What groups of environmental factors affect animals. The influence of environmental factors on the vital activity of organisms

Environmental factors

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

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

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

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

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

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 the reserve capabilities of the 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 sphere (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,

Soil, 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.

Environmental factors are an integral part of the existence of populations and the creation of living conditions. The study of each factor separately creates many additional factors that express the whole complex of its influence, action and significance in nature.

Classification of environmental factors

Systematization of the properties of the environment simplifies the perception, compilation and study of their parameters. The components of the environment are divided according to the nature and range of impact on the natural and anthropogenic environment. These include:

• Fast acting. The impact of the factor on the processes of energy and information metabolism for the implementation, which requires a minimum amount of time.
• Indirect. The impact of individual factors is limiting or concomitant for the development of processes, metabolism or changes in the material composition of an element, group of organisms or environmental substances.
• The selective impact is aimed at the components of the environment, characterizing them as limiting for a certain type of organisms or processes.

Certain types of animals eat only one type of food, their selective influence will be the habitat with this plant. The overall spectrum of impact is a factor that determines the impact of a complex of environmental conditions on different levels of life organization.

A variety of environmental factors allows them to be classified according to the signs of their action:

• by habitat;
• by time;
• by frequency;
• by the nature of the impact;
• by origin;
• by the object of influence.

Their classification has a multicomponent description and within each factor is divided into many independent ones. This makes it possible to describe in detail the environmental conditions and their combined influence at different levels of life organization.

Groups of environmental factors

The conditions for the existence of organisms, regardless of the level of its organization, are influenced by environmental factors, which are divided into groups according to their organization. There are three groups of factors: abiotic; biotic; anthropogenic.

Anthropogenic factors called the impact on the environment: products of human activity, changes in the natural environment with replacement by artificially created objects. These factors complement pollution by residual products of industry, life (emissions, waste, fertilizers).

Abiotic environmental factors. The natural environment consists of components that make it up as a whole. It consists of factors that determine it as a habitat for different levels of life organization. Its components:

• Light. The attitude to light determines the habitat, the main processes of plant metabolism, the diversity of animals and their vital activity.
• Water. It is a component present in living organisms of all levels of organization of life on Earth. This habitat element occupies most of the Earth and is the habitat. A variety of living organisms in most of their species belongs to this environment.
• Atmosphere. The gaseous shell of the earth, in which the processes that regulate the climate and temperature regimes of the planet take place. These regimes determine the belts of the planet and the conditions of existence on them.
• Edaphic or soil factors. The soil is the result of the erosion of the Earth's rocks with its properties determine the appearance of the planet. The inorganic components that make up its composition serve as a nutrient medium for plants.
• Terrain relief. The orographic conditions of the area are regulated by changes in the surface under the influence of the geological erosion processes of the earth. These include hills, hollows, river valleys, plateaus and other geographical boundaries of the Earth's surface.
• The influence of abiotic and biotic factors is interrelated. Each factor has a positive or negative effect on living organisms.

Biotic environmental factors. The relationship between organisms and their influence on objects of inanimate nature is called biotic environmental factors. These factors are classified according to the actions and relationships of organisms:

Type of interaction of individuals, their ratio and description

Action of environmental factors

Environmental factors have a complex effect on organisms. Their action is characterized by quantitative indicators expressed in the general flow of their influence. The ability to adapt to the action of environmental factors is called the ecological valence of the species. The threshold of influence is expressed by the zone of tolerance. A wide range of distribution and adaptability of the species characterizes it as a eurybiont, and a narrow range - wall-beaten.

The combined influence of factors is characterized by the ecological spectrum of the species. Patterns of influence of factors. The law of action of factors:

• Relativity. Each factor affects jointly and characterizes it: intensity, direction and quantity in a certain period of time.
• Optimality of factors - the average range of their impact is favorable.
• Relative substitutability and absolute irreplaceability Living conditions depend on irreplaceable abiotic environmental factors (water, light) and their absolute absence is irreplaceable for the species. The compensatory effect is exerted by an excess of other factors.

Influence of environmental factors

The influence of each factor is due to their characteristics. The main groups of these factors are:

• Abiotic. Light affects the physiological processes in the human body, the vital activity of animals and the vegetation of plants. Biotic. When the seasons change, the tree sheds its leaves and fertilizes the upper soil layer.
• Anthropogenic. Since the Stone Age, human activity has had an impact on the natural environment. With the development of industry and economic activity, its pollution is the main human impact on the environment.
• Ecofactors have a contiguous effect and it is difficult to describe their separate impact.

Environmental factors: examples

Examples of environmental factors are the basic conditions of existence at the population level. Main factors:

• Light. Plants use light for vegetative processes. Physiological processes under the influence of light in the human body are genetically determined in the process of evolution.
• Temperature. The biodiversity of organisms is expressed in the existence of species in different temperature ranges. Under the influence of temperature, metabolic processes in the body are carried out.
• Water. An element of the environment that influences the existence and adaptation of organisms. They also include air, wind, soil, man. These factors create dynamic processes in nature and exert their influence on the processes in it.

Environmental pollution is a paramount concern for ecological communities, environmental protection. Waste facts (anthropogenic environmental factors):

• Waste island discovered in the Pacific Ocean (plastic bottles and other substances). Plastic decomposes over 100 years, film - 200 years. Water can accelerate this process and this will become another factor in the pollution of the hydrosphere. Animals eat plastic, mistaking them for jellyfish. Plastic is not digested and the animal may die.
• Air pollution in China, India and other industrial cities poisons the body. Toxic waste from industrial enterprises enters rivers with sewage and poisons water, which, along the water balance chain, can pollute air masses, groundwater and are dangerous to humans.
• In Australia, the Society for the Protection of Animals and the Conservation of Biodiversity is stretching vines along the highway. This protects koalas from death.
• To protect the rhinoceros from extinction as a species, they cut off the horn.

Ecological factors are multifactorial conditions for the existence of each species at different levels of life organization. Each level of the organization uses them rationally and the way they are used is different.

Concepts such as "habitat" and "conditions of existence" from the point of view of ecologists are not equivalent.

Habitat - part of nature that surrounds the organism and with which it directly interacts during its life cycle.

The habitat of each organism is complex and variable in time and space. It includes many elements of animate and inanimate nature and elements introduced by man and his economic activities. In ecology, these elements of the environment are called factors. All environmental factors in relation to the body are unequal. Some of them affect his life, while others are indifferent to him. The presence of some factors is obligatory and necessary for the life of the organism, while others are not necessary.

Neutral Factors- components of the environment that do not affect the body and do not cause any reaction in it. For example, for a wolf in the forest, the presence of a squirrel or a woodpecker, the presence of a rotten stump or lichens on trees is indifferent. They have no direct effect on him.

Environmental factors- properties and components of the environment that affect the body and cause responses in it. If these reactions are adaptive in nature, then they are called adaptations. Adaptation(from lat. adaptatio- adjustment, adaptation) - a sign or a set of signs that ensure the survival and reproduction of organisms in a particular habitat. For example, the streamlined body shape of fish facilitates their movement in dense water environments. In some dryland plant species, water can be stored in leaves (aloe) or stems (cactus).

In the environment, environmental factors vary in importance for each organism. For example, carbon dioxide is not important for animal life, but is essential for plant life, but neither one nor the other can exist without water. Therefore, certain ecological factors are required for the existence of organisms of any kind.

The conditions of existence (life) are a complex of environmental factors without which an organism cannot exist in a given environment.

The absence of at least one of the factors of this complex in the environment leads to the death of the organism or the suppression of its vital activity. So, the conditions for the existence of a plant organism include the presence of water, a certain temperature, light, carbon dioxide, minerals. Whereas for an animal organism, water, a certain temperature, oxygen, and organic substances are mandatory.

All other environmental factors are not vital for the organism, although they can affect its existence. They are called secondary factors. For example, for animals, carbon dioxide and molecular nitrogen are not vital, and for the existence of plants, the presence of organic substances is not necessary.

Classification of environmental factors

Environmental factors are diverse. They play a different role in the life of organisms, have a different nature and specificity of action. And although environmental factors affect the body as a single complex, they are classified according to different criteria. This facilitates the study of the patterns of interaction of organisms with the environment.

The diversity of environmental factors by nature of origin allows us to divide them into three large groups. In each of the groups, several subgroups of factors can be distinguished.

Abiotic factors- elements of inanimate nature that directly or indirectly affect the body and cause a response in it. They are divided into four subgroups:

1. climatic factors- all the factors that shape the climate in a given habitat (light, gas composition of the air, precipitation, temperature, air humidity, atmospheric pressure, wind speed, etc.);
2. edaphic factors(from the Greek. edafos - soil) - the properties of the soil, which are divided into physical (humidity, lumpiness, air and moisture permeability, density, etc.) and chemical(acidity, mineral composition, organic matter content);
3. orographic factors(relief factors) - features of the nature and specificity of the terrain. These include: height above sea level, latitude, steepness (the angle of the terrain in relation to the horizon), exposure (the position of the terrain relative to the cardinal points);
4. physical factors- physical phenomena of nature (gravity, the Earth's magnetic field, ionizing and electromagnetic radiation, etc.).

Biotic factors- elements of wildlife, i.e. living organisms that affect another organism and cause responses in it. They are of the most diverse nature and act not only directly, but also indirectly through elements of inorganic nature. Biotic factors are divided into two subgroups:

1. intraspecific factors- the influence is exerted by an organism of the same species as the given organism (for example, in a forest, a tall birch obscures a small birch; in amphibians with a high abundance, large tadpoles secrete substances that slow down the development of smaller tadpoles, etc.);
2. interspecies factors- individuals of other species have an impact on this organism (for example, spruce inhibits the growth of herbaceous plants under its crown, nodule bacteria provide legumes with nitrogen, etc.).

Depending on who the influencing organism is, biotic factors are divided into four main groups:

1. phytogenic (from the Greek. phyton- plant) factors - the influence of plants on the body;
2. zoogenic (from the Greek. zoon- animal) factors - the influence of animals on the body;
3. mycogenic (from the Greek. mykes- mushroom) factors - the effect of fungi on the body;
4. microgenic (from the Greek. micros- small) factors - the influence of other microorganisms (bacteria, protists) and viruses on the body.

Anthropogenic factors- a variety of human activities that affect both the organisms themselves and their habitats. Depending on the method of exposure, two subgroups of anthropogenic factors are distinguished:

1. direct factors- direct human impact on organisms (mowing grass, planting forests, shooting animals, breeding fish);
2. indirect factors- the influence of man on the habitat of organisms by the very fact of his existence and through economic activity. As a biological being, a person absorbs oxygen and emits carbon dioxide, withdraws food resources. As a social being, he exerts influence through agriculture, industry, transport, household activities, etc.

Depending on the consequences of the impact, these subgroups of anthropogenic factors, in turn, are divided into factors of positive and negative influence. Factors of positive influence increase the number of organisms to an optimal level or improve their habitat. Their examples are: planting and fertilizing plants, breeding and protecting animals, protecting the environment. Factors of negative influence reduce the number of organisms below the optimal level or worsen their habitat. These include deforestation, environmental pollution, habitat destruction, laying roads and other communications.

According to the nature of origin, indirect anthropogenic factors can be divided into:

1. physical- electromagnetic and radioactive radiation created in the course of human activity, direct impact on the ecosystems of construction, military, industrial and agricultural equipment in the process of its use;
2. chemical— fuel combustion products, pesticides, heavy metals;
3. biological— species of organisms spread in the course of human activity that can invade natural ecosystems and thereby disturb the ecological balance;
4. social- the growth of cities and communications, interregional conflicts and wars.

The habitat is the part of nature with which the organism directly interacts during its life. Environmental factors are the properties and components of the environment that affect the body and cause responses in it. According to the nature of origin, environmental factors are divided into: abiotic (climatic, edaphic, orographic, physical), biotic (intraspecific, interspecific) and anthropogenic (direct, indirect) factors.

The environment is a kind of complex of conditions surrounding a living organism that affect it, it can be a combination of phenomena, material bodies, energies. An environmental factor is an environmental factor to which organisms have to adapt. This can be a decrease or increase in temperature, humidity or drought, background radiation, human activities, competition among animals, etc. The term "habitat" essentially means a part of nature in which organisms live, among what affects them direct or indirect influence. These are the factors, because they affect the subject in one way or another. The environment is constantly changing, its components are diverse, so animals, plants and even people have to constantly adapt, adapt to new conditions in order to somehow survive and reproduce.

Classification of environmental factors

Living organisms can be subjected to both natural and artificial effects. There are several types of classifications, but the most common are such types of environmental factors as abiotic, biotic and anthropogenic. All living organisms are affected in one way or another by the phenomena and components of inanimate nature. These are abiotic factors that affect the life of humans, plants, and animals. They, in turn, are divided into edaphic, climatic, chemical, hydrographic, pyrogenic, orographic.

Light regime, humidity, temperature, atmospheric pressure and precipitation, solar radiation, wind can be attributed to climatic factors. Edaphic affect living organisms through thermal, air and its chemical composition and mechanical structure, groundwater level, acidity. Chemical factors are the salt composition of water, the gas composition of the atmosphere. Pyrogenic - the effect of fire on the environment. Living organisms are forced to adapt to the terrain, elevation changes, as well as to the characteristics of water, the content of organic and mineral substances in it.

The biotic environmental factor is the relationship of living organisms, as well as the impact of their relationship on the environment. The influence can be both direct and indirect. For example, some organisms are able to influence the microclimate, change, etc. Biotic factors are divided into four types: phytogenic (plants affect the environment and each other), zoogenic (animals affect the environment and each other), mycogenic ( fungi have an impact) and microbiogenic (microorganisms are at the center of events).

Anthropogenic environmental factor is a change in the living conditions of organisms in connection with human activities. Actions can be both conscious and unconscious. However, they lead to irreversible changes in nature. Man destroys the soil layer, pollutes the atmosphere and water with harmful substances, violates natural landscapes. Anthropogenic factors can be divided into four main subgroups: biological, chemical, social and physical. All of them, to one degree or another, affect animals, plants, microorganisms, contribute to the emergence of new species and erase old ones from the face of the earth.

The chemical impact of environmental factors on organisms mainly negatively affects the environment. To achieve good harvests, people use mineral fertilizers, kill pests with poisons, thereby polluting the soil and water. Transport and industrial waste should also be added here. Physical factors include moving in airplanes, trains, cars, the use of nuclear energy, the impact on organisms of vibration and noise. Do not forget about the relationship of people, life in society. Biological factors include organisms for which a person is a source of food or habitat, food should also be included here.

Environmental conditions

Depending on their characteristics and strengths, different organisms react differently to abiotic factors. Environmental conditions change over time and, of course, change the rules for the survival, development and reproduction of microbes, animals, fungi. For example, the life of green plants at the bottom of a reservoir is limited by the amount of light that can penetrate through the water column. The number of animals is limited by the abundance of oxygen. Temperature has a huge impact on living organisms, because its decrease or increase affects development and reproduction. During the ice age, not only mammoths and dinosaurs died out, but also many other animals, birds and plants, thereby changing the environment. Humidity, temperature and light are the main factors that determine the conditions for the existence of organisms.

Light

The sun gives life to many plants, it is not as important to animals as it is to representatives of the flora, but still they cannot do without it. Natural lighting is a natural source of energy. Many plants are divided into light-loving and shade-tolerant. Different types of animals show a negative or positive reaction to light. But the sun has the most important influence on the change of day and night, because different representatives of the fauna lead an exclusively nocturnal or daytime lifestyle. The effect of environmental factors on organisms is difficult to overestimate, but if we talk about animals, then lighting does not affect them directly, it only signals the need to restructure the processes occurring in the body, due to which living beings respond to changes in external conditions.

Humidity

Dependence on water in all living beings is very large, because it is necessary for their normal functioning. Most organisms are unable to live in dry air, sooner or later they die. The amount of precipitation falling during a specific period characterizes the humidity of the area. Lichens catch water vapor from the air, plants feed on the roots, animals drink water, insects, amphibians are able to absorb it through the integument of the body. There are creatures that get fluid through food or through the oxidation of fats. Both plants and animals have many adaptations that allow them to waste water more slowly, to save it.

Temperature

Each organism has its own temperature range. If it goes beyond, rising or falling, then he can simply die. The influence of environmental factors on plants, animals and humans can be both positive and negative. Within the temperature interval, the organism develops normally, but as soon as the temperature approaches the lower or upper limits, life processes slow down, and then stop altogether, which leads to the death of the creature. Someone needs cold, someone needs warmth, and someone can live under different environmental conditions. For example, bacteria, lichens withstand a wide range of temperatures, tigers feel good in the tropics and in Siberia. But most organisms survive only within narrow temperature limits. For example, corals grow in water at 21°C. Lowering the temperature or overheating is deadly for them.

In tropical regions, weather fluctuations are almost imperceptible, which cannot be said about the temperate zone. Organisms are forced to adapt to the change of seasons, many make long migrations with the onset of winter, and plants die off altogether. Under unfavorable temperature conditions, some creatures hibernate in order to wait out an inopportune period for them. These are only the main environmental factors, atmospheric pressure, wind, and altitude also affect organisms.

The impact of environmental factors on a living organism

The habitat has a significant impact on the development and reproduction of living beings. All groups of environmental factors usually act in a complex, and not one at a time. The strength of the influence of one depends on the others. For example, lighting cannot be replaced by carbon dioxide, but by changing the temperature, it is quite possible to stop the photosynthesis of plants. All factors affect organisms in one way or another differently. The leading role may change depending on the season. For example, in spring, temperature is important for many plants, soil moisture during flowering, and air humidity and nutrients when ripe. There is also an excess or deficiency of which is close to the limits of the organism's endurance. Their action is manifested even when living beings are in a favorable environment.

The influence of environmental factors on plants

For each representative of the flora, the environment is considered to be the surrounding nature. It is she who creates all the necessary environmental factors. The habitat provides the plant with the necessary soil and air moisture, lighting, temperature, wind, and the optimal amount of nutrients in the soil. A normal level of environmental factors allows organisms to grow, develop and reproduce normally. Some conditions can negatively affect plants. For example, if you plant a crop in a depleted field that does not have sufficient soil nutrients, it will grow very weak or not grow at all. Such a factor can be called a limiting factor. But still, most plants adapt to living conditions.

Representatives of the flora growing in the desert adapt to the conditions with the help of a special form. They usually have very long and powerful roots, which can reach 30 m deep into the ground. A superficial root system is also possible, which allows it to collect moisture during short rains. Trees and bushes store water in trunks (often deformed), leaves, branches. Some desert dwellers are able to wait several months for life-giving moisture, while others delight the eye for only a few days. For example, ephemera scatter seeds that germinate only after rain, then the desert blooms early in the morning, and already at noon the flowers fade.

The influence of environmental factors on plants is also affected in cold conditions. The tundra has a very harsh climate, the summer is short, you can’t call it warm, but the frosts last from 8 to 10 months. The snow cover is insignificant, and the wind completely exposes the plants. Representatives of the flora usually have a superficial root system, thick skin of leaves with a waxy coating. Plants accumulate the necessary supply of nutrients during the period when it lasts. Tundra trees produce seeds that germinate only once every 100 years during the period of most favorable conditions. But lichens and mosses have adapted to reproduce vegetatively.

Plants allow them to develop in a variety of conditions. Representatives of the flora are dependent on humidity, temperature, but most of all they need sunlight. It changes their internal structure, appearance. For example, a sufficient amount of light allows trees to grow a luxurious crown, but bushes and flowers that have grown in the shade seem oppressed and weak.

Ecology and man very often follow different paths. Human activities are detrimental to the environment. The work of industrial enterprises, forest fires, transport, air pollution from power plants, factories, water and soil with oil residues - all this negatively affects the growth, development and reproduction of plants. In recent years, many species of flora have been included in the Red Book, many have died out altogether.

The influence of environmental factors on humans

Even just two centuries ago, people were much healthier and physically stronger than they are today. Labor activity constantly complicates the relationship between man and nature, but up to a certain point they managed to get along. This was achieved due to the synchronism of the way of life of people with natural regimes. Each season had its own working mood. For example, in the spring, peasants plowed the land, sowed cereals and other crops. In summer they took care of crops, grazed cattle, in autumn they harvested crops, in winter they did household chores and rested. The culture of health was an important element of the general culture of man, the consciousness of the individual changed under the influence of natural conditions.

Everything changed dramatically in the 20th century, during the period of a huge leap in the development of technology and science. Of course, even before that, human activity significantly harmed nature, but here all records of a negative impact on the environment were broken. The classification of environmental factors allows you to determine what people influence to a greater extent, and what - to a lesser extent. Mankind lives in a production cycle mode, and this cannot but affect the state of health. There is no periodicity, people do the same work throughout the year, they have little rest, they are constantly in a hurry somewhere. Of course, working and living conditions have changed for the better, but the consequences of such comfort are very unfavorable.

Today, water, soil, air are polluted, destroying plants and animals fall out, damaging structures and structures. The thinning of the ozone layer also cannot but frighten the consequences. All this leads to genetic changes, mutations, people's health is deteriorating every year, the number of patients with incurable diseases is growing inexorably. A person is largely influenced by environmental factors, biology studies this effect. Previously, people could die from cold, heat, hunger, thirst, in our time, humanity "digs its own grave." Earthquakes, tsunamis, floods, fires - all these natural phenomena take the lives of people, but even more people harm themselves. Our planet is like a ship heading for the rocks at high speed. We need to stop before it's too late, correct the situation, try to pollute the atmosphere less, get closer to nature.

Human impact on the environment

People complain about a drastic change in the environment, deterioration in health and general well-being, but at the same time they rarely realize that they themselves are to blame for this. Various types of environmental factors have changed over the centuries, there were periods of warming, cooling, the seas dried up, islands went under water. Of course, nature forced a person to adapt to the conditions, but she did not set rigid limits for people, did not act spontaneously and quickly. With the development of technology and science, everything has changed significantly. In one century, humanity has polluted the planet so much that scientists clutch their heads, not knowing how to change the situation.

We still remember mammoths and dinosaurs that became extinct during the ice age due to a sharp cold snap, and how many species of animals and plants have been wiped off the face of the earth over the past 100 years, how many more are on the verge of extinction? Large cities are crammed with plants and factories, pesticides are actively used in the villages, polluting the soil and water, everywhere there is saturation with transport. There are practically no places left on the planet that can boast of clean air, unpolluted land and water. Deforestation, endless fires, which can be caused not only by abnormal heat, but also by human activity, pollution of water bodies with oil products, harmful emissions in the atmosphere - all this negatively affects the development and reproduction of living organisms and does not improve people's health in any way.

“Either a person will reduce the amount of smoke in the air, or the smoke will reduce the number of people on Earth,” these are the words of L. Baton. Indeed, the picture of the future looks depressing. The best minds of mankind are struggling with how to reduce the scale of pollution, programs are being created, various cleaning filters are being invented, alternatives are being sought for those objects that today pollute nature the most.

Ways to solve environmental problems

Ecology and man today cannot reach a consensus. All governmental and should work together to solve existing problems. Everything must be done to transfer production to non-waste, closed cycles, on the way to this, energy and material-saving technologies can be used. Nature management should be rational and take into account the peculiarities of the regions. The increase in species of creatures that are on the verge of extinction requires the immediate expansion of protected areas. Well, and most importantly, the population should be educated, in addition to general environmental education.

LECTURE №4

TOPIC: ENVIRONMENTAL FACTORS

PLAN:

1. The concept of environmental factors and their classification.

2. Abiotic factors.

2.1. Ecological role of the main abiotic factors.

2.2. topographic factors.

2.3. space factors.

3. Biotic factors.

4. Anthropogenic factors.

1. The concept of environmental factors and their classification

Ecological factor - any element of the environment that can directly or indirectly affect a living organism, at least at one of the stages of its individual development.

Environmental factors are diverse, and each factor is a combination of the corresponding environmental conditions and its resource (reserve in the environment).

Environmental environmental factors are usually divided into two groups: factors of inert (non-living) nature - abiotic or abiogenic; factors of living nature - biotic or biogenic.

Along with the above classification of environmental factors, there are many others (less common) that use other distinguishing features. So, there are factors that depend and do not depend on the number and density of organisms. For example, the effect of macroclimatic factors is not affected by the number of animals or plants, while epidemics (mass diseases) caused by pathogenic microorganisms depend on their number in a given area. Classifications are known in which all anthropogenic factors are classified as biotic.

2. Abiotic factors

In the abiotic part of the habitat (in inanimate nature), all factors, first of all, can be divided into physical and chemical. However, to understand the essence of the phenomena and processes under consideration, it is convenient to represent abiotic factors as a set of climatic, topographic, space factors, as well as characteristics of the composition of the environment (aquatic, terrestrial or soil), etc.

Physical factors- these are those whose source is a physical state or phenomenon (mechanical, wave, etc.). For example, the temperature, if it is high - there will be a burn, if it is very low - frostbite. Other factors can also affect the effect of temperature: in water - current, on land - wind and humidity, etc.

Chemical Factors are those that come from the chemical composition of the environment. For example, the salinity of water, if it is high, life in a reservoir may be completely absent (Dead Sea), but at the same time, most marine organisms cannot live in fresh water. The life of animals on land and in water depends on the adequacy of the oxygen content, etc.

Edaphic factors(soil) is a set of chemical, physical and mechanical properties of soils and rocks that affect both the organisms living in them, that is, for which they are a habitat, and the root system of plants. The effects of chemical components (biogenic elements), temperature, humidity, and soil structure on the growth and development of plants are well known.

2.1. Ecological role of the main abiotic factors

solar radiation. Solar radiation is the main source of energy for the ecosystem. The energy of the Sun propagates in space in the form of electromagnetic waves. For organisms, the wavelength of perceived radiation, its intensity and duration of exposure are important.

About 99% of the total energy of solar radiation is rays with a wavelength of k = nm, including 48% is in the visible part of the spectrum (k = nm), 45% is in the near infrared (k = nm) and about 7% is in the ultraviolet. (to< 400 нм).

Rays with X = nm are of primary importance for photosynthesis. Long-wave (far infrared) solar radiation (k > 4000 nm) has little effect on the vital processes of organisms. Ultraviolet rays with k\u003e 320 nm in small doses are necessary for animals and humans, since under their action vitamin D is formed in the body. Radiation with k< 290 нм губи­тельно для живого, но до поверхности Земли оно не доходит, поглощаясь озоновым слоем атмосферы.

As it passes through atmospheric air, sunlight is reflected, scattered, and absorbed. Pure snow reflects approximately 80-95% of sunlight, polluted - 40-50%, chernozem soil - up to 5%, dry light soil - 35-45%, coniferous forests - 10-15%. However, the illumination of the earth's surface varies significantly depending on the time of year and day, geographic latitude, slope exposure, atmospheric conditions, etc.

Due to the rotation of the Earth, daylight and darkness alternate periodically. Flowering, seed germination in plants, migration, hibernation, animal reproduction and much more in nature are associated with the duration of the photoperiod (day length). The need for light for plants determines their rapid growth in height, the layered structure of the forest. Aquatic plants spread mainly in the surface layers of water bodies.

Direct or diffuse solar radiation is not required only by a small group of living beings - some types of fungi, deep-sea fish, soil microorganisms, etc.

The most important physiological and biochemical processes carried out in a living organism, due to the presence of light, include the following:

1. Photosynthesis (1-2% of the solar energy falling on the Earth is used for photosynthesis);

2. Transpiration (about 75% - for transpiration, which ensures the cooling of plants and the movement of aqueous solutions of mineral substances through them);

3. Photoperiodism (ensures the synchronism of life processes in living organisms to periodically changing environmental conditions);

4. Movement (phototropism in plants and phototaxis in animals and microorganisms);

5. Vision (one of the main analyzing functions of animals);

6. Other processes (synthesis of vitamin D in humans in the light, pigmentation, etc.).

The basis of the biocenoses of central Russia, like most terrestrial ecosystems, are producers. Their use of sunlight is limited by a number of natural factors and, first of all, by temperature conditions. In this regard, special adaptive reactions have been developed in the form of layering, mosaic leaves, phenological differences, etc. According to the requirements for lighting conditions, plants are divided into light or light-loving (sunflower, plantain, tomato, acacia, melon), shady or non-light-loving (forest herbs, mosses) and shade-tolerant (sorrel, heather, rhubarb, raspberries, blackberries).

Plants form the conditions for the existence of other types of living beings. That is why their reaction to lighting conditions is so important. Environmental pollution leads to a change in illumination: a decrease in the level of solar insolation, a decrease in the amount of photosynthetically active radiation (PAR - part of solar radiation with a wavelength of 380 to 710 nm), a change in the spectral composition of light. As a result, this destroys cenoses based on the arrival of solar radiation in certain parameters.

Temperature. For the natural ecosystems of our zone, the temperature factor, along with light supply, is decisive for all life processes. The activity of populations depends on the time of year and time of day, since each of these periods has its own temperature conditions.

Temperature is mainly related to solar radiation, but in some cases is determined by the energy of geothermal sources.

At temperatures below the freezing point, a living cell is physically damaged by the resulting ice crystals and dies, and at high temperatures, denaturation of enzymes occurs. The vast majority of plants and animals cannot withstand negative body temperatures. The upper temperature limit of life rarely rises above 40–45 °C.

In the range between the extreme limits, the rate of enzymatic reactions (hence, the metabolic rate) doubles with every 10°C increase in temperature.

A significant part of organisms is able to control (maintain) body temperature, and primarily the most vital organs. Such organisms are called homeothermic- warm-blooded (from the Greek homoios - similar, therme - warmth), in contrast to poikilothermic- cold-blooded (from the Greek poikilos - various, changeable, diverse), having a variable temperature, depending on the ambient temperature.

Poikilothermic organisms in the cold season of the year or day reduce the level of vital processes up to anabiosis. This primarily concerns plants, microorganisms, fungi and poikilothermic (cold-blooded) animals. Only homoiothermic (warm-blooded) species remain active. Heterothermic organisms, being in an inactive state, have a body temperature not much higher than the temperature of the external environment; in the active state - quite high (bears, hedgehogs, bats, ground squirrels).

Thermoregulation of homoiothermic animals is provided by a special type of metabolism that goes with the release of heat in the body of animals, the presence of heat-insulating covers, size, physiology, etc.

As for plants, they have developed a number of properties in the process of evolution:

cold resistance– the ability to endure low positive temperatures for a long time (from 0°С to +5°С);

winter hardiness– the ability of perennial species to endure a complex of unfavorable winter conditions;

frost resistance- the ability to endure negative temperatures for a long time;

anabiosis- the ability to endure a period of prolonged lack of environmental factors in a state of a sharp decrease in metabolism;

heat resistance– the ability to endure high (over +38°…+40°С) temperatures without significant metabolic disorders;

ephemerality– reduction of ontogenesis (up to 2-6 months) in species growing under conditions of a short period of favorable temperature conditions.

In the aquatic environment, due to the high heat capacity of water, temperature changes are less abrupt and conditions are more stable than on land. It is known that in regions where the temperature varies greatly during the day, as well as in different seasons, the diversity of species is less than in regions with more constant daily and annual temperatures.

Temperature, like light intensity, depends on latitude, season, time of day, and slope exposure. Extreme temperatures (low and high) are exacerbated by strong winds.

The change in temperature as you rise in the air or dive into the aquatic environment is called temperature stratification. Usually, in both cases, a continuous decrease in temperature with a certain gradient is observed. However, there are other options as well. So, in summer, surface waters heat up more than deep ones. Due to a significant decrease in the density of water as it is heated, its circulation begins in the surface heated layer without mixing with the denser, colder water of the underlying layers. As a result, an intermediate zone with a sharp temperature gradient is formed between the warm and cold layers. All this affects the placement of living organisms in the water, as well as the transfer and dispersion of incoming impurities.

A similar phenomenon also occurs in the atmosphere, when the cooled layers of air move down and are located under the warm layers, i.e., there is a temperature inversion that contributes to the accumulation of pollutants in the surface air layer.

Inversions are facilitated by some features of the relief, such as pits and valleys. It occurs when there are substances at a certain height, such as aerosols, heated directly by direct solar radiation, which causes more intense heating of the upper air layers.

In the soil environment, daily and seasonal stability (fluctuations) of temperature depend on depth. A significant temperature gradient (as well as humidity) allows the inhabitants of the soil to provide themselves with a favorable environment with minor movements. The presence and abundance of living organisms can affect temperature. For example, under the canopy of a forest or under the leaves of an individual plant, there is a different temperature.

Precipitation, humidity. Water is essential for life on Earth, ecologically it is unique. Under almost the same geographical conditions on Earth, there are both a hot desert and a tropical forest. The difference is only in the annual amount of precipitation: in the first case, 0.2–200 mm, and in the second, 900–2000 mm.

Precipitation, closely related to air humidity, is the result of condensation and crystallization of water vapor in the high layers of the atmosphere. In the surface layer of air, dews and fogs form, and at low temperatures moisture crystallization is observed - frost falls.

One of the main physiological functions of any organism is to maintain an adequate level of water in the body. In the process of evolution, organisms have developed various adaptations for obtaining and economical use of water, as well as for experiencing a dry period. Some desert animals get water from food, others through the oxidation of timely stored fats (for example, a camel, capable of obtaining 107 g of metabolic water from 100 g of fat by biological oxidation); at the same time, they have a minimum water permeability of the outer integument of the body, and dryness is characterized by falling into a state of rest with a minimum metabolic rate.

Land plants obtain water mainly from the soil. Low rainfall, rapid drainage, intense evaporation, or a combination of these factors lead to desiccation, and excess moisture leads to waterlogging and waterlogging of soils.

The moisture balance depends on the difference between the amount of precipitation and the amount of water evaporated from the surfaces of plants and soil, as well as by transpiration]. In turn, evaporation processes directly depend on the relative humidity of the atmospheric air. At a humidity close to 100%, evaporation practically stops, and if the temperature further decreases, then the reverse process begins - condensation (fog forms, dew, frost fall).

In addition to the above, air humidity as an environmental factor at its extreme values ​​(high and low humidity) enhances the effect (aggravates) the effect of temperature on the body.

Saturation of air with water vapor rarely reaches its maximum value. Humidity deficit - the difference between the maximum possible and actually existing saturation at a given temperature. This is one of the most important environmental parameters, since it characterizes two quantities at once: temperature and humidity. The higher the moisture deficit, the drier and warmer, and vice versa.

Precipitation regime is the most important factor determining the migration of pollutants in the natural environment and their leaching from the atmosphere.

In relation to the water regime, the following ecological groups of living beings are distinguished:

hydrobionts- inhabitants of ecosystems, the entire life cycle of which takes place in water;

hygrophytes– plants of wet habitats (marsh marigold, European swimsuit, broad-leaved cattail);

hygrophiles- animals living in very damp parts of ecosystems (mollusks, amphibians, mosquitoes, wood lice);

mesophytes– plants of moderately humid habitats;

xerophytes– plants of dry habitats (feather grass, wormwood, astragalus);

xerophiles- inhabitants of arid territories that cannot tolerate high humidity (some species of reptiles, insects, desert rodents and mammals);

succulents- plants of the most arid habitats, capable of accumulating significant moisture reserves inside the stem or leaves (cacti, aloe, agave);

sclerophytes– plants of very arid territories, capable of withstanding severe dehydration (common camel's thorn, saxaul, saksagyz);

ephemera and ephemeroids- annual and perennial herbaceous species with a shortened cycle, coinciding with a period of sufficient moisture.

Water consumption of plants can be characterized by the following indicators:

drought tolerance– ability to tolerate reduced atmospheric and (or) soil drought;

moisture resistance- the ability to tolerate waterlogging;

transpiration rate- the amount of water spent on the formation of a unit of dry mass (for white cabbage 500-550, for pumpkin-800);

coefficient of total water consumption- the amount of water consumed by the plant and soil to create a unit of biomass (for meadow grasses - 350–400 m3 of water per ton of biomass).

Violation of the water regime, pollution of surface waters is dangerous, and in some cases fatal for cenoses. Changes in the water cycle in the biosphere can lead to unpredictable consequences for all living organisms.

The mobility of the environment. The causes of the movement of air masses (wind) are primarily uneven heating of the earth's surface, causing pressure drops, as well as the rotation of the Earth. The wind is directed towards warmer air.

Wind is the most important factor in the spread of moisture, seeds, spores, chemical impurities, etc. over long distances. It contributes both to a decrease in the near-Earth concentration of dust and gaseous substances near the place of their entry into the atmosphere, and to an increase in background concentrations in the air due to emissions from distant sources, including transboundary transport.

The wind accelerates transpiration (evaporation of moisture by the ground parts of plants), which especially worsens the conditions of existence at low humidity. In addition, it indirectly affects all living organisms on land, participating in the processes of weathering and erosion.

Mobility in space and mixing of water masses contribute to maintaining the relative homogeneity (homogeneity) of the physical and chemical characteristics of water bodies. The average speed of surface currents lies in the range of 0.1-0.2 m/s, reaching 1 m/s in some places, and 3 m/s near the Gulf Stream.

Pressure. Normal atmospheric pressure is considered to be the absolute pressure at the level of the World Ocean surface of 101.3 kPa, corresponding to 760 mm Hg. Art. or 1 atm. Within the globe there are constant areas of high and low atmospheric pressure, and at the same points seasonal and daily fluctuations are observed. As the altitude increases relative to the ocean level, the pressure decreases, the partial pressure of oxygen decreases, and transpiration in plants increases.

Periodically, areas of low pressure are formed in the atmosphere with powerful air currents moving in a spiral towards the center, which are called cyclones. They are characterized by high rainfall and unstable weather. Opposite natural phenomena are called anticyclones. They are characterized by stable weather, light winds and, in some cases, temperature inversion. During anticyclones, sometimes unfavorable meteorological conditions arise, which contribute to the accumulation of pollutants in the surface layer of the atmosphere.

There are also sea and continental atmospheric pressure.

The pressure in the aquatic environment increases as you dive. Due to the significantly (800 times) greater density of water than air, for every 10 m of depth in a freshwater reservoir, the pressure increases by 0.1 MPa (1 atm). The absolute pressure at the bottom of the Mariana Trench exceeds 110 MPa (1100 atm).

ionizingradiation. Ionizing radiation is the radiation that forms pairs of ions when passing through a substance; background - radiation created by natural sources. It has two main sources: cosmic radiation and radioactive isotopes, and elements in the minerals of the earth's crust that arose sometime in the process of formation of the Earth's substance. Due to the long half-life, the nuclei of many primordial radioactive elements have survived in the bowels of the Earth to this day. The most important of them are potassium-40, thorium-232, uranium-235 and uranium-238. Under the influence of cosmic radiation in the atmosphere, more and more new nuclei of radioactive atoms are constantly formed, the main of which are carbon-14 and tritium.

The radiation background of the landscape is one of the indispensable components of its climate. All known sources of ionizing radiation take part in the formation of the background, but the contribution of each of them to the total radiation dose depends on a specific geographical point. Man, as an inhabitant of the natural environment, receives the bulk of exposure from natural sources of radiation, and it is impossible to avoid this. All living things on Earth are exposed to radiation from the Cosmos. Mountain landscapes, due to their significant height above sea level, are characterized by an increased contribution of cosmic radiation. Glaciers, acting as an absorbing screen, retain in their mass the radiation of the underlying bedrock. Differences in the content of radioactive aerosols over the sea and land were found. The total radioactivity of sea air is hundreds and thousands of times less than that of continental air.

There are areas on the Earth where the exposure dose rate is ten times higher than the average values, for example, areas of uranium and thorium deposits. Such places are called uranium and thorium provinces. A stable and relatively higher level of radiation is observed in the outcrops of granite rocks.

The biological processes accompanying the formation of soils significantly affect the accumulation of radioactive substances in the latter. With a low content of humic substances, their activity is weak, while chernozems have always been distinguished by a higher specific activity. It is especially high in chernozem and meadow soils located close to granite massifs. According to the degree of increase in the specific activity of the soil, it can be tentatively arranged in the following order: peat; chernozem; soils of the steppe zone and forest-steppe; soils developing on granites.

The effect of periodic fluctuations in the intensity of cosmic radiation near the earth's surface on the radiation dose of living organisms is practically insignificant.

In many regions of the globe, the exposure dose rate due to the radiation of uranium and thorium reaches the level of exposure that existed on Earth in a geologically observable time, at which the natural evolution of living organisms took place. In general, ionizing radiation has a more detrimental effect on highly developed and complex organisms, and a person is particularly sensitive. Some substances are evenly distributed throughout the body, such as carbon-14 or tritium, while others accumulate in certain organs. So, radium-224, -226, lead-210, polonium-210 accumulate in bone tissues. The inert gas radon-220 has a strong effect on the lungs, sometimes released not only from deposits in the lithosphere, but also from minerals mined by man and used as building materials. Radioactive substances can accumulate in water, soil, precipitation or air if the rate of their entry exceeds the rate of radioactive decay. In living organisms, the accumulation of radioactive substances occurs when they are ingested with food.

2.2. Topographic factors

The influence of abiotic factors largely depends on the topographic characteristics of the area, which can greatly change both the climate and the features of soil development. The main topographic factor is the height above sea level. With altitude, average temperatures decrease, the daily temperature difference increases, the amount of precipitation, wind speed and radiation intensity increase, and pressure decreases. As a result, vertical zonality of vegetation distribution is observed in mountainous areas, corresponding to the sequence of changes in latitudinal zones from the equator to the poles.

Mountain ranges can serve as climatic barriers. Rising above the mountains, the air cools, which often causes precipitation and thus reduces its absolute moisture content. Getting then to the other side of the mountain range, the dried air helps to reduce the intensity of rain (snowfall), which creates a "rain shadow".

Mountains can play the role of an isolating factor in the processes of speciation, as they serve as a barrier to the migration of organisms.

An important topographical factor is exposition(illuminance) of the slope. In the Northern Hemisphere it is warmer on the southern slopes, while in the Southern Hemisphere it is warmer on the northern slopes.

Another important factor is slope steepness affecting drainage. Water flows down the slopes, washing away the soil, reducing its layer. In addition, under the influence of gravity, the soil slowly slides down, which leads to its accumulation at the base of the slopes. The presence of vegetation inhibits these processes, however, at slopes of more than 35°, soil and vegetation are usually absent and screes of loose material are created.

2.3. Space factors

Our planet is not isolated from the processes taking place in outer space. The Earth periodically collides with asteroids, approaches comets, cosmic dust, meteorite substances fall on it, various types of radiation from the Sun and stars. Cyclically (one of the cycles has a period of 11.4 years), solar activity changes.

Science has accumulated many facts confirming the influence of the Cosmos on the life of the Earth.

3. Biotic factors

All living things that surround an organism in a habitat constitute a biotic environment or biota. Biotic factors- is a set of influences of the vital activity of some organisms on others.

The relationships between animals, plants, and microorganisms are extremely diverse. First of all, distinguish homotypic reactions, i.e., the interaction of individuals of the same species, and heterotypic- relations between representatives of different species.

Representatives of each species are able to exist in such a biotic environment, where connections with other organisms provide them with normal living conditions. The main form of manifestation of these relationships is the nutritional relationships of organisms of various categories, which form the basis of food (trophic) chains, networks and the trophic structure of the biota.

In addition to food relations, spatial relationships also arise between plant and animal organisms. As a result of the action of many factors, diverse species are not united in an arbitrary combination, but only under the condition of adaptation to cohabitation.

Biotic factors manifest themselves in biotic relationships.

The following forms of biotic relationships are distinguished.

Symbiosis(cohabitation). This is a form of relationship in which both partners or one of them benefit from the other.

Cooperation. Cooperation is a long-term, inseparable mutually beneficial cohabitation of two or more species of organisms. For example, the relationship of a hermit crab and sea anemone.

Neutralism. The mutual independence of different species living in the same territory is called neutralism. For example, squirrels and moose do not compete with each other, but drought in the forest affects both, although to different degrees.

Recently, more and more attention has been paid to anthropogenic factors- a set of human impacts on the environment, due to its urban-technogenic activities.

4. Anthropogenic factors

The current stage of human civilization reflects such a level of knowledge and capabilities of mankind that its impact on the environment, including biological systems, acquires the character of a global planetary force, which we single out into a special category of factors - anthropogenic, i.e. generated by human activity. These include:

Changes in the Earth's climate as a result of natural geological processes, enhanced by the greenhouse effect caused by changes in the optical properties of the atmosphere by emissions of mainly CO, CO2, and other gases into it;

Debris in near-Earth space (NES), the consequences of which have not yet been fully understood, except for the real danger to spacecraft, including communication satellites, locations of the earth's surface, and others that are widely used in modern systems of interaction between people, states and governments;

Reducing the power of the stratospheric ozone screen with the formation of the so-called “ozone holes”, which reduce the protective capabilities of the atmosphere against the ingress of hard short-wave ultraviolet radiation dangerous for living organisms to the Earth's surface;

Chemical pollution of the atmosphere with substances that contribute to the formation of acid precipitation, photochemical smog and other compounds that are dangerous for biospheric objects, including humans and artificial objects created by them;

Pollution of the ocean and changes in the properties of ocean waters due to oil products, their saturation with carbon dioxide of the atmosphere, which in turn is polluted by vehicles and thermal power plants, burial of highly toxic chemical and radioactive substances in ocean waters, pollution from river runoff, disturbances in the water balance of coastal areas due to regulation rivers;

Depletion and pollution of all kinds of springs and land waters;

Radioactive contamination of individual sites and regions with a tendency to spread over the Earth's surface;

Soil pollution due to polluted precipitation (eg acid rain), suboptimal use of pesticides and mineral fertilizers;

Changes in the geochemistry of landscapes in connection with thermal power engineering, redistribution of elements between the bowels and the surface of the Earth as a result of mining and smelting redistribution (for example, the concentration of heavy metals) or the extraction of anomalous, highly mineralized groundwater and brines to the surface;

Continued accumulation on the surface of the Earth of household garbage and all kinds of solid and liquid waste;

Violation of the global and regional ecological balance, the ratio of ecological components in the coastal part of the land and the sea;

The continuing, and in some places - increasing desertification of the planet, the deepening of the process of desertification;

Reducing the area of ​​tropical forests and northern taiga, these main sources of maintaining the oxygen balance of the planet;

Release as a result of all the above processes of ecological niches and filling them with other species;

Absolute overpopulation of the Earth and relative demographic overpopulation of certain regions, extreme differentiation of poverty and wealth;

Deterioration of the living environment in overcrowded cities and metropolitan areas;

The exhaustion of many mineral deposits and the gradual transition from rich to ever poorer ores;

Strengthening social instability as a result of the increasing differentiation of the rich and poor part of the population of many countries, the increase in the level of armament of their population, criminalization, natural environmental disasters.

Decrease in the immune status and health status of the population of many countries of the world, including Russia, repeated repetition of epidemics, which are becoming more massive and severe in their consequences.

This is by no means a complete circle of problems, in solving each of which a specialist can find his place and work.

The most large-scale and significant is the chemical pollution of the environment by substances of a chemical nature unusual for it.

The physical factor as a pollutant of human activity is an unacceptable level of thermal pollution (especially radioactive).

Biological pollution of the environment is a variety of microorganisms, the most dangerous among which are various diseases.

Control questions and tasks

1. What are environmental factors?

2. What environmental factors are classified as abiotic, which are biotic?

3. What is the name of the totality of the influences of the life activity of some organisms on the life activity of others?

4. What are the resources of living beings, how are they classified and what is their ecological significance?

5. What factors should be taken into account in the first place when creating ecosystem management projects. Why?