Animal

ground-air

Water

The soil

Other organisms

white shark

grass frog

common mole

Ascaris human

Cancer river

Starfish

Amoeba dysentery

Earthworm

mallard duck

Earthworm

Beet nematode

4. Light.

5. Plowing land.

6. Salinity.

7. Wolf in the forest.

8. Pork tapeworm in the body.

9. Water pollution by oil products.

10. Fleas in animal fur.

11. Exhaust gases of cars.

12. Burial of radioactive waste in the soil.

2. Conversation on questions.

- What did you learn new in the lesson?

What did you learn by studying the basics of ecology?

Where can you apply your knowledge, skills and abilities?

3. Determining the types of environmental interactions (work on cards).

v. Homework : textbook, abstract, draw up diagrams and drawings of biotic relationships.

In the complex of action of factors, it is possible to single out some patterns that are largely universal (general) in relation to organisms. These patterns include the rule of optimum, the rule of interaction of factors, the rule of limiting factors, and some others.

Optimum rule . In accordance with this rule, for an organism or a certain stage of its development, there is a range of the most favorable (optimal) value of the factor. The more significant the deviation of the action of the factor from the optimum, the more this factor inhibits the vital activity of the organism. This range is called the zone of oppression. The maximum and minimum tolerated values ​​of the factor are critical points, beyond which the existence of the organism is no longer possible.

The maximum population density is usually confined to the optimum zone. Zones of optimum for different organisms are not the same. The wider the amplitude of fluctuations of the factor, at which the organism can remain viable, the higher its stability, i.e. tolerance to one or another factor (from Lat. tolerance- patience). Organisms with a wide amplitude of resistance belong to the group eurybionts (gr. eury- wide, bios- life). Organisms with a narrow range of adaptation to factors are called stenobionts (gr. stenos- narrow). It is important to emphasize that the zones of optimum in relation to various factors differ, and therefore organisms fully show their potential capabilities if they exist in the conditions of the entire spectrum of factors with optimal values.

Rule of interaction of factors . Its essence lies in the fact that some factors can enhance or mitigate the force of other factors. For example, an excess of heat can be somewhat mitigated by low air humidity, a lack of light for plant photosynthesis can be compensated by an increased content of carbon dioxide in the air, etc. It does not, however, follow that the factors can be interchanged. They are not interchangeable.

Rule of Limiting Factors . The essence of this rule lies in the fact that a factor that is in deficiency or excess (near critical points) negatively affects organisms and, in addition, limits the possibility of manifestation of the strength of other factors, including those that are at the optimum. Limiting factors usually determine the boundaries of the distribution of species, their ranges. The productivity of organisms depends on them.

A person by his activity often violates almost all of the listed patterns of factors. This is especially true for limiting factors (destruction of habitats, disruption of water and mineral nutrition, etc.).

Habitat- this is that 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 being lives in a complex changing world, constantly adapting to it and regulating its life activity in accordance with its changes.

Organisms' adaptations to their environment are called adaptations. The ability to adapt is one of the main properties of life in general, as it provides the very possibility of its existence, the ability of organisms to survive and reproduce. Adaptations appear in 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 change during the evolution of species. Separate 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 beings, promote or hinder survival and reproduction. Environmental factors have a different nature and specificity of action. Environmental factors are divided into abiotic and biotic, anthropogenic.

In the complex of action of factors, it is possible to single out some patterns that are largely universal (general) in relation to organisms. These patterns include the rule of optimum, the rule of interaction of factors, the rule of limiting factors, and some others.

Optimum rule. In accordance with this rule, for an organism or a certain stage of its development, there is a range of the most favorable (optimal) value of the factor. The more significant the deviation of the action of the factor from the optimum, the more this factor inhibits the vital activity of the organism. This range is called the zone of oppression. The maximum and minimum tolerated values ​​of the factor are critical points beyond which the existence of an organism is no longer possible.

The maximum population density is usually confined to the optimum zone. Zones of optimum for different organisms are not the same. The wider the amplitude of fluctuations of the factor, at which the organism can remain viable, the higher its stability, i.e. tolerance to this or that factor (from lat. tolerance - patience). Organisms with a wide amplitude of resistance belong to the group of eurybionts (Greek euri - wide, bios - life). Organisms with a narrow range of adaptation to factors are called stenobionts(Greek stenos - narrow). It is important to emphasize that the zones of optimum in relation to various factors differ, and therefore organisms fully show their potential capabilities if they exist in the conditions of the entire spectrum of factors with optimal values.

Rule of interaction of factors. Its essence lies in the fact that some factors can enhance or mitigate the force of other factors. For example, an excess of heat can be somewhat mitigated by low air humidity, a lack of light for plant photosynthesis can be compensated by an increased content of carbon dioxide in the air, etc. It does not, however, follow that the factors can be interchanged. They are not interchangeable.

Rule of limiting factors. The essence of this rule lies in the fact that a factor that is in deficiency or excess (near critical points) negatively affects organisms and, in addition, limits the possibility of manifestation of the strength of other factors, including those that are at the optimum. Limiting factors usually determine the boundaries of the distribution of species, their ranges. The productivity of organisms depends on them.

A person by his activity often violates almost all of the listed patterns of factors. This is especially true for limiting factors (destruction of habitats, disruption of water and mineral nutrition, etc.).

Habitat- a part of nature (a set of specific conditions of animate and inanimate nature) that directly surrounds a living organism and has a direct or indirect effect on its state: growth, development, reproduction, survival, etc.

Conditions of existence- this is a combination of vital environmental factors, without which a living organism cannot exist (light, heat, moisture, air, soil, etc.).

Environmental Factors and their classification

Environmental factors- These are individual elements of the habitat that can affect organisms, populations and natural communities, causing adaptive reactions (adaptations) in them.

❖ Classification of environmental factors according to the nature of the action:

■ periodic factors(they act constantly and have a daily, seasonal and annual cycle: change of day and night, tides, alternation of seasons, etc.);

■ non-periodic factors(act on organisms or populations suddenly, episodically);

❖ Classification of environmental factors by origin:

■ abiotic factors- all factors of inanimate nature: physical , or climatic (light, temperature, humidity, pressure), edaphic , or soil and ground (mechanical structure of the soil, its mineral composition), topographic or orographic (terrain), chemical (water salinity, air gas composition, soil and water pH), etc.;

■ biotic factors- various forms of influence of some living organisms on the vital activity of others. At the same time, some organisms can serve as food for others, be their habitat, promote reproduction and settlement, exert mechanical, chemical and other effects;

■ anthropogenic factors- various forms of human activity that change nature as a habitat for other species or directly affect their lives (pollution of the environment with industrial waste, hunting, etc.).

Patterns of the action of environmental factors on organisms

❖ The nature of the effect of environmental factors on organisms:

■ how irritants they cause adaptive changes in physiological and biochemical functions;

■ how limiters determine the impossibility of the existence of certain organisms in given conditions;

■ how modifiers determine morphological, structural-functional and anatomical changes in organisms;

■ how signals they indicate changes in other environmental factors.

❖ According to the strength of the impact on the body, environmental factors are divided into:
■ optimal;
■ normal;
■ depressing (stressful);
■ limit;
■ limiting.

Body endurance limits is the range of factor intensity within which the existence of an organism is possible. This range is limited by extreme threshold minimum and maximum points and characterizes tolerance organism. When the intensity of the factor is less than the minimum point (lower limit) or greater than the maximum point (upper limit), the organism dies.

biological optimum- the most favorable intensity of the factor for the organism. The factor intensity values ​​lying near the biological optimum are optimum zone.

Zones of stress, oppression (or pessimism) are ranges with a sharp deficiency or excess of the factor; in these zones, the intensity of the factor lies within the limits of endurance, but goes beyond the boundaries of the biological optimum.

Zone of normal activity lies between the zone of optimum and the zone of pessimum (stress).

Tolerance— the ability of organisms to endure deviations of the environmental factor from their optimal values.

■ The same intensity of a factor can be optimal for one species, depressing (stressful) for another, and go beyond endurance for a third.

eurybionts- organisms capable of withstanding significant deviations from the biological optimum (i.e. having wide limits of endurance); example: crucian carp is able to live in various water bodies.

Stenobionts- organisms, for the existence of which strictly defined, relatively constant environmental conditions are necessary; example: trout lives only in waters with a high oxygen content.

Ecological valence- the ability of an organism to inhabit a variety of habitats.

Ecological plasticity- the ability of an organism to adapt to a certain range of variability of environmental factors.

Interaction of environmental factors. Limiting Factor

Complex impact of factors: environmental factors affect a living organism in a complex way, i.e. simultaneously and jointly, and the effect of one factor to a certain extent depends on the intensity of the other factor. Examples: heat is easier to bear in dry air than in humid air; you can freeze faster in frost with a strong wind than in calm weather, etc.

compensation effect- the phenomenon of partial compensation for the lack (excess) of one environmental factor by the excess (deficiency) of another factor.

Independent adaptation to the action of factors: organisms adapt to each of the acting factors in a relatively independent way. The degree of endurance to any factor does not mean a similar endurance to the action of other factors.

Ecological spectrum- the totality of the body's ability to exist under the influence of various environmental factors.

Limiting (limiting) factor- this is an environmental factor, the values ​​of which go beyond the endurance of the organism, which makes it impossible for this organism to exist in these conditions.

❖ The role of limiting factors:
■ they define the geographic ranges of species;
■ they are stronger than other factors affect the vital activity of the organism and act according to the rule of minimum;
■ their action is vital for the body, despite the favorable combination of other factors. Examples: the distribution of organisms in the Arctic is limited by a lack of heat, in deserts by a lack of moisture, etc.

1. Habitat: water, land-air, soil and environment as a living organism.

2. Conditions and environmental factors: abiotic, biotic and anthropogenic factors.

1. There are four main habitats on Earth, developed and inhabited by organisms. This - water, land-air, soil and, finally, the environment formed by themselves living organisms . Each of them has its own specific living conditions.

The aquatic environment is characterized by liquid state of aggregation and depending on the depth can be like aerobic (surface layers of various water bodies), and anaerobic (at great depths of the ocean, in water bodies with high temperatures). This environment is denser than air, more favorable from the standpoint of the production of water by the body and its preservation in it, and is also richer in food resources. Life originated in the aquatic environment in the distant geological past.

The forms of organisms living in water are diverse; among them there are those that breathe oxygen both dissolved in water and contained in the atmosphere, as well as anaerobic organisms. Various protozoa, algae, fish, arthropods, mollusks, echinoderms and representatives of other types and classes of the animal and plant world live in this environment.

Ground-air environment in the course of evolution, mastered later than water, it is more complex and requires more high level organization of the living. Here, air temperature, oxygen content, humidity, weather, light intensity play an essential role, which is especially important for plants. This aerobic an environment in which an intensive exchange of gases and water is carried out, which is necessary for the life of living beings. Therefore, organisms living in this environment are adapted to obtaining and maintaining moisture, and animals have the ability to move quite quickly and actively. Birds, many species of arthropods, mammals, various types of angiosperms, etc. live in this environment.

The soil as a habitat for many micro- and macro-organisms, as well as plant roots, has its own ecological characteristics. In the soil, factors such as structure, chemical composition and humidity, but light or sudden temperature fluctuations practically do not play a role. The inhabitants of the soil environment are called edophobic or geobionts . Here you can meet various representatives of the type of protozoa, various algae, fungi, various types of various worms, mollusks, various representatives of higher animals. The soil is the substrate various kinds higher plants, which are characterized by a terrestrial environment.

2. Conditions and environmental factors- interrelated concepts that characterize the habitat of organisms. Environmental conditions are usually defined as environmental factors that influence (positively or negatively) the existence and geographical distribution Living creatures.

Environmental factors are very diverse both in nature and in their impact on living organisms. Conventionally, all environmental factors are divided into three main groups - abiotic, biotic And anthropogenic.

Abiotic factors called the whole set of factors of the inorganic environment that affect the life and distribution of animals and plants. This is, first of all climatic:

sunlight, temperature, humidity,

And local:

topography, soil properties, salinity, currents, wind, radiation, etc.

These factors can affect organisms directly, i.e. directly, as light or heat, or indirectly, such as relief, which determines the action of direct factors - illumination, moisture, wind, etc.

Biotic factors- This various forms of influence of living organisms on each other and on the environment. Biotic relationships are extremely complex and idiosyncratic and can also be direct And indirect.

Anthropogenic factors- it's all those forms of human activity that affect the natural environment, changing the living conditions of living organisms, or directly affect individual species of plants and animals.

In turn, organisms themselves can influence the conditions of their existence. For example, the presence of vegetation cover moderates diurnal temperature fluctuations near the Earth's surface, fluctuations in humidity and wind, and also affects the structure and chemical composition of soils.

All environmental factors present in nature affect the life of organisms in different ways and have varying degrees of importance for individual species. At the same time, the set of factors and their significance for organisms depend on the environment.