Briefly answer the following questions.

1. What is the scientific name for the "orderlies of the planet" who destroy the dead remains of organisms and turn them into inorganic and elementary organic compounds?
2. What is the most important environmental factor for aerobic organisms concentrated in the atmosphere?
3. What is the name of a closed cycle of processes and phenomena?
4. What are the names of species of living organisms that have a limited range, represented within one small geographic area?
5. What is the name of the environmental factor, the impact of which can go beyond the limits of the body's endurance?
6. Name a group of abiotic factors associated with the supply of solar energy, the direction of the winds, the ratio of humidity and temperature.
7. What is the name of the environmental factor, which implies direct human impact on some organism or its habitat?
8. What is the best combination of living conditions called?
9. What is the body's response to a change in the seasons, regulated by photoperiodism?

Correct answer:1 - reducers, 2 - oxygen, 3 - circulation, 4 - endemics, 5 - limiting (limiting), 6 - climatic (meteorological, weather), 7 - anthropogenic factor, 8 - biological optimum, 9 - seasonal rhythm (seasonal biorhythm, circadian rhythm or diurnal).

Assessment:

Total - 9 points.

Task 2. "Environmental protection" (7 points)

From the list below, select measures to reduce the rate of erosion processes:

1. transition to low-waste technologies;
2. organization of wildlife sanctuaries and reserves;
3. moldboard-free and flat-cut plowing;
4. plowing across slopes;
5. regulation of snow melting;
6. fight against water and air pollution;
7. creation of field-protective, water-regulating and forest belts;
8. soil cultivation with seam turnover;
9. the use of heavy machinery in soil cultivation;
10. construction of ponds on the tops of ravines, accumulating runoff;
11. construction of earth embankments in places of active water flow;
12. construction of drainage channels in habitats with high humidity.

Correct statements– 3, 4, 5, 7, 10, 11, 12.

Assessment:1 point for each correct answer. If incorrect activities are indicated as correct, then 1 point is deducted for each such incorrectly selected item. As a result, if there are more incorrectly selected than correctly selected, then the resulting score will be zero.

Total - 7 points.

Task 3. “The number of populations. (5 points)"

Analyze the 2000 data on the age composition of the population of Russia (150 million inhabitants) and Indonesia (190 million inhabitants), shown in the table below.

Using the materials in the table, answer the following questions.

1. Calculate the share (in%) of young people (ages 0-30) in Russia and Indonesia.
2. Which country's population will grow noticeably in the future and why?
3. Which country's population is most likely stable and not showing a pronounced upward trend? Explain why.
4. Why is the group from 51 to 60 years old in the age pyramid of the population of Russia smaller than in the previous and subsequent groups?
5. In which country are the age groups of people most different in terms of population? What, in your opinion, can this be connected with?

Correct answer:

1. In Russia 44%, in Indonesia 62%.
2. Indonesia. Because the population in the first category (0-10 years) is noticeably higher than in the subsequent categories.
3. Russia. Because the population in the first category (0–10 years old) is slightly less than in the subsequent categories.
4. People of this group were born in the 40s and 50s. At this time, due to the Second World War, hunger and devastation in the country there was a high mortality rate of the reproductive part of the population, so the proportion of births was significantly less than in the neighboring decades (30-40s and 50-60s).
5. In Indonesia. In this country, more children are born and fewer older people survive. Therefore, in comparison with Russia, different age groups differ more in number. This is typical for countries with rapidly growing populations.

Assessment: 1 point for each correct answer.

Total - 5 points.

Task 4. "Environmental protection" (10 points)

Fill out the table "Major air pollutants and their effects on nature and humans". In the center column, write the main sources of atmospheric pollutants (select from the list), in the right column, describe the danger these substances pose to nature and human health. When completing the table, keep in mind that some sources of pollution can relate to several types of air pollutants.

Sources that pollute the atmosphere:

1. transport;
2. manufacturing enterprises;
3. cement plants;
4. accidents at nuclear reactors;
5. production, which burns coal, shale, oil products;
6. burning peat and wood;
7. production and transportation of atomic weapons;
8. iron and copper production;
9. sulfuric acid production;
10. production of nitric acid;
11. thermal power plants (TPP) operating on coal, peat and fuel oil;
12. tests of atomic and hydrogen bombs.

Correct answer:

Substances that pollute the atmosphere	Main sources of pollution	Impact of pollutants on nature and humans
Carbon oxides (CO, CO 2)	1) transport; 2) combustion of coal, shale, oil products; 3) burning peat and wood	Cause the greenhouse effect
Sulfur oxides (SO 3, SO 2)	1) Combustion of coal, shale, oil products; 2) production of iron, copper; 3) production of sulfuric acid. 4) TPPs operating on coal, peat and fuel oil	Causes acid rain, London type smog. Deteriorate human health, negatively affect living organisms
Nitrogen oxides (NO, NO 2)	1) transport; 2) production of nitric acid.	Causing acid rain, Los Angeles-type smog. They worsen people's health, negatively affect living organisms.
Suspended substances (dust, soot, etc.)	1) industrial enterprises; 2) transport; 3) TPPs operating on coal, peat and fuel oil; 4) cement plants	They cause reflection of solar rays from the Earth, reduce surface heating, and impede photosynthesis in plants. Increase the likelihood of diseases of the respiratory system of humans and animals
Radioactive substances	1) testing of atomic and hydrogen bombs; 2) manufacturing and transportation of atomic weapons; 3) accidents at nuclear reactors	They cause mutational processes, threaten the life and health of living beings

Assessment: 1 point for each correctly filled table cell.

In the column "Main sources of pollution", a correctly filled cell is one in which two or more sources of pollution are correctly indicated.

In the column "Effects of pollutants on nature and humans", a correctly filled cell is considered to be the one in which one or more of the hazards posed by these substances are correctly indicated.

Total - 10 points.

Task 5. "Population ecology" (4 points)

Give several examples of organisms at each point that have an island type of population distribution:

• a) among aquatic organisms (2 to 4 examples);
• b) among terrestrial organisms (2 to 4 examples).

Examples of correct answers:

and) lake dwellers: crucian carp, pike, daphnia, cyclops, etc. You can bring examples of marine organisms - for example, fish and invertebrates of the Aral and Caspian seas.

b) inhabitants of real islands: Arctic fox, Sakhalin bear. Here you can also indicate the inhabitants of oases in the desert: date palm, moisture-loving plants, moisture-loving rodents, lizards, turtles, etc.

You can also mention animals that have fragmented their range due to human activities (bison, bison, Far Eastern leopard, kiwi and others).

Assessment: 1 point for 1–2 examples and 2 points for 3–4 examples separately for each sub-item of the question.

Total - 4 points.

Task 6. "Interaction of species in ecosystems" (4 points)

Components of a freshwater ecosystem can be:

• fish;
• bacteria;
• daphnia, molluscs;
• algae and higher aquatic plants;
• protozoa - ciliates;
• mushrooms.

Draw a diagram of the flows of matter and energy in the ecosystem of the reservoir. Select its components with blocks, and with arrows (directed both in one direction and in both), the flows of matter and energy. Explain why the exclusion of some elements, for example, small invertebrates, from this scheme will lead to a sharp disruption in the equilibrium of this ecosystem.

Correct answer:

Final scheme:

The exclusion of daphnia, molluscs and ciliates from this ecosystem will, on the one hand, lead to the disappearance of the food base for fish and, accordingly, their death, and, on the other hand, to a strong growth of algae and higher aquatic plants (water will bloom).

Evaluation: 1 point for 1–4 correctly placed arrows (including those with the correct direction), 2 points for 5–8 correctly placed arrows, 3 points for 9–12 correctly placed arrows. Double-edged arrows count as two!

Plus 1 point for a correct explanation about the exclusion of daphnia, molluscs and ciliates.

Total - 4 points.

Task 7. "Population ecology" (6 points)

In nature, biocenoses change and transform over time.

Describe the general patterns of self-development of ecosystems that are not negatively affected by anthropogenic factors.

Correct answer:

The correct answer should include the following points:

1. a gradual increase in species diversity;
2. change of dominant species;
3. complication of power circuits;
4. strengthening mutually beneficial ties;
5. increasing total biomass and community production;
6. increased consumption of products in food chains.

Assessment:1 point for each correctly indicated item.

Total - 6 points.

Living organisms and their inanimate environment are inextricably linked with each other and are in constant interaction. Co-living organisms of various types exchange matter and energy between themselves and the physical environment around them. This network of material-energy relationships unites living organisms and their environment into complex ecological systems.

The subject of ecology. Ecology (from the Greek "oikos" - dwelling, refuge and "logos" - science) is the science of the relationship between living organisms and their environment. Ecology deals with individuals, populations (made up of individuals of the same species), communities (made up of populations), and ecosystems (including communities and their environment). Ecologists study how the environment affects living organisms and how organisms affect the environment. By studying populations, ecologists solve questions about individual species, about stable changes and fluctuations in population size. When studying communities, their composition or structure is considered, as well as the passage of energy and matter through the communities, that is, what is called the functioning of communities.

Ecology occupies a significant place among other biological disciplines and is associated with genetics, evolutionary doctrine, ethology (the science of behavior), physiology.

The closest link exists between ecology and the theory of evolution. Thanks to natural selection in the process of the historical development of the organic world, only those species, populations and communities remained that survived in the struggle for existence and adapted to the changing habitat.

The concept of "ecology" is very widespread. In most cases, ecology is understood as any interaction between man and nature, or, most often, the deterioration of the quality of our environment caused by economic activity. In this sense, ecology concerns each member of society.

Ecology, understood as the quality of the environment, affects and is determined by the economy, invades social life, affects the domestic and foreign policies of states and depends on politics.

Concern about the deteriorating state of the environment is growing in society and a sense of responsibility for the state of the earth's natural systems is beginning to form. Environmental thinking, that is, the analysis of all economic decisions taken from the point of view of maintaining and improving the quality of the environment, has become absolutely necessary in the development of any projects for the development and transformation of territories.

The nature in which a living organism lives is its habitat. The surrounding conditions are varied and changeable. Not all environmental factors affect living organisms with the same force. Some may be necessary for organisms, others, on the contrary, are harmful; there are those who are generally indifferent to them. Environmental factors that affect the body are called environmental factors.

According to the origin and nature of the action, all environmental factors are divided into abiotic, i.e., factors of the inorganic (inanimate) environment, and biotic, associated with the influence of living beings. These factors are subdivided into a number of particular factors.

Biological optimum. It often happens in nature that some environmental factors are in abundance (for example, water and light), while others (for example, nitrogen) are in insufficient quantities. The factors that reduce the viability of the organism are called limiting factors. For example, brook trout live in water with an oxygen content of at least 2 mg / l. If the oxygen content in water is less than 1.6 mg / l, trout dies. Oxygen is the limiting factor for trout.

The limiting factor may be not only its lack, but also its excess. Heat, for example, is necessary for all plants. However, if the temperature is high for a long time in the summer, then the plants, even with moist soil, may suffer from leaf burns.

Consequently, for each organism there is the most suitable combination of abiotic and biotic factors, optimal for its growth, development and reproduction. The best combination of conditions is called the biological optimum.

Identification of the biological optimum, knowledge of the patterns of interaction of environmental factors are of great practical importance. Skillfully maintaining the optimal conditions for the life of agricultural plants and animals, you can increase their productivity.

The adaptability of organisms to their environment. In the process of evolution, organisms have adapted to specific environmental conditions. They have developed special adaptations to avoid or overcome the effect of an unfavorable factor. For example, desert plants can tolerate prolonged droughts because they have different adaptations to extract water and reduce evaporation. Some plants have deep and branched root systems that absorb water more efficiently, while others (for example, cacti) accumulate water in tissues. In some plants, the leaves have a waxy coating and therefore evaporate less moisture. In the dry season, many plants reduce the leaf area, and individual shrubs shed all leaves and even entire branches. The smaller the leaves, the less evaporation and the less water you need to survive in heat and drought.

A characteristic feature of the adaptations of organisms is settlement in an environment where the conditions for life are closest to their biological optimum. Organisms always adapt to the whole complex of environmental factors, and not to any one factor.

1. What role do different abiotic factors (temperature, humidity) play in the life of higher plants and animals?
2. Give examples of how a person uses knowledge about the relationship of organisms in his practice.
3. Give examples of the biological optimum for plants, animals, fungi you know.
4. Explain how changes in environmental factors affect crops.

Habitat - this is the part of nature that surrounds a living organism and with which it directly interacts. The components and properties of the environment are diverse and changeable. Any living creature lives in a complex, changing world, constantly adapting to it and regulating its life in accordance with its changes.

Individual properties or elements of the environment that affect organisms are called environmental factors. Environmental factors are diverse. They may be necessary or, conversely, harmful to living things, facilitate or hinder survival and reproduction. Environmental factors are of a different nature and specificity of action. Among them are abioticand biotic, anthropogenic.

Abiotic factors - temperature, light, radioactive radiation, pressure, air humidity, salt composition of water, wind, currents, terrain - these are all the properties of inanimate nature that directly or indirectly affect living organisms.

Biotic factors - these are forms of influence of living beings on each other. Each organism constantly experiences the direct or indirect influence of other creatures, enters into contact with representatives of its own species and other species - plants, animals, microorganisms, depends on them and has an effect on them. The surrounding organic world is an integral part of the environment of every living being.

The interconnections of organisms are the basis for the existence of biocenoses and populations; their consideration belongs to the field of syn-ecology.

Anthropogenic factors - these are forms of human society activity that lead to a change in nature as the habitat of other species or directly affect their lives. In the course of human history, the development of first hunting, and then agriculture, industry, transport, has greatly changed the nature of our planet. The importance of anthropogenic impacts on the entire living world of the Earth continues to grow rapidly.

Although a person influences wildlife through a change in abiotic factors and biotic relationships of species, the activities of people on the planet should be distinguished as a special force that does not fit into the framework of this classification. At present, practically the fate of the Earth's living cover, of all types of organisms is in the hands of human society, depends on the anthropogenic influence on nature.

One and the same environmental factor has a different meaning in the life of co-living organisms of different species. For example, a strong wind in winter is unfavorable for large, openly living animals, but does not affect smaller ones, which take refuge in holes or under the snow. The salt composition of the soil is important for plant nutrition, but is indifferent for most land animals, etc.

Changes in environmental factors over time can be: 1) regularly-periodic, changing the strength of the impact in connection with the time of day, or the season of the year, or the rhythm of the ebb and flow in the ocean; 2) irregular, without a clear periodicity, for example, changes in weather conditions in different years, phenomena of a catastrophic nature - storms, showers, landslides, etc .; 3) directed over known, sometimes long, periods of time, for example, when the climate is cold or warming, water bodies are overgrown, cattle are constantly grazing in the same area, etc.

Among the environmental factors, resources and conditions are distinguished. Resources of the environment, organisms use, consume, thereby reducing their number. Resources include food, water when it is scarce, shelters, convenient breeding grounds, etc. Terms - these are factors to which organisms are forced to adapt, but usually cannot influence them. One and the same environmental factor can be a resource for some and a condition for others. For example, light is a vital energy resource for plants, and for sighted animals it is a condition of visual orientation. For many organisms, water can be both a living condition and a resource.

2.2. Organisms adaptations

The adaptation of organisms to the environment is called adaptation. Adaptation refers to any changes in the structure and functions of organisms that increase their chances of survival.

The ability to adapt is one of the basic properties of life in general, as it provides the very possibility of its existence, the ability of organisms to survive and reproduce. Adaptations are manifested at different levels: from the biochemistry of cells and the behavior of individual organisms to the structure and functioning of communities and ecological systems. Adaptations arise and develop during the evolution of species.

The main mechanisms of adaptation at the level of the organism: 1) biochemical- manifest themselves in intracellular processes, such as a change in the work of enzymes or a change in their quantity; 2) physiological - for example, increased sweating with an increase in temperature in a number of species; 3) morpho-anatomical - features of the structure and shape of the body associated with lifestyle; 4) behavioral - for example, the search for favorable habitats by animals, the creation of burrows, nests, etc .; five) ontogenetic - acceleration or deceleration of individual development, contributing to survival under changing conditions.

Environmental factors of the environment have various effects on living organisms, that is, they can affect both irritants,causing adaptive changes in physiological and biochemical functions; as limiters,making it impossible to exist in these conditions; as modifiers,causing morphological and anatomical changes in organisms; as signals,indicating changes in other environmental factors.

2.3. General laws of the action of environmental factors on organisms

Despite the wide variety of environmental factors, a number of general patterns can be identified in the nature of their impact on organisms and in the responses of living beings.

1. Law of the optimum.

Each factor has certain limits of positive influence on organisms (Fig. 1). The result of the action of a variable factor depends primarily on the strength of its manifestation. Both insufficient and excessive action of the factor negatively affects the vital activity of individuals. The favorable force of influence is called zone of optimum ecological factor or simply optimum for organisms of this species. The stronger the deviations from the optimum, the more pronounced the depressing effect of this factor on organisms. (pessimum zone). The maximum and minimum tolerated values \u200b\u200bof the factor are critical points,behindwithin which existence is no longer possible, death occurs. The endurance limits between the critical points are called ecological valence living beings in relation to a specific environmental factor.

Fig. 1. Scheme of action of environmental factors on living organisms

Representatives of different species differ greatly from each other both in the position of the optimum and in the ecological valence. For example, Arctic foxes in the tundra can tolerate air temperature fluctuations in the range of more than 80 ° C (from +30 to -55 ° C), while warm-water crustaceans Copilia mirabilis can withstand water temperature changes in the range of no more than 6 ° C (from +23 up to +29 ° C). One and the same strength of the factor manifestation may be optimal for one species, pessimal - for another, and go beyond the limits of endurance for a third (Fig. 2).

The wide ecological valence of the species in relation to abiotic environmental factors is indicated by the addition of the prefix "evry" to the name of the factor. Eurythermalspecies - enduring significant temperature fluctuations, eurybate- wide pressure range, euryhaline - different degrees of salinity of the environment.

Fig. 2. Position of the optimum curves on the temperature scale for different species:

1, 2 - stenothermal species, cryophiles;

3–7 - eurythermal species;

8, 9 - stenothermal species, thermophiles

The inability to tolerate significant fluctuations in the factor, or narrow ecological valence, is characterized by the prefix "steno" - stenothermal, stenobate, stenohalinespecies, etc. In the broader sense of the word, species for the existence of which strictly defined ecological conditions are required are called stenobiontic, and those that are able to adapt to different environmental conditions - eurybiontic.

Conditions approaching by one or several factors at once to critical points are called extreme.

The position of the optimum and critical points on the factor gradient can be shifted within certain limits by the action of environmental conditions. This occurs regularly in many species as the seasons change. In winter, for example, sparrows withstand severe frosts, and in summer they die from cooling at temperatures slightly below zero. The phenomenon of a shift of the optimum in relation to any factor is called acclimation. In terms of temperature, this is a well-known process of heat hardening of the body. A significant period of time is required for temperature acclimation. The mechanism is a change in the cells of enzymes that catalyze the same reactions, but at different temperatures (the so-called isozymes).Each enzyme is encoded by its own gene, therefore, it is necessary to turn off some genes and activate others, transcription, translation, assembly of a sufficient amount of new protein, etc. The overall process takes on average about two weeks and is stimulated by changes in the environment. Acclimation, or hardening, is an important adaptation of organisms that occurs under gradually approaching unfavorable conditions or when it enters a territory with a different climate. In these cases, it is an integral part of the overall acclimatization process.

2. Ambiguity of the effect of a factor on different functions.

Each factor has a different effect on different body functions (Fig. 3). An optimum for some processes may be a pessimum for others. So, the air temperature from +40 to +45 ° C in cold-blooded animals greatly increases the rate of metabolic processes in the body, but inhibits physical activity, and the animals fall into thermal torpor. For many fish, the water temperature, which is optimal for the maturation of reproductive products, is unfavorable for spawning, which occurs at a different temperature range.

Fig. 3. Scheme of the dependence of photosynthesis and plant respiration on temperature (according to V. Larher, 1978): t min, t opt, t max- temperature minimum, optimum and maximum for plant growth (shaded area)

The life cycle, in which at certain periods the organism performs mainly certain functions (nutrition, growth, reproduction, dispersal, etc.), is always consistent with seasonal changes in the complex of environmental factors. Mobile organisms can also change their habitat for the successful implementation of all their vital functions.

3. Variety of individual reactions to environmental factors.The degree of endurance, critical points, optimal and pessimal zones of individual individuals do not coincide. This variability is determined both by the hereditary qualities of individuals and by sex, age and physiological differences. For example, the mill moth butterfly, one of the pests of flour and grain products, has a critical minimum temperature for caterpillars -7 ° C, for adult forms -22 ° C, and for eggs -27 ° C. Frost at -10 ° C kills caterpillars, but is not dangerous for adults and eggs of this pest. Consequently, the ecological valence of a species is always wider than the ecological valence of each individual individual.

4. Relative independence of the adaptation of organisms to different factors.The degree of hardiness to any factor does not mean the corresponding ecological valence of the species in relation to other factors. For example, species that tolerate wide temperature changes do not have to be adapted to wide fluctuations in humidity or salt regime either. Eurythermal species can be stenohaline, stenobate, or vice versa. The ecological valences of a species in relation to different factors can be very diverse. This creates an extraordinary variety of adaptation in nature. The set of ecological valences in relation to different environmental factors is ecological spectrum of the species.

5. The discrepancy between the ecological spectra of certain species.Each species is specific in its ecological capabilities. Even in species that are similar in ways of adaptation to the environment, there are differences in relation to any individual factors.

Fig. 4. Changes in the participation of certain plant species in meadow herbage depending on moisture (according to L.G. Ramenskiy et al., 1956): 1 - meadow clover; 2 - common yarrow; 3 - Delyavin's keleria; 4 - meadow bluegrass; 5 - fescue; 6 - the bedstraw is real; 7 - early sedge; 8 - common meadowsweet; 9 - hill geranium; 10 – field korostavnik; 11 - short-nosed goatbeard

Rule of ecological identity of speciesit was formulated by the Russian botanist L. G. Ramenskiy (1924) in relation to plants (Fig. 4), then it was widely confirmed by zoological studies.

6. Interaction of factors.The optimal zone and limits of endurance of organisms in relation to any environmental factor can shift depending on how forcefully and in what combination other factors act simultaneously (Fig. 5). This pattern was named interaction of factors. For example, heat is easier to tolerate in dry rather than humid air. The risk of freezing is much higher in cold weather with strong winds than in calm weather. Thus, the same factor combined with others has a different environmental impact. On the contrary, the same ecological result can be obtained in different ways. For example, wilting of plants can be halted by both increasing the amount of moisture in the soil and lowering the air temperature, which reduces evaporation. The effect of partial substitution of factors is created.

Fig. five. Mortality of eggs of pine silkworm Dendrolimus pini under different combinations of temperature and humidity

At the same time, mutual compensation for the action of environmental factors has certain limits, and it is impossible to completely replace one of them with another. The complete absence of water or at least one of the basic elements of mineral nutrition makes plant life impossible, despite the most favorable combinations of other conditions. The extreme heat deficit in polar deserts cannot be compensated for by either an abundance of moisture or round-the-clock illumination.

Taking into account the patterns of interaction of environmental factors in agricultural practice, it is possible to skillfully maintain the optimal conditions for the life of cultivated plants and domestic animals.

7. The rule of limiting factors.The possibilities for the existence of organisms are primarily limited by those environmental factors that are most distant from the optimum. If at least one of the environmental factors approaches or goes beyond the critical values, then, despite the optimal combination of other conditions, individuals are threatened with death. Any factors strongly deviating from the optimum become of paramount importance in the life of a species or its individual representatives in specific periods of time.

Environmental limiting factors determine the geographic range of the species. The nature of these factors can be different (Fig. 6). So, the movement of the species to the north can be limited by a lack of heat, to arid regions - by a lack of moisture or too high temperatures. Biotic relations, for example, the occupation of a territory by a stronger competitor or the lack of pollinators for plants, can also serve as a limiting factor for the spread. So, the pollination of figs is entirely dependent on a single species of insect - the wasp Blastophaga psenes. The birthplace of this tree is the Mediterranean. Figs brought to California did not bear fruit until pollinating wasps were brought there. The distribution of legumes in the Arctic is limited by the distribution of pollinating bumblebees. On Dikson Island, where there are no bumblebees, there are no legumes either, although due to temperature conditions, the existence of these plants there is still permissible.

Fig. 6. Deep snow cover is a limiting factor in the distribution of deer (according to G.A. Novikov, 1981)

To determine whether a species will be able to exist in a given geographic area, it is necessary first of all to find out whether any environmental factors go beyond its ecological valence, especially during the most vulnerable period of development.

Identifying limiting factors is very important in agricultural practice, since by directing the main efforts to eliminate them, you can quickly and effectively increase plant productivity or animal productivity. So, on strongly acidic soils, the wheat yield can be slightly increased by applying different agronomic influences, but the best effect will be obtained only as a result of liming, which removes the limiting effects of acidity. Knowing the limiting factors is thus the key to managing organisms. At different periods of the life of individuals, various environmental factors act as limiting factors, therefore, skillful and constant regulation of the living conditions of grown plants and animals is required.

2.4. Principles of ecological classification of organisms

In ecology, the diversity and diversity of methods and ways of adaptation to the environment create the need for multiple classifications. Using any single criterion, it is impossible to reflect all aspects of the adaptability of organisms to the environment. Environmental classifications reflect the similarities that emerge among members of a wide variety of groups when they use similar ways of adaptation. For example, if we classify animals according to their modes of movement, then the ecological group of species that move in water in a reactive way will include such animals different in systematic position as jellyfish, cephalopods, some ciliates and flagellates, larvae of a number of dragonflies, etc. (Fig. 7). A wide variety of criteria can be used as the basis for environmental classifications: ways of feeding, movement, relation to temperature, humidity, salinity of the environment, pressureand so on. The division of all organisms into eurybiontic and stenobiontic according to the latitude of the range of adaptation to the environment is an example of the simplest ecological classification.

Fig. 7. Representatives of the ecological group of organisms that move in water in a reactive way (according to S. A. Zernov, 1949):

1 - flagellate Medusochloris phiale;

2 - ciliate Craspedotella pileosus;

3 - jellyfish Cytaeis vulgaris;

4 - pelagic sea cucumber Pelagothuria;

5 - dragonfly-rocker larva;

6 - swimming octopus Octopus vulgaris:

and- direction of the water jet;

b- the direction of movement of the animal

Another example is the division of organisms into groups. by the nature of the diet.Autotrophs - these are organisms that use inorganic compounds as a source for building their body. Heterotrophs - all living things in need of food of organic origin. In turn, autotrophs are divided into phototrophsand chemotrophs.The former use the energy of sunlight for the synthesis of organic molecules, the latter use the energy of chemical bonds. Heterotrophs are divided into saprophytes,using solutions of simple organic compounds, and holozoev.Holozoa possess a complex complex of digestive enzymes and can eat complex organic compounds, decomposing them into simpler components. Holozoi are divided into saprophages(feed on dead plant debris) phytophages(consumers of living plants), zoophages(in need of live food) and necrophages(cadaverous animals). In turn, each of these groups can be subdivided into smaller ones, which have their own specifics in the nature of nutrition.

Otherwise, you can build a classification by the way of getting food.Among animals, for example, groups such as filtrators(small crustaceans, toothless, whale, etc.), grazing forms(ungulates, leaf beetles), collectors(woodpeckers, moles, shrews, chicken), moving prey hunters(wolves, lions, flies-ktyri, etc.) and a number of other groups. So, despite the great dissimilarity in organization, the same way of mastering prey leads to a number of analogies in lions and flies-chicks in their hunting habits and general structural features: lean body, strong muscular development, the ability to develop a short-term high speed, etc.

Environmental classifications help to identify possible in nature ways of adaptation of organisms to the environment.

2.5. Active and hidden life

Metabolism is one of the most important properties of life, which determines the close material-energy connection of organisms with the environment. Metabolism is highly dependent on the conditions of existence. In nature, we observe two basic states of life: active life and rest. With active life, organisms feed, grow, move, develop, multiply, characterized by an intensive metabolism. Rest can be different in depth and duration, while many body functions are weakened or not performed at all, since the level of metabolism falls under the influence of external and internal factors.

In a state of deep rest, that is, a reduced material-energy metabolism, organisms become less dependent on the environment, acquire a high degree of stability and are able to endure conditions that could not withstand active life. These two conditions alternate in the life of many species, being an adaptation to habitats with an unstable climate, sharp seasonal changes, which is typical for most of the planet.

With deep suppression of metabolism, organisms may not show visible signs of life at all. The question of whether it is possible to completely stop metabolism with a subsequent return to active life, that is, a kind of "resurrection from the dead", has been debated in science for more than two centuries.

First appearance imaginary deathwas discovered in 1702 by Anthony van Leeuwenhoek - the discoverer of the microscopic world of living things. The "animalculi" (rotifers) observed by him, when dried, wrinkled water droplets, looked dead and could remain in this state for a long time (Fig. 8). Placed back in water, they swelled and went on to active life. Levenguk explained this phenomenon by the fact that the shell of the "animalcules", obviously, "does not allow the slightest evaporation" and they remain alive in dry conditions. However, after several decades, naturalists were already arguing about the possibility that "life can be completely stopped" and restored again "in 20, 40, 100 years or more."

In the 70s of the XVIII century. the phenomenon of "resurrection" after drying was discovered and confirmed by numerous experiments in a number of other small organisms - wheat eels, free-living nematodes and tardigrades. J. Buffon, repeating the experiments of J. Needham with acne, argued that "these organisms can be made to die as many times as necessary and come to life again." L. Spallanzani first drew attention to the deep dormancy of seeds and plant spores, regarding it as their preservation in time.

Fig. 8. Rotifer Philidina roseola at different stages of drying (according to P. Yu. Schmidt, 1948):

1 - active; 2 - starting to shrink; 3 - completely contracted before drying; 4 - in a state of suspended animation

In the middle of the XIX century. it was convincingly established that the resistance of dry rotifers, tardigrades and nematodes to high and low temperatures, lack or absence of oxygen increases in proportion to the degree of their dehydration. However, the question remained open whether this is a complete interruption of life or only its deep oppression. In 1878, Claude Bernal put forward the concept "Hidden life"which he characterized by the termination of metabolism and "a break in the relationship between being and the environment."

This issue was finally resolved only in the first third of the XX century with the development of deep vacuum dehydration technology. The experiments of G. Ram, P. Becquerel and other scientists showed the possibility complete reversible stop of life.In a dry state, when no more than 2% of water remained in the cells in a chemically bound form, organisms such as rotifers, tardigrades, small nematodes, seeds and spores of plants, bacterial and fungal spores withstood being in liquid oxygen (-218.4 ° C ), liquid hydrogen (-259.4 ° C), liquid helium (-269.0 ° C), i.e. temperatures close to absolute zero. In this case, the contents of the cells harden, there is not even the thermal movement of molecules, and any metabolism, of course, is stopped. Once placed under normal conditions, these organisms continue to develop. In some species, stopping the metabolism at ultra-low temperatures is possible without drying, provided that water freezes not in a crystalline, but in an amorphous state.

The complete temporary stop of life was named suspended animation. The term was proposed by V. Preyer back in 1891. In a state of suspended animation, organisms become resistant to a wide variety of influences. For example, tardigrades underwent in the experiment ionizing radiation up to 570 thousand roentgens for 24 hours. Dehydrated larvae of one of the African chironomus mosquitoes, Polypodium vanderplanki, retain the ability to revive after exposure to temperatures of +102 ° C.

The state of suspended animation greatly expands the boundaries of preserving life, including in time. For example, in the thickness of the Antarctic glacier, during deep drilling, microorganisms (spores of bacteria, fungi and yeasts) were found, which subsequently developed on ordinary nutrient media. The age of the corresponding ice horizons reaches 10–13 thousand years. Spores of some viable bacteria have also been isolated from deeper layers hundreds of thousands of years old.

Anabiosis, however, is a rare occurrence. It is not possible for all species and is an extreme state of dormancy in wildlife. Its necessary condition is the preservation of intact thin intracellular structures (organelles and membranes) during drying or deep cooling of organisms. This condition is impracticable for most species with a complex organization of cells, tissues and organs.

The ability to anabiosis is found in species that have a simple or simplified structure and live in conditions of sharp fluctuations in humidity (drying up shallow water bodies, upper soil layers, cushions of moss and lichens, etc.).

Much more widespread in nature are other forms of dormancy associated with a state of decreased vital activity as a result of partial inhibition of metabolism. Any degree of decrease in the level of metabolism increases the stability of organisms and allows more economical use of energy.

Forms of rest in a state of reduced vital activity are divided into hypobiosis and cryptobiosis, or forced peace and physiological rest. In hypobiosis, inhibition of activity, or numbness, arises under the direct pressure of unfavorable conditions and stops almost immediately after these conditions return to normal (Fig. 9). Such suppression of vital processes can occur with a lack of heat, water, oxygen, with an increase in osmotic pressure, etc. In accordance with the leading external factor, forced rest is distinguished cryobiasis(at low temperatures), anhydrobiosis(with a lack of water), anoxybiosis(under anaerobic conditions), hyperosmobiosis(with a high salt content in water), etc.

Not only in the Arctic and Antarctic, but also in the middle latitudes, some frost-resistant arthropod species (collembolans, a number of flies, ground beetles, etc.) winter in a state of numbness, quickly thawing and turning to activity under the sun's rays, and then again lose their mobility when the temperature drops. ... Plants that have emerged in spring stop and resume their growth and development following a cooling and warming. After a rainfall, the bare ground often turns green due to the rapid reproduction of soil algae that were in forced dormancy.

Fig. nine. Pagon - a piece of ice with freshwater inhabitants frozen in it (from S.A.Zernov, 1949)

The depth and duration of the suppression of metabolism during hypobiosis depends on the duration and intensity of the inhibitory factor. Forced dormancy occurs at any stage of ontogenesis. The benefits of hypobiosis are the rapid restoration of active life. However, this is a relatively unstable state of organisms and, with a long duration, can be damaging due to the imbalance of metabolic processes, depletion of energy resources, accumulation of under-oxidized metabolic products and other unfavorable physiological changes.

Cryptobiosis is a fundamentally different type of dormancy. It is associated with a complex of endogenous physiological rearrangements that occur in advance, before the onset of unfavorable seasonal changes, and the organisms are ready for them. Cryptobiosis is an adaptation primarily to the seasonal or other periodicity of abiotic environmental factors, their regular cyclicity. It forms part of the life cycle of organisms, arises not at any, but at a certain stage of individual development, timed to experience critical periods of the year.

The transition to a state of physiological rest takes time. It is preceded by the accumulation of reserve substances, partial dehydration of tissues and organs, a decrease in the intensity of oxidative processes and a number of other changes that generally lower tissue metabolism. In a state of cryptobiosis, organisms become many times more resistant to adverse environmental influences (Fig. 10). In this case, the main biochemical rearrangements are in many respects common for plants, animals, and microorganisms (for example, the switch of metabolism to varying degrees to the glycolysis pathway due to reserve carbohydrates, etc.). Exit from cryptobiosis also requires time and energy and cannot be carried out simply by stopping the negative action of the factor. This requires special conditions that are different for different species (for example, freezing, the presence of drip-liquid water, a certain length of daylight hours, a certain quality of light, mandatory temperature fluctuations, etc.).

Cryptobiosis as a survival strategy under periodically unfavorable conditions for active life is a product of long-term evolution and natural selection. It is widespread in wildlife. The state of cryptobiosis is typical, for example, for plant seeds, cysts and spores of various microorganisms, fungi, and algae. Diapause of arthropods, hibernation of mammals, deep dormancy of plants are also different types of cryptobiosis.

Fig. ten. Earthworm in a state of diapause (according to V. Tishler, 1971)

The states of hypobiosis, cryptobiosis and anabiosis ensure the survival of species in natural conditions of different latitudes, often extreme ones, allow organisms to be preserved for long unfavorable periods, spread in space, and in many ways push the boundaries of the possibility and distribution of life in general.

1. Topographic environmental factors include ...

height above sea level population density of organisms

Decision:
Topography (from the Greek "topos" - place, locality; "grapho" - I write) - the surface of a locality, the relative position of its points, parts. Topographic factors, that is, factors associated with the topography of the area, are sometimes called geomorphological. The influence of abiotic factors largely depends on the topographic characteristics of the area, which can greatly change both the climate and the characteristics of soil development. The main topographic factor is height above sea level. With altitude, average temperatures decrease, the daily temperature drop increases, the amount of precipitation, wind speed and radiation intensity increase, and pressure decreases. As a result, in the mountainous terrain, as it rises, there is a vertical zoning of the distribution of vegetation, corresponding to the sequence of changing latitudinal zones from the equator to the poles. Also, topographic factors include the steepness of the slope, exposure.

Biotic abiotic anthropogenic climatic

1. Natural abiotic factors include ...

Fire symbiosis introduction reclamation

1. Anthropogenic factors can be divided into groups such as factors ...

direct and indirect impact trophic and topical relationships

phytogenic and zoogenic influences of regular and irregular frequency

Climatic anthropogenic edaphic biotic

Decision:
By nature, environmental factors are divided into abiotic, biotic and anthropogenic. Abiotic factors are components of inanimate nature that directly or indirectly affect the body. They are divided into the following groups: climatic factors (light, temperature, humidity, wind, atmospheric pressure, etc.); geological factors (earthquakes, volcanic eruptions, movement of glaciers, radioactive radiation, etc.); orographic factors, or relief factors (the height of the terrain above sea level, the steepness of the terrain - the angle of inclination of the terrain to the horizon, the exposure of the terrain - the position of the terrain in relation to the cardinal points, etc.); edaphic, or soil-soil, factors (particle size distribution, chemical composition, density, structure, pH, etc.); hydrological factors (current, salinity, pressure, etc.).

Anthropogenic phytogenic hydrographic orographic

Decision:
The totality of human influences on the life of organisms is called anthropogenic factors. Anthropogenic factors, depending on the consequences of exposure, are divided into positive ones that improve the life of organisms or increase their number (planting and feeding plants, breeding and protecting animals, etc.), and negative factors (cutting down trees, environmental pollution, destruction of habitats, etc.) etc.) that worsen the life of organisms or reduce their numbers. Depending on the nature of the impact, anthropogenic factors are divided into two groups: factors of direct impact - this is the direct impact of man on the body (mowing grass, deforestation, shooting animals, catching fish, etc.); factors of indirect influence are the influence of a person by the fact of his existence (every year, in the process of breathing of people, a significant amount of carbon dioxide enters the atmosphere and 2.7 × 10 15 kcal of energy is withdrawn from the environment in the form of food) and through economic activities (agriculture, industry, transport, household activities, etc.).

Primary secondary phytogenic zoogenic

1. According to the impact of environmental factors on living organisms, they distinguish ...

stimuli, limiters, modifiershumidifiers, heaters, illuminators

single, double, triple

one-time, multiple, indefinite

Decision:
Environmental factors affect organisms in different ways. They can act as stimuli causing adaptive changes in physiological functions; as constraints that make it impossible for certain organisms to exist under given conditions; as modifiers that determine morphological and anatomical changes in organisms.

1. The totality of physical and chemical properties of soils that can affect living organisms are called _________________ factors.

Edaphic climatic anthropogenic microbogenic

Decision:
Soil is a product of physical, chemical and biological transformation (weathering) of rocks; is a three-phase medium containing solid, liquid and gaseous components. It is formed as a result of complex interactions of climate, plants, animals, microorganisms and is considered as a bioinert body containing living and nonliving components. The physical and chemical properties of soil collectively represent edaphic (soil) factors.

Intraspecific interspecies chemical physical

10. Among the soil factors, the most important property influencing the growth and productivity of plants is its….

Fertility humidity porosity pressure

11. Annual total solar radiation, the state of the atmosphere, the nature of the relief, etc. is determined by such an abiotic factor as ..

humidity acidity pressure shine

4. Limiting factor. Liebig's law of minimum and Shelford's law of tolerance

1. In the figure illustrating the law of tolerance (using the example of the effect on the body of the concentration of a certain substance as an environmental factor), under the number 1) is indicated ...

optimum life state

peak in the zone of ecological stress pessimum of species existence

Decision:
Living organisms have a certain set of needs in terms of living conditions. For each species, there is a so-called environmental preference for different environmental factors. For example, thermal preferendum - preferred temperature, biotopic preferendum - preferred biotopes. According to V. Shelford's law (the law of tolerance), any living organism has certain, evolutionarily inherited upper and lower limits of resistance (tolerance) to any environmental factor. The ecological optimum for organisms of this species is the most favorable effect of any factor (a certain range of temperature, humidity, the nature of the biotope, etc.), that is, the optimum of the vital state.

2. The pattern, according to which the action of one factor depends on the force and in what combination other factors act simultaneously, is called the principle of ____________ factors.

Interactions anti-aggregation unidirectional

3. The ability of an organism to withstand deviations of environmental factors from the values \u200b\u200boptimal for its vital activity is called ...

Tolerance fertility comfort variability

Decision:
The wider the amplitude of fluctuations of the factor at which the organism can maintain its viability, the higher its resistance, that is, tolerance to one factor or another (from the Latin "tolerantia" - patience). Hence, the word “tolerant” is translated as stable, tolerant, and tolerance can be defined as the ability of an organism to withstand deviations of environmental factors from the values \u200b\u200boptimal for its vital activity. Tolerant organisms are organisms that are resistant to adverse environmental changes.

6. The phenomenon of partial interchangeability of the action of environmental factors is called the effect ...

Compensation adapt the summation of prosperity

7. The graph below illustrates the law of tolerance ...

W. Shelford R. Lindemann B. Commoner J. Liebig

Decision:
V. Shelford's law of tolerance is a law according to which the limiting factor for the prosperity of an organism can be at least or a maximum of an ecological factor, the range between which determines the value of the organism's tolerance (endurance) to this factor.

8. Yu. Odum supplemented the law of tolerance with provisions, one of which says that organisms with a wide range of tolerance in relation to all environmental factors usually ...

most common least adapted

larger in size less productive

Decision:
The law of tolerance was proposed by the American zoologist W. Shelford, but was later supplemented by J. Odum (1975) with the following provisions:
1) organisms can have a wide range of tolerance for one environmental factor and a low range for another;
2) organisms with a wide range of tolerance for all environmental factors are usually the most common;
3) if the conditions for one ecological factor are not optimal for the species, then the range of tolerance may narrow with respect to other ecological factors.

10. The combination of environmental conditions most favorable for the life and reproduction of a given organism is called it ...

Optimum pessimum continuum society

Decision:
On the gradient of any ecological factor, the distribution of the species is limited by the limits of tolerance. Between these limits there is a segment where the conditions for a particular species are most favorable and therefore the largest biomass and the highest population density are formed. This is its ecological optimum. To the left and to the right of the optimum, conditions for the life of the species are less favorable. These are zones of pessimum, that is, oppression of organisms, when the population density decreases and the species becomes most vulnerable to the action of unfavorable environmental factors (including human influence). In the optimum zone, the life of the body is most comfortable and it spends a minimum amount of energy to maintain it. In areas of pessimum, to maintain vital activity, you have to spend a lot more energy and turn on special "survival mechanisms". For example, warm-blooded animals spend energy stored in adipose tissues to keep warm in the cold. Plants under pessimum conditions spend most of the products of photosynthesis on respiration and grow slowly.

11. The law, according to which the limiting factor of prosperity can be at least as well as the maximum of the ecological factor, the range between which determines the value of the organism's endurance to this factor, is called law ...

liebig's minimum ecology of Vernadsky's commoner noosphere shelford's tolerance

12. Between individual factors, special interactions can be established, when the influence of one factor to some extent changes the nature of the effect of another when ...

Single activity of an individual with a complex effect on the body

Passive resistance of the organism to the adaptive behavior of the organism

13. According to the rule established by V.V. Alekhin in 1951 for vegetation, widespread species in the south grow on the northern slopes, and in the north they are found only on the southern slopes. This pattern is called the rule ...

Preliminaries fluctuations in numbers

Territoriality of interaction of factors

Decision:
The rule of anticipation is a pattern (discovered by Alekhine and Walter in 1951), according to which the slopes of the northern exposure bear plant groups characteristic of the more northern vegetation zone (or subzone), and the slopes of the southern exposure bear plant groups characteristic of the more southern vegetation. zones (or subzones). According to V. Alekhin, an upland species, or an upland phytocenosis, is preceded in the south or in the north in the appropriate habitat conditions. This deviation from the zoning rules is due to the angle of incidence of the sun's rays.

14. A functional place in an ecosystem, determined by its biotic potential and a combination of environmental factors to which it is adapted, is called ecological.

Group spectrum niche the norm

15. The types of living organisms that endure significant temperature fluctuations are called ..

Eurythermal eurybiontic stenothermal stenobiontic

16. The degree of adaptability of a living organism to changes in environmental conditions is called ecological

tolerance self-management optimization valence