The largest ecological systems on earth form. Characteristics, structure and types of natural ecosystems. Classification and structuring

All living organisms do not live on Earth in isolation from each other, but form communities. Everything in them is interconnected, both living organisms and such formation in nature is called an ecosystem that lives according to its own specific laws and has specific features and qualities that we will try to get acquainted with.

The concept of an ecosystem

There is such a science as ecology, which studies But these relationships can only be carried out within the framework of a certain ecosystem and occur not spontaneously and chaotically, but according to certain laws.

There are different types of ecosystems, but they are all a collection of living organisms that interact with each other and with environment through the exchange of matter, energy and information. That is why the ecosystem remains stable and sustainable over a long period of time.

Ecosystem classification

Despite the great diversity of ecosystems, they are all open, without which their existence would be impossible. The types of ecosystems are different, and the classification may be different. If we keep in mind the origin, then ecosystems are:

1. natural or natural. In them, all interaction is carried out without the direct participation of a person. They, in turn, are divided into:

• Ecosystems that are completely dependent on solar energy.
• Systems that receive energy from both the sun and other sources.

2. Artificial ecosystems. Created by human hands, and can only exist with his participation. They are also divided into:

• Agroecosystems, that is, those associated with economic activity person.
• Technoecosystems appear in connection with the industrial activities of people.
• urban ecosystems.

Another classification distinguishes the following types of natural ecosystems:

1. Ground:

• Rainforests.
• Desert with grassy and shrubby vegetation.
• Savannah.
• Steppes.
• Deciduous forest.
• Tundra.

2. Freshwater ecosystems:

• stagnant reservoirs
• flowing waters(rivers, streams).
• Swamps.

3. Marine ecosystems:

• Ocean.
• continental shelf.
• Fishing areas.
• Mouths of rivers, bays.
• Deep water rift zones.

Regardless of the classification, one can see the diversity of ecosystem species, which is characterized by its set of life forms and numerical composition.

Distinguishing features of an ecosystem

The concept of an ecosystem can be referred to as natural formations as well as those artificially created by man. If we talk about natural, then they are characterized by the following features:

• In any ecosystem required elements are living organisms and abiotic environmental factors.
• In any ecosystem, there is a closed cycle from the production of organic substances to their decomposition into inorganic components.
• The interaction of species in ecosystems ensures stability and self-regulation.

Whole the world It is represented by various ecosystems, which are based on living matter with a certain structure.

Biotic structure of an ecosystem

Even if ecosystems differ in species diversity, abundance of living organisms, their life forms, the biotic structure in any of them is still the same.

Any types of ecosystems include the same components; without their presence, the functioning of the system is simply impossible.

1. Producers.
2. Consumers of the second order.
3. Reducers.

The first group of organisms includes all plants that are capable of the process of photosynthesis. They produce organic matter. This group also includes chemotrophs, which form organic compounds. But only for this they use not solar energy, but the energy of chemical compounds.

Consumers include all organisms that need organic matter from outside to build their bodies. This includes all herbivorous organisms, predators and omnivores.

Decomposers, which include bacteria, fungi, convert the remains of plants and animals into inorganic compounds suitable for use by living organisms.

Functioning of ecosystems

The largest biological system is the biosphere, which, in turn, consists of individual components. You can make the following chain: species-population-ecosystem. The smallest unit in an ecosystem is the species. In each biogeocenosis, their number can vary from several tens to hundreds and thousands.

Regardless of the number of individuals and individual species in any ecosystem, there is a constant exchange of matter and energy not only among themselves, but also with the environment.

If we talk about the exchange of energy, then it is quite possible to apply the laws of physics. The first law of thermodynamics states that energy does not disappear without a trace. It only changes from one species to another. According to the second law, in a closed system, energy can only increase.

If physical laws are applied to ecosystems, then we can conclude that they support their vital activity due to the presence of solar energy, which organisms are able not only to capture, but also to transform, use, and then release into the environment.

Energy is transferred from one trophic level to another; during the transfer, one type of energy is converted into another. Part of it, of course, is lost in the form of heat.

Whatever types of natural ecosystems exist, such laws operate absolutely in each.

Ecosystem structure

If we consider any ecosystem, then in it we can definitely see that various categories, for example, producers, consumers and decomposers, are always represented by a whole set of species. Nature provides that if something suddenly happens to one of the species, then the ecosystem will not die from this, it can always be successfully replaced by another. This explains the stability of natural ecosystems.

A large variety of species in the ecosystem, diversity ensures the stability of all processes that take place within the community.

In addition, any system has its own laws, which all living organisms obey. Based on this, several structures can be distinguished within the biogeocenosis:

Any structure is necessarily present in any ecosystem, but it can differ significantly. For example, if we compare the biogeocenosis of the desert and rainforest, the difference is visible to the naked eye.

artificial ecosystems

Such systems are created by human hands. Despite the fact that in them, as in natural ones, all components of the biotic structure are necessarily present, there are still significant differences. Among them are the following:

1. Agrocenoses are poor species composition. Only those plants grow there that man grows. But nature takes its toll, and always, for example, on a wheat field you can see cornflowers, daisies, various arthropods settle. In some systems, even birds have time to build a nest on the ground and hatch chicks.
2. If a person does not take care of this ecosystem, then cultivated plants will not withstand competition with their wild relatives.
3. Agrocenoses also exist due to the additional energy that a person brings, for example, by applying fertilizers.
4. Since the grown biomass of plants is withdrawn along with the harvest, the soil is depleted nutrients. Therefore, for further existence, again, the intervention of a person who will have to fertilize in order to grow the next crop is necessary.

It can be concluded that artificial ecosystems do not belong to sustainable and self-regulating systems. If a person stops caring for them, they will not survive. Gradually, wild species will displace cultivated plants, and the agrocenosis will be destroyed.

For example, an artificial ecosystem of three types of organisms can easily be created at home. If you put an aquarium, pour water into it, place a few branches of elodea and settle two fish, here you have an artificial system ready. Even such a simple one cannot exist without human intervention.

The value of ecosystems in nature

Globally speaking, all living organisms are distributed across ecosystems, so their importance is difficult to underestimate.

1. All ecosystems are interconnected by the circulation of substances that can migrate from one system to another.
2. Due to the presence of ecosystems in nature, biological diversity is preserved.
3. All the resources that we draw from nature are given to us by ecosystems: clean water, air,

Any ecosystem is very easy to destroy, especially given the capabilities of man.

Ecosystems and man

Since the appearance of man, his influence on nature has increased every year. Developing, man imagined himself the king of nature, began without hesitation to destroy plants and animals, destroy natural ecosystems, thereby began to cut the branch on which he himself sits.

By interfering with centuries-old ecosystems and violating the laws of the existence of organisms, man has led to the fact that all ecologists of the world are already shouting with one voice that the world has come. Most scientists are sure that natural disasters, which in Lately began to occur more often, are the answer of nature to the thoughtless interference of man in its laws. It's time to stop and think that any kind of ecosystems were formed for centuries, long before the appearance of man, and perfectly existed without him. Can humanity live without nature? The answer suggests itself.

In ecology - the science of the interaction of living organisms with each other and with the environment - the concept of an ecosystem is one of the main ones. The person who introduced it into use was the British botanist and one of the first ecologists in the world, Arthur Tensley. The term "ecosystem" appeared in 1935. However, in domestic ecology it was preferred to replace it with such concepts as "biogeocenosis" and "biocenosis", which is not entirely true.

The article reveals the concept of an ecosystem, the structure of an ecosystem and its individual components.

The essence of the concept

All communities of currently existing living organisms are connected with the inorganic environment by close material and energy ties. So, plants can develop only due to the constant supply of water, oxygen, carbon dioxide, and mineral salts. The vital activity of heterotrophs is possible only at the expense of autotrophs. However, they also need water and oxygen. Any particular habitat could provide the inorganic compounds necessary for the life of the organisms inhabiting it only for a short period if they were not renewed.

The return of biogenic elements to the environment occurs continuously. The process occurs both during the life of organisms (respiration, defecation, excretion) and after their death. In other words, their community with an inorganic environment forms a certain specific system. In it, the flow of atoms, due to the vital activity of organisms, is closed, as a rule, in a cycle. In fact, this is the ecosystem. The structure of an ecosystem allows a deeper study of its structure and the nature of existing relationships.

Ecosystem Definition

Eugene Odum, an American biologist known for his pioneering work in this field, is considered the father of ecosystem ecology. In this regard, perhaps it would be logical to give his interpretation of the term considered in the article.

According to Yu. Odum, any unity, which includes all organisms of a given area, interacting with the physical environment in such a way that an energy flow is created with a clearly defined trophic structure, species diversity and the circulation of substances (energy and substance exchange between the abiotic and biotic parts ) inside the system, there is an ecosystem. The structure of an ecosystem can be viewed from different points of view. Traditionally, its three types are distinguished: trophic, species and spatial.

Correlation between the concepts of ecosystem and biogeocenosis

The doctrine of biogeocenosis was developed by the Soviet geobotanist and geographer Vladimir Sukachev in 1942. It is practically not used abroad. If we turn to the definitions of the terms "ecosystem" and "biogeocenosis", it is clear that there is no difference between them, in fact, they are synonyms.

However, in practice, there is a very widespread opinion that they can be called identical only with a certain degree of conventionality. The term "biogeocenosis" focuses on the connection of the biocenosis with any particular site. aquatic environment or sushi. While the ecosystem implies any abstract site. In this regard, biogeocenoses are usually considered as its special cases.

On the composition and structure of ecosystems

In any ecosystem, two components can be distinguished - abiotic (non-living) and biotic (living). The latter, in turn, is divided into heterotrophic and autotrophic, depending on the way organisms obtain energy. These components form the so-called trophic structure.

The only source of maintenance of various processes in the ecosystem and energy for it are producers, i.e. organisms capable of assimilating the energy of the sun. They represent the first trophic level. Subsequent ones are formed at the expense of consumers. The trophic structure of the ecosystem is closed by decomposers, whose function is to convert inanimate organic matter into a mineral form, which can later be assimilated by autotrophic organisms. That is, the same circulation and continuous return of biogenic elements to the environment, which Y. Odum spoke about, is observed.

Components of ecosystems

The ecosystem community structure has the following constituent parts:

• climatic regime, which determines lighting, humidity, temperature and other physical characteristics of the environment;
• included in the cycle inorganic substances(nitrogen, phosphorus, water, etc.);
• organic compounds that bind the abiotic and biotic parts in the process of energy and matter cycling;
• creators of primary products - producers;
• phagotrophs (macroconsumers) - heterotrophs or large particles of organic substances that eat other organisms;
• decomposers - bacteria and fungi (mainly) that destroy dead organic matter by mineralization, thereby returning it to the cycle.

So, the biotic structure of ecosystems consists of three trophic levels: producers, consumers and decomposers. It is they who form the so-called biomass (the total mass of animal and plant organisms) of biogeocenosis. For the Earth as a whole, it is equal to 2423 billion tons, with people "giving" about 350 million tons, which is negligible compared to the total weight.

Producers

Producers are always the first link in the food chain. This term unites all organisms that have the ability to produce organic substances from inorganic substances, that is, they are autotrophs. The main producers are represented by green plants. They synthesize organic compounds from inorganic compounds in the process of photosynthesis. In addition, several types of chemotrophic bacteria can be attributed to them. They can only carry out chemical synthesis without the energy of sunlight.

Consumers

The biotic structure and composition of the ecosystem also includes heterotrophic organisms that consume ready-made organic compounds created by autotrophs. They are called consumers. They, unlike decomposers, do not have the ability to decompose organic substances to inorganic compounds.

Interestingly, in different food chains, the same species can belong to different orders of consumers. There are a great many examples of this. Particularly the mouse. She is a consumer of both the first and second order, as she feeds on both herbivorous insects and plants.

decomposers

The term "reducers" is of Latin origin and literally translates as "I restore, return." This fully reflects their importance in the ecological structure of ecosystems. Reducers or destructors are organisms that destroy, turning into the simplest organic and inorganic compounds, the dead remains of the living. They return water and mineral salts to the soil in an accessible form for producers and, thereby, close the cycle of substances in nature. No ecosystem can do without decomposers.

Of no less interest is the species and spatial structure of ecosystems. They reflect species diversity organisms and their distribution in space in accordance with individual needs and living conditions.

species structure

The species structure is a set of all species that make up an ecosystem, their relationship with each other and the ratio of abundance. In some cases, primacy is for animals, for example, biocenosis coral reef, in others the leading role is played by plants (floodplain meadows, oak and spruce forests, feather grass steppe). The species structure of an ecosystem reflects its composition, including the number of species. It depends mainly on the geographical location of the place. The most well-known pattern is that the closer to the equator, the more diverse the flora and fauna. And this applies to all forms of life, from insects to mammals, from lichens and mosses to flowering plants.

Thus, one hectare of the Amazon rainforest is home to almost 400 trees belonging to more than 90 species, and each of them grows more than 80 different epiphytes. At the same time, on a similar area of ​​spruce or pine forest only 8-10 species of trees grow in the temperate zone, and in the taiga the diversity is limited to 2-5 species.

Horizontal spatial structure of an ecosystem

Numerous species of an ecosystem in space can be distributed in various ways, but always in accordance with their needs and habitat requirements. This arrangement of animals and plants in an ecosystem is called the spatial structure. It can be horizontal and vertical.

Living organisms are unevenly distributed in space. As a rule, they form groupings, which is an opportunistic feature. Such accumulations determine the horizontal structure of the ecosystem. It manifests itself in spotting, patterning. For example, coral colonies, migratory birds, herds of antelope, thickets of heather (pictured above) or lingonberries. The structural (elementary) units of the horizontal structure of plant communities include microgrouping and microcenosis.

Vertical spatial structure

Jointly growing groups of different plant species that differ in the position of assimilating organs (stems and leaves, rhizomes, bulbs, tubers, etc.) are called tiers. They characterize the vertical structure of the ecosystem. The forest ecosystem is the most prominent example in this case. As a rule, tiers are represented by various life forms of shrubs, shrubs, trees, grasses and mosses.

Tiers of the spatial structure

The first tier is almost always represented by large trees, in which the foliage is located high above the ground and is well lit by the sun. The second (underground) tier is made up of not so tall species, they can absorb unused light. Next is the undergrowth, represented by real shrubs (hazel, buckthorn, mountain ash, etc.), as well as shrub forms of trees (forest apple, pear, etc.), which, when normal conditions could grow to the height of the trees of the first tier. The next level is a teenager. It includes young trees, which in the future can "stretch" into the first tier. For example, pine, oak, spruce, hornbeam, alder.

The vertical type of the ecosystem structure (spatial) is characterized by the presence of a grass-shrub layer. It is made up of forest shrubs and herbs: strawberries, oxalis, lily of the valley, ferns, blueberries, blackberries, raspberries, etc. It is followed by the final layer - moss-lichen.

As a rule, it is impossible to see a clear boundary between ecosystems in nature if it is not represented by various landscape factors (rivers, mountains, hills, cliffs, etc.). Most often they are united by smooth transitions. The latter can actually be separate ecosystems themselves. Communities formed at the junction are commonly called ecotones. The term was introduced in 1905 by the American botanist and ecologist F. Clements.

The role of an ecotone is to maintain the biological diversity of the ecosystems between which it is located due to the so-called edge effect - a combination of certain environmental factors inherent in different ecosystems. This causes great conditions for life, and hence ecological niches. In this regard, species from different ecosystems, as well as highly specific species, can exist in an ecotone. An example of such a zone is the mouth of a river with coastal aquatic plants.

Temporal boundaries of ecosystems

Nature under the influence various factors is changing. Different ecosystems can develop in the same place over time. The period of time during which the change occurs can be both long and relatively short (1-2 years). The duration of the existence of a certain ecosystem is determined by the so-called succession, i.e., the regular and consistent replacement of some communities by others in a certain area of ​​\u200b\u200bthe territory as a result of internal factors in the development of biogeocenosis.

01/15/2018 article

The term "ecosystem" is familiar to each of us from school, and if we look deeper into the bins of memory, then even today we can say: an ecosystem is a functional unity of living organisms and their habitat (that is, inanimate nature surrounding these organisms). And this is the answer to "excellent" ... for a sixth grader.

In fact, the essence and role of ecological systems is much more complex than it might seem at first glance. As the basic functional units of ecology and structural components biospheres, ecosystems are amazing not only in species diversity, but also a wide range the functions they perform.

The fundamental importance that ecological systems have for mankind is an opportunity to get to know them better and learn something new about them. – something that may be a discovery for you.

How did the concept of an ecosystem come about?

The existence of a close relationship between all living organisms in nature was not a secret already in antiquity. People could not fail to notice patterns that unite various natural processes, however, the term denoting the totality of living organisms in a certain habitat did not exist at that time.

At the end of the 19th century, the German scientist K. Möbius took another step towards defining the concept of an ecosystem, giving the community of organisms in an oyster jar the name "biocenosis". And in 1887, thanks to his American colleague S. Forbes, the term "microcosm" appears, which he uses to define the lake in conjunction with all the organisms that live in it.

The emergence of the term "ecosystem"

Only at the beginning of the 18th century the Moscow Chistye Prudy received their current name after they were put in order through the efforts of Prince Menshikov, whose property they became at that time. Previously, the ponds were called Poganykh, acting as a giant sewer.

The term "ecological system" in the sense in which it is familiar to us today was introduced into use relatively recently. – in 1935 – English biologist Arthur Tansley.

The scientist defines an ecosystem as a set of objects of animate and inanimate nature. Simply put – organisms and their environment.

Along with this term, similar concepts appear in related sciences. For example, in geology, the concept of "geosystem" is gaining ground, and F. Clements in 1930 introduces the term "Holocene". IN AND. Vernadsky owns the name "bio-inert body", which he introduced into use in 1944. Judging objectively, the concept of ecosystems is basic for all areas of environmental science.

The Ecosystem in Detail

The main features of any ecological system are its openness and ability for self-regulation, self-organization and self-development. Thus, far from any biological system can be called an ecosystem, since not each of them has a certain self-sufficiency and cannot exist for a long time without external regulation. A prime example a biosystem that is not an ecosystem can serve as an aquarium or a fish pool.

This community is just one part of a larger complex system and is called "microcosm" or "facies" (in geoecology).

Ecosystem and biogeocenosis

The whim of a member of the New York Biological Society, Yevgeny Sheffelin, ended in ecological disaster. For the past 100 years, the starlings he brought to New York's Central Park have seriously disrupted the work of all ecosystems in the United States, with the exception of a few states where feathered immigrants have not yet had time to get. The intentions of the scientist were exceptionally good - to allow the inhabitants of the city to admire all the types of birds mentioned by Shakespeare in his works.

Ecosystem and biogeocenosis are almost synonymous. The difference between these concepts lies in the breadth of their meanings. If an ecosystem can be any territory (including the entire biosphere of the planet), then biogeocenosis is characterized by binding to a particular land area. Thus, biogeocenosis can be considered an ecosystem in a simplified form.

Ecosystems at the service of humanity

Since the first Homo sapiens landed on the Hawaiian Islands, 71 species of birds have disappeared here.

The ability of ecosystems to self-repair and self-regulate – their most valuable quality, both for the whole planet and for man in particular. Thanks to the so-called services that ecosystems provide us, the population of the earth is provided not only with food and drinking water but also by air.

These services are difficult to overestimate, but scientists nevertheless made an attempt to calculate and announce the price of the help that ecosystems provided to humanity in 2014. The amount was more than impressive. – 125 trillion US dollars.

What are the services so kindly provided to us by nature itself?

"Providing" services

This includes all the benefits that a person from time immemorial has been accustomed to receive from the earth free of charge, that is, for free: food (both vegetable and animal origin), water for drinking and household needs, industrial raw materials and Construction Materials, components for the manufacture of medicines, food supplements and cosmetics (vegetable and animal).

"Ancillary" services

As a habitat for many living organisms that are eaten not only by humans, but also by other inhabitants, ecosystems play an important supporting role. They essentially provide a table and shelter for millions of living beings, and also provide their species diversity. This fact is extremely important for the nature of the Earth, since the number of species of animals and plants grown by man is significantly inferior to the “wild” diversity provided by ecological systems.

"Regulatory" services

Every year, 11 million hectares of tropical forests cease to exist on earth.

Ensuring proper soil quality, water resources and air, pollination of cultivated plants – all this relates to the regulatory function of ecological systems. Absolutely all ecosystems take part in its provision. For example, microorganisms living in wetlands destroy pathogenic flora that form in wastewater, ensuring that it is filtered and the waste is decomposed.

And one more function performed by ecosystems, which is difficult to overestimate – release of oxygen into the atmosphere by plants. woodlands and other green spaces contribute to the decomposition of carbon dioxide into oxygen and carbon, giving other living beings the opportunity to breathe freely.

"Cultural" services

This category of values ​​that we receive from ecosystems includes our aesthetic pleasure from communicating with nature, our love for our native lands and the countless joys of tourist recreation. Indeed, if we analyze the list of cultural benefits that travel gives us (contemplation of architecture and picturesque landscapes, acquaintance with the original culture of different peoples), it turns out that most of them are closely related to natural features given territory (climate, soil, landscape, flora and fauna); in other words – with the characteristics of the ecosystems that exist in the area.

Objects play a special role in the provision of services in this category. cultural heritage UNESCO.

Based on the above facts, the conclusion suggests itself: the importance attached by scientists to ecological systems is by no means exaggerated and the preservation of their integrity today – task number one for all mankind. How to do it? – There is no question more difficult and at the same time easier than this one.

Natural ecosystems that have not been affected by destructive human activities make up only 3-4% of the land in Europe. Most of these sites are protected areas.

Do not try to solve the problem globally, feeling responsible for the entire population the globe. It is enough just to reconsider your habits, which can directly or indirectly affect the ecosystems surrounding you personally. The scope of activity in this area is literally limitless. At the very least, you can start sorting the garbage that you throw in a container in the yard and take the batteries to a special collection point. And the maximum ... well, everyone determines it for himself –

Community is a set of certain living organisms, for example, plant community steppes.

Ecosystem (biocenosis)- this is a combination of living organisms and their habitat, characterized by the circulation of substances and the flow of energy (pond, meadow, forest).

Biogeocenosis- an ecosystem located in a particular area of ​​​​land and inextricably linked with this particular area. (Temporary, artificial and aquatic ecosystems are not considered biogeocenoses.)

Processes in ecosystems

Circulation of substances in an ecosystem occurs due to food chains: producers take inorganic substances from inanimate nature and make them organic; at the end of the food chain, decomposers do the opposite.

Energy flow: most ecosystems receive energy from the sun. Plants store it in organic matter during photosynthesis. This energy is used for the life of all other organisms in the ecosystem. Passing through the food chains, this energy is gradually consumed (10% rule), in the end, all the solar energy absorbed by the producers turns into heat.

Self-regulation- the main property of ecosystems: due to biotic relationships, the number of all species is maintained at a constant level. Self-regulation allows ecosystems to withstand adverse impacts. For example, a forest can survive (recover) after several years of drought, rapid reproduction of May beetles and/or hares.

Ecosystem sustainability. The more species in an ecosystem, the more food chains there, and the more stable (balanced) the cycle of substances and the ecosystem itself are. If the number of species (biological diversity) decreases, then the ecosystem becomes unstable and loses the ability to self-regulate.

Ecosystem change (succession). An ecosystem that produces more organic matter than it consumes is unsustainable. She overgrows, this is a normal process of ecosystem self-development (living organisms themselves change their habitat). For example, a forest pond turns into a swamp, a steppe into a forest-steppe, a birch forest into an oak forest, etc. External influences, such as fire or deforestation, can also lead to a change in the ecosystem. All of these were examples of secondary succession, the primary occurring in a lifeless area.

1. Choose three options. Ecosystem sustainability is ensured
1) a variety of species and food chains
2) closed circulation of substances
3) high abundance of individual species
4) fluctuations in the number of species
5) self-regulation
6) short supply chains

Answer

2. Choose three correct answers from six and write down the numbers under which they are indicated. What signs indicate the stability of biogeocenosis?
1) species diversity
2) relief
3) climate
4) closed circuit
5) branched food chains
6) number of energy sources

Answer

3. Choose three correct answers from six and write down the numbers under which they are indicated. Resilience of the wet ecosystem equatorial forest determined
1) great species diversity
2) the absence of decomposers
3) a large number of predators
4) branched food webs
5) population fluctuations

Answer

4. Choose three correct answers from six and write down the numbers under which they are indicated. What characteristics ensure the sustainability of a natural ecosystem?
1) a high number of individuals of functional groups of organisms
2) the balance of the circulation of substances
3) short food chains
4) self-regulation
5) decrease in energy in the food chain
6) application of mineral fertilizers

Answer

1. Establish the sequence of processes occurring during the overgrowth of rocks
1) bare rocks
2) overgrowing with mosses
3) colonization by lichen
4) formation of a thin layer of soil
5) formation of a herbaceous community

Answer

2. Establish the sequence of processes occurring during the change of biogeocenoses (succession)
1) settlement by shrubs
2) colonization of bare rocks by lichens
3) formation of a sustainable community
4) germination of seeds of herbaceous plants
5) settlement of the territory with mosses

Answer

3. Establish a sequence of succession processes. Write down the corresponding sequence of numbers.
1) soil formation as a result of erosion of the parent rock and the death of lichens
2) the formation of an extensive power supply network
3) germination of seeds of herbaceous plants
4) settlement of the territory with mosses

Answer

4. Establish the sequence of appearance and development of ecosystems on bare rocks. Write down the corresponding sequence of numbers.
1) scale lichens and bacteria
2) herbaceous-shrub community
3) forest community
4) herbaceous flowering plants
5) mosses and bushy lichens

Answer

1. Establish a sequence of recovery steps spruce forest after the fire. Write down the corresponding sequence of numbers.
1) the appearance of shrubs and deciduous trees
2) overgrowing of the conflagration with light-loving herbaceous plants
3) development of young spruces under the canopy of deciduous trees
4) shaping finely deciduous forest
5) education upper tier adult firs

Answer

2. Establish the sequence of secondary succession processes after cutting down a spruce forest damaged by a typographer beetle. Write down the corresponding sequence of numbers.
1) growth of shrubs with birch and aspen undergrowth
2) spruce forest formation
3) development of deciduous forest with spruce undergrowth
4) overgrowing of the clearing with perennial light-loving grasses
5) formation of a mixed forest

Answer

3. Establish a sequence of ecosystem changes during secondary succession. Write down the corresponding sequence of numbers.
1) swamp
2) deciduous forest
3) mixed forest
4) lake
5) coniferous forest
6) meadow

Answer

Choose one, the most correct option. Through self-regulation in the ecosystem
1) no species is completely destroyed by another species
2) the number of populations is constantly declining
3) there is a cycle of substances
4) organisms reproduce

Answer

Choose three options. What are the essential features of an ecosystem?
1) a high number of consumer species of the III order
2) the presence of the circulation of substances and the flow of energy
3) seasonal changes in temperature and humidity
4) uneven distribution of individuals of the same species
5) the presence of producers, consumers and destroyers
6) the relationship of abiotic and biotic components

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Biogeocenoses are characterized
1) complex food chains
2) simple food chains
3) lack of species diversity
4) the presence of natural selection
5) dependence on human activities
6) steady state

Answer

Choose one, the most correct option. The main cause of ecosystem instability is
1) medium temperature fluctuation
2) lack of food resources
3) imbalance of the circulation of substances
4) increased abundance of some species

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. The biogeocenosis of the fresh water body of the river is characterized by
1) the presence of producers of organic matter - autotrophs
2) the absence of organic destroyers - decomposers
3) the presence of flowering plants in shallow water
4) the absence of predatory fish
5) the constant number of animal populations inhabiting it
6) closed circulation of substances

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. In an ecosystem broadleaf forest– oak forest
1) short food chains
2) sustainability is provided by a variety of organisms
3) the initial link in the food chain is represented by plants
4) population composition animals do not change over time
5) source of primary energy - sunlight
6) there are no decomposers in the soil

Answer

Choose one, the most correct option. The circulation of oxygen between various inorganic objects of nature and communities of living organisms is called
1) population waves
2) self-regulation
3) gas exchange
4) the circulation of substances

Answer

Choose one, the most correct option. An example of a biocenosis is a set
1) trees and shrubs in the park
2) plants grown in the botanical garden
3) birds and mammals living in the spruce forest
4) organisms living in the swamp

Answer

Choose one, the most correct option. One of the factors that maintain balance in the biosphere
1) variety of species and relationships between them
2) adaptation to the environment
3) seasonal changes in nature
4) natural selection

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Self-regulation in natural ecosystems is manifested in the fact that
1) populations of consumers of the first order are completely destroyed by consumers of the third order
2) consumers of the third order perform a sanitary role and regulate the number of consumers of the first order
3) mass reproduction of consumers of the first order leads to the mass death of producers
4) the number of producers is reduced as a result of the action of abiotic environmental factors
5) the number of consumers of the first order depends on the number of producers
6) the number of consumers of the first order is regulated by consumers of the second order

Answer

Below is a list of terms. All but two of them are used to describe ecological patterns. Find two terms that "fall out" of the general series, and write down the numbers under which they are indicated.
1) parthenogenesis
2) symbiosis
3) succession
4) aromorphosis
5) consumer

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Examples of the natural change of ecosystems in the process of community development are
1) swamping of floodplain meadows after the construction of hydraulic structures
2) the formation of farmland in situ from a plowed area of ​​the steppe
3) overgrowing of rocks with lichens
4) overgrowing of the pond and the formation of a swamp
5) the formation of a burnt place in the forest as a result of a fire from an unextinguished cigarette
6) change of birch forest to spruce forest

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. The cycle of substances in an ecosystem provides
1) its stability
2) repeated use by organisms of the same chemical elements
3) seasonal and daily changes in nature
4) peat accumulation
5) continuity of life
6) speciation

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Primary succession is characterized by:
1) starts after deforestation
2) a biogeocenosis is formed in a sand pit
3) starts on rich soils
4) soil is formed for a long time
5) scale lichens settle on stones
6) cutting down turns into a forest

Answer

Establish a correspondence between examples and types of successions: 1) primary, 2) secondary. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) runs fast
B) reforestation after a fire
B) runs slowly
D) develops after a violation of the biocenosis
D) the development of territories where previously there were no living creatures

Answer

© D.V. Pozdnyakov, 2009-2019

Classification and properties of ecosystems.

Composition and structure of ecosystems.

Energy and Ecosystem Products

Ecological pyramids

Types of ecosystems.

Composition and structure of ecosystems

If you turn to lecture No. 1 of this course, you will find that the field of study of ecology includes three main levels of life organization: population, ecosystem and biospheric. To solve many global problems and make decisions, the study of the organismal level plays a key role.

As you know, living organisms and their non-living (abiotic) environment are inseparably connected with each other and are in constant interaction, forming ecosystems.

An ecosystem is a collection of all living organisms living in a common area together with their inanimate environment.

The ecosystem is the main functional unit in ecology, since it includes both organisms and the inanimate environment - components that mutually influence each other's properties and are necessary to maintain life in its form that exists on Earth.

An example is a meadow, forest, lake.

Quite often, the concept of an ecosystem is identified with the concept of biogeocenosis, but these terms are not synonymous. The concept of an ecosystem is broader, it covers all types of sets of living organisms and habitats, only natural formations (forest, meadow, etc.) can be called biogeocenosis. That. any biogeocenosis is an ecosystem, but not every ecosystem is a biogeocenosis.

IN compound The ecosystem is represented by two groups of components: abiotic - components of inanimate nature (ecotope) and biotic - components of wildlife (biocenosis).

Biocenosis - a set of representatives of the plant (phytocenosis), animal (zoocenosis) world and the world of microorganisms (microbiocenosis). The ecotope includes two main components: the climate in all its diverse manifestations and the geological environment - soil-soils or edaphotope. All components of this system are in constant and complex interaction (Fig. 1).

It is quite obvious that the ecosystem is not homogeneous in space and time, and therefore, it is quite important to consider spatial structure biogeocenosis. First of all, this tiered structure phytocenoses, which is an adaptation in the struggle for sunlight. In deciduous forests, up to 6 tiers are distinguished.

In the spatial structure of biogeocenosis, there is also mosaic- change in the plant and animal community in terms of area (concentration of vegetation around water bodies).

The participation of different species in the formation of an ecosystem is not the same, so representatives of one species can dominate in an ecosystem (for example: Scotch pine in a pine forest), others can occur singly (snow leopard).

Species that dominate in numbers are called dominant. Among them there are those without which other species cannot exist or edifactors. Minor species - small and even rare - play a huge role in the formation of a sustainable ecosystem. Thus, the world law of ecosystem stability was established, according to which: the higher the biodiversity of an ecosystem, respectively, the more “minor” species, the more stable it is.

From point of view trophic structure(from the Greek trophe - food) the ecosystem can be divided into two tiers:

upper autotrophic (self-feeding) tier or " green belt”, which includes plants or their parts containing chlorophyll, where the fixation of light energy, the use of simple inorganic compounds and the accumulation of complex organic compounds predominate. Organisms included in the "Green Belt" are called autotrophic(from Latin: auto-self, tropho-nutrition). The main feature of these organisms is the ability to synthesize organic substances from inorganic substances in the process of photosynthesis. Since, being autotrophs, they create primary organic matter, producing it from inorganic matter, they are called producers.

lower heterotrophic (other-fed) tier, or "brown belt", dominated by the use, transformation and decomposition of complex compounds. Organisms included in this belt cannot build their own substance from mineral components, they are forced to use what is created by autotrophs by eating them. They are called heterotrophs (from Latin: hetero-other tropho-nutrition).

However, the specificity of heterotrophs can be different. So the part of organisms that use ready-made plant nutrients in nutrition is called phytophages- herbivores (phytos - plant, phagos - devourer, gr.) or herbivores. Phytophages are secondary accumulators of solar energy originally accumulated by plants. consumers of the first order (for example: a hare, a cow). This group of organisms belongs to primary consumers.

For many animals, evolution predetermined the need to use animal proteins. This group zoophagous or predators eating phytophages and smaller predators. Predators are the most important regulators of biological balance: they not only regulate the number of phytophagous animals, but act as orderlies, eating, first of all, sick and weakened animals. An example is eating birds of prey field mice. This group of organisms belongs to secondary consumers. Animals that feed on second-order consumers are called third-order consumers, and so on.

In any system, organic wastes (animal corpses, excrement, etc.) are inevitably formed, which can also serve as food for heterotrophic organisms, called decomposers or saprophytes.

Therefore, from a biological point of view, it is convenient to distinguish the following components in the ecosystem:

inorganic substances (C, N, CO2, H2O, etc.) included in the cycles.

organic compounds (proteins, carbohydrates, lipids, humic substances) that bind the biotic and abiotic parts.

air, water and substrate environment, including the climatic regime and other physical factors.

producers, autotrophic organisms, mostly green plants that can produce food from simple inorganic substances.

macroconsumers or phagotrophs (from the Greek phagos - eater) - heterotrophic organisms, mainly animals that feed on other organisms or particles of organic matter.

microconsumers, saprotrophs, destructortrophs - heterotrophic organisms, mainly bacteria and fungi, that obtain energy either by decomposing dead tissues or by absorbing dissolved organic matter released spontaneously or extracted by saprotrophs from plants and other organisms.

All organisms that make up the ecosystem are connected by close food ties (this is how one organism serves as food for another, which is eaten by a third, etc.). thus, in the biogeocenosis, a chain of successive transfer of matter and its equivalent energy from one organism to another, or the so-called trophic chain, is formed.

Examples of such circuits are:

reindeer moss  deer  wolf (tundra ecosystem);

grass cow human (anthropogenic ecosystem);

microscopic algae (phytoplankton) bugs and daphnia (zooplankton) roach pike gulls (aquatic ecosystem).

One trophic chain in an ecosystem is closely intertwined, forming food webs. So widely known is the phenomenon of the “trophic cascade”: sea urchins feed on sea urchins that eat brown algae, the destruction of otters by hunters led to the destruction of algae due to an increase in the population of urchins. When hunting for otters was banned, algae began to return to their habitats.

A significant part of heterotrophs are saprophages and saprophytes (fungi), which use the energy of detritus. Therefore, two types of trophic chains are distinguished: chains eating, or grazing, which begin by eating photosynthetic organisms, and detritus appreciate the decay that begins with the remains of dead plants, carcasses and animal excrement

Energy and Ecosystem Products

The main (and practically the only) source of energy in the ecosystem is sunlight. The block diagram of the flows of matter and energy in the ecosystem is shown in fig. 3.

The flow of energy is directed in one direction, part of the incoming solar energy is converted by the community and goes to a qualitatively new level, transforming into organic matter, which is a more concentrated form of energy than sunlight, but most of the energy degrades, passes through the system and leaves it in the form low-quality thermal energy (heat sink). It should be noted that only about 2% of the energy entering the earth's surface is assimilated by autotrophic organisms, most (up to 98%) is dissipated in the form of thermal energy.

Fig.3. Diagram of matter and energy flows in an ecosystem.

Energy can be stored and then released again or exported, but it cannot be reused. Unlike energy, nutrients, including biogenic elements necessary for life (carbon, nitrogen, phosphorus, etc.), and water can be reused. Recycling efficiencies and the size of imports and exports of nutrients vary greatly depending on the type of ecosystem.

On the functional diagram, the community is depicted as a food web formed by autotrophs and heterotrophs, interconnected by the corresponding energy flows, cycles of biogenic elements.

Rice. 4. Energy flow in the food chain:

OPE - total solar energy input; NE - energy unused by the ecosystem; C - energy absorbed by plants; H - part of the energy (with primary production) used by organisms of trophic levels; CH - part of the absorbed energy dissipated in thermal form; D 1 D 2, D 3 - energy loss for breathing; E - loss of matter in the form of excrement and secretions; P in - gross output of producers; P 1 - net primary production; P 2 and P 3 - consumer products; the circle shows bioreducers - destructors of dead organic matter.

The trophic chain in biogeocenosis is at the same time an energy chain, i.e., a sequential ordered flow of the transfer of solar energy from producers to all other links (Fig. 4).

Consumer organisms (consumers), feeding on the organic matter of producers, receive energy from them, partly used to build their own organic matter and bound in the molecules of the corresponding chemical compounds, and partly spent on breathing, heat transfer, performing movements in the process of searching for food, eluding enemies and so on.

Thus, in the ecosystem there is a continuous flow of energy, which consists in transferring it from one food level to another. By virtue of the second law of thermodynamics, this process is associated with the dissipation of energy at each subsequent link, i.e., with its losses and an increase in entropy. It is clear that this dissipation is always compensated by the influx of energy from the Sun.

In the process of life of the community, organic matter is created and consumed. This means that each ecological system has a certain productivity.

The productivity of an ecological system is the rate at which producers absorb radiant energy through photosynthesis and chemosynthesis, producing organic matter that can be used as food. There are different levels of production of organic matter: primary production, created by producers per unit of time, and secondary production - an increase in the mass of consumers per unit time. Primary production is subdivided into gross and net production. Gross primary production is the total mass of gross organic matter created by a plant per unit time at a given rate of photosynthesis, including the plant's expenditure on respiration - from 40 to 70% of gross production. That part of the gross output that is not spent "for breathing" is called the net primary production, represents the value of the increase in plants, and it is this product that is consumed by consumers and decomposers. Secondary production is no longer divided into gross and net, since consumers and decomposers, i.e. all heterotrophs, increase their mass due to the primary previously created products.

All living components of the ecosystem make up the total biomass of the community as a whole or of certain groups of organisms. It is expressed in g / cm 3 in raw or dry form, or in energy units - in calories, joules, etc. If the rate of biomass withdrawal by consumers lags behind the rate of plant growth, then this leads to a gradual increase in the biomass of producers and to an excess of dead organic matter. The latter leads to the peating of swamps and the overgrowth of shallow reservoirs. In stable communities, almost all production is spent in food webs, and biomass remains almost constant.

Environmentalpyramids

Functional relationships, i.e., the trophic structure, can be depicted graphically, in the form of the so-called ecological pyramids. The base of the pyramid is the level of producers, and the subsequent levels of nutrition form the floors and top of the pyramid. There are three main types of ecological pyramids: 1) pyramid of numbers, reflecting the number of organisms at each level (Elton's pyramid); 2) biomass pyramid characterizing the mass of living matter - total dry weight, caloric content, etc.; 3) product pyramid(or energy), which has a universal character, showing the change in primary production (or energy) at successive trophic levels.

The pyramid of numbers reflects a clear pattern discovered by Elton: the number of individuals that make up a series of links from producers to consumers is steadily decreasing (Fig. 5.). This pattern is based, firstly, on the fact that many small bodies are needed to balance the mass of a large body; secondly, the amount of energy is lost from the lower trophic levels to the higher ones (only 10% of the energy reaches the previous one from each level) and, thirdly, the inverse dependence of metabolism on the size of individuals (the smaller the organism, the more intense the metabolism, the higher the growth rate their abundance and biomass).

Rice. 5. Simplified diagram of Elton's pyramid

However, the pyramids of abundance will vary greatly in shape in different ecosystems, so it is better to give the abundance in tabular form, but biomass - in graphical form. It clearly indicates the amount of all living matter at a given trophic level, for example, in units of mass per unit area - g / m 2 or per volume - g / m 3, etc.

In terrestrial ecosystems, the following rule applies pyramidsbiomass: the total mass of plants exceeds the mass of all herbivores, and their mass exceeds the entire biomass of predators. This rule is observed, and the biomass of the entire chain changes with changes in the value of net production, the ratio of the annual growth of which to the biomass of the ecosystem is small and fluctuates in forests of different geographical areas from 2 to 6%. And only in meadow plant communities it can reach 40-55%, and in individual cases, in semi-deserts - 70-75%. On fig. 6 shows the biomass pyramids of some biocenoses. As can be seen from the figure, for the ocean, the above biomass pyramid rule is invalid - it has an inverted (inverted) form.

Rice. 6. Pyramids of biomass of some biocenoses: P - producers; RK - herbivorous consumers; PC - carnivorous consumers; F, phytoplankton; Z - zooplankton

The ocean ecosystem tends to accumulate biomass at high levels, in predators. Predators live for a long time and the turnover rate of their generations is low, but for producers - phytoplankton algae, the turnover rate can be hundreds of times higher than the biomass reserve. This means that their net production here also exceeds the production absorbed by consumers, i.e., more energy passes through the level of producers than through all consumers.

From this it is clear that an even more perfect reflection of the influence of trophic relations on the ecosystem should beproduct pyramid rule(orenergy): at each previous trophic level, the amount of biomass created per unit of time (or energy) is greater than at the next.

Trophic or food chains can be represented in the form of a pyramid. The numerical value of each step of such a pyramid can be expressed by the number of individuals, their biomass or the energy accumulated in it.

In accordance with R. Lindemann's energy pyramid law and ten percent rule, approximately 10% (from 7 to 17%) of energy or matter in energy terms passes from each stage to the next stage (Fig. 7). Note that at each subsequent level, with a decrease in the amount of energy, its quality increases, i.e. the ability to do the work of a unit of animal biomass is a corresponding number of times higher than the same plant biomass.

A striking example is the high seas food chain, represented by plankton and whales. The mass of plankton is dispersed in the ocean water and, with the bioproductivity of the open sea less than 0.5 g/m 2 day -1 , the amount of potential energy in a cubic meter of ocean water is infinitely small compared to the energy of a whale, whose mass can reach several hundred tons. As you know, whale oil is a high-calorie product that was even used for lighting.

In accordance with the last digit, one percent rule: for the stability of the biosphere as a whole, the share of possible final consumption of net primary production in energy terms should not exceed 1%.

In the destruction of organics, a corresponding sequence is also observed: for example, about 90% of the energy of pure primary production is released by microorganisms and fungi, less than 10% by invertebrates, and less than 1% by vertebrates, which are final cosuments.

Ultimately, all three rules of the pyramids reflect energy relations in the ecosystem, and the pyramid of production (energy) has a universal character.

In nature, in stable systems, biomass changes insignificantly, i.e., nature tends to use the entire gross production. Knowledge of the energy of the ecosystem and its quantitative indicators make it possible to accurately take into account the possibility of removing one or another amount of plant and animal biomass from the natural ecosystem without undermining its productivity.

A person receives a lot of products from natural systems, nevertheless, agriculture is the main source of food for him. Having created agro-ecosystems, a person seeks to get as much pure vegetation production as possible, but he needs to spend half of the plant mass on feeding herbivores, birds, etc., a significant part of the production goes to industry and is lost in garbage, i.e., it is lost about 90% of pure production and only about 10% is directly used for human consumption.

In natural ecosystems, energy flows also change in intensity and nature, but this process is regulated by the action of environmental factors, which is manifested in the dynamics of the ecosystem as a whole.

Relying on food chain, as the basis for the functioning of the ecosystem, it is also possible to explain the cases of accumulation in the tissues of certain substances (for example, synthetic poisons), which, as they move along the trophic chain, do not participate in the normal metabolism of organisms. According to biological amplification rules there is an approximately tenfold increase in the concentration of the pollutant when moving to a higher level of the ecological pyramid. In particular, a seemingly insignificant elevated content of radionuclides in river water at the first level of the trophic chain is assimilated by microorganisms and plankton, then it is concentrated in fish tissues and reaches maximum values ​​in gulls. Their eggs have a level of radionuclides 5000 times higher than background pollution.

Types of ecosystems:

There are several classifications of ecosystems. First, ecosystems are subdivided by nature of origin and are divided into natural (swamp, meadow) and artificial (arable land, garden, spaceship).

By size ecosystems are divided into:

micro-ecosystems (for example, the trunk of a fallen tree or a clearing in a forest)

mesoecosystems (forest or steppe kolok)

macroecosystems (taiga, sea)

ecosystems of the global level (planet Earth)

Energy is the most convenient basis for classifying ecosystems. There are four fundamental types of ecosystems type of energy source:

driven by the sun, little subsidized

driven by the Sun, subsidized by other natural sources

driven by the sun and subsidized by man

driven by fuel.

In most cases, two sources of energy can be used - the Sun and fuel.

Natural ecosystems driven by the Sun, little subsidized- these are open oceans, alpine forests. All of them receive energy from practically only one source - the Sun and have low productivity. The annual energy consumption is estimated at approximately 10 3 -10 4 kcal-m 2 . The organisms living in these ecosystems are adapted to the scarce amounts of energy and other resources and use them efficiently. These ecosystems are very important for the biosphere, as they occupy vast areas. The ocean covers about 70% of the earth's surface. In fact, these are the main life support systems, mechanisms that stabilize and maintain conditions on the “ spaceship» - Earth. Here, huge volumes of air are cleaned daily, water is returned to circulation, climatic conditions are formed, temperature is maintained, and other functions that ensure life are performed. In addition, at no cost to man, some food and other materials are produced here. It should also be said about the aesthetic values ​​​​of these ecosystems that cannot be taken into account.

Natural ecosystems driven by the Sun, subsidized by other natural sources, are ecosystems that are naturally fertile and produce excess organic matter that can accumulate. They receive natural energy subsidies in the form of tidal energy, surf, currents coming from the catchment area with rain and wind of organic and mineral substances, etc. Energy consumption in them ranges from 1 * 10 4 to 4 * 10 4 kcal * m - 2 *year -1 . The coastal part of an estuary such as the Neva Bay is a good example of such ecosystems, which are more fertile than adjacent land areas receiving the same amount of solar energy. Excessive fertility can also be observed in rainforests.

ecosystems,movablesun and subsidizedhuman, are terrestrial and aquatic agro-ecosystems that receive energy not only from the Sun, but also from humans in the form of energy subsidies. Their high productivity is supported by muscle energy and fuel energy, which are spent on cultivation, irrigation, fertilization, selection, processing, transportation, etc. Bread, corn, potatoes are "partially made from oil." The most productive agriculture receives about the same amount of energy as the most productive natural ecosystems of the second type. Their production reaches approximately 50,000 kcal*m -2 year -1 . The difference between them lies in the fact that a person directs as much energy as possible to the production of food products of a limited type, while nature distributes them among many types and accumulates energy for a “rainy day”, as if putting it into different pockets. This strategy is referred to as the “diversity-for-survival strategy”.

Fuel-driven industrial-urban ecosystems, - the crown of human achievements. In industrial cities, highly concentrated fuel energy does not supplement, but replaces solar energy. Food - the product of systems driven by the Sun - is brought into the city from outside. A feature of these ecosystems is the huge need for energy in densely populated urban areas - it is two to three orders of magnitude greater than in the first three types of ecosystems. If in non-subsidized ecosystems the energy influx ranges from 10 3 to 10 4 kcal*m -2 year -1 , and in subsidized systems of the second and third type - from 10 4 to 4*10 in large industrial cities, energy consumption reaches several million kilocalories per 1 m 2: New York - 4.8 * 10 6, Tokyo - 3 * 10 6, Moscow - 10 6 kcal * m -2 year -1.

Energy consumption by a person in a city averages more than 80 million kcal*year -1; for food, he needs only about 1 million kcal * year -1, therefore, for all other activities (household, transport, industry, etc.), a person spends 80 times more energy than is required for the physiological functioning of the body. Of course, in developing countries the situation is somewhat different.