Competitors, etc. - are characterized by significant variability in time and space. The degree of variability of each of these factors depends on the characteristics of the habitat. For example, temperatures vary greatly on the surface of the land, but are almost constant at the bottom of the ocean or in the depths of caves.

One and the same environmental factor has a different meaning in the life of cohabiting organisms. For example, the salt regime of the soil plays a primary role in the mineral nutrition of plants, but is indifferent to most land animals. The intensity of illumination and the spectral composition of light are extremely important in the life of phototrophic plants, while in the life of heterotrophic organisms (fungi and aquatic animals), light does not have a noticeable effect on their vital activity.

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.

Classification of environmental factors

It is customary to allocate biotic, anthropogenic and abiotic environmental factors.

• Biotic factors- the whole set of environmental factors associated with the activity of living organisms. These include phytogenic (plants), zoogenic (animals), microbiogenic (microorganisms) factors.
• Anthropogenic factors- all the many factors associated with human activity. These include physical (the use of atomic energy, movement in trains and planes, the impact of noise and vibration, etc.), chemical (the use of mineral fertilizers and pesticides, pollution of the Earth's shells with industrial and transport waste); biological (food products; organisms for which a person may be a habitat or a source of food), social (related to human relations and life in society) factors.
• Abiotic factors- all the many factors associated with processes in inanimate nature. These include climatic (temperature, humidity, pressure), edaphogenic (mechanical composition, air permeability, soil density), orographic (relief, altitude), chemical (gas composition of air, salt composition of water, concentration, acidity), physical (noise, magnetic fields, thermal conductivity, radioactivity, cosmic radiation)

A common classification of environmental factors (environmental factors)

BY TIME: evolutionary, historical, current

BY PERIODICITY: periodic, non-periodic

IN ORDER OF APPEARANCE: primary, secondary

BY ORIGIN: cosmic, abiotic (aka abiogenic), biogenic, biological, biotic, natural-anthropogenic, anthropogenic (including man-made, environmental pollution), anthropogenic (including disturbances)

BY THE ENVIRONMENT OF APPEARANCE: atmospheric, water (aka humidity), geo-morphological, edaphic, physiological, genetic, population, biocenotic, ecosystem, biospheric

THE NATURE: material-energy, physical (geophysical, thermal), biogenic (aka biotic), informational, chemical (salinity, acidity), complex (environmental, evolutionary, backbone, geographic, climatic)

BY OBJECT: individual, group (social, ethological, socio-economic, socio-psychological, species (including human, social life)

ACCORDING TO ENVIRONMENTAL CONDITIONS: density dependent, density independent

BY THE DEGREE OF IMPACT: lethal, extreme, limiting, disturbing, mutagenic, teratogenic; carcinogenic

ACCORDING TO THE SPECTRUM OF IMPACT: selective, general action

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See what the "Environmental factor" is in other dictionaries:

environmental factor- - EN ecological factor An environmental factor that, under some definite conditions, can exert appreciable influence on organisms or their communities, causing the increase or… …

environmental factor- 3.3 environmental factor: Any indivisible element of the environment that can have a direct or indirect effect on a living organism at least during one of the stages of its individual development. Notes 1. Environmental… …

environmental factor- ekologinis veiksnys statusas T sritis augalininkystė apibrėžtis Bet kuris aplinkos veiksnys, veikiantis augalą ar jų bendriją ir sukeliantis prisitaikomumo reakcijas. atitikmenys: engl. ecological factor eng. environmental factor... Žemės ūkio augalų selekcijos ir sėklininkystės terminų žodynas

LIMITING FACTOR- (LIMITING) any environmental factor, the quantitative and qualitative indicators of which somehow limit the vital activity of the organism. Ecological Dictionary, 2001 Factor limiting (limiting) any environmental factor, ... ... Ecological dictionary

Ecological- 23. Ecological passport of a thermal power plant: title= Ecological passport of a thermal power plant. Basic provisions of LDNTP. L., 1990. Source: P 89 2001: Recommendations for the diagnostic control of filtration and hydrochemical ... ... Dictionary-reference book of terms of normative and technical documentation

FACTOR ENVIRONMENTAL- any property or component of the environment that affects the organism. Ecological Dictionary, 2001 An environmental factor is any property or component of the environment that affects the body ... Ecological dictionary

environmental hazard- A natural process caused by the evolution of the earth and leading directly or indirectly to a decrease in the quality of environmental components below established standards. [RD 01.120.00 CTN 228 06] Topics oil pipeline transport ... Technical Translator's Handbook

CONCERN FACTOR- an anthropogenic factor that has a harmful effect on the life of wild animals. disturbance factors can be various noises, direct human intrusion into natural systems; especially noticeable during the breeding season ... Ecological dictionary

SUBSTANCE-ENERGY FACTOR- any factor whose force of influence is adequate to the transported flow of matter and energy. Wed Information factor. Ecological encyclopedic dictionary. Chisinau: Main edition of the Moldavian Soviet Encyclopedia. I.I. Grandpa. 1989... Ecological dictionary

ATMOSPHERIC FACTOR- a factor associated with the physical state and chemical composition of the atmosphere (temperature, degree of rarefaction, the presence of pollutants). Ecological encyclopedic dictionary. Chisinau: Main edition of the Moldavian Soviet Encyclopedia. I.I.… … Ecological dictionary

Books

• Lobbying activities of corporations in modern Russia, Andrey Bashkov. The influence of the environmental factor on the implementation of modern political processes, both in Russia and in the world, has been increasing in recent years. In the current political realities...
• Aspects of environmental responsibility of economic entities of the Russian Federation, A. P. Garnov, O. V. Krasnobaeva. Today, the environmental factor is acquiring transboundary significance, unequivocally correlating with the largest geosociopolitical processes in the world. One of the main sources of negative...

1. What environmental factor limits the spread of plants to great depths?

1. Water salinity

2. Lack of light

3. Atmospheric pressure

4. Lack of minerals

Explanation: in all kingdoms there are organisms more or less adapted to extreme environmental conditions, but for each group there are basic factors without which it cannot live. For plants, such a factor is sunlight (since plants are phototrophs and without light they will not be able to build organic substances for their life activity). The correct answer is 2.

2. The humidity of the environment necessary for the life of organisms is a factor

1. Biological

2. Abiotic

3. Anthropogenic

4. Non-periodic

Explanation: humidity of the environment refers to the factors of the inanimate environment, such factors are called abiotic. The correct answer is 2.

3. What is the limiting factor for plants in the steppe zone?

1. Lack of moisture

2. High temperature

3. Lack of minerals

4. Increased UV radiation

Explanation: in the steppe zone there is very low humidity and very high evaporation, so the plants of the steppe zone have a lack of moisture. The correct answer is 1.

4. Which of the following examples illustrates the competitive relationship between organisms?

1. Squirrel - woodpecker

2. Oak - white mushroom

3. Cow - bull tapeworm

4. Already - a frog

5. What type of relationship do pine and boletus enter into?

1. Symbiosis

3. Predator - prey

4. Competition

Explanation: a symbiosis occurs between tree roots and fungal hyphae in forests. The interaction between fungi and a tree is called mycorrhiza. Mycorrhiza is a symbiosis of fungal hyphae and tree roots, while the tree receives minerals that are obtained from the breakdown of organic matter during the metabolism of the fungus, and the fungus consumes ready-made organic substances that are formed during photosynthesis in the plant. The correct answer is 1.

6. Which of the following examples illustrates the predator-prey relationship?

1. Hermit crab - sea anemone

2. Bumblebee - clover

3. Tit - caterpillar

4. Woodpecker - squirrel

Explanation: hermit crab and anemone live in a mutually beneficial relationship, like a bumblebee with a clover. The tit eats the caterpillar (such relationships are called predation - predator-prey), the squirrel and the woodpecker have a similar diet, so the type of relationship between them is interspecific competition. The correct answer is 3.

7. An example of symbiosis, as a special form of biotic relationships, is

1. Mycorrhiza of tree roots and hyphae of cap mushrooms

2. Dwelling of a skin mite on a dog's fur

3. Cuckoo laying eggs in the nests of insectivorous birds

4. The formation of a Finn flatworm in the body of a bull

Explanation: symbiosis - the relationship of organisms in which both organisms receive only pluses. For example, lichens are a symbiosis of a fungus and algae, thus a cycle is carried out: the algae produces organic substances, and the fungus, a heterotroph, decomposes them to inorganic substances. Another variant of symbiosis is the interaction of the roots of the tree and the hyphae of the fungus, while the tree supplies the fungus with organic substances, and the fungus breaks them down to inorganic ones, thus the circulation of substances is carried out. The correct answer is 1.

8. What is the name of the relationship between a dog and a pasture tick?

1. Symbiosis

2. Competition

3. Predation

9. What adaptation contributes to the cooling of plants when the air temperature rises?

1. Decreased metabolic rate

2. Increase the intensity of photosynthesis

3. Reducing the intensity of breathing

4. Increase water evaporation

Explanation: The main energy-giving process in the body is respiration. Part of the resulting energy is spent in heat, therefore, in order to cool the body, it is necessary to reduce the intensity of breathing. The correct answer is 3.

1. Abiotic

2. Biotic

3. Anthropogenic

4. Limiting

Explanation: interactions of organisms, their influence on each other - biotic factors, factors of wildlife. The correct answer is 2.

11. What is the name of the type of relationship between the tinder fungus and the birch on which it lives?

1. Predation

2. Symbiosis

3. Competition

12. Relationships of which organisms serve as an example of symbiosis?

1. Ticks and dogs

2. Pines and butter dish

3. Pike and crucian

13. Feeding ungulates in winter in order to preserve the number of their populations is referred to as a factor

1. Evolutionary

2. Anthropogenic

3. Physiological

4. Abiotic

Explanation: feeding is carried out by man, and human impact is called the anthropogenic factor. The correct answer is 2.

14. All types of human activity are classified as factors

1. Abiotic

2. Biotic

3. Anthropogenic

4. Periodic

Explanation: biotic factors - factors of living nature, abiotic - inanimate, anthropogenic - factors associated with human activity. The correct answer is 3.

15. Most plant and animal species do not have adaptations to anthropogenic factors due to the fact that their impact

1. Consistency is shown

2. Has a random character

3. Depends on climatic conditions

4. Has a rhythmic nature

Explanation: most plants and animals encounter people very rarely and such encounters are random. Only domestic animals have adaptations to anthropogenic factors, since they were bred specifically for life next to humans. The correct answer is 2.

16. High numbers of wolves can be a limiting factor for

1. Hares-hare

2. Sable

3. Bears

4. Kunits

Explanation: high numbers will be a limiting factor for organisms that are food for wolves. These are the hare-hare. The correct answer is 1.

Tasks for independent solution

1. The signal for the autumn migration of birds in central Russia is

1. Lowering the air temperature

3. The onset of the first frost

4. Reducing the length of daylight hours

The correct answer is 4.

2. What factor underlies the seasonal changes in bird life?

1. Increase in the number of predators

2. Violation of biotic bonds

3. Temperature change

4. Changing the length of daylight hours

The correct answer is 4.

3. Relationships of which organisms serve as an example of competition?

1. Wolf and boar

2. Pike and perch

3. Bees and bark beetle

4. Sea anemones and hermit crab

The correct answer is 2.

1. Meadows and swamps

2. Mixed and coniferous forests

3. Tropical rain forests

4. Tundra and desert

The correct answer is 4.

5. The mutual influence of organisms of the same or different species is referred to as factors

1. Biotic

2. Limiting

3. Anthropogenic

4. Abiotic

The correct answer is 1.

6. An external signal that causes the onset of leaf fall in plants of the central strip is

1. Accumulation of harmful substances in leaves

2. Increased rainfall

3. Reducing the length of daylight hours

4. Decrease in nutrients in the soil

The correct answer is 3.

7. Minerals used by plants in the process of soil nutrition are classified as a group of factors

1. Seasonal

2. Anthropogenic

3. Biotic

4. Abiotic

The correct answer is 4.

8. Abiotic factors include

1. Change in air temperature during the season

2. The influence of plants on animal life

3. Drainage of wetlands

4. Plant competition for light absorption

The correct answer is -1.

9. The main factor causing leaf fall in plants is change

1. Soil composition

2. Humidity

3. Daylength

4.Temperatures

The correct answer is 3.

10. Mutual influences of organisms of the same or different species on each other are referred to as factors

1. Abiotic

2. Biotic

3. Anthropogenic

4. Limiting

The correct answer is 2.

11. Relationships of which organisms serve as an example of symbiosis?

1. Ticks and dogs

2. Pines and butter dish

3. Pike and crucian

4. Sundew and Insect Plants

The correct answer is 2.

12. Feeding ungulates in winter in order to preserve the number of their populations is referred to as a factor

1. Evolutionary

2. Anthropogenic

3. Physiological

4. Abiotic

The correct answer is 2.

13. All types of human activity are classified as factors

1. Abiotic

2. Biotic

3. Anthropogenic

4. Periodic

The correct answer is 3.

14. What factor limits the life of plants at great depths?

1. Nutrients

2. Warmth

3. Light

4. Oxygen

The correct answer is 3.

15. The lack of what environmental factor causes the appearance of light green leaves in plants?

1. Water

2. Carbon dioxide

3. Light

4. Oxygen

The correct answer is 3.

16. What is the nature of the relationship between organisms of different species that need the same food resources?

1. Predator - prey

3. Competition

4. Mutual assistance

The correct answer is 3.

17. Thanks to indirect development in animals, competition between

1. Individuals of different species

2. Populations of different species

3. Larvae and adults

4. Adult individuals of the species

The correct answer is 3.

18. In the vicinity of a number of cities, there is a mass death of pine trees due to the fact that in these areas

1. Climate instability is manifested

2. The soil is infertile

3. Trees are not fertilized with minerals

4. Air and soil heavily polluted by industrial waste

The correct answer is 4.

19. Indicate the abiotic factor necessary for plant life.

1. The presence of carbon dioxide in the atmosphere

2. Human application of mineral fertilizers

3. Presence of consumers in the ecosystem

4. Competition between pines for light

The correct answer is 1.

20. The mutually beneficial existence of leguminous plants and nodule bacteria is

1. Mycorrhiza

2. Lodging

3. Symbiosis

4. Competition

The correct answer is 3.

21. What is the name of the type of relationship between the tinder fungus and the birch on which it lives?

2. Competition

3. Predation

4. Symbiosis

The correct answer is 1.

22. The intensity of any environmental factor, the most favorable for life, is called

1. Maximum

2. Restraining

3. Optimal

4. Limiting

The correct answer is 3.

23. What relationships in the biocenosis of the steppe are typical for wild ungulates of different species?

1. Predation

2. Competition

3. Symbiosis

4. Neutralism

The correct answer is 2.

24. A limiting factor is a factor in the presence of which in a population

1. Organisms function normally

2. The fitness of individuals increases

3. Ecological isolation occurs

4. The existence of the species becomes impossible

The correct answer is 4.

25. What factor limits the life of plants in the steppe zone?

1. High temperature

2. Lack of moisture

3. No humus

4. Ultraviolet rays

The correct answer is 2.

26. Abiotic factors include

1. Undermining the roots of wild boars

2. Heavy snowfall

3. Vegetable litter

4 Locust Invasion

The correct answer is 2.

27. Anthropogenic factors are called

1. Related to human activities

2. Abiotic character

3. Caused by historical changes in the earth's crust

4. Determining the functioning of biogeocenoses

The correct answer is 1.

28. Anthropogenic factors that cause a decrease in the perch population in a reservoir include

1. Formation of an ice cover on the surface of a reservoir

2. Increasing the number of fry of other fish species

3. Pollution of the reservoir with sewage

4. Lowering the water temperature

The correct answer is 3.

29. Human impact on the life of any ecosystem - an example of a factor

1. Abiotic

2. Biotic

3. Limiting

4. Anthropogenic

The correct answer is 4.

30. Ecological factors characterizing the relationship in the biogeocenosis between individuals of different populations are called

1. Limiting

2. Biotic

3. Abiotic

4. Anthropogenic

The correct answer is 2.

31. What example illustrates the manifestation of a biotic factor in the natural environment?

1. Pollution of water bodies located near agrocenoses

2. Ladybug larvae eating apple aphids

3. Freezing of wheat seedlings during spring frosts

4. Lowering of the groundwater level during prolonged drought

The correct answer is 2.

32. According to the teachings of V. I. Vernadsky about the biosphere, limestones, coal were formed as a result of

1. Settling of cosmic dust

2. Activities of living organisms

3. Volcanic activity

4. Orogenic processes

The correct answer is 2.

33. What is the limiting factor for granivorous birds in winter in the taiga?

1. Light intensity

2. Changes in atmospheric pressure

3. No insects

4. Snow depth

The correct answer is 4.

34. Unicellular green algae enter into symbiosis in lichen with

1. Bacteriophages

2. Bacteria-saprotrophs

3. The simplest

4. Mushrooms

The correct answer is 4.

35. Loosening the soil under the crown of fruit trees is the effect on the plant of the factor

1. Anthropogenic

2. Biotic

3. Limiting

4. Limiting

The correct answer is 1.

36. Factors, the value of which goes beyond the endurance of organisms, are called

1. Environmental

2. Abiotic

3. Anthropogenic

4. Limiting

The correct answer is 4.

37. In angiosperms living in the aquatic environment, compared with terrestrial

1. Well developed tissues

2. Photosynthesis proceeds more intensively

3. Poorly developed root system

4. Stomata are located on the underside of the leaf

The correct answer is 3.

Environmental factors and the concept of an ecological niche

The concept of environmental factor

1.1.1. The concept of environmental factors and their classification

From an environmental point of view Wednesday - These are natural bodies and phenomena with which the organism is in direct or indirect relations. The environment surrounding the body is characterized by great diversity, consisting of many elements, phenomena, conditions that are dynamic in time and space, which are considered as factors .

Environmental factor - is any environmental condition, capable of exerting a direct or indirect effect on living organisms, at least during one of the phases of their individual development. In turn, the organism reacts to the environmental factor with specific adaptive reactions.

In this way, environmental factors- these are all elements of the natural environment that affect the existence and development of organisms, and to which living creatures they react with adaptation reactions (death occurs outside the ability of adaptation).

It should be noted that in nature, environmental factors act in a complex way. It is especially important to keep this in mind when evaluating the impact of chemical contaminants. In this case, the "total" effect, when the negative effect of one substance is superimposed on the negative effect of others, and the influence of a stressful situation, noise, and various physical fields is added to this, significantly changes the MPC values ​​given in reference books. This effect is called synergistic.

The most important concept is limiting factor, that is, the level (dose) of which approaches the endurance limit of the organism, the concentration of which is lower or higher than optimal. This concept is defined by Liebig's (1840) minimum laws and Shelford's (1913) tolerance laws. The most frequently limiting factors are temperature, light, nutrients, currents and pressure in the environment, fires, etc.

The most common are organisms with a wide range of tolerance for all environmental factors. The highest tolerance is characteristic of bacteria and blue-green algae, which survive in a wide range of temperatures, radiation, salinity, pH, etc.

Ecological studies related to the determination of the influence of environmental factors on the existence and development of certain types of organisms, the relationship of the organism with the environment, are the subject of science autecology . The section of ecology that studies the associations of populations of various plant, animal, microorganism species (biocenoses), the ways of their formation and interaction with the environment is called synecology . Within the boundaries of synecology, phytocenology, or geobotany (the object of study is plant groups), biocenology (groups of animals) is distinguished.

Thus, the concept of an ecological factor is one of the most general and extremely broad concepts of ecology. In accordance with this, the task of classifying environmental factors turned out to be very difficult, so there is still no generally accepted version. At the same time, agreement was reached on the advisability of using certain features in the classification of environmental factors.

Traditionally, three groups of environmental factors have been distinguished:

1) abiotic (inorganic conditions - chemical and physical, such as the composition of air, water, soil, temperature, light, humidity, radiation, pressure, etc.);

2) biotic (forms of interaction between organisms);

3) anthropogenic (forms of human activity).

Today, ten groups of environmental factors are distinguished (the total number is about sixty), united in a special classification:

1. by time - factors of time (evolutionary, historical, acting), periodicity (periodic and non-periodic), primary and secondary;

2. by origin (cosmic, abiotic, biotic, natural, technogenic, anthropogenic);

3. by the environment of occurrence (atmospheric, water, geomorphological, ecosystem);

4. by nature (informational, physical, chemical, energy, biogenic, complex, climatic);

5. by the object of influence (individual, group, specific, social);

6. according to the degree of influence (lethal, extreme, limiting, disturbing, mutagenic, teratogenic);

7. according to the conditions of action (dependent or independent of density);

8. according to the spectrum of influence (selective or general action).

First of all, environmental factors are divided into external (exogenous or entopic) and domestic (endogenous) in relation to this ecosystem.

To external include factors whose actions, to one degree or another, determine the changes taking place in the ecosystem, but they themselves practically do not experience its reverse impact. These are solar radiation, precipitation intensity, atmospheric pressure, wind speed, current speed, etc.

Unlike them internal factors correlate with the properties of the ecosystem itself (or its individual components) and actually form its composition. Such are the numbers and biomass of populations, the reserves of various substances, the characteristics of the surface layer of air, water or soil mass, etc.

The second common classification principle is the division of factors into biotic and abiotic . The former include a variety of variables that characterize the properties of living matter, and the latter - non-living components of the ecosystem and its environment. The division of factors into endogenous - exogenous and biotic - abiotic do not coincide. In particular, there are both exogenous biotic factors, for example, the intensity of the introduction of seeds of a certain species into the ecosystem from outside, and endogenous abiotic factors, such as the concentration of O 2 or CO 2 in the surface layer of air or water.

Widespread use in environmental literature is the classification of factors according to the general nature of their origin or object of influence. For example, among exogenous factors, there are meteorological (climatic), geological, hydrological, migration (biogeographic), anthropogenic factors, and among endogenous - micrometeorological (bioclimatic), soil (edaphic), water and biotic.

An important classification indicator is nature of dynamics environmental factors, in particular the presence or absence of its periodicity (daily, lunar, seasonal, long-term). This is due to the fact that the adaptive reactions of organisms to certain environmental factors are determined by the degree of constancy of the impact of these factors, that is, their periodicity.

Biologist A.S. Monchadsky (1958) singled out primary periodic factors, secondary periodic factors, and non-periodic factors.

To primary periodic factors are mainly phenomena associated with the rotation of the Earth: the change of seasons, the daily change in illumination, tidal phenomena, etc. These factors, which are characterized by the correct periodicity, acted even before the appearance of life on Earth, and emerging living organisms had to immediately adapt to them.

Secondary periodic factors - a consequence of primary periodic ones: for example, humidity, temperature, precipitation, dynamics of plant food, the content of dissolved gases in water, etc.

To non-periodic include factors that do not have the correct periodicity, cyclicality. These are the soil and ground factors, all sorts of natural phenomena. Anthropogenic impacts on the environment are often referred to as non-periodic factors that may appear suddenly and irregularly. Since the dynamics of natural periodic factors is one of the driving forces of natural selection and evolution, living organisms, as a rule, do not have time to develop adaptive reactions, for example, to a sharp change in the content of certain impurities in the environment.

A special role among environmental factors belongs to summative (additive) factors characterizing the abundance, biomass or density of populations of organisms, as well as stocks or concentrations of various forms of matter and energy, the temporal changes of which are subject to conservation laws. Such factors are called resources . For example, they talk about the resources of heat, moisture, organic and mineral food, etc. In contrast, factors such as intensity and spectral composition of radiation, noise level, redox potential, wind or current speed, size and shape of food, etc., which greatly affect organisms, are not classified as resources, because .to. conservation laws do not apply to them.

The number of possible environmental factors seems to be potentially unlimited. However, in terms of the degree of impact on organisms, they are far from equivalent, as a result of which, in ecosystems of various types, some factors stand out as the most significant, or imperative . In terrestrial ecosystems, among the exogenous factors, they usually include the intensity of solar radiation, air temperature and humidity, the intensity of precipitation, wind speed, the rate of introduction of spores, seeds and other embryos or the influx of adults from other ecosystems, as well as all kinds of forms anthropogenic impact. Endogenous imperative factors in terrestrial ecosystems are the following:

1) micrometeorological - illumination, temperature and humidity of the surface layer of air, the content of CO 2 and O 2 in it;

2) soil - temperature, humidity, soil aeration, physical and mechanical properties, chemical composition, humus content, availability of mineral nutrition elements, redox potential;

3) biotic - the density of populations of different species, their age and sex composition, morphological, physiological and behavioral characteristics.

1.1.2. The space of environmental factors and the function of the response of organisms to a set of environmental factors

The intensity of the impact of each environmental factor can be numerically characterized, that is, described by a mathematical variable that takes on a value on a certain scale.

Environmental factors can be ordered by their strength relative to the impact on the organism, population, ecosystem, that is ranked . If the value of the first influencing factor is measured by the variable X 1 , second - variable X 2 , … , n-th - variable x n etc., then the whole complex of environmental factors can be represented by a sequence ( X 1 , X 2 , … , x n, …). In order to characterize the set of various complexes of environmental factors that are obtained at different values ​​of each of them, it is advisable to introduce the concept of the space of environmental factors, or, in other words, the ecological space.

The space of environmental factors Let's call the Euclidean space, the coordinates of which are compared to the ranked environmental factors:

To quantify the impact of environmental factors on the vital activity of individuals, such as the rate of growth, development, fertility, life expectancy, mortality, nutrition, metabolism, motor activity, etc. (let them be numbered with an index k= 1, …, m), the concept of f at n to c and I X about t to l and ka . Values ​​accepted by an indicator with a number k on a certain scale when varying environmental factors, as a rule, are limited from below and from above. Denote by segment on the scale of values ​​of one of the indicators ( k th) the life of the ecosystem.

response function k-th indicator on the totality of environmental factors ( X 1 , X 2 , … , x n, …) is called a function φk, representing ecological space E on the scale Ik:

,

which to each point ( X 1 , X 2 , … , x n, …) spaces E matches a number φk(X 1 , X 2 , … , x n, …) on the scale Ik .

Although the number of environmental factors is potentially unlimited and, therefore, the dimensions of the ecological space are infinite. E and number of response function arguments φk(X 1 , X 2 , … , x n, …), in fact, it is possible to isolate a finite number of factors, for example n, which can be used to explain the specified part of the total variation of the response function. For example, the first 3 factors can explain 80% of the total variation in the indicator φ , the first 5 factors - 95%, the first 10 - 99%, etc. The rest, not included in the number of these factors, do not have a decisive impact on the indicator under study. Their influence can be seen as some " ecological"noise superimposed on the action of imperative factors.

This allows from infinite dimensional space E go to it n-dimensional subspace En and consider the narrowing of the response function φk to this subspace:

and , where εn+1 - random " environmental noise".

Any living organism does not need temperature, humidity, mineral and organic substances or any other factors in general, but their specific regime, that is, there are some upper and lower limits of the amplitude of permissible fluctuations of these factors. The wider the limits of any factor, the higher the stability, that is tolerance of this organism.

In typical cases, the response function has the form of a convex curve, monotonically increasing from the minimum value of the factor xj s (lower limit of tolerance) to a maximum at the optimal value of the factor xj 0 and monotonically decreasing to the maximum value of the factor xj e (upper limit of tolerance).

Interval Xj = [x j s , x j e] is called tolerance interval on this factor, and the point xj 0 , at which the response function reaches an extremum, is called optimum point on this factor.

The same environmental factors affect organisms of different species living together in different ways. For some they may be favorable, for others they may not. An important element is the reaction of organisms to the strength of the impact of an environmental factor, the negative effect of which may occur in case of an excess or lack of a dose. Therefore, there is the concept of a favorable dose or optimum zone factor and pessimum zones (the range of dose values ​​of the factor in which organisms feel oppressed).

The ranges of the optimum and pessimum zones are the criterion for determining ecological valence - the ability of a living organism to adapt to changes in environmental conditions. Quantitatively, it is expressed by the range of the environment within which the species normally exists. The ecological valency of different species can be very different (reindeer can withstand fluctuations in air temperature from -55 to +25÷30°C, and tropical corals die even when the temperature changes by 5-6°C). According to ecological valency, organisms are divided into stenobionts - with low adaptability to environmental changes (orchids, trout, Far Eastern hazel grouse, deep-sea fish) and eurybionts - with greater adaptability to environmental changes (Colorado potato beetle, mice, rats, wolves, cockroaches, reeds, wheatgrass). Within the boundaries of eurybionts and stenobionts, depending on a specific factor, organisms are divided into eurythermal and stenothermic (by reaction to temperature), euryhaline and stenohaline (by reaction to salinity of the aquatic environment), eurythoty and stenofoty (by reaction to lighting).

To express the relative degree of tolerance, there are a number of terms in ecology that use prefixes steno -, which means narrow, and evry - - wide. Species that have a narrow tolerance interval (1) are called stenoeks , and species with a wide tolerance interval (2) euryekami on this factor. Imperative factors have their own terms:

by temperature: stenothermic - eurythermal;

by water: stenohydric - euryhydric;

by salinity: stenohaline - euryhaline;

by food: stenophagous - euryphagic;

according to the choice of habitat: wall-stained - euryoic.

1.1.3. Law of the limiting factor

The presence or prosperity of an organism in a given habitat depends on a complex of ecological factors. For each factor there is a range of tolerance beyond which the organism is not able to exist. The impossibility of prosperity or the absence of an organism is determined by those factors whose values ​​approach or go beyond tolerance.

limiting we will consider such a factor for which, in order to achieve a given (small) relative change in the response function, a minimum relative change in this factor is required. If

then the limiting factor will be Xl, that is, the limiting factor is the one along which the gradient of the response function is directed.

It is obvious that the gradient is directed along the normal to the boundary of the tolerance region. And for the limiting factor, there are more chances, all other things being equal, to go beyond the tolerance area. That is, the limiting factor is the one whose value is closest to the lower limit of the tolerance interval. This concept is known as " law of the minimum " Liebig.

The idea that the endurance of an organism is determined by the weakest link in the chain of its ecological needs was first clearly shown in 1840. organic chemist J. Liebig, one of the founders of agricultural chemistry, who put forward theory of mineral nutrition of plants. He was the first to start studying the influence of various factors on plant growth, establishing that crop yields are often limited by nutrients that are not required in large quantities, such as carbon dioxide and water, since these substances are usually present in the environment in in abundance, but those that are required in the smallest quantities, for example, zinc, boron or iron, which are very few in the soil. Liebig's conclusion that "the growth of a plant depends on that element of nutrition which is present in the minimum amount" became known as Liebig's "Law of the Minimum".

After 70 years, the American scientist W. Shelford showed that not only a substance present in a minimum can determine the yield or viability of an organism, but also an excess of some element can lead to undesirable deviations. For example, an excess of mercury in the human body in relation to a certain norm causes severe functional disorders. With a lack of water in the soil, the assimilation of mineral nutrition elements by the plant is difficult, but an excess of water leads to similar consequences: it is possible for the roots to suffocate, the occurrence of anaerobic processes, the acidification of the soil, etc. Excess and lack of pH in the soil also reduces the yield in a given location. According to W. Shelford, factors present both in excess and in deficiency are called limiting, and the corresponding rule is called the law of "limiting factor" or " the law of tolerance ".

The law of the limiting factor is taken into account in measures to protect the environment from pollution. Exceeding the norm of harmful impurities in the air and water poses a serious threat to human health.

We can formulate a number of auxiliary principles that complement the "law of tolerance":

1. Organisms can have a wide range of tolerance for one factor and a narrow range for another.

2. Organisms with a wide range of tolerance to all factors are usually the most widely distributed.

3. If the conditions for one environmental factor are not optimal for the species, then the range of tolerance to other environmental factors may narrow.

4. In nature, organisms very often find themselves in conditions that do not correspond to the optimal range of one or another environmental factor, determined in the laboratory.

5. The breeding season is usually critical; during this period, many environmental factors often become limiting. The tolerance limits for breeding individuals, seeds, embryos and seedlings are usually narrower than for non-breeding adult plants or animals.

The actual limits of tolerance in nature are almost always narrower than the potential range of activity. This is due to the fact that the metabolic costs of physiological regulation at extreme values ​​of the factors narrow the range of tolerance. As conditions approach extremes, adaptation becomes increasingly costly and the body less and less protected from other factors such as disease and predators.

1.1.4. Some basic abiotic factors

Abiotic factors of the terrestrial environment . The abiotic component of the terrestrial environment is a set of climatic and soil factors, consisting of many dynamic elements that affect both each other and living beings.

The main abiotic factors of the terrestrial environment are as follows:

1) Radiant energy coming from the sun (radiation). It propagates in space in the form of electromagnetic waves. Serves as the main source of energy for most processes in ecosystems. On the one hand, the direct effect of light on protoplasm is fatal to the organism, on the other hand, light serves as the primary source of energy, without which life is impossible. Therefore, many morphological and behavioral characteristics of organisms are associated with the solution of this problem. Light is not only a vital factor, but also a limiting one, both at the maximum and at the minimum levels. About 99% of all solar radiation energy is rays with a wavelength of 0.17÷4.0 µm, including 48% is in the visible part of the spectrum with a wavelength of 0.4÷0.76 µm, 45% is in the infrared (wavelength from 0.75 µm to 1 mm) and about 7% - to ultraviolet (wavelength less than 0.4 microns). Infrared rays are of primary importance for life, and orange-red and ultraviolet rays play the most important role in the processes of photosynthesis.

2) Illumination of the earth's surface associated with radiant energy and determined by the duration and intensity of the light flux. Due to the rotation of the Earth, daylight and darkness alternate periodically. Illumination plays a crucial role for all living things and organisms are physiologically adapted to the change of day and night, to the ratio of dark and light periods of the day. Almost all animals have so-called circadian (diurnal) rhythms of activity associated with the change of day and night. In relation to light, plants are divided into light-loving and shade-tolerant.

3) Temperature on the surface of the globe is determined by the temperature regime of the atmosphere and is closely related to solar radiation. It depends both on the latitude of the area (the angle of incidence of solar radiation on the surface), and on the temperature of the incoming air masses. Living organisms can exist only within a narrow range of temperatures - from -200°C to 100°C. As a rule, the upper limit values ​​of the factor are more critical than the lower ones. The range of temperature fluctuations in water is usually smaller than on land, and the range of temperature tolerance in aquatic organisms is usually narrower than that of the corresponding terrestrial animals. Thus, temperature is an important and very often limiting factor. Temperature rhythms, together with light, tidal and humidity rhythms, largely control the seasonal and diurnal activity of plants and animals. Temperature often creates zoning and stratification of habitats.

4) Atmospheric air humidity associated with its saturation with water vapor. The lower layers of the atmosphere are richest in moisture (up to a height of 1.5–2 km), where up to 50% of all moisture is concentrated. The amount of water vapor contained in the air depends on the temperature of the air. The higher the temperature, the more moisture the air contains. For each temperature there is a certain limit of saturation of air with water vapor, which is called maximum . The difference between the maximum and given saturation is called humidity deficiency (lack of saturation). Humidity deficiency - the most important environmental parameter, since it characterizes two quantities at once: temperature and humidity. It is known that an increase in moisture deficit in certain periods of the growing season contributes to increased fruiting of plants, and in a number of animals, such as insects, leads to reproduction up to the so-called "outbreaks". Therefore, many methods for predicting various phenomena in the world of living organisms are based on the analysis of the dynamics of moisture deficit.

5) Precipitation , closely related to air humidity, are the result of condensation of water vapor. Atmospheric precipitation and air humidity are of decisive importance for the formation of the water regime of the ecosystem and, thus, are among the most important imperative environmental factors, since water supply is the main condition for the life of any organism, from a microscopic bacterium to a giant sequoia. The amount of precipitation depends mainly on the paths and nature of the large movements of air masses, or the so-called "weather systems". The distribution of precipitation by season is an extremely important limiting factor for organisms. Precipitation - one of the links in the water cycle on Earth, and in their fallout there is a sharp unevenness, in connection with which they distinguish humid (wet) and arid (dry) zones. The maximum precipitation is in tropical forests (up to 2000 mm/year), the minimum is in deserts (0.18 mm/year). Zones with rainfall less than 250 mm/year are already considered dry. As a rule, uneven distribution of precipitation over the seasons occurs in the tropics and subtropics, where the wet and dry seasons are often well defined. In the tropics, this seasonal rhythm of humidity regulates the seasonal activity of organisms (especially reproduction) in much the same way that the seasonal rhythm of temperature and light regulates the activity of organisms in the temperate zone. In temperate climates, precipitation is usually distributed more evenly over the seasons.

6) Gas composition of the atmosphere . Its composition is relatively constant and includes mainly nitrogen and oxygen with an admixture of a small amount of CO 2 and argon. Other gases - in trace amounts. In addition, the upper atmosphere contains ozone. Usually in the atmospheric air there are solid and liquid particles of water, oxides of various substances, dust and smoke. Nitrogen - the most important biogenic element involved in the formation of protein structures of organisms; oxygen , mainly coming from green plants, provides oxidative processes; carbon dioxide (СО 2) is a natural damper of solar and reciprocal terrestrial radiation; ozone performs a shielding role in relation to the ultraviolet part of the solar spectrum, which is detrimental to all living things. Impurities of the smallest particles affect the transparency of the atmosphere, prevent the passage of sunlight to the surface of the Earth. The concentrations of oxygen (21% by volume) and CO2 (0.03% by volume) in the modern atmosphere are to some extent limiting for many higher plants and animals.

7) Movement of air masses (wind) . The reason for the occurrence of wind is the pressure drop caused by uneven heating of the earth's surface. The wind flow is directed in the direction of lower pressure, that is, where the air is warmer. The force of the Earth's rotation affects the circulation of air masses. In the surface layer of air, their movement affects all meteorological elements of the climate: temperature, humidity, evaporation from the Earth's surface, and plant transpiration. Wind - the most important factor in the transfer and distribution of impurities in the atmospheric air. The wind performs an important function of transporting matter and living organisms between ecosystems. In addition, the wind has a direct mechanical effect on vegetation and soil, damaging or destroying plants and destroying the soil cover. Such wind activity is most typical for open flat areas of land, seas, coasts and mountainous regions.

8) atmospheric pressure . Pressure cannot be called a limiting factor of direct action, although some animals undoubtedly react to its changes; however, pressure is directly related to weather and climate, which have a direct limiting effect on organisms.

Abiotic soil cover factors . Soil factors are clearly endogenous, since the soil is not only a factor of the environment surrounding organisms, but also a product of their vital activity. The soil - this is the framework, the foundation on which almost any ecosystem is built.

The soil - the final result of the action of climate and organisms, especially plants, on the parent rock. Thus, the soil consists of the source material - the underlying mineral substrate and organic component, in which organisms and their metabolic products are mixed with finely divided and modified source material. The gaps between the particles are filled with gases and water. texture and soil porosity are the most important characteristics that largely determine the availability of biogenic elements to plants and soil animals. In the soil, the processes of synthesis, biosynthesis are carried out, various chemical reactions of transformation of substances occur, associated with the vital activity of bacteria.

1.1.5. Biotic factors

Under biotic factors understand the totality of the influences of the life activity of some organisms on others.

The relationship between animals, plants, microorganisms (they are also called co-shares ) are extremely diverse. They can be divided into straight and indirect, are mediated through change by their presence of appropriate abiotic factors.

The interactions of living organisms are classified in terms of their reaction to each other. In particular, they distinguish homotypic reactions between interacting individuals of the same species and heterotypic reactions during coactions between individuals of different species.

One of the most important biotic factors is food (trophic) factor . The trophic factor is characterized by the quantity, quality and availability of food. Any kind of animal or plant has a clear selectivity to the composition of food. Distinguish types monophages that feed on only one species, polyphages , feeding on several species, as well as species feeding on a more or less limited range of food, called wide or narrow oligophages .

Relationships between species are naturally necessary. Cannot be divided into enemies and them victims because the relationships between species are mutually reversible. Disappearance² victims² can lead to extinction ² enemy².

ENVIRONMENTAL FACTORS

Environmental factors - these are certain conditions and elements of the environment that have a specific effect on a living organism. The body reacts to the action of environmental factors with adaptive reactions. Environmental factors determine the conditions for the existence of organisms.

Classification of environmental factors (by origin)

• 1. Abiotic factors are a set of factors of inanimate nature that affect the life and distribution of living organisms. Among them are distinguished:
• 1.1. Physical factors- such factors, the source of which is a physical state or phenomenon (for example, temperature, pressure, humidity, air movement, etc.).
• 1.2. Chemical Factors- Factors that are chemical composition environment (water salinity, oxygen content in the air, etc.).
• 1.3. Edaphic factors(soil) - a set of chemical, physical, mechanical properties of soils and rocks that affect both the organisms for which they are the habitat and the root system of plants (humidity, soil structure, content of nutrients, etc.).
• 2. Biotic factors - a set of influences of the life activity of some organisms on the life activity of others, as well as on the non-living component of the habitat.
• 2.1. Intraspecific interactions characterize the relationships between organisms at the population level. They are based on intraspecific competition.
• 2.2. Interspecies interactions characterize the relationship between different species, which can be favorable, unfavorable and neutral. Accordingly, we denote the nature of the impact as +, - or 0. Then the following types of combinations of interspecies relationships are possible:
• 00 neutralism- both types are independent and have no effect on each other; rarely found in nature (squirrel and elk, butterfly and mosquito);

+0 commensalism- one species benefits, while the other does not have any benefit, harm too; (large mammals (dogs, deer) serve as carriers of fruits and seeds of plants (burdock), without receiving any harm or benefit);

-0 amensalism- one species experiences inhibition of growth and reproduction from another; (light-loving herbs growing under a spruce suffer from shading, and this is indifferent to the tree itself);

++ symbiosis- mutually beneficial relationship:

• ? mutualism- species cannot exist without each other; figs and pollinating bees; lichen;
• ? proto-operation- coexistence is beneficial to both species, but is not a prerequisite for survival; pollination by bees of different meadow plants;
• - - competition- each of the species has an adverse effect on the other; (plants compete with each other for light and moisture, i.e. when they use the same resources, especially if they are insufficient);

Predation - a predatory species feeds on its prey;

There is another classification of environmental factors. Most factors qualitatively and quantitatively change over time. For example, climatic factors (temperature, illumination, etc.) change during the day, season, and year. Factors that change regularly over time are called periodical . These include not only climatic, but also some hydrographic - ebbs and flows, some ocean currents. Factors that arise unexpectedly (volcanic eruption, predator attack, etc.) are called non-periodic .

Environmental factors of the environment

Test on the topic "Ecological factors of the environment"

Choose one correct answer:

1. What abiotic factor can lead to a sharp decline in the beaver population?

1) heavy rains in summer

2) increase in the number of aquatic plants

3) drying up of the reservoir

4) intensive shooting of animals

(correct answer: 3)

2. What anthropogenic factor can lead to an increase in the population of hares in the forest?

1) cutting trees

2) shooting wolves and foxes

3) trampling plants

4) making fires

(Correct answer: 2)

3. What environmental factor serves as a signal for the preparation of birds for flights?

1) lowering the air temperature

2) change in daylight hours

3) increase in cloudiness

4) change in atmospheric pressure

(correct answer: 2)

4. The greenhouse effect can contribute to the rapid development of plants in the biosphere, as it leads

1) to the accumulation of oxygen in the atmosphere

2) to increase the transparency of the atmosphere

3) to an increase in the density of the atmosphere

4) to the accumulation of carbon dioxide in the atmosphere

(correct answer: 1)

5. All factors of animate and inanimate nature that affect individuals, populations, species are called

1) abiotic

2) biotic

3)environmental

4) anthropogenic

(correct answer: 3)

6. The abiotic factors are

1) undermining the roots by boars

2) locust invasion

3) the formation of bird colonies

4) heavy snowfall

(correct answer: 4)

7.The food chains in an ecosystem are called

1) abiotic

2) anthropogenic

3) limiting

4) biotic

(correct answer: 4)

8.Factors causing environmental pollution,
associated with human activities are called

1) limiting

2) anthropogenic

3) biotic

4) abiotic

(correct answer: 2)

9.What factors are called anthropogenic?

1) related to human activities

2) abiotic nature

3) biotic character

4) determining the functioning of agrocenoses

(correct answer: 1)

10. The biotic components of the ecosystem include

1) gas composition of the atmosphere

2) the composition and structure of the soil

3) features of climate and weather

4) producers, consumers, decomposers

(correct answer: 4)

Choose one correct answer

Question 1. Environmental conditions are usually defined as:

1. environmental factors that influence (positively or negatively) the existence and geographical distribution of living beings;

2. changes in the environment-forming components or their combinations, which are of an oscillatory nature with the restoration of the previous living conditions;

3. the degree of compliance of natural conditions with the needs of people or other living organisms;

4. balance of natural or human-modified environmental components and natural processes;

5. addition of natural and anthropogenic factors, creating in total new ecological conditions for the habitat of organisms and biotic communities.

(correct answer: 1)

Question 2. Which definition corresponds to the concept of "abiotic environmental factors":

1. components and phenomena of inanimate, inorganic nature, directly or indirectly affecting living organisms;

2. natural bodies and phenomena with which the organism is in direct or indirect relationship;

3. change in the environment-forming components or their combinations, which cannot be compensated in the course of natural restoration processes;

4. factors that have both direct and indirect effects on organisms;

5. relationships between species, in which organisms of one species live off the nutrients of other species.

(correct answer: 1)

Question 3. Biotic environmental factors are:

1. the totality of the influences of the life activity of some organisms on the life activity of others, as well as on the non-living environment;

2. physiological and ecological adaptation of organisms, providing a high level of metabolism during the period of animal activity and low energy losses during hibernation;

3. the ratio between the energy received by the body from the outside, and its expenditure on building the body and life processes;

4. environmental factors that have the greatest impact on the number and vital activity of organisms.

5. forces and phenomena of nature, the origin of which is not directly related to the vital activity of living organisms.

(correct answer: 1)

Question 4. Anthropogenic factors are:

1. forms of human activity that affect the natural environment, changing the living conditions of living organisms;

2. the totality of the influences of the life activity of some organisms on the life activity of others, as well as on the non-living environment;

3. the totality of natural features of the existence of organisms and anthropogenic impacts;

4. a group of factors associated with both direct and indirect influence of living organisms on the environment;

5. factors that ensure a high level of metabolism during the period of animal activity and low energy losses during hibernation.

(correct answer: 1)

Question 5. The construction of a dam can be seen as an example of a factor:

1. abiotic;

2. biotic;

3. anthropogenic;

4. not ecological at all;

5. hydrobiont.

(correct answer: 3)

B 4. Establish a correspondence between the characteristics of the environment and its factor

ENVIRONMENTAL FACTORS

A) biotic

B) abiotic

CHARACTERISTIC

1) the constancy of the gas composition of the atmosphere

2) change in the thickness of the ozone screen

3) change in air humidity

4) change in the number of consumers

5) change in the number of producers

(correct answer: A-4,5,6. B-1,2,3.)

B 6. Establish in what order the levels of organization of the living are arranged:

A) biocenotic

B) species

B) popular

D) biogeocenotic

D) organismic

E) biospheric

(correct answer:D, B, C, A, D, E.)

C 3. Read the text and find sentences in it that contain biological errors. First write down the numbers of these sentences, and then formulate them correctly.

1. All environmental factors affecting organisms are divided into biotic, geological and anthropogenic.

2. Biotic factors are temperature, climatic conditions, humidity, illumination.

3. Anthropogenic factors - the impact of man and the products of his activities on the environment.

4. The factor, the value of which is currently within the limits of endurance and deviates to the greatest extent from the optimal value, is called limiting.

5. Mutualism is a form of mutually negative interactions between organisms.

Answers:

1-on Abiotic, Biotic and Anthropogenic.

3-correct

4-correct

5-mutually positive interactions (mutually beneficial relationships between individuals)