1. Integrity. The flows of matter and energy ensure the integrity of the ecosystem - the relationship of its organisms with each other and with the natural environment.
2. Self-reproducibility. The main conditions for the self-reproduction of an ecosystem are:
The presence of food and energy in the environment (for autotrophs - solar, for chemotrophs - chemical);
The ability of organisms to reproduce
· the ability of organisms to reproduce the chemical composition and physical properties of the natural environment (soil structure, water transparency).
3. Ecosystem sustainability. Natural ecosystems are capable of long-term existence. Even with significant fluctuations in external factors, internal parameters remain stable. The stability of ecosystems decreases with the depletion of the species composition. The most stable are tropical forests rich in life (over 8,000 plant species), temperate forests (2,000 species) are quite stable, tundra biocenoses (500 species) are less stable, oceanic island ecosystems are not very stable. Orchards are even less stable, and crop fields without human support cannot exist at all, they are quickly overgrown with weeds and destroyed by pests.
4. Self-regulation of ecosystems. The effectiveness of self-regulation is determined by the diversity of species and food relationships between them. If the number of one of the primary consumers decreases, then with a variety of species, predators switch to feeding on more numerous animals that were previously secondary to them.
5. Emergent properties (eng. emergent unexpectedly appearing) - new, unique properties of an ecosystem that arise as a result of the synergistic interaction of its components. For example, some algae and coelenterates coevolve to form a coral reef system, resulting in an efficient nutrient cycling mechanism that allows such a combined system to maintain high productivity in very nutrient-poor waters. Consequently, the enormous productivity and diversity of coral reefs is an emergent property characteristic only of the reef community level.
36.Evolution of ecosystems.
Any ecological system is constantly changing, adapting to changes in the external environment. Allogeneic changes are caused by geochemical forces acting on the ecosystem from the outside, as well as by the action of geological factors. Autogenic changes occur under the influence of factors that arise within the ecosystem.
Ecological succession is a process of directed development of an ecosystem, proceeding through the successive replacement of a simple community by a more complex one, with richer biological diversity, with a more complex spatial and trophic structure, as a result of which the ecosystem becomes more stable.
Characteristic signs of succession:
Occurs under the action of the biotic component of the ecosystem, since the biotic community changes the physical environment and due to these changes, certain succession rates, its character and flow limits are established.
Orderly development of the ecosystem associated with a change in the species structure of the community.
It proceeds until the ecosystem becomes stabilized, that is, when the unit of energy flow accounts for the maximum biomass and the maximum number of interspecific interactions. This state is called climacteric.
In the course of succession, the ecosystem passes through certain intermediate stages of development, each of which has its own biocenosis. This sequence is the so-called succession series (series).
The following types and types of successions of ecological systems are distinguished:
Exogenetic (exodynamic) changes in the ecosystem are caused by external factors in relation to the ecological system. Endogenetic ones are caused by internal factors of the ecosystem.
Primary successions - begin on lifeless, lifeless substrates (rocks, products of a volcanic eruption) and in the process of their flow, not only phytocenoses, but also soils are formed.
Secondary successions - occur at the site of disturbed or destroyed climax ecosystems (after a fire, deforestation, drought, etc.). They proceed much faster than the primary ones, since they start from intermediate stages. Secondary succession is possible only when a person does not have a strong and permanent influence on the developing ecosystem.
Autotrophic succession: Autotrophs (green plants) appear first in the community. Autotrophic successions are the most common and they proceed until the climax stage of ecosystem development is established.
Heterotrophic succession: Occurs in substrates that lack living plants (producers) and involve only animals (heterotrophs) and dead plants. These successions proceed only as long as there is a supply of organic matter. After its completion, the succession series ends, the ecosystem breaks up.
Destructive successions - do not end with a final climax state. Human impact on the ecological system often leads to simplification of the ecosystem - that is, degression.
The change of communities as a result of degression ends not with climax communities with a more complex structure, but with stages of catocenosis, which often end with the complete collapse of the ecosystem.
Catastrophic succession - caused by some natural or man-made disaster.
Patterns of the successional process:
At the initial stages, the species diversity is insignificant, productivity and biomass are small, as the succession develops, the indicators increase.
As succession progresses, the number of biotic relationships increases, with the number of symbiotic relationships increasing most strongly. Circuits and power networks are becoming more complex.
The number of free ecological niches is decreasing. In the climax community, they are either absent or present in a minimal amount.
The processes of circulation of substances, energy and respiration of the ecosystem are intensified.
Each subsequent stage of succession lasts longer than the previous one, is characterized by a higher ratio of biomass to the value of the energy flow, as well as by its dominant species.
The rate of succession is highly dependent on the lifespan of those organisms that affect the functioning of the ecosystem (autotrophs).
The duration of the last stages of succession is long, but the dynamic processes do not stop, but only slow down. Most of the processes at these stages are dynamic, cyclic processes.
In the mature stage of the climax community, the biomass of the ecosystem reaches a maximum or values close to the maximum, but in the climax community itself, the productivity is somewhat lower. This is explained by the fact that in the climax community, the maximum of primary production is consumed by consumers; that the ecosystem develops a large green mass, as a result of which the illumination decreases, the intensity of photosynthesis decreases, and the cost of breathing increases.
Ecosystems and their main properties
Ecosystem is a Greek word oikos- house, system- a whole, that is, made up of parts or a combination. This term was introduced into ecology by Henri Barry Tensley (1935). He wrote: « Although organisms may claim to be the focus of attention, however, if we think more deeply, we cannot separate them from the specific environment with which they constitute a single physical system. Such systems, from the point of view of an ecologist, are the basic units of nature on the earth's surface. .BUT. Tensley represented an ecosystem as a combination of a biotope and a biocenosis.
Consequently, an ecosystem is open, but integral and stable systems of living (autotrophic producers and heterotrophs ─ consumers and decomposers) and non-living (abiotic environment) components historically formed in the biosphere and in that particular territory or water area.
According to K. Willi, the term "ecosystem" is understood by ecologists as a natural unit representing a combination of living and non-living elements: as a result of the interaction of these elements, a stable system is created, where the circulation of substances between living and non-living parts takes place.
In these definitions, an ecosystem is characterized by energy flows and the possibility of its accumulation, internal and external cycles of substances that have the ability to regulate all processes in it (Fig. 3.7). The ecological system is considered the main (main) functional unit in ecology, since it includes living organisms and inanimate environment, elements that mutually influence each other and provide the necessary conditions for maintaining life in the form that exists on our planet.
Respiration, CO 2
Fig.3.7 .
Scheme of the main components of the ecosystem
(according to E.A. Krikunovsky, 1995)
An ecosystem as a natural complex formed by living organisms and their habitat, interconnected by the exchange of matter and energy, is one of the main concepts in ecology.
Ecosystems are classified according to the following ranks:
─ microsystems (for example, a small reservoir, a puddle, a rotten stump in a forest, etc.);
─ mesoecosystems (forest, river, pond, etc.);
─ macroecosystems (ocean, continent, aerotope);
─ global ecosystem (biosphere as a whole).
From this hierarchy, it follows that large ecosystems include ecosystems of a lower rank.
Biocenosis and biotope influence each other, which is manifested mainly in the continuous exchange of matter and energy both between the two components and within each of them. The ecosystem also includes communities (phytocenoses, zoocenoses, microbiocenoses, mycocenoses) united by food and chorological (spatial) links, as well as such environmental factors as ecotope, climatotope and edaphotope. Natural ecological systems are open systems in which the environment is considered at the input and output (Fig. 3.8).
The permanent existence of organisms in any limited space is possible only in ecosystems, within which the waste products of some species of organisms are utilized by other species. Consequently, any ecosystem capable of long-term existence must include autotrophs, heterotrophs, and decomposers (saprophytes) that feed on dead matter, but even such an ecosystem is not immune from death. The stability of ecosystems is determined by the correspondence of the species composition to the living conditions and the degree of development of these systems.
Wednesday
Recycled
Energy and matter
Migration of organisms
Input JF + S + OE = Ecosystem
At the exit
Substance and organism
Fig.3.8. Ecosystem Functioning (According to Odum, 1986)
Possible changes in the environment fluctuate strongly and depend on many variable dimensions of the system (the larger the system, the less it depends on external influences); the intensity of the flows of substances and energy (the more intense it is, the greater their outflow and inflow); balance of autotrophic and heterotrophic processes (the more this balance is disturbed, the stronger the external influx of substances and energy must be to restore it); stage and degree of development of the ecosystem. At its core, an ecological system is a complex in which there is a constant exchange of matter, energy and information between abiotic and biotic elements.
Ecosystem quality assessment . Ecological patterns and basic concepts of ecology contribute to the determination of the qualitative and quantitative state of the ecosystem.
The quantitative state of an ecosystem refers to its productivity, while the qualitative state refers to its resistance to adverse impact factors. The same regularities contribute to the determination of the qualitative and quantitative state of the biocenoses of a particular ecosystem.
According to first regularity the ecosystem must correspond to the characteristics of the environment, second – biocenosis should be relatively cheap if possible, third and fourth – the ecosystem should provide maximum utilization and sustainability. For example, if we create industrial production in an ecosystem, then we must create a circulating water supply system; residual production waste - to be disposed of and recycled; residual heat - to be used for other technological processes, for heating greenhouses, etc. Academician S. Schwartz proposed to evaluate the quality of ecosystems according to five criteria: biomass, productivity, noise immunity, exchange rate and redundancy.
Biomass of all the main components should be high and correlated with the rest of the ecosystem components. If we take the agroecosystem, then its feature is the predominance of phytomass over zoomass, which is expressed in a sharp form, it ensures the production of oxygen, the production of products of animal and vegetable origin.
Productivity Ecosystems - this is the output of products per unit area, volume (biogeocenosis and ecosystems), when it reaches its maximum, it must satisfy all needs and keep the ecosystem in a stable state. As a negative example, uncontrolled deforestation can be cited, as a result of which the biomass of forest areas decreases and this can lead to the destruction of the ecosystem within a few years.
Noise immunity- this is the resistance of an ecosystem to pollution up to a certain limit, which does not put it out of action. At present, a large number of ecosystems are extremely unstable, we can see only two conditionally positive aspects in them: they gave and give us the opportunity to increase material wealth, and they also caused an "environmental crisis". Ecosystem stability is subdivided into resistant stability and resilient. resistive sustainability (resistance) is a property (ability) of an ecosystem to resist disturbances, maintaining its structure and function. elastic stability - the ability of a system to quickly recover after a violation of structure and function.
Exchange rate substance and energy flows in the ecosystem with such intensity that, with high pollution, its rapid biological purification is ensured. But speed - cleaning is not an end in itself! For example, excessive chlorination of water speeds up the process of its disinfection, but chlorine compounds in water can produce dioxins - supertoxicants that are dangerous for living organisms, including humans. Chlorine destroys tooth enamel, and this leads to dental caries. Receiving water ozonation is more expensive, but relatively safer for the ecosystem and humans.
Reservation- this is the ability of an ecosystem to quickly restructure and adapt to changing conditions without losing other positive properties. Man should strive to create good ecosystems wherever required and wherever possible. It should not worsen, but improve the natural environment: by eliminating the centers of especially dangerous diseases, sharply reducing the breeding areas of locusts, stopping the movement of sands, etc. Here it is appropriate to refer to the principle of Le Chatelier-Brown: with an external impact that brings the ecological system out of a state of stable equilibrium, the balance always shifts in the direction in which the effect of the impact is weakened.
The spatial structure of ecosystems is caused by the fact that autotrophic and heterotrophic processes are usually separated in space. The former actively flow in the upper layers, where sunlight is available, while the latter are more intense in the lower layers (soils and bottom sediments). In addition, they are also separated in time, since there is a time gap between the formation of organic substances by plants and their mineralization by consumers.
From the point of view of the spatial structure in natural ecosystems, the following tiers can be distinguished:
- upper, autotrophic tier or green belt of the Earth , which includes plants or their parts containing chlorophyll: here the fixation of solar energy, the use of inorganic compounds and the accumulation of energy in complex substances synthesized by plants take place;
- lower, heterotrophic tier or "brown belt" The earth is represented by soils, bottom sediments, in which the processes of decomposition of dead organic remains of plants and animals predominate.
Ecosystems are open non-equilibrium thermodynamic systems that constantly exchange energy and matter with the environment, thereby reducing entropy inside themselves, but increasing it externally, in accordance with the laws of thermodynamics. The ability of living organisms to reduce disorder within themselves is interpreted as the ability to accumulate negative entropy - negentropy.
Energy in ecosystems. Energy this is one of the main properties of matter, which is capable of producing work, and in a broad sense, energy is a force. It is the source of life, the basis and means of controlling all natural systems, the driving force of the universe. The fundamental laws of thermodynamics are of universal importance in nature, and the understanding of these laws is important to provide an effective approach to the problems of environmental management.
Exergy is the maximum work that a thermodynamic system performs during the transition from a given state to a state of physical equilibrium with the environment.
Exergy is the useful work of the energy involved in some process, the value of which is determined by the degree of difference of some parameter of the system from its value in the environment.
First law of thermodynamics- the law of conservation of energy - says: Energy is neither created nor destroyed, but is transformed from one form into another. On earth, the energy of the sun is converted by photosynthesis into the energy of food. Ecology considers here only the existing connection between sunlight and ecological systems in which the conversion of solar energy into the energy of organic matter takes place.
According to the second law of thermodynamics any kind of energy eventually goes into the least usable and most dissipative form - entropy, which becomes unusable. All energy processes are characterized by the process of transition from a higher level of organization (order) to a lower level (disorder). The tendency of energy to degrade is expressed by the term " entropy increase ". Entropy is a measure of disorder. The energy of food absorbed by animals is partly used for the course of biochemical processes in the body, and partly converted into heat to warm the body.
Living matter differs from non-living matter by the ability to accumulate free energy from the surrounding space and transform it in such a way as to resist entropy. In nature, the quality of sunlight energy is considered to be the formation of a higher quality form of energy (Table 3.2).
Table 3.2. Qualitative state of the received energy, kcal
So, from 2000 kcal of solar energy entering the leaf surface of plants, 200 kcal of food energy is obtained, and the energy contained in wood is only 20, in coal - 1.0 kcal. When converting coal energy into electrical energy, only 0.2 kWh is obtained.
In order for solar energy to do the same work that electrical energy can do, its quality must be increased by 10 thousand times. At each new level, 90% of the potential energy is dissipated, turning into heat. For physiological functioning, a person needs about 1 million kcal of food energy per year. Mankind produces only approximately 8∙10 15 kcal of energy (with a population of 6.7 billion people), but this energy is distributed extremely unevenly across the planet. For example, in a city, energy consumption per person reaches 80 million kcal per year, this amount of energy is distributed to all types of activities (transport, household, industry), i.e. a person spends 80 times more energy than is necessary for the functioning of the body.
At present, humanity is in the stage of an energy crisis and the nature of the future civilization, its quality and composition are limited, first of all, by energy costs. The way out for human society from this crisis state is the use of alternative energy and large-scale energy saving.
Energy maximization law(G.Odum–Yu.Odum): in competition with other ecosystems, the one that best contributes to the supply of energy and uses its maximum amount in the most efficient way survives (preserves).
Marine ecosystems. The depth of the ocean is quite large, in some places it reaches 11.5 km. Unlike land and fresh waters, the marine ecosystem is continuous. Life in the ocean exists in all its corners, but is richest near the continents and islands. There are practically no abiotic zones in the ocean, despite the fact that temperature, salinity and depth are barriers to the movement of animals.
Thanks to the constant winds trade winds, in the oceans and seas there is a constant circulation of water due to powerful currents (Gulf Stream - warm, California - cold, etc.), which eliminates the lack of oxygen in the depths of the ocean.
Upwelling places are the most productive in the World Ocean. Upwelling - the process of rising cold waters from the depths of the ocean, where winds constantly mix warm water near a steep continental slope, in exchange for which cold water enriched with nutrients rises from the depths.
Where there is no such water exchange, biogenic elements from submerged organic residues remain in bottom sediments for a long time. They are highly productive and rich in nutrients, due to their introduction from land, water of estuaries (deltas).
Y. Odum calls this phenomenon outwelling.
In the coastal zone, the role of ebbs and flows caused by the attraction of the Moon and the Sun is very large. They provide a noticeable periodicity in the life of communities (biological clock). Marine reservoirs are characterized by a stable alkaline environment: pH = 8.2, but the ratio of salts and salinity change. In the water of the brackish estuaries of the rivers of the coastal zone, the salinity varies significantly according to the seasons of the year. Therefore, organisms in the coastal zone are euryhaline, while those in the open ocean are stenohaline.
Nutrients are an important limiting factor in the marine environment, where they are present in a few parts per million parts of water. In addition, their residence time in water outside organisms is much shorter than sodium and magnesium and other elements. Biogenic elements dissolved in water are quickly intercepted by organisms and enter their trophic chains; they practically do not enter the heterotrophic zone (they do not go through the biological cycle). Therefore, the low concentration of biogenic elements in sea water does not indicate their general deficiency.
The main factor that differentiates marine biota is the depth of water in the seas and oceans. In general, the sea water column in the section is divided into the following zones: euphotic zone - the uppermost part of the ocean where light penetrates and where primary production is created. Its thickness reaches 200 m in the open ocean, and no more than 30 m in the coastal part. This is a relatively thin film, which is separated by a compensation (up to 1.0 - 1.5 km) zone from a much larger water column, right down to the very bottom - aphotic zones.
Just as in freshwater lentic (fluid) ecosystems, the entire population of the ocean is divided into plankton, nekton and benthos. Plankton and nekton, that is, everything that lives in the open waters of the ocean, forms the so-called pelagic zone.
The biotic community of each of the above zones, except for the euphotic one, is divided into benthic and pelagic zones. They include zooplankton as primary consumers, insects in the sea are ecologically replaced by crustaceans. The vast majority of large animals are predators. They are scarce in freshwater systems. Many of them resemble plants and hence their names, for example, sea lilies. Mutualism and commensalism are widely developed here. All benthic animals in their life cycle go through the pelagic stage in the form of larvae.
Characteristics of marine ecosystems. The area of the continental shelf, the non-retic area, is limited to a depth of 200 m, which is about 8% of the ocean area.
(29 million km 2). The coastal zone is favorable in terms of nutrition, even in rainforests there is no such diversity of life as here. Plankton is very rich in food due to the larvae of the benthic fauna. The larvae that remain uneaten settle on the substrate and form either epifauna (attached) or infauna (burrowing).
Upwelling areas are located along the western desert coasts of the continents. They are rich in fish and birds living on the islands. But when the wind direction changes, plankton blooms and mass death of fish due to eutrophication is observed.
Estuaries - These are semi-enclosed coastal reservoirs, they are ecotopes between freshwater and marine ecosystems. Estuaries are usually included in the mainland (coastal) zone, subject to ebbs and flows. Estuaries are highly productive and are traps for biogenic substances. They serve as a feeding place for juveniles and are rich in a whole range of seafood (fish, crabs, shrimps, oysters, etc.). Getting into the sphere of economic activity, they lose significantly their productivity due to pollution of the aquatic environment.
ocean areas, euphotic zone of the open ocean, poor in biogenic elements. To a certain extent, these waters in terms of productivity can be equated with terrestrial deserts. The Arctic and Antarctic zones are much more productive, as plankton density increases as you move from warm to cold seas, and fish and cetacean fauna are much richer.
Phytoplankton is the primary source of energy in the food chains of the pelagic region - the producer. Large fish and animals here are mainly secondary consumers feeding on zooplankton. Both phytoplankton and planktonic larvae of mollusks, sea lilies, etc. are the producers for zooplankton.
The species diversity of the fauna decreases with depth, and yet the diversity of fish in the zone is high, despite the fact that it is practically devoid of producers. The diversity is associated with the stability of conditions in the abyssal zone (at a depth of 2000 to 5000 m) over a long geological time, which slowed down evolution and preserved many species from distant geological epochs.
The ocean is the cradle of life on the planet, and many more mysteries keep its water column and ocean floor. The emergence of life in the ocean marked the beginning of the formation of the biosphere. And now, occupying more than 2/3 of the land surface, it largely determines, in combination with continental ecosystems, the integrity of the modern biosphere of the Earth.
The most important properties of ecosystems are a consequence of the hierarchical organization of living levels. As subsystems combine into larger systems, the latter acquire unique properties that were not present at the previous level, which cannot be predicted based on the properties of lower-order systems that make up the system of a higher level of organization. In ecology, this quality is called emergent, that is, unexpectedly appearing.
Biological systems have properties that cannot be reduced to the sum of the properties of their constituent subsystems. For example, hydrogen and oxygen, when combined, form water - a liquid whose properties cannot be predicted based on the properties of the initial gases, or the psychology of the crowd is not the sum of the psychological portraits of individual people.
The American ecologist Y. Odum wrote: “The well-known principle of the irreducibility of the properties of the whole to the sum of the properties of its parts should serve as the first working commandment of the ecologist,” i.e., to study highly organized systems, it is necessary to study their specific properties. To save a civilization, it is not enough to study it at the level of a cell or an organism. To study the problem, for example, pollution, it is necessary to study the laws of functioning of higher systems.
The most important function of any ecosystem is the interaction of autotrophic and heterotrophic processes. Approximately one million years ago, some of the synthesized matter was not consumed, but was preserved and accumulated in sediments. The predominance of the rate of synthesis over the rate of decomposition of organic substances led to a decrease in the content of carbon dioxide and the accumulation of oxygen in the atmosphere. Without the presence of life, the composition of the atmosphere on Earth would approach the composition of the lifeless planets of Mars and Venus. This means that green organisms played a major role in shaping the geochemical environment of the Earth, favorable for other organisms. The currently observed ratio of gases in the atmosphere developed approximately 60 million years ago. The ratio of the rates of autotrophic and heterotrophic processes is one of the main functional characteristics of ecosystems and is defined as the ratio of CO 2 and O 2 concentrations in ecosystems, i.e., as the ratio of energy accumulated by producers and dissipated by consumers. The balance of these processes in ecosystems can be positive or negative. Systems with a predominance of autotrophic processes (tropical forest, shallow lake) have a positive balance. Systems in which heterotrophic processes predominate (mountain river, city) have a negative balance. Man, burning organic matter in the form of fossil fuels, farming, destroying forests, accelerates the processes of decomposition. A large amount of CO 2 is released into the air, previously bound in coal, oil, peat, and wood. The established balance of autotrophic and heterotrophic processes on Earth is maintained due to the ability of ecosystems and the biosphere to self-regulate. Self-regulation of ecosystems - the most important factor of their existence - is provided by internal mechanisms, stable integrative links between their components, trophic and energy relationships. Man is the most powerful being capable of changing the functioning of ecosystems. Man belongs to heterotrophs, despite the perfection of technology, he needs life support resources given by nature. It is possible to save a person only with the help of regulatory mechanisms that allow the biosphere to adapt to individual anthropogenic influences. To maintain his life support, a person should strive to preserve the self-regulation regimes of the natural life support systems of the planet.
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Slides captions:
Public speaking on a socially significant topic The objectives of the lesson: to consolidate knowledge about the features of oratory; to form the ability to create their own statement on a socially significant topic; develop speech skills, the ability to master the audience; to replenish the vocabulary of students; educate the culture of oral speech. Prepare students for public speaking
Today in the lesson we have to consolidate knowledge about oratory public speech, replenish our vocabulary, continue working on the culture of oral speech; prepare for public speaking. Before you are familiar words: eloquence, rhetoric, orator, oratorical pathos. Explain their lexical meaning, make phrases using all the ways of subordinating words.
Linguistic simulator eloquence rhetoric speaker oratorical pathos
test yourself rich eloquence oratorical voice study rhetoric speak with pathos oratory talent
Test Orator The science of the laws of preparing and delivering a public speech in order to have the desired impact on the audience Eloquence An applied section of linguistics that deals with two questions: how to speak correctly and how to speak well Rhetoric A person delivering a public speech Culture of speech Passionate enthusiasm, uplift, enthusiasm, caused by some high idea Paphos Ability, ability to speak beautifully, convincingly; oratorical talent
Test yourself Orator The science of the laws of preparing and delivering public speech in order to have the desired impact on the audience Eloquence An applied branch of linguistics that deals with two questions: how to speak correctly and how to speak well Rhetoric A person delivering a public speech Culture of speech Passionate enthusiasm, uplift, enthusiasm , caused by any high idea Paphos Ability, ability to speak beautifully, convincingly; oratorical talent
Kozhinov Vadim Valerianovich Date of birth: June 5, 1930 Place of birth: Moscow, USSR Date of death: January 25, 2001 (aged 70) Place of death: Moscow, Russia Citizenship: USSR, Russia Occupation: literary critic, publicist Language of works: Russian.
Chaliapin Fyodor Chaliapin Fyodor Chaliapin Fyodor Chaliapin Fyodor F. Chaliapin
N.Plevitskaya
L. Ruslanova
B. Shtokolov
D. Hvorostovsky
Tula folk choir
v. Stoyanovo
K. Shulzhenko
V. Bunchikov
I. Talkov
V. Ganichev
Requirements for oral presentation 1. Content, clarity of expression. 2. Persuasiveness, evidence of speech. 3. Expressiveness of speech. 4. Mandatory preliminary preparation. Use quotations, after grouping them according to the points of the plan. Preparation plan 1. The presence of an appeal (addressee of the statement). 2. Convincing arguments (facts, examples, references to authority). 3. Elimination of categoricalness (use of introductory and plug-in structures). 4. Conscription final of the speech. Eighth graders give examples, facts, train, prepare speeches. Homework: prepare a speech in a journalistic style on the topic “The Meaning of the Song”.
Reflection Today at the lesson we repeated ... The new understanding was that ... I was convinced that ... It will help me to prepare a public speech ... I consolidated the concepts: ....
On the topic: methodological developments, presentations and notes
Russian language lesson in grade 8 "Public speaking on a socially significant topic"
International humanitarian law (IHL) is studied not only in literature lessons. Russian language lesson in grade 8 based on the story "Smile" by R. Bradbury improves the skills of writing journalistic texts ...
