The lack of what environmental factor limits growth. environmental factors. ecological niche. limiting factors. Environmental Research Methods

Communities) with each other and with the environment. This term was first proposed by the German biologist Ernst Haeckel in 1869. As an independent science, it stood out at the beginning of the 20th century along with physiology, genetics and others. The scope of ecology is organisms, populations and communities. Ecology considers them as a living component of a system called an ecosystem. In ecology, the concepts of population - communities and ecosystems have clear definitions.

A population (in terms of ecology) is a group of individuals of the same species, occupying a certain territory and, usually, to some extent isolated from other similar groups.

A community is any group of organisms various kinds living in the same area and interacting with each other through trophic (food) or spatial relationships.

An ecosystem is a community of organisms with their environment interacting with each other and forming an ecological unit.

All ecosystems of the Earth are combined into or ecosphere. It is clear that it is absolutely impossible to cover the entire biosphere of the Earth with research. Therefore, the point of application of ecology is the ecosystem. However, an ecosystem, as can be seen from the definitions, consists of populations, individual organisms and all factors of inanimate nature. Based on this, several different approaches to the study of ecosystems are possible.

Ecosystem Approach.With the ecosystem approach, the ecologist studies the flow of energy in the ecosystem as well. The greatest interest in this case are the relationships of organisms with each other and with the environment. This approach makes it possible to explain the complex structure of interconnections in an ecosystem and give recommendations for rational nature management.

Community studies. With this approach, the species composition of communities and the factors that limit the distribution of specific species are studied in detail. In this case, clearly distinguishable biotic units (meadow, forest, swamp, etc.) are studied.
an approach. The point of application of this approach, as the name implies, is the population.
Habitat research. In this case, a relatively homogeneous area of ​​the environment where the given organism lives is studied. Separately, as an independent line of research, it is usually not used, but gives necessary material to understand the ecosystem as a whole.
It should be noted that all the approaches listed above should ideally be applied in combination, but at the moment this is practically impossible due to the large scale of the objects under study and the limited number of field researchers.

Ecology as a science uses a variety of research methods to obtain objective information about the functioning of natural systems.

Ecological research methods:

• observation
• experiment
• population count
• simulation method

The interaction of man and his environment has been the object of study of medicine at all times. To assess the effects of various environmental conditions, the term "environmental factor" was proposed, which is widely used in environmental medicine.

Factor (from the Latin factor - making, producing) - the reason, the driving force of any process, phenomenon, which determines its nature or certain features.

An environmental factor is any environmental impact that can have a direct or indirect effect on living organisms. An environmental factor is an environmental condition to which a living organism reacts with adaptive reactions.

Environmental factors determine the conditions for the existence of organisms. The conditions for the existence of organisms and populations can be considered as regulatory environmental factors.

Not all environmental factors (for example, light, temperature, humidity, presence of salts, availability of nutrients, etc.) are equally important for the successful survival of an organism. The relationship of the organism with the environment is a complex process in which the weakest, "vulnerable" links can be distinguished. Those factors that are critical or limiting for the life of an organism are of the greatest interest, primarily from a practical point of view.

The idea that the endurance of an organism is determined by the weakest link among

all his needs, was first expressed by K. Liebig in 1840. He formulated the principle, which is known as Liebig's law of the minimum: "The crop is controlled by a substance that is at a minimum, and the magnitude and stability of the latter in time is determined."

The modern formulation of J. Liebig's law is as follows: "The life possibilities of an ecosystem are limited by those of the ecological environmental factors, the quantity and quality of which are close to the minimum required by the ecosystem, their reduction leads to the death of the organism or the destruction of the ecosystem."

The principle, originally formulated by K. Liebig, is currently extended to any environmental factors, but it is supplemented by two restrictions:

Applies only to systems that are in a stationary state;

It refers not only to one factor, but also to a complex of factors that are different in nature and interact in their influence on organisms and populations.

According to prevailing ideas, the limiting factor is considered to be such a factor, according to which, in order to achieve a given (sufficiently small) relative change in the response, a minimum relative change in this factor is required.

Along with the influence of a lack, a "minimum" of environmental factors, the influence of an excess, that is, a maximum of factors such as heat, light, moisture, can also be negative. The concept of the limiting influence of the maximum along with the minimum was introduced by W. Shelford in 1913, who formulated this principle as the "law of tolerance": The limiting factor for the prosperity of an organism (species) can be both a minimum and a maximum of environmental impact, the range between which determines the value of endurance ( tolerance) of the body in relation to this factor.

The law of tolerance, formulated by W. Shelford, was supplemented with a number of provisions:

Organisms may have a wide tolerance range for one factor and a narrow tolerance for another;

The most widespread are organisms with a large range of tolerance;

The range of tolerance for one environmental factor may depend on other environmental factors;

If the conditions for one ecological factor are not optimal for the species, then this also affects the range of tolerance for other environmental factors;

The limits of tolerance significantly depend on the state of the organism; thus, the limits of tolerance for organisms during the breeding season or at an early stage of development are usually narrower than for adults;

The range between the minimum and maximum of environmental factors is commonly called the limits or range of tolerance. To indicate the limits of tolerance to environmental conditions, the terms "eurybiontic" - an organism with a wide tolerance limit - and "stenobiont" - with a narrow one are used.

At the level of communities and even species, the phenomenon of factor compensation is known, which is understood as the ability to adapt (adapt) to environmental conditions in such a way as to weaken the limiting influence of temperature, light, water and other physical factors. Species with a wide geographical distribution almost always form populations adapted to local conditions - ecotypes. In relation to people, there is the term ecological portrait.

It is known that not all natural environmental factors are equally important for human life. So, the most significant consider the intensity of solar radiation, air temperature and humidity, the concentration of oxygen and carbon dioxide in the surface layer of air, the chemical composition of soil and water. The most important environmental factor is food. To maintain life, for the growth and development, reproduction and preservation of the human population, energy is needed, which is obtained from the environment in the form of food.

There are several approaches to the classification of environmental factors.

In relation to the body, environmental factors are divided into: external (exogenous) and internal (endogenous). It is believed that external factors acting organism, they themselves are not subject or almost not subject to its influence. These include environmental factors.

External environmental factors in relation to the ecosystem and to living organisms are the impact. The response of an ecosystem, biocenosis, populations and individual organisms to these impacts is called a response. The nature of the response to the impact depends on the ability of the body to adapt to environmental conditions, adapt and acquire resistance to influence. various factors environment, including adverse effects.

There is also such a thing as a lethal factor (from Latin - letalis - deadly). This is an environmental factor, the action of which leads to the death of living organisms.

When certain concentrations are reached, many chemical and physical pollutants can act as lethal factors.

Internal factors correlate with the properties of the organism itself and form it, i.e. are included in its composition. Internal factors are the number and biomass of populations, the amount of various chemicals, the characteristics of the water or soil mass, etc.

According to the criterion of "life" environmental factors are divided into biotic and abiotic.

The latter include non-living components of the ecosystem and its external environment.

Abiotic environmental factors - components and phenomena of inanimate, inorganic nature, directly or indirectly affecting living organisms: climatic, soil and hydrographic factors. The main abiotic environmental factors are temperature, light, water, salinity, oxygen, electromagnetic characteristics, and soil.

Abiotic factors are divided into:

Physical

Chemical

Biotic factors (from the Greek biotikos - life) - factors of the living environment that affect the vital activity of organisms.

Biotic factors are divided into:

Phytogenic;

microbiogenic;

Zoogenic:

Anthropogenic (socio-cultural).

The action of biotic factors is expressed in the form of mutual influences of some organisms on the vital activity of other organisms and all together on the environment. Distinguish between direct and indirect relationships between organisms.

In recent decades, the term anthropogenic factors has been increasingly used, i.e. caused by man. Anthropogenic factors are opposed to natural, or natural factors.

The anthropogenic factor is a set of environmental factors and impacts caused by human activity in ecosystems and the biosphere as a whole. The anthropogenic factor is the direct impact of a person on organisms or the impact on organisms through a change by a person in their habitat.

Environmental factors are also divided into:

1. Physical

Natural

Anthropogenic

2. Chemical

Natural

Anthropogenic

3. Biological

Natural

Anthropogenic

4. Social (socio-psychological)

5. Informational.

Environmental factors are also divided into climatic-geographical, biogeographical, biological, as well as soil, water, atmospheric, etc.

physical factors.

Physical natural factors include:

Climatic, including the microclimate of the area;

geomagnetic activity;

Natural radiation background;

Cosmic radiation;

Terrain;

Physical factors are divided into:

Mechanical;

vibration;

Acoustic;

EM radiation.

Physical anthropogenic factors:

Microclimate of settlements and premises;

Pollution of the environment by electromagnetic radiation (ionizing and non-ionizing);

Noise pollution of the environment;

Thermal pollution of the environment;

Deformation of the visible environment (changes in the terrain and colors in populated areas).

chemical factors.

Natural chemicals include:

Chemical composition of the lithosphere:

Chemical composition of the hydrosphere;

The chemical composition of the atmosphere,

The chemical composition of food.

The chemical composition of the lithosphere, atmosphere and hydrosphere depends on the natural composition + the release of chemicals as a result of geological processes (for example, impurities of hydrogen sulfide as a result of the eruption of a volcano) and the vital activity of living organisms (for example, impurities in the air of phytoncides, terpenes).

Anthropogenic chemical factors:

household waste,

Industrial waste,

Synthetic materials used in everyday life, agriculture and industrial production,

pharmaceutical industry products,

Food additives.

The effect of chemical factors on the human body can be due to:

Excess or deficiency of natural chemical elements in

environment (natural microelementoses);

Excess content of natural chemical elements in the environment

environment associated with human activities (anthropogenic pollution),

The presence in the environment of unusual chemical elements

(xenobiotics) due to anthropogenic pollution.

Biological factors

Biological, or biotic (from the Greek biotikos - life) environmental factors - factors of the living environment that affect the vital activity of organisms. The action of biotic factors is expressed in the form of mutual influences of some organisms on the vital activity of others, as well as their joint influence on the environment.

Biological factors:

bacteria;

Plants;

Protozoa;

Insects;

Invertebrates (including helminths);

Vertebrates.

Social environment

Human health is not completely determined by the biological and psychological properties acquired in ontogenesis. Man is a social being. He lives in a society governed by state laws, on the one hand, and on the other, by the so-called generally accepted laws, moral principles, rules of conduct, including those involving various restrictions, etc.

Every year society becomes more and more complex and has an increasing impact on the health of the individual, population, and society. For enjoying the benefits of a civilized society, a person must live in rigid dependence on the way of life accepted in society. For these benefits, often very dubious, the person pays with part of his freedom, or completely with all his freedom. And a person who is not free, dependent cannot be completely healthy and happy. Some part of human freedom, given to a technocritical society in exchange for the advantages of a civilized life, constantly keeps him in a state of neuropsychic tension. Constant neuro-psychic overstrain and overstrain leads to a decrease in mental stability due to a decrease in reserve capabilities nervous system. In addition, there are many social factors that can lead to the disruption of a person's adaptive capabilities and the development of various diseases. These include social disorder, uncertainty about the future, moral oppression, which are regarded as the leading risk factors.

Social factors

Social factors are divided into:

1. social system;

2. production area (industry, Agriculture);

3. household sphere;

4. education and culture;

5. population;

6. zo and medicine;

7. other spheres.

There is also the following grouping of social factors:

1. Social policy that forms a sociotype;

2. Social security, which has a direct impact on the formation of health;

3. Environmental policy that forms the ecotype.

Sociotype is an indirect characteristic of the integral social burden in terms of the totality of factors of the social environment.

Sociotype includes:

2. working conditions, rest and life.

Any environmental factor in relation to a person can be: a) favorable - contributing to his health, development and realization; b) unfavorable, leading to his illness and degradation, c) influencing both. It is no less obvious that in reality most influences are of the latter type, having both positive and negative aspects.

In ecology, there is a law of optimum, according to which any ecological

the factor has certain limits of positive influence on living organisms. The optimal factor is the intensity of the environmental factor that is most favorable for the organism.

The impacts can also differ in scale: some affect the entire population of the country as a whole, others affect the inhabitants of a particular region, others affect groups identified by demographic characteristics, and others affect an individual citizen.

Interaction of factors - simultaneous or sequential total impact on organisms of various natural and anthropogenic factors, leading to a weakening, strengthening or modification of the action of a single factor.

Synergism is the combined effect of two or more factors, characterized by the fact that their combined biological effect significantly exceeds the effect of each component and their sum.

It should be understood and remembered that the main harm to health is caused not by individual environmental factors, but by the total integral environmental load on the body. It consists of an ecological burden and a social burden.

Environmental burden is a combination of factors and conditions of the natural and man-made environment that are unfavorable for human health. An ecotype is an indirect characteristic of an integral ecological load based on a combination of factors of the natural and man-caused environment.

Ecotype assessments require hygiene data on:

The quality of housing

drinking water,

air,

soils, food,

Medicines, etc.

Social burden is a set of factors and conditions of social life unfavorable for human health.

Environmental factors that shape the health of the population

1. Climatic-geographical characteristics.

2. Socio-economic characteristics of the place of residence (city, village).

3. Sanitary and hygienic characteristics of the environment (air, water, soil).

4. Features of nutrition of the population.

5. Characteristics of labor activity:

Profession,

Sanitary and hygienic working conditions,

The presence of occupational hazards,

Psychological microclimate at work,

6. Family and household factors:

family composition,

The nature of the housing

Average income per family member,

Organization of family life.

Distribution of non-working time,

Psychological climate in the family.

Indicators that characterize the attitude to the state of health and determine the activity to maintain it:

1. Subjective assessment of one's own health (healthy, sick).

2. Determining the place of personal health and the health of family members in the system of individual values ​​(hierarchy of values).

3. Awareness about the factors contributing to the preservation and promotion of health.

4. Availability bad habits and dependencies.

Environmental factors is a set of environmental conditions that affect living organisms. Distinguish inanimate factors- abiotic (climatic, edaphic, orographic, hydrographic, chemical, pyrogenic), wildlife factors— biotic (phytogenic and zoogenic) and anthropogenic factors (impact of human activity). Limiting factors include any factors that limit the growth and development of organisms. The adaptation of an organism to its environment is called adaptation. The appearance of an organism, reflecting its adaptability to environmental conditions, is called a life form.

The concept of environmental environmental factors, their classification

Individual components of the environment that affect living organisms, to which they react with adaptive reactions (adaptations), are called environmental factors, or ecological factors. In other words, the complex of environmental conditions that affect the life of organisms is called ecological factors of the environment.

All environmental factors are divided into groups:

1. include components and phenomena of inanimate nature that directly or indirectly affect living organisms. Among the many abiotic factors leading role are playing:

• climatic(solar radiation, light and light regime, temperature, humidity, precipitation, wind, atmospheric pressure, etc.);
• edaphic(mechanical structure and chemical composition of the soil, moisture capacity, water, air and thermal conditions of the soil, acidity, humidity, gas composition, groundwater level, etc.);
• orographic(relief, slope exposure, slope steepness, elevation difference, height above sea level);
• hydrographic(transparency of water, fluidity, flow, temperature, acidity, gas composition, content of mineral and organic substances, etc.);
• chemical(gas composition of the atmosphere, salt composition of water);
• pyrogenic(effect of fire).

2. - a set of relationships between living organisms, as well as their mutual influences on the environment. The action of biotic factors can be not only direct, but also indirect, expressed in the adjustment of abiotic factors (for example, changes in the composition of the soil, microclimate under the forest canopy, etc.). Biotic factors include:

• phytogenic(the influence of plants on each other and on environment);
• zoogenic(the influence of animals on each other and on the environment).

3. reflect the intense impact of a person (directly) or human activity (indirectly) on the environment and living organisms. These factors include all forms of human activity and human society that lead to a change in nature as a habitat and other species and directly affect their lives. Each living organism is influenced by inanimate nature, organisms of other species, including humans, and in turn affects each of these components.

The influence of anthropogenic factors in nature can be both conscious and accidental, or unconscious. Man, plowing up virgin and fallow lands, creates agricultural land, breeds highly productive and disease-resistant forms, settles some species and destroys others. These impacts (conscious) are often negative in nature, for example, the rash resettlement of many animals, plants, microorganisms, the predatory destruction of a number of species, environmental pollution, etc.

Biotic factors of the environment are manifested through the relationship of organisms that are part of the same community. In nature, many species are closely interrelated, their relationships with each other as components of the environment can be extremely complex. As for the connections between the community and the surrounding inorganic environment, they are always bilateral, mutual. Thus, the nature of the forest depends on the corresponding type of soil, but the soil itself is largely formed under the influence of the forest. Similarly, the temperature, humidity and light in the forest are determined by vegetation, but the climatic conditions that have developed in turn affect the community of organisms living in the forest.

The impact of environmental factors on the body

The impact of the environment is perceived by organisms through environmental factors called ecological. It should be noted that the environmental factor is only a changing element of the environment, causing in organisms, when it changes again, response adaptive ecological and physiological reactions, which are hereditarily fixed in the process of evolution. They are divided into abiotic, biotic and anthropogenic (Fig. 1).

They name the whole set of factors of the inorganic environment that affect the life and distribution of animals and plants. Among them are distinguished: physical, chemical and edaphic.

Physical factors - those whose source is the physical state or a phenomenon (mechanical, wave, etc.). For example, temperature.

Chemical Factors- those that come from chemical composition environment. For example, water salinity, oxygen content, etc.

Edaphic (or soil) factors are a combination of chemical, physical and mechanical properties of soils and rocks that affect both the organisms for which they are the habitat, and root system plants. For example, the influence of nutrients, moisture, soil structure, humus content, etc. on the growth and development of plants.

Rice. 1. Scheme of the impact of the habitat (environment) on the body

- factors of human activity affecting the natural environment (and hydrospheres, soil erosion, deforestation, etc.).

Limiting (limiting) environmental factors called such factors that limit the development of organisms due to a lack or excess of nutrients compared to the need (optimal content).

So, when growing plants at different temperatures, the point at which maximum growth is observed will be optimum. The entire range of temperatures, from minimum to maximum, at which growth is still possible, is called range of stability (endurance), or tolerance. Its limiting points, i.e. maximum and minimum habitable temperatures, - stability limits. Between the optimum zone and the limits of stability, as the latter is approached, the plant experiences increasing stress, i.e. we are talkingabout stress zones, or zones of oppression, within the stability range (Fig. 2). As the distance from the optimum goes down and up on the scale, not only does stress increase, but when the limits of the organism's resistance are reached, its death occurs.

Rice. 2. Dependence of the action of the environmental factor on its intensity

Thus, for each species of plants or animals, there are optimum, stress zones and limits of stability (or endurance) in relation to each environmental factor. When the value of the factor is close to the limits of endurance, the organism can usually exist only for a short time. In a narrower range of conditions, long-term existence and growth of individuals is possible. In an even narrower range, reproduction occurs, and the species can exist indefinitely. Usually, somewhere in the middle part of the stability range, there are conditions that are most favorable for life, growth and reproduction. These conditions are called optimal, in which individuals of a given species are the most adapted, i.e. leaving the largest number of offspring. In practice, it is difficult to identify such conditions, so the optimum is usually determined by individual indicators of vital activity (growth rate, survival rate, etc.).

Adaptation is the adaptation of the organism to the conditions of the environment.

The ability to adapt is one of the basic properties of life in general, providing the 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. All adaptations of organisms to existence in various conditions have developed historically. As a result, groupings of plants and animals specific to each geographical area were formed.

Adaptations can be morphological, when the structure of an organism changes up to the formation of a new species, and physiological, when changes occur in the functioning of the body. Morphological adaptations are closely related to the adaptive coloration of animals, the ability to change it depending on the illumination (flounder, chameleon, etc.).

Widely known examples of physiological adaptation are hibernation of animals, seasonal flights of birds.

Very important for organisms are behavioral adaptations. For example, instinctive behavior determines the action of insects and lower vertebrates: fish, amphibians, reptiles, birds, etc. Such behavior is genetically programmed and inherited (innate behavior). This includes: the method of building a nest in birds, mating, raising offspring, etc.

There is also an acquired command received by the individual in the course of his life. Education(or learning) - the main mode of transmission of acquired behavior from one generation to another.

The ability of an individual to control his cognitive abilities in order to survive unexpected environmental changes is intellect. The role of learning and intelligence in behavior increases with the improvement of the nervous system - an increase in the cerebral cortex. For man, this is the determining mechanism of evolution. The ability of species to adapt to a particular range of environmental factors is denoted by the concept ecological mysticism of the species.

The combined effect of environmental factors on the body

Environmental factors usually act not one by one, but in a complex way. The effect of any one factor depends on the strength of the influence of others. Combination various factors has a significant impact on optimal conditions the life of the organism (see Fig. 2). The action of one factor does not replace the action of another. However, under the complex influence of the environment, one can often observe the “substitution effect”, which manifests itself in the similarity of the results of the influence of different factors. Thus, light cannot be replaced by an excess of heat or an abundance of carbon dioxide, but by acting on changes in temperature, it is possible to suspend, for example, the photosynthesis of plants.

In the complex influence of the environment, the impact of various factors for organisms is unequal. They can be divided into main, accompanying and secondary. The leading factors are different for different organisms, even if they live in the same place. The role of the leading factor at different stages of the life of the organism can be either one or the other elements of the environment. For example, in the life of many cultivated plants, such as cereals, temperature is the leading factor during germination, soil moisture during heading and flowering, and the amount of nutrients and air humidity during ripening. The role of the leading factor in different time years may change.

The leading factor may not be the same in the same species living in different physical and geographical conditions.

The concept of leading factors should not be confused with the concept of. A factor whose level in qualitative or quantitative terms (lack or excess) turns out to be close to the endurance limits of a given organism, is called limiting. The action of the limiting factor will also manifest itself in the case when other environmental factors are favorable or even optimal. Both leading and secondary environmental factors can act as limiting ones.

The concept of limiting factors was introduced in 1840 by the chemist 10. Liebig. Studying the influence of the content of various chemical elements in the soil on plant growth, he formulated the principle: “The minimum substance controls the crop and determines the magnitude and stability of the latter in time.” This principle is known as Liebig's Law of the Minimum.

The limiting factor can be not only a lack, as Liebig pointed out, but also an excess of such factors as, for example, heat, light and water. As noted earlier, organisms are characterized by ecological minimum and maximum. The range between these two values ​​is usually called the limits of stability, or tolerance.

AT general view the entire complexity of the influence of environmental factors on the body is reflected in the law of tolerance by W. Shelford: the absence or impossibility of prosperity is determined by the lack or, conversely, the excess of any of a number of factors, the level of which may be close to the limits tolerated by the given organism (1913). These two limits are called tolerance limits.

Numerous studies have been carried out on the "ecology of tolerance", thanks to which the limits of the existence of many plants and animals have become known. One such example is the effect of an air pollutant on the human body (Fig. 3).

Rice. 3. Effect of air pollutant on the human body. Max - maximum vital activity; Dop - allowable vital activity; Opt - optimal (not affecting vital activity) concentration of a harmful substance; MPC - the maximum allowable concentration of a substance that does not significantly change vital activity; Years - lethal concentration

The concentration of the influencing factor (harmful substance) in fig. 5.2 is marked with the symbol C. At concentration values ​​C = C years, a person will die, but irreversible changes in his body will occur at much lower values ​​C = C pdc. Therefore, the range of tolerance is limited precisely by the value C pdc = C lim. Hence, C plc must be determined experimentally for each polluting or any harmful chemical compound and not allowed to exceed its C plc in a particular habitat (living environment).

In environmental protection, it is important upper limits of organism resistance to harmful substances.

Thus, the actual concentration of the pollutant C actual should not exceed C MPC (C actual ≤ C MPC = C lim).

The value of the concept of limiting factors (Clim) lies in the fact that it gives the ecologist a starting point in the study of complex situations. If an organism is characterized by a wide range of tolerance to a factor that is relatively constant, and it is present in the environment in moderate amounts, then this factor is unlikely to be limiting. On the contrary, if it is known that one or another organism has a narrow range of tolerance to some variable factor, then this factor deserves careful study, since it can be limiting.

Environmental factors are all environmental factors acting on the body. They are divided into 3 groups:

The best value of a factor for an organism is called optimal(optimum point), for example, optimum temperature air for a person - 22º.

Biotic factors are
Methods of nutrition of living organisms, they are
Intra- and interspecies struggle for existence

3. Symbionts- receive nutrition from another organism on a mutually beneficial basis. For example:

• Mycorrhiza (fungal root) - a symbiosis of a fungus and a plant. The plant gives the fungus glucose (which it makes during photosynthesis), and the fungus gives the plant water and mineral salts.
• Lichen is a symbiosis of fungi and algae. Algae provide the fungus with glucose, while the fungus provides algae with salt and water.
• Nodule bacteria live in special thickenings (nodules) on the roots of plants of the legume family. Plants give glucose to bacteria, and bacteria give nitrogen salts to plants, which they get when they fix nitrogen in the air.

4. Competitors- need the same food and/or theory. The most intense competition occurs between individuals of the same species.

5. Saprophytes/saprotrophs(they are not biotic factors and variants of BZS, only a way of feeding) - they feed on dead organisms (larvae of blowflies, mold fungi, decay bacteria).

Anthropogenic factors

Human influences change the environment too quickly. This leads to the fact that many species become rare and die out. Biodiversity is decreasing because of this.

For example, consequences of deforestation:

• The habitat for the inhabitants of the forest (animals, fungi, lichens, grasses) is being destroyed. They may disappear completely (decreased biodiversity).
• The forest with its roots holds the top fertile soil layer. Without support, the soil can be blown away by the wind (you get a desert) or water (you get ravines).
• The forest evaporates a lot of water from the surface of its leaves. If you remove the forest, then the air humidity in the area will decrease, and the soil moisture will increase (a swamp may form).
• In reality, the forest releases very little oxygen "out" because the heterotrophs of this forest actively respire. What to do on the exam with options about oxygen in the atmosphere, the ozone layer and the greenhouse effect - decide according to the circumstances.

ABIOTIC
1. Choose three correct answers out of six and write down the numbers under which they are indicated in the table. Which of the following environmental factors are abiotic?
1) air temperature
2) greenhouse gas pollution
3) the presence of non-recyclable garbage
4) the presence of a road
5) illumination
6) oxygen concentration

Answer

2. Choose three correct answers out of six and write down in the answer the numbers under which they are indicated. The abiotic components of the steppe ecosystem include:
1) herbaceous vegetation
2) wind erosion
3) the mineral composition of the soil
4) rainfall mode
5) species composition of microorganisms
6) seasonal livestock grazing

Answer

ABIOTIC TEXT
Read the text. Choose three sentences that describe abiotic factors. Write down the numbers under which they are indicated.(1) The main source of light on Earth is the Sun. (2) light-loving plants, as a rule, strongly dissected leaf blades, a large number of stomata in the epidermis. (3) The humidity of the environment is an important condition for the existence of living organisms. (4) Plants evolved adaptations to maintain water balance organism. (5) The content of carbon dioxide in the atmosphere is essential for living organisms.

Answer

ABIOTIC - BIOTIC
1. Establish a correspondence between the example and the group of environmental factors that it illustrates: 1) biotic, 2) abiotic
A) overgrowing of the pond with duckweed
B) increase in the number of fish fry
C) eating fish fry by a swimming beetle
D) ice formation
E) flushing into the river of mineral fertilizers

Answer

2. Establish a correspondence between the process taking place in the forest biocenosis and the environmental factor that it characterizes: 1) biotic, 2) abiotic
A) the relationship between aphids and ladybugs
B) waterlogging of the soil
C) daily change in illumination
D) competition between species of thrushes
D) increase in air humidity
E) the effect of the tinder fungus on the birch

Answer

3. Establish a correspondence between examples and environmental factors that are illustrated by these examples: 1) abiotic, 2) biotic. Write the numbers 1 and 2 in the correct order.
A) an increase in atmospheric air pressure
B) change in the topography of the ecosystem caused by an earthquake
C) a change in the population of hares as a result of an epidemic
D) interaction between wolves in a pack
D) competition for territory between pine trees in the forest

Answer

4. Establish a correspondence between the characteristics of the environmental factor and its type: 1) biotic, 2) abiotic. Write the numbers 1 and 2 in the correct order.
A) ultraviolet rays
B) drying up of water bodies during a drought
C) animal migration
D) pollination of plants by bees
D) photoperiodism
E) a decrease in the number of squirrels in lean years

Answer

Answer

6f. Establish a correspondence between examples and environmental factors that are illustrated by these examples: 1) abiotic, 2) biotic. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) an increase in soil acidity caused by a volcanic eruption
B) change in the relief of the biogeocenosis of the meadow after the flood
C) change in the population of wild boars as a result of the epidemic
D) interaction between aspens in the forest ecosystem
E) competition for territory between male tigers

Answer

COLLECTING 7:
A) the displacement of the black rat from the range by individuals of the gray rat
B) departure of swallows and swifts to wintering grounds due to the reduction of daylight hours

ABIOTIC - ANTHROPOGENIC
Establish a correspondence between the characteristics of the environment and the environmental factor: 1) anthropogenic, 2) abiotic. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) deforestation
B) tropical showers
B) melting glaciers
D) forest plantations
D) draining swamps
E) an increase in the length of the day in spring

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2. Match the examples with the environmental factors illustrated by these examples: 1) Biotic, 2) Abiotic, 3) Anthropogenic. Write the numbers 1, 2 and 3 in the correct order.
A) autumn leaves
B) Planting trees in the park
C) The formation of nitric acid in the soil during a thunderstorm
D) Illumination
E) The struggle for resources in the population
E) Freon emissions into the atmosphere

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3. Establish a correspondence between examples and environmental factors: 1) abiotic, 2) biotic, 3) anthropogenic. Write down the numbers 1-3 in the order corresponding to the letters.
A) change in the gas composition of the atmosphere
B) dispersal of plant seeds by animals
C) human draining of swamps
D) an increase in the number of consumers in the biocenosis
D) change of seasons
E) deforestation

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BIOTIC
Choose three correct answers from six and write down the numbers under which they are indicated. Specify biotic factors among environmental factors.
1) flood
2) competition between individuals of the species
3) lowering the temperature
4) predation
5) lack of light
6) mycorrhiza formation

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ANTHROPOGENIC
1. Choose three options. What anthropogenic factors influence the size of the wild boar population in the forest community?
1) increase in the number of predators
2) shooting animals
3) feeding animals
4) the spread of infectious diseases
5) cutting down trees
6) severe weather in winter

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2. Choose three correct answers from six and write down the numbers under which they are indicated. What anthropogenic factors influence the size of the May lily of the valley population in the forest community?
1) cutting down trees
2) increase in shading

4) collection of wild plants
5) low air temperature in winter
6) trampling the soil

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3. Choose three correct answers from six and write down the numbers under which they are indicated. What processes in nature are classified as anthropogenic factors?
1) ozone depletion
2) daily change in illumination
3) competition in the population
4) accumulation of herbicides in the soil
5) relationship between predators and their prey
6) increased greenhouse effect

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4. Choose three correct answers from six and write down the numbers under which they are indicated. What anthropogenic factors influence the number of plants listed in the Red Book?
1) destruction of their living environment
2) increase in shading
3) lack of moisture in summer
4) expansion of the areas of agrocenoses
5) sudden temperature changes
6) trampling the soil

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5. Choose three correct answers from six and write down the numbers under which they are indicated. What environmental disturbances in the biosphere are caused by anthropogenic interference?
1) the destruction of the ozone layer of the atmosphere
2) seasonal changes in the illumination of the land surface
3) decline in the number of cetaceans
4) the accumulation of heavy metals in the bodies of organisms near highways
5) accumulation of humus in the soil as a result of leaf fall
6) accumulation of sedimentary rocks in the depths of the oceans

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6. Choose three correct answers from six and write down the numbers under which they are indicated. The following anthropogenic factors can change the number of producers in an ecosystem:
1) collection of flowering plants
2) increase in the number of consumers of the first order
3) trampling of plants by tourists
4) decrease in soil moisture
5) cutting down hollow trees
6) increase in the number of consumers of the second and third orders

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1. Choose three correct answers out of six and write them down in the numbers under which they are indicated. The following factors lead to a decrease in the number of squirrels in a coniferous forest:
1) reduction in the number of birds of prey and mammals
2) cutting down coniferous trees
3) harvest of spruce cones after a warm dry summer
4) increase in activity of predators
5) outbreak of epidemics
6) deep snow cover in winter

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3. Choose three correct answers from six and write down the numbers under which they are indicated. The number of consumers of the first order in a freshwater reservoir may decrease due to
1) increase in the number of crustaceans
2) manifestations of the action of stabilizing selection
3) reduction in the number of pikes
4) increase in the number of gray herons
5) deep freezing of the reservoir in winter
6) increase in the number of burbot and perch

Answer

1. Choose three correct answers from six and write down the numbers under which they are indicated. The destruction of forests in vast areas leads to
1) an increase in the amount of harmful nitrogen impurities in the atmosphere
2) violation of the ozone layer
3) violation of the water regime
4) change of biogeocenoses
5) violation of the direction of air flows
6) reduction in species diversity

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2. Choose three correct answers from six and write down the numbers under which they are indicated. Massive deforestation in the biosphere leads to changes:
1) direction of air flow
2) decrease in the ozone layer
3) extinction of species
4) soil erosion
5) saturation of the atmosphere with water vapor
6) reduction of the greenhouse effect

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. What environmental factors may be limiting for brook trout?
1) fresh water
2) oxygen content less than 1.6 mg/l
3) water temperature +29 degrees
4) water salinity
5) illumination of the reservoir
6) the speed of the river

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. With a sharp decrease in the number of pollinating insects in the meadow over time
1) the number of insect pollinated plants is reduced
2) the number of birds of prey is increasing
3) the number of herbivores is increasing
4) the number increases wind pollinated plants
5) the water horizon of the soil changes
6) the number of insectivorous birds is decreasing

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PREDATION
Choose three correct answers from six and write down the numbers under which they are indicated. The predator-prey relationship is established between
1) Maybug and insectivorous birds
2) dog and fleas
3) hare and fox
4) salmon and lamprey
5) pig and man
6) man and pork tapeworm

Answer

PREDATORY - COMPETITION
Establish a correspondence between organisms and the type of interspecific relationships they enter into: 1) predation, 2) competition. Write the numbers 1 and 2 in the correct order.
A) cyclops and hydra
B) swimming beetle and tadpole
C) dragonfly larva and fish fry
D) infusoria-shoe and bacteria
D) squirrel and crossbill
E) crucian and carp

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SHAPING 4:
A) lamprey - mackerel
B) caterpillar - rider
C) liver fluke - cow

D) liver fluke - small pond snail

Answer

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SYMBIOSIS
Choose one, the most correct option. What is mycorrhiza?
1) mushroom root
2) the root system of the plant
3) mycelium spread in the soil
4) filaments of the fungus that form the fruiting body

Answer

Choose one, the most correct option. The mycorrhiza of the fungus is
1) mycelium, on which fruiting bodies develop
2) many elongated cells
3) complex interweaving of hyphae
4) cohabitation of the fungus and plant roots

Answer

Choose three correct answers from six and write down the numbers under which they are indicated. Mycorrhiza form
1) birch and boletus
2) birch and birch chaga
3) aspen and boletus
4) pine and boletus
5) corn and smut
6) rye and ergot

Answer

SYMBIOSIS EXAMPLES
1. Choose three correct answers from six and write down the numbers under which they are indicated. Examples of symbiotic relationships are:
1) tinder fungus and birch
2) sundew and insects
3) nodule bacteria and leguminous plants
4) cellulose-destroying bacteria and herbivorous animals
5) cannibalism in predatory fish
6) sea anemone and hermit crab

Answer

2. Choose three correct answers from six and write down the numbers under which they are indicated. In a mixed forest ecosystem, symbiotic relationships are established between
1) birches and firs
2) birches and tinder mushrooms
3) aphids and ants
4) hedgehogs and insectivorous birds
5) birch and boletus
6) bird cherry and pollinating flies

Answer

SYMBIOSIS - COMPETITION
Establish a correspondence between populations of organisms in an ecosystem and the type of interspecific relationships that are characteristic of these populations: 1) competition, 2) symbiosis. Write down the numbers 1 and 2 in the order corresponding to the letters.
A) rhino and bullock birds
B) birch and boletus
C) pike and perch
D) beans and nodule bacteria
D) cabbage butterfly and burdock butterfly
E) potatoes and couch grass

Answer

© D.V. Pozdnyakov, 2009-2019

An environmental factor is any element of the environment that can have a direct or indirect effect on living organisms at least during one of the phases of their individual development.

Any organism in the environment is exposed to a huge number of environmental factors. The most traditional classification of environmental factors is their division into abiotic, biotic and anthropogenic.

Abiotic factors - this is a complex of environmental conditions that affect a living organism (temperature, pressure, background radiation, illumination, humidity, day length, composition of the atmosphere, soil, etc.). These factors can affect the body directly (directly), like LIGHT and heat, or indirectly, like, for example, the terrain, which causes the action of direct factors (illumination, wind moisture, etc.).

Anthropogenic factors are a combination of the impacts of human activity on the environment (emissions of harmful substances, destruction of the soil layer, violation of natural landscapes). One of the most important anthropogenic factors is pollution.
- physical: the use of nuclear energy, travel in trains and planes, the impact of noise and vibration
- chemical: the use of mineral fertilizers and pesticides, pollution of the Earth's shells by industrial and transport waste
- biological: food; organisms for which a person can be a habitat or source of food
- social - related to people's relationships and life in society

Environmental conditions

Environmental conditions, or ecological conditions, are called abiotic environmental factors that change in time and space, to which organisms react differently depending on their strength. Environmental conditions impose certain restrictions on organisms. The amount of light penetrating through the water column limits the life of green plants in water bodies. The abundance of oxygen limits the number of air-breathing animals. Temperature determines the activity and controls the reproduction of many organisms.
The most important factors that determine the conditions for the existence of organisms in almost all living environments include temperature, humidity and light.

Photo: Gabriel

Temperature

Any organism is able to live only within a certain temperature range: individuals of the species die at too high or too low temperatures. Somewhere within this interval, the temperature conditions are most favorable for the existence of a given organism, its vital functions are carried out most actively. As the temperature approaches the boundaries of the interval, the speed of life processes slows down and, finally, they stop altogether - the organism dies.
The limits of thermal endurance in different organisms are different. There are species that can tolerate temperature fluctuations over a wide range. For example, lichens and many bacteria are able to live at very different temperatures. Among animals, warm-blooded animals are characterized by the largest range of temperature endurance. The tiger, for example, tolerates both the Siberian cold and the heat of the tropical regions of India or the Malay Archipelago equally well. But there are also species that can only live within more or less narrow temperature limits. This includes many tropical plants, such as orchids. In the temperate zone, they can only grow in greenhouses and require careful care. Some reef-forming corals can only live in seas where the water temperature is at least 21°C. However, corals also die off when the water is too hot.

In the land-air environment, and even in many parts of the aquatic environment, the temperature does not remain constant and can vary greatly depending on the season of the year or on the time of day. In tropical areas, annual temperature fluctuations can be even less noticeable than daily ones. Conversely, in temperate regions, the temperature varies significantly at different times of the year. Animals and plants are forced to adapt to the unfavorable, winter season, during which active life difficult or simply impossible. In tropical areas, such adaptations are less pronounced. In a cold period with unfavorable temperature conditions, there seems to be a pause in the life of many organisms: hibernation in mammals, leaf shedding in plants, etc. Some animals make long migrations to places with a more suitable climate.
The example of temperature shows that this factor is tolerated by the body only within certain limits. The organism dies if the environment temperature is too low or too high. In an environment where the temperature is close to these extreme values, living inhabitants are rare. However, their number increases as the temperature approaches the average value, which is the best (optimum) for this species.

Humidity

For most of its history, wildlife was represented exclusively by aquatic forms of organisms. Having conquered the land, they, nevertheless, did not lose their dependence on water. Water is an integral part of the vast majority of living beings: it is necessary for their normal functioning. A normally developing organism constantly loses water and therefore cannot live in absolutely dry air. Sooner or later, such losses can lead to the death of the organism.
In physics, humidity is measured by the amount of water vapor in the air. However, the simplest and most convenient indicator characterizing the humidity of a particular area is the amount of precipitation that falls here for a year or another period of time.
Plants extract water from the soil using their roots. Lichens can capture water vapor from the air. Plants have a number of adaptations that ensure minimal water loss. All terrestrial animals need a periodic supply to compensate for the inevitable loss of water due to evaporation or excretion. Many animals drink water; others, such as amphibians, some insects and mites, absorb it through the integument of the body in a liquid or vapor state. Most desert animals never drink. They meet their needs with water from food. Finally, there are animals that obtain water in an even more complex way in the process of fat oxidation. Examples are the camel and certain types of insects, such as rice and barn weevil, clothes moths that feed on fat. Animals, like plants, have many adaptations to conserve water.

Light

For animals, light as an ecological factor is incomparably less important than temperature and humidity. But light is absolutely necessary for living nature, since it is practically the only source of energy for it.
For a long time, light-loving plants have been distinguished, which can develop only under the sun's rays, and shade-tolerant plants, which can grow well under the forest canopy. Most of the undergrowth in the beech forest, which is particularly shady, is formed by shade-tolerant plants. This is of great practical importance for the natural regeneration of the forest stand: the young shoots of many tree species are able to develop under the cover of large trees. In many animals, normal light conditions manifest themselves in a positive or negative reaction to light.

However, light has the greatest ecological significance in the change of day and night. Many animals are exclusively diurnal (most passerines), others are exclusively nocturnal (many small rodents, the bats). Small crustaceans hovering in the water column stay at night in surface waters, and during the day they sink to the depths, avoiding too bright light.
Compared to temperature or humidity, light has almost no direct effect on animals. It serves only as a signal for the restructuring of the processes occurring in the body, which allows them to respond in the best possible way to the ongoing changes in external conditions.

The factors listed above do not exhaust the set of ecological conditions that determine the life and distribution of organisms. The so-called secondary climatic factors are important, for example, wind, atmospheric pressure, altitude. The wind has an indirect effect: increasing evaporation, increasing dryness. Strong wind helps to cool. This action is important in cold places, in the highlands or in the polar regions.

The heat factor (temperature conditions) significantly depends on the climate and the microclimate of the phytocenosis, but the orography and nature of the soil surface play an equally important role; the humidity factor (water) also primarily depends on the climate and microclimate (precipitation, relative humidity, etc.), but the orography and biotic influences play an equally important role; climate plays a major role in the action of the light factor, but the orography (for example, slope exposure) and biotic factors (for example, shading) are of no less importance. The properties of the soil here are almost unimportant; chemistry (including oxygen) primarily depends on the soil, as well as on the biotic factor (soil microorganisms, etc.), however, the climatic state of the atmosphere is also important; finally, mechanical factors primarily depend on biotic factors (trampling, haymaking, etc.), but here orography (slope fall) and climatic influences (for example, hail, snow, etc.) are of certain importance.

According to the mode of action, environmental factors can be divided into direct (ie, directly on the body) and indirect (affecting other factors). But one and the same factor in some conditions can be direct, and in others - indirectly. Moreover, sometimes indirectly acting factors can be of very great (determining) importance, changing the cumulative effect of other, direct acting factors (for example, geological structure, altitude, slope exposure, etc.).

Here is another several types of classification of environmental factors.

1. Constant factors (factors that do not change) - solar radiation, atmospheric composition, gravity, etc.
2. Factors that change. They are divided into periodic (temperature - seasonal, daily, annual; high and low tides, lighting, humidity) and non-periodic (wind, fire, thunderstorm, all forms of human activity).

Spending classification:

Resources - elements of the environment that the body consumes, reducing their supply in the environment (water, CO2, O2, light)
Conditions - elements of the environment that are not consumed by the body (temperature, air movement, soil acidity).

Classification by direction:

Vectorized - directionally changing factors: waterlogging, soil salinization
Multi-year-cyclic - with alternating multi-year periods of strengthening and weakening of the factor, for example, climate change due to the 11-year solar cycle
Oscillatory (impulse, fluctuation) - fluctuations in both directions from a certain average value (daily fluctuations in air temperature, change in the average monthly precipitation during the year)

According to frequency, they are divided into:
- periodic (regularly repeated): primary and secondary
- non-periodic (arise unexpectedly).