The ecological factor that determines the boundaries of the distribution of species is called. The main factors of the natural environment. The impact of environmental factors on the body
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 impact environment, which 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 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 on the organism, are themselves not subject to 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 are components and phenomena of inanimate, inorganic nature that directly or indirectly affect 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 man's 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. The presence of bad habits and addictions.
The natural environment is a collection of ecological systems, or ecosystems.
The interaction between organisms and their environment is based on cause-and-effect relationships. The organism receives information from the environment in the form of certain signals of a material nature, and reacts to these signals. In ecology, the signals that come to the body are called factors.
Environmental factor- this is any element of the environment that can have a direct or indirect effect on a living organism at least at one of the stages of its development.
Environmental factors affecting living organisms are beneficial or harmful, promote or hinder survival and reproduction. There are several approaches to the classification of environmental factors.
First of all, environmental factors are divided into external (exogenous) and internal (endogenous) in relation to the analyzed system.
To external include factors whose action to one degree or another determines the changes occurring in the ecosystem, but they themselves do not experience its reverse impact. These are, for example, solar radiation, atmospheric pressure, wind, etc.
Unlike external factors domestic correlate with the properties of the ecosystem itself (or its individual components) and actually form its composition. Such, for example, are the characteristics of the surface layer of air, the concentration of substances in water bodies, and soil.
Another classification principle is the division of factors into biotic and abiotic.
Abiotic factors- temperature, light, radiation, pressure, air humidity, salt composition of water, wind, currents, terrain. These properties of inanimate nature directly or indirectly affect living organisms.
Biotic factors- various manifestations of the impact of living beings on each other. The mutual relations of organisms are the basis for the existence of populations and biocenoses (a set of plants, animals and microorganisms that inhabit a given piece of land or water body - the biocenosis of a forest, lake, etc.).
But in their origin, abiotic and biotic factors can be both natural as well as anthropogenic.
Anthropogenic factors- the result of human activity, leading to a change in nature as a habitat for other species or directly affecting their lives. In the process of evolution, man mastered hunting, agriculture, industry, transport, and thereby gradually changed the natural conditions on the planet. The scale and forms of human relations with nature have steadily grown from the use of individual species of plants and animals to almost complete involvement natural resources in the life support of modern industrial society. At present, the state of the Earth's cover and all types of organisms is determined by the anthropogenic impact on nature.
The number of possible environmental factors is considered to be potentially unlimited. However, within the framework of industrial ecology, the most significant are abiotic factors of an endogenous nature, due to the action of industrial production.
These factors should include chemicals introduced into the environment. atmospheric emissions, discharges into the water, as well as solid waste, removed from the production cycle, and various influences of physical nature: radiation (thermal, electromagnetic, high-frequency and superhigh-frequency, ionizing and non-ionizing of various nature), magnetic and electric fields, noise.
The manifestation of these factors in the working area and on the industrial site of the enterprise is the sphere of labor protection. The presence of these factors behind these zones in the natural environment in contact with production is the sphere of interest of industrial ecology. The actual absence of a boundary between the working area (production environment), the industrial site and the nearby natural environment leads to the fact that many methods developed in the field of labor protection will also be effective in solving problems of industrial ecology.
With the growth of productive forces and the expansion of economic activity Negative consequences human impact on the environment Wednesday become more and more tangible. At present, negative human impacts on nature often lead to unforeseen changes in ecological systems, in the processes of the biosphere.
As a biological entity, man is largely dependent on the physical environment. Deterioration of its condition affects human health and its performance.
Under industrial ecology understand the section of "big ecology", which considers the influence of industry (sometimes the entire economy) - from individual enterprises to the technosphere - on nature and, conversely, the influence of environmental conditions on the functioning of enterprises and their complexes. Ecology should contribute to solving problems of conservation High Quality environment by engineering methods, which is possible only if production specialists have knowledge in the field of ecology, which allows them to evaluate their production from an environmental standpoint, i.e. have an ecological mindset.
Ultimately, this knowledge and ecological thinking form a kind of “restrictive complex” for the nature user: having it, the specialist determines not only what and how to do, but what and why it is impossible to do, i.e., to observe the principle of “what not to do, so as not to cause harm."
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 more or less adapted to extreme conditions environment organisms, but for each group there are basic factors without which it cannot live. For plants, this 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. Mutual influence of organisms of one or different types are considered to be 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 fruit trees is the effect on the plant of a 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 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
Answer
Answer
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
Answer
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
Answer
Answer
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
Answer
Answer
Answer
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
Answer
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
Answer
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
Answer
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
Answer
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
Answer
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
Answer
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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
Answer
Answer
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
Answer
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 of wind-pollinated plants increases
5) the water horizon of the soil changes
6) the number of insectivorous birds is decreasing
Answer
Answer
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
Answer
Answer
Answer
Answer
SHAPING 4:
A) lamprey - mackerel
B) caterpillar - rider
C) liver fluke - cow
D) liver fluke - small pond snail
Answer
Answer
Answer
Answer
Answer
Answer
Answer
Answer
Answer
SYMBIOSIS
Choose one, the most correct option. What is mycorrhiza?
1) mushroom root
2) root system plants
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
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
Separate components of the habitat 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 the 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 the vegetation, but the formed climatic conditions 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 the chemical composition of the 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 the root system of 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 stop, 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 of 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 vitality) concentration 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.
