidizing sources).
Since biomes (macroecosystems) are distributed according to consortia , ecosystems are usually classified according to the type of predominant phytocenosis:
Terrestrial biomes
Evergreen tropical rain forest.
Semi-evergreen tropical forest.
Desert: grassy and bushy.
Chaparral - Areas with rainy winters and dry summers.
Tropical steppes and savannah.
Steppe of the temperate zone.
Temperate deciduous forest.
Boreal coniferous forests.
Tundra: arctic and alpine.
Aquatic ecosystems are classified according to their distinctive features: water salinity, characteristics of the reservoir.
Types of freshwater ecosystems
Stagnant waters: lakes, ponds, etc.
Flowing waters: rivers, streams, etc.
Wetlands: Marshes and swampy forests.
Types of marine ecosystems
Open ocean.
Continental shelf waters (coastal waters).
Upwelling areas (areas where deep waters rise to the surface; fertile areas with productive fishing).
Estuaries (coastal bays, straits, river mouths, salt marshes, etc.).
It should be borne in mind that the above classification covers only large ecosystems - biomes.
Ecosystem components
The ecosystem can be divided into two components - biotic and abiotic. Biotic is divided into autotrophic(organisms that receive primary energy for existence from photo- and chemosynthesis or producers) and heterotrophic (organisms that receive energy from the processes of oxidation of organic matter - consumers and reducers) components that formtrophicecosystem structure.
The only source of energy for the existence of an ecosystem and the maintenance of various processes in it are producers who assimilate energysun. Solar energy is absorbed unevenly in the biosphere, which can be seen in Fig. 4.
Rice. 4. Receipt and distribution of solar energy
Energy the sun is absorbed only partially, and only about 10% passes to each new trophic level (Lindemann's Rule), which causes a limited length of food chains (usually 5-6 levels), respectively, we can say that the share of consumers has much less energy than the share carnivores, carnivores - less than phytophages, etc. (fig. 5).
Rice. 5. Scheme of energy distribution among producers and consumers
Each ecosystem is characterized by its inherent set of properties and structure.
From the point of view of the structure in the ecosystem, there are:
Climatic regime, which determines temperature, humidity, lighting regime and other physical characteristics of the environment.
Inorganic substances included in the cycle.
Organic compounds that bind biotic and abiotic parts in the cycle of matter and energy.
Producers are autotrophic organisms that create primary products.
Consumables are heterotrophs that eat other organisms (predatory) or large particles of organic matter.
Reducers - heterotrophs, inmainly fungi and bacteria,which destroy dead organic matter, mineralizing it, thereby returning it to the circulation.
The last three components form the biomass of the ecosystem.
From the point of view of the functioning of the ecosystem, the following functional blocks of organisms (in addition to autotrophs) are distinguished:
Biophages - organisms that eat other living organisms.
Saprophages - organisms that eat dead organic matter.
This division according to the type of food ensures the circulation of biomaterials in the ecosystem. A significant period of time can elapse between the dying off of organic matter and the re-inclusion of its constituents in the cycle of matter in the ecosystem, for example, in the case of a pine log, 100 years or more.
All these components are interconnected in space and time and form a single structural and functional system.
Among the components are also distinguished ecotope, climatopes, edaphotop, biotope and biocenosis.
Ecotop - the territory (or water area) of the habitat of organisms, characterized by a certain combination of ecological conditions: soils, grounds, microclimate, etc., while not altered by the activity of organisms (newly formed landforms).
Climatop - the air (or water) part of the ecosystem, which differs from the surrounding by its composition, air (water) regime, humidity (salinity) and / or other parameters.
Edaphotop - soil, as part of the environment that is transformed by organisms.
Biotope - an ecotope transformed by a biota, or, more precisely, a site of territory that is homogeneous in terms of living conditions for certain species of plants or animals, or for the formation of a certain biocenosis.
Biocenosis - a historically formed set of plants, animals, microorganisms inhabiting a land area or water body (biotope). Biocenoses are limited to the distribution of determinants (determinants) of zoocenoses (consortia - plant populations with accompanying organisms), in which dominant plant species create conditions for the life of other organisms.
The cycle of matter in the biosphere
The Earth differs from other planets in that its biosphere contains a substance that is sensitive to the flow of solar radiation - chlorophyll. It is chlorophyll that ensures the conversion of electromagnetic energy of solar radiation into chemical energy, with the help of which the process of reduction of carbon and nitrogen oxides in biosynthesis reactions takes place.
In a green plant, photosynthesis takes place - the process of forming carbohydrates from water and oxygen dioxide (which is in the air or water). This produces oxygen as a by-product. Green plants are classified as autotrophs - organisms that take all the chemical elements they need for life from the inert matter surrounding them and do not require ready-made organic compounds of another organism to build their body.
Heterotrophs are organisms that need organic matter formed by other organisms for their nutrition. Heterotrophs gradually transform the organic matter formed by autotrophs, bringing it to its original mineral state.
The destructive (destructive) function is performed by representatives of each of the kingdoms of living matter. Decay, decomposition is an inalienable property of the metabolism of every living organism. Plants form organic matter and are the largest producers of carbohydrates on Earth, but they also release oxygen necessary for life as a byproduct of photosynthesis.
In the process of respiration, carbon dioxide is formed in the bodies of all living species, which plants again use for photosynthesis. There are also such types of living things for which the destruction of dead organic matter is a way of feeding. There are organisms with a mixed type of food, they are called mixotrophs.
In the biosphere, the processes of transformation of inorganic, inert matter into organic and reverse restructuring of organic matter into mineral take place. The movement and transformation of substances in the biosphere is carried out with the direct participation of living matter, all types of which have specialized in various methods of nutrition.
The finite amount of matter that is in the biosphere has acquired the property of infinity through the circulation of substances. All components of the biosphere interact with each other (Fig. 6), ensuring the stability of the system.
Rice. 6. Environmental components
In the course of biogeochemical cycles, the atoms of most chemical elements passed through a living being countless times. For example, all the oxygen in the atmosphere “turns around” through living matter in 2000 years, carbon dioxide in 200-300 years, and all water in the biosphere in 2 million years.
Living matter is a perfect receiver of solar energy. The energy absorbed and used in the reaction of photosynthesis, and then stored in the form of chemical energy of carbohydrates, is very large, there is evidence that it is comparable to the energy consumed by 100 thousand large cities over 100 years. Heterotrophs use the organic matter of plants as food: organic matter is oxidized by oxygen, which is delivered to the body by the respiratory organs, with the formation of carbon dioxide - the reaction goes in the opposite direction. Thus, the simultaneous existence of autotrophs and heterotrophs makes life "eternal".
The facts and reasoning about the "wheel of life" in the biosphere give the right to speak about the law of biogenic migration of atoms, which was formulated by V.I. Vernadsky: the migration of chemical elements on the earth's surface and in the biosphere as a whole is carried out either with the direct participation of living matter, or it occurs in an environment, the geochemical features of which are due to living matter, both the one that now inhabits the biosphere and the one that acted on the Earth throughout geological history.
The living matter of different kingdoms and of various kinds ensures the continuous circulation of substances and the transformation of energy. Thus, the law of biogenic migration of V.I. Vernadsky: in the biosphere, the migration of chemical elements occurs with the obligatory direct participation of living organisms. Biogenic migration of atoms ensures the continuity of life in the biosphere with a finite amount of matter and a constant flow of energy.
The biosphere is a global ecosystem.
An ecosystem, as already discussed above, is a system of interaction between living organisms and their habitat. Ecosystems come in various levels of complexity and size. Smaller ecosystems are part of larger ones, and those, in turn, are even larger. Macroecosystems (continents, oceans, etc.) form a global ecosystem - the Biosphere.
The biosphere is characterized by the circulation of energy, due to the different trophic roles of producers, consumers and decomposers. It is one of the key ecosystem attributes that ensures the stability of the ecosystem.
The biosphere is characterized by all the properties of ecosystems:
The biosphere includes living organisms that inhabit the Earth, as well as their habitat: oceans, land, atmosphere.
There are cycles of matter in the biosphere: large (ocean-land) and small (living - inert matter).
All three participants in the trophic chain are present in the biosphere: producers, represented by autotrophs; consumers (heterotrophic organisms), and decomposers (heterotrophic organisms that decompose organic matter)
The biosphere, as an ecosystem, is stable and potentially immortal as long as there are producers. Among all ecosystems, the biosphere, as the largest, has the greatest stability.
On this basis, the biosphere is an ecosystem. Since the biosphere unites all ecosystems on the planet, it is called the "Global" ecosystem.
Conclusion
Based on the results of the fulfillment of the tasks set in the introduction, conclusions can be drawn regarding the work performed.
The biosphere is a global ecosystem, as it has all the properties of ecosystems. Consequently, the biosphere tends to change. The change in the biosphere under the influence of human activity is an irreversible transformation of the biosphere into the technosphere. Under the conditions of modern disruption of the chains of interaction between organisms and their habitat (destruction of binders in trophic chains, habitats, etc.), the most relevant is the negative fact that the violation of the integrity of the system due to the rupture of connections reduces its natural tendency to balance, which is destructive for all life on the planet, which owes its existence primarily to an equilibrium exchange of energy.
Realizing that the biosphere, as an ecosystem, has the main quality of any system - the existence of mutually beneficial relationships, it is also important to understand that a change in any component of the biosphere inevitably affects all the others, in the end, on the very main modern force of change in the biosphere - man; that is why it is so important for the preservation of the biosphere to know about its organization and mechanism of functioning.
List of used literature
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http://dic.academic.ru/dic.nsf/ecolog/149
http://www.xumuk.ru/ecochem/5.html
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