Anthropogenic factors (definition and examples). Their influence on biotic and abiotic factors of the natural environment. Environmental factors

Anthropogenic environmental factors

Anthropogenic factors are the result of human impact on the environment in the course of economic and other activities. Anthropogenic factors can be divided into 3 groups:

) having a direct impact on the environment as a result of sudden, intense and short-term activities, for example. laying of a road or railroad through the taiga, seasonal commercial hunting in a certain area, etc .;

) indirect impact - through economic activities of a long-term nature and low intensity, for example. pollution environment gaseous and liquid emissions from a plant built near a paved railway without the necessary treatment facilities leading to gradual drying out of trees and slow poisoning by heavy metals of animals inhabiting the surrounding taiga;

) the complex impact of the above factors, leading to a slow but significant change in the environment (population growth, an increase in the number of domestic animals and animals accompanying human settlements - crows, rats, mice, etc., transformation of land, the appearance of impurities in water, etc.) etc.).

Anthropogenic impact on the geographic shell of the earth

At the beginning of the twentieth century, a new era began in the interaction of nature and society. The impact of society on the geographic environment, anthropogenic impact, has increased dramatically. This led to the transformation of natural landscapes into anthropogenic ones, as well as to the emergence of global environmental problems, i.e. problems that know no boundaries. The Chernobyl tragedy has endangered all of Eastern and Northern Europe. Waste emissions affect global warming, ozone holes threaten life, and animals migrate and mutate.

The degree of influence of society on the geographic envelope primarily depends on the degree of industrialization of the society. Today, about 60% of the land area is occupied by anthropogenic landscapes. Such landscapes include cities, villages, communication lines, roads, industrial and agricultural centers. The eight most developed countries consume more than half natural resources Earth and emit 2/5 of the pollution into the atmosphere.

Air pollution

Human activity leads to the fact that pollution enters the atmosphere mainly in two forms - in the form of aerosols (suspended particles) and gaseous substances.

The main sources of aerosols are the building materials industry, cement production, open pit mining of coal and ores, ferrous metallurgy and other industries. The total amount of aerosols of anthropogenic origin entering the atmosphere during the year is 60 million tons. This is several times less than the volume of natural pollution (dust storms, volcanoes).

A much greater danger is posed by gaseous substances, which account for 80-90% of all anthropogenic emissions. These are compounds of carbon, sulfur and nitrogen. Compounds of carbon, especially carbon dioxide, is not poisonous in itself, but its accumulation is associated with the danger of such a global process as the "greenhouse effect". In addition, thrown away carbon monoxide, mainly by internal combustion engines. anthropogenic pollution atmosphere hydrosphere

Nitrogen compounds are represented by poisonous gases - nitrogen oxide and peroxide. They are also formed during the operation of internal combustion engines, during the operation of thermal power plants, during the incineration of solid waste.

The greatest danger is the pollution of the atmosphere with sulfur compounds, and above all with sulfur dioxide. Sulfur compounds are emitted into the atmosphere during the combustion of coal fuel, oil and natural gas, as well as in the smelting of non-ferrous metals and the production of sulfuric acid. Anthropogenic sulfur pollution is twice as high as natural. Sulfur dioxide reaches the highest concentrations in the northern hemisphere, especially over the territory of the United States, foreign Europe, the European part of Russia, and Ukraine. It is lower in the southern hemisphere.

The release of sulfur and nitrogen compounds into the atmosphere is directly related to the fallout of acid rain. The mechanism of their formation is very simple. Sulfur dioxide and nitrogen oxides in the air combine with water vapor. Then, together with rains and fogs, they fall to the ground in the form of dilute sulfuric and nitric acids. Such precipitation sharply violates the norms of soil acidity, worsen the water exchange of plants, and contribute to the drying out of forests, especially conifers. Once in rivers and lakes, they oppress their flora and fauna, often leading to the complete destruction of biological life - from fish to microorganisms. Acid rains cause great harm and various designs(bridges, monuments, etc.).

The main regions of the distribution of acid precipitation in the world are the USA, foreign Europe, Russia and the CIS countries. But in Lately they are noted in the industrial regions of Japan, China, Brazil.

The distance between the regions of formation and regions of acid precipitation can even reach thousands of kilometers. For example, the main culprits of acid precipitation in Scandinavia are the industrial regions of Great Britain, Belgium and the Federal Republic of Germany.

Anthropogenic pollution of the hydrosphere

Scientists distinguish between three types of pollution of the hydrosphere: physical, chemical and biological.

Physical pollution is understood primarily as thermal pollution resulting from the discharge of heated water used for cooling at thermal power plants and nuclear power plants. The discharge of such waters leads to a violation of the natural water regime. For example, rivers where such waters are discharged do not freeze. In enclosed water bodies, this leads to a decrease in the oxygen content, which leads to the death of fish and the rapid development of unicellular algae ("bloom" of water). Physical contamination also includes radioactive contamination.

Biological pollution is created by microorganisms, often pathogens. V aquatic environment they enter with chemical waste, pulp and paper, Food Industry and livestock complexes. Such effluents can be sources of various diseases.

A special issue in this topic is the pollution of the World Ocean. It happens in three ways. The first of them is river runoff, together with which millions of tons fall into the ocean. various metals, phosphorus compounds, organic pollution. At the same time, almost all suspended and most dissolved substances are deposited in river mouths and adjacent shelves.

The second way of pollution is associated with atmospheric precipitation, with which most of the lead, half of the mercury and pesticides enter the World Ocean.

Finally, the third path is directly related to human economic activity in the waters of the World Ocean. The most common type of pollution is oil pollution during the transportation and production of oil.

The results of anthropogenic impact

the warming of the climate of our planet began. As a result of the "greenhouse effect", the temperature of the Earth's surface over the past 100 years has increased by 0.5-0.6єС. The sources of CO2 responsible for most of the greenhouse effect are the combustion of coal, oil and gas and the disruption of the activity of the communities of soil microorganisms in the tundra, which consume up to 40% of the CO2 emitted into the atmosphere;

Due to the anthropogenic load on the biosphere, new environmental problems have arisen:

the process of the rise in the level of the World Ocean has considerably accelerated. Over the past 100 years, the sea level has risen by 10-12 cm and now this process has accelerated tenfold. This threatens to flood vast areas below sea level (Holland, Venice region, St. Petersburg, Bangladesh, etc.);

there was a depletion of the ozone layer of the Earth's atmosphere (ozonosphere), which traps ultraviolet radiation, which is destructive for all living things. It is believed that the main contribution to the destruction of the ozonosphere is made by chlorine-fluorine-carbons (i.e. freons). They are used as refrigerants and in aerosol cans.

Pollution of the World Ocean, the burial of poisonous and radioactive substances in it, the saturation of its waters with carbon dioxide from the atmosphere, pollution with oil products, heavy metals, complex organic compounds, the rupture of the normal ecological connection between the ocean and land waters due to the construction of dams and other hydraulic structures.

Depletion and pollution of surface water of land and groundwater, imbalance between surface and groundwater.

Radioactive contamination of local areas and some regions, in connection with the Chernobyl accident, the operation of atomic devices and atomic tests.

Continuous accumulation of toxic and radioactive substances, household waste and industrial waste (especially non-degradable plastics) on the land surface, the emergence of secondary chemical reactions in them with the formation of toxic substances.

Desertification of the planet, expansion of existing deserts and deepening of the desertification process itself.

Reduction of areas of tropical and northern forests, leading to a decrease in the amount of oxygen and the disappearance of species of animals and plants.

Anthropogenic factors - a set of various human influences on inanimate and living nature. Only by their very physical existence, people have a noticeable effect on the environment: in the process of breathing, they annually emit 1 · 10 12 kg of CO 2 into the atmosphere, and with food they consume more than 5-10 15 kcal.

As a result of human impact, the climate, surface relief, chemical composition atmosphere, species and natural ecosystems are disappearing, etc. The most important anthropogenic factor for nature is urbanization.

Anthropogenic activity significantly affects climatic factors, changing their regimes. For example, massive emissions of solid and liquid particles into the atmosphere from industrial enterprises can dramatically change the mode of dispersion of solar radiation in the atmosphere and reduce the arrival of heat to the Earth's surface. Destruction of forests and other vegetation, creation of large artificial reservoirs on former territories Lands increase energy reflection, while dust pollution, such as snow and ice, on the contrary, increases absorption, which leads to their intense melting.

To a much greater extent, the production activity of people affects the biosphere. As a result of this activity, the relief, the composition of the earth's crust and atmosphere, the climate change, fresh water is redistributed, natural ecosystems disappear and artificial agro- and technoecosystems are created, cultivated plants are cultivated, animals are domesticated, etc.

Human impact can be direct or indirect. For example, deforestation and uprooting of a forest have not only a direct effect, but also an indirect one - the conditions for the existence of birds and animals change. It is estimated that since 1600, 162 species of birds, over 100 species of mammals and many other species of plants and animals have been destroyed by man. But, on the other hand, it creates new varieties of plants and breeds of animals, increases their productivity and productivity. Artificial relocation of plants and animals also affects the life of ecosystems. Thus, the rabbits brought to Australia multiplied so much that they caused enormous damage to agriculture.

The most obvious manifestation of anthropogenic influence on the biosphere is environmental pollution. The importance of anthropogenic factors is constantly growing, as man more and more subjugates nature.

Human activity is a combination of human transformation for his own purposes of natural environmental factors and the creation of new ones that did not previously exist in nature. Smelting metals from ores and manufacturing equipment are impossible without creating high temperatures, pressures, and powerful electromagnetic fields. Obtaining and maintaining high yields of agricultural crops requires the production of fertilizers and chemical plant protection from pests and pathogens. Modern healthcare cannot be imagined without chemotherapy and physiotherapy.

Achievements of scientific and technological progress began to be used for political and economic purposes, which was manifested in the extreme way in the creation of special environmental factors affecting a person and his property: from firearms to means of mass physical, chemical and biological impact. In this case, they speak of a combination of anthropotropic (directed at the human body) and anthropocidal factors that cause environmental pollution.

On the other hand, in addition to such targeted factors, in the process of exploitation and processing of natural resources, secondary chemical compounds and zones of high levels of physical factors are inevitably formed. Under the conditions of accidents and catastrophes, these processes can be of a spasmodic nature with severe environmental and material consequences. Hence, it was required to create methods and means of protecting a person from dangerous and harmful factors, which has now been implemented in the above-mentioned system - life safety.

Environmental plasticity. Despite the wide variety of environmental factors, a number of general patterns can be identified in the nature of their impact and in the responses of living organisms.

The effect of the influence of factors depends not only on the nature of their action (quality), but also on the quantitative value perceived by organisms - high or low temperature, degree of illumination, humidity, amount of food, etc. In the process of evolution, the ability of organisms has developed to adapt to environmental factors within certain quantitative limits. A decrease or an increase in the value of a factor outside these limits inhibits vital activity, and when a certain minimum or maximum level is reached, the death of organisms occurs.

The zones of action of the ecological factor and the theoretical dependence of the vital activity of an organism, population or community depend on the quantitative value of the factor. The quantitative range of any environmental factor most favorable for life is called the ecological optimum (lat. ortimus - best). The values ​​of the factor lying in the zone of oppression are called the ecological pessimum (the worst).

The minimum and maximum values ​​of the factor at which death occurs are called respectively ecological minimum and ecological maximum

Any types of organisms, populations or communities are adapted, for example, to exist in a certain temperature range.

The property of organisms to adapt to existence in a particular range of environmental factors is called environmental plasticity.

The wider the range of the ecological factor within which a given organism can live, the greater its ecological plasticity.

According to the degree of plasticity, two types of organisms are distinguished: stenobiont (stenoecs) and eurybiontic (euryecs).

Stenobiontic and eurybiontic organisms differ in the range of environmental factors in which they can live.

Stenobionts(column stenos- narrow, close), or narrowly adapted, species are able to exist only with small deviations

factor from the optimal value.

Eurybiontic(column eirys - wide) are called broadly adapted organisms that can withstand a large amplitude of fluctuations of the ecological factor.

Historically, adapting to environmental factors, animals, plants, microorganisms are distributed in various environments, forming the whole variety of ecosystems that form the biosphere of the Earth.

Limiting factors. The concept of limiting factors is based on two laws of ecology: the law of minimum and the law of tolerance.

Minimum law. In the middle of the last century, the German chemist J. Liebig (1840), while studying the effect of nutrients on plant growth, discovered that the harvest does not depend on those nutrients that are required in large quantities and are present in abundance (for example, CO 2 and H 2 0), and from those that, although the plant needs in smaller quantities, are practically absent in the soil or are inaccessible (for example, phosphorus, zinc, boron).

Liebig formulated this pattern as follows: "The growth of a plant depends on the element of nutrition that is present in a minimum amount." This finding later became known as Liebig's law of minimum and has been extended to many other environmental factors. Heat, light, water, oxygen, and other factors can limit, or limit, the development of organisms, if their value corresponds to the ecological minimum. For example, tropical angelfish dies if the water temperature drops below 16 ° C. And the development of algae in deep-sea ecosystems is limited by the depth of penetration sunlight: there are no algae in the bottom layers.

Liebig's law of minimum general view can be formulated as follows: the growth and development of organisms depend, first of all, on those factors of the natural environment, the values ​​of which are approaching the ecological minimum.

Research has shown that the law of minimum has two limitations that should be taken into account in practical application.

The first limitation is that Liebig's law is strictly applicable only under the conditions of a stationary state of the system. For example, in a certain body of water, the growth of algae is naturally limited by a lack of phosphates. Nitrogen compounds are present in excess in water. If sewage with a high content of mineral phosphorus is discharged into this reservoir, then the reservoir may "bloom". This process will progress until one of the elements is used up to the limiting minimum. Now it can be nitrogen if the phosphorus continues to flow. At the transitional moment (when there is still enough nitrogen, and there is already enough phosphorus), the effect of the minimum is not observed, that is, none of these elements affects the growth of algae.

The second limitation is related to the interaction of several factors. Sometimes the body is able to replace the deficient element with another chemically similar one. So, in places where there is a lot of strontium, in the shells of mollusks, it can replace calcium with a lack of the latter. Or, for example, the need for zinc in some plants decreases if they grow in the shade. Consequently, a low concentration of zinc will limit plant growth less in shade than in bright light. In these cases, the limiting effect of even an insufficient amount of one or another element may not manifest itself.

The law of tolerance(lat ... tolerantia- patience) was discovered by the English biologist W. Shelford (1913), who drew attention to the fact that not only those ecological factors, the values ​​of which are minimal, but also those that are characterized by an ecological maximum, can limit the development of living organisms. Too much heat, light, water, and even nutrients can be just as damaging as a lack of them. The range of the ecological factor between the minimum and maximum W. Shelford called limit of tolerance.

The tolerance limit describes the amplitude of fluctuations of factors, which ensures the most full-fledged existence of the population. Individuals may have slightly different tolerance ranges.

Later, the limits of tolerance were established for various environmental factors for many plants and animals. The laws of J. Liebig and W. Shelford helped to understand many phenomena and the distribution of organisms in nature. Organisms cannot be distributed everywhere because populations have a certain tolerance limit in relation to fluctuations in environmental factors.

V. Shelford's law of tolerance is formulated as follows: the growth and development of organisms depend primarily on those environmental factors, the values ​​of which are close to the ecological minimum or ecological maximum.

The following was found:

Organisms with a wide range of tolerance to all factors are widespread in nature and are often cosmopolitan, for example, many pathogenic bacteria;

Organisms can have a wide tolerance range for one factor and a narrow range for another. For example, people are more tolerant to lack of food than to lack of water, that is, the limit of tolerance for water is narrower than for food;

If the conditions for one of the environmental factors become suboptimal, then the tolerance limit for other factors may change. For example, when there is a lack of nitrogen in the soil, cereals require much more water;

The real limits of tolerance observed in nature are less than the potential capabilities of the organism to adapt to this factor. This is explained by the fact that in nature the limits of tolerance in relation to the physical conditions of the environment can be narrowed by biotic relations: competition, the absence of pollinators, predators, etc. Any person better realizes his potential in favorable conditions(gathering athletes for special training before important competitions, for example). The potential ecological plasticity of an organism, determined in laboratory conditions, is greater than the realized possibilities in natural conditions. Accordingly, a distinction is made between potential and realized ecological niches;

The limits of tolerance in breeding individuals and offspring are less than in adults, that is, females during the breeding season and their offspring are less hardy than adult organisms. Thus, the geographical distribution of game birds is more often determined by the influence of climate on eggs and chicks, and not on adult birds. Caring for offspring and respect for motherhood are dictated by the laws of nature. Unfortunately, sometimes social “achievements” are contrary to these laws;

Extreme (stress) values ​​of one of the factors lead to a decrease in the tolerance limit for other factors. If heated water is dumped into the river, then fish and other organisms spend almost all of their energy to overcome stress. They do not have enough energy to get food, protect themselves from predators, reproduce, which leads to a gradual extinction. Psychological stress can also cause many somatic (column soma - body) diseases not only in humans, but also in some animals (for example, in dogs). Under stressful values ​​of the factor, adaptation to it becomes more and more “expensive”.

Many organisms are capable of changing tolerance to certain factors if conditions change gradually. For example, you can get used to the high temperature of the water in the bath, if you get into warm water, and then gradually add hot water. This adaptation to slow factor changes is a useful protective property. But it can also be dangerous. Sudden, without warning signals, even a small change can be critical. A threshold effect sets in: the “last straw” can be fatal. For example, a thin twig can fracture an already congested camel's back.

If the value of at least one of the environmental factors approaches a minimum or maximum, the existence and prosperity of an organism, population or community becomes dependent precisely on this factor limiting its vital activity.

A limiting factor is any environmental factor that approaches or exceeds the extreme values ​​of the tolerance limits. Such factors deviating from the optimum are of paramount importance in the life of organisms and biological systems. It is they who control the conditions of existence.

The value of the concept of limiting factors is that it allows you to understand the complex relationships in ecosystems.

Fortunately, not all possible environmental factors govern the relationship between the environment, organisms, and humans. Various limiting factors are prioritized in a given period of time. These are the factors that an ecologist must focus on when studying and managing ecosystems. For example, the oxygen content in terrestrial habitats is high and it is so available that it almost never serves as a limiting factor (with the exception of high altitudes and anthropogenic systems). Oxygen is of little interest to terrestrial ecologists. And in water, it is often a factor limiting the development of living organisms ("killing" of fish, for example). Therefore, a hydrobiologist always measures the oxygen content in water, unlike a veterinarian or ornithologist, although oxygen is no less important for terrestrial organisms than for aquatic organisms.

Limiting factors also determine the geographic range of the species. So, the movement of organisms to the south is limited, as a rule, by a lack of heat. Biotic factors also often limit the distribution of certain organisms. For example, figs brought from the Mediterranean to California did not bear fruit there until they guessed to bring there a certain species of wasp - the only pollinator of this plant. Identifying the limiting factors is very important for many activities, especially Agriculture... By targeted action on limiting conditions, it is possible to quickly and effectively increase plant productivity and animal productivity. So, when cultivating wheat on acidic soils, no agronomic measures will give an effect if liming is not applied, which will reduce the limiting effect of acids. Or if you grow corn on soils with a very low phosphorus content, then even if enough water, nitrogen, potassium and other nutrients it stops growing. Phosphorus in this case is the limiting factor. And only phosphorus fertilizers can save the harvest. Plants can die from too a large number water or excess fertilizer, which in this case are also limiting factors.

Knowing the limiting factors provides the key to ecosystem management. However, in different periods of an organism's life and in different situations, various factors act as limiting factors. Therefore, only skillful regulation of living conditions can give effective management results.

Interaction and compensation of factors. In nature, environmental factors do not act independently of each other - they interact. Analysis of the influence of one factor on an organism or a community is not an end in itself, but a way of assessing the comparative significance different conditions acting together in real ecosystems.

Joint influence of factors can be considered by the example of the dependence of the mortality of crab larvae on temperature, salinity and the presence of cadmium. In the absence of cadmium, the ecological optimum (minimum mortality) is observed in the temperature range from 20 to 28 ° C and salinity - from 24 to 34%. If cadmium, toxic to crustaceans, is added to the water, then the ecological optimum shifts: the temperature lies in the range from 13 to 26 ° C, and the salinity is from 25 to 29%. The limits of tolerance are also changing. The difference between the ecological maximum and minimum for salinity after the addition of cadmium decreases from 11 - 47% to 14 - 40%. The tolerance limit for the temperature factor, on the contrary, expands from 9 - 38 ° С to 0 - 42 ° С.

Temperature and humidity are the most important climatic factors in terrestrial habitats. The interaction of these two factors essentially forms two main types of climate: marine and continental.

Reservoirs soften the climate of the land, since water has a high specific heat of melting and heat capacity. Therefore, the maritime climate is characterized by less sharp fluctuations in temperature and humidity than the continental one.

The effect of temperature and humidity on organisms also depends on the ratio of their absolute values. So, temperature has a more pronounced limiting effect if the humidity is very high or very low. Everyone knows that high and low temperatures are less tolerated when high humidity than with moderate

The interrelation of temperature and humidity as the main climatic factors is often depicted in the form of climogram graphs, which make it possible to visually compare different years and regions and predict the production of plants or animals for certain climatic conditions.

Organisms are not slaves to the environment. They adapt to the conditions of existence and change them, that is, they compensate for the negative impact of environmental factors.

Compensation of environmental factors is the desire of organisms to weaken the limiting effect of physical, biotic and anthropogenic influences. Factor compensation is possible at the organism and species level, but is most effective at the community level.

At different temperatures, the same species, which has a wide geographical distribution, can acquire physiological and morphological (column torphe - shape, outline) features adapted to local conditions. For example, in animals, the ears, tails, and paws are shorter, and the body is the more massive, the colder the climate.

This pattern is called Allen's rule (1877), according to which the protruding body parts of warm-blooded animals increase as they move from north to south, which is associated with adaptation to maintaining a constant body temperature in different climatic conditions. So, foxes living in the Sahara have long limbs and huge ears; the European fox is more squat, its ears are much shorter; and the arctic fox, the polar fox, has very small ears and a short muzzle.

In animals with well-developed motor activity, compensation of factors is possible due to adaptive behavior. So, lizards are not afraid of sudden cooling, because during the day they go out into the sun, and at night they hide under heated stones. Changes arising in the process of adaptation are often genetically fixed. At the community level, compensation of factors can be carried out by changing species along the gradient of environmental conditions; for example, with seasonal changes, there is a regular change in plant species.

Organisms also use the natural periodicity of changes in environmental factors to distribute functions over time. They “program” life cycles to make the most of the favorable conditions.

The most striking example is the behavior of organisms depending on the length of the day - photoperiod. The amplitude of the day length increases with latitude, which allows organisms to take into account not only the season, but also the latitude of the area. The photoperiod is a "time relay" or trigger for a sequence of physiological processes. It determines the flowering of plants, molting, migration and reproduction in birds and mammals, etc. The photoperiod is associated with the biological clock and serves as a universal mechanism for regulating functions in time. The biological clock links the rhythms of environmental factors with physiological rhythms, allowing organisms to adapt to the diurnal, seasonal, tidal and other dynamics of factors.

By changing the photoperiod, it is possible to induce changes in body functions. So, flower growers, changing the light regime in greenhouses, get off-season flowering of plants. If you immediately increase the length of the day after December, this can cause phenomena that occur in spring: flowering of plants, molting in animals, etc. In many higher organisms, adaptations to the photoperiod are fixed genetically, that is, the biological clock can work even in the absence of a regular daily or seasonal dynamics.

Thus, the point of analyzing environmental conditions is not to compile an immense list of environmental factors, but to discover functionally important limiting factors and to assess the extent to which the composition, structure and functions of ecosystems depend on the interaction of these factors.

Only in this case it is possible to reliably predict the results of changes and disturbances and manage ecosystems.

Anthropogenic limiting factors. It is convenient to consider fires and anthropogenic stress as examples of anthropogenic limiting factors that make it possible to manage natural and man-made ecosystems.

Fires as an anthropogenic factor, they are often assessed only negatively. Research over the past 50 years has shown that natural fires can be part of the climate in many terrestrial habitats. They influence the evolution of flora and fauna. Biotic communities have "learned" to compensate for this factor and adapt to it, as to temperature or humidity. Fire can be viewed and studied as an environmental factor, along with temperature, precipitation and soil. At correct use fire can be a valuable ecological tool. Some tribes burned forests for their needs long before people began to systematically and purposefully change the environment. The fire is very important factor, including because a person can control him to a greater extent than other limiting factors. It is difficult to find a piece of land, especially in dry season areas, where there has not been a fire at least once in 50 years. The most common cause of fires in nature is a lightning strike.

Fires are of different types and have different consequences.

Horseback or "wild" fires are usually very intense and uncontrollable. They destroy the crown of trees and destroy all organic matter in the soil. Fires of this type have a limiting effect on almost all organisms in the community. It will take many years for the site to rebuild.

Grassroots fires are completely different. They have a selective effect: for some organisms they turn out to be more limiting than for others. Thus, ground fires promote the development of organisms with a high tolerance to their consequences. They can be natural or specially organized by man. For example, planned forest burning is undertaken to eliminate competition for the valuable swamp pine species from the outside. deciduous trees... Marsh pine, unlike deciduous trees, is resistant to fire, since the apical bud of its seedlings is protected by a bunch of long, poorly burning needles. In the absence of fires, the overgrowth of deciduous trees drowns out pine, as well as cereals and legumes. This leads to the oppression of partridges and small herbivores. Therefore, virgin pine forests with abundant game are ecosystems of the “fire” type, that is, requiring periodic ground fires. In this case, the fire does not lead to the loss of nutrients in the soil, does not harm ants, insects and small mammals.

A small fire is even beneficial for nitrogen-fixing legumes. Burning out is carried out in the evening, so that at night the fire can be extinguished with dew, and the narrow fire front can be easily stepped over. In addition, small ground fires complement the bacteria's ability to convert dead residues into mineral nutrients suitable for the next generation of plants. For the same purpose, fallen leaves are often burned in spring and autumn. Planned burning is an example of managing a natural ecosystem using a limiting ecological factor.

The decision as to whether the possibility of fires should be completely ruled out or whether fire should be used as a control factor should depend entirely on what type of community is desired in the area. The American ecologist G. Stoddard (1936) was one of the first to “defend” controlled planned burning to increase the production of valuable timber and game back in the days when, from the point of view of foresters, any fire was considered harmful.

The close relationship of burnout to grass composition plays a key role in maintaining the amazing diversity of antelope and predators in the East African savannas. Fires have a positive effect on many cereals, since their growth points and energy reserves are underground. After the dry aboveground parts are burned out, the nutrients quickly return to the soil and the grasses grow luxuriantly.

The question "to burn or not to burn", of course, can be confusing. Through negligence, a person is often the cause of an increase in the frequency of destructive "wild" fires. Struggle for fire safety in forests and recreation areas - the second side of the problem.

A private person in no case has the right to deliberately or accidentally cause a fire in nature - this is the privilege of specially trained people who are familiar with the rules of land use.

Anthropogenic stress can also be regarded as a kind of limiting factor. Ecosystems are largely able to compensate for anthropogenic stress. It is possible that they are naturally adapted to acute recurrent stresses. And many organisms require occasional disturbances that contribute to their long-term resilience. Large bodies of water often have good self-purification properties and recover from pollution in the same way as many terrestrial ecosystems. However, long-term disruptions can lead to pronounced and lasting negative consequences. In such cases, the evolutionary history of adaptation cannot help organisms - compensation mechanisms are not unlimited. This is especially true of those cases when highly toxic waste is dumped, which is constantly produced by an industrialized society and which were previously absent in the environment. If we cannot isolate this toxic waste from global life support systems, then they will directly threaten our health and become the main limiting factor for humanity.

Anthropogenic stress is conventionally divided into two groups: acute and chronic.

The first is characterized by a sudden onset, a rapid rise in intensity and a short duration. In the second case, violations of low intensity continue for a long time or are repeated. Natural systems often have sufficient capacity to cope with acute stress. For example, the dormant seed strategy allows the forest to recover after being cleared. The consequences of chronic stress can be more severe because the responses to stress are less obvious. It may take years for changes in organisms to be noticed. Thus, the connection between cancer and smoking was identified only a few decades ago, although it existed for a long time.

The threshold effect partly explains why some environmental problems appear unexpectedly. In fact, they have been accumulating over the years. For example, in forests mass death of trees begins after prolonged exposure to air pollutants. We begin to notice the problem only after the death of many forests in Europe and America. By this time, we were 10-20 years late and could not prevent the tragedy.

During the period of adaptation to chronic anthropogenic impact the tolerance of organisms to other factors, for example, diseases, also decreases. Chronic stress is often associated with toxic substances, which, although in small concentrations, are constantly released into the environment.

The article "Poisoning America" ​​(The Times magazine, 09.22.80) provides the following data: "Of all human interventions in the natural order of things, none is growing at such an alarming rate as the creation of new chemical compounds. In the USA alone, cunning "alchemists" create about 1,000 new drugs every year. There are about 50,000 different chemicals on the market. Many of them are undoubtedly of great benefit to humans, but the nearly 35,000 compounds used in the US are definitely or potentially harmful to human health. ”

The danger, possibly catastrophic, is the pollution of groundwater and deep aquifers, which make up a significant proportion of water resources on the planet. Unlike surface waters, groundwater is not subject to natural self-purification processes due to the lack of sunlight, rapid current and biotic components.

The concern is not only caused by harmful substances entering water, soil and food. Millions of tons of hazardous compounds are released into the atmosphere. Only over America in the late 70s. emitted: suspended particles - up to 25 million tons / year, SO 2 - up to 30 million tons / year, NO - up to 23 million tons / year.

We all contribute to air pollution through the use of cars, electricity, manufactured goods, and more. Air pollution is a clear negative feedback signal that can save society from death, as it is easily detected by everyone.

Solid Waste Treatment for a long time was considered a secondary matter. Until 1980, there were cases when residential quarters were built on former radioactive waste dumps. Now, albeit with some delay, it became clear: the accumulation of waste is limiting the development of industry. Without the creation of technologies and centers for their removal, neutralization and recycling, further progress of the industrial society is impossible. First of all, it is necessary to safely isolate the most toxic substances. The illegal practice of "night discharges" must be replaced with reliable isolation. We need to look for substitutes for toxic chemicals. At the right leadership waste disposal and recycling can become a special industry that will create new jobs and contribute to the economy.

The solution to the problem of man-made stress must be based on a holistic concept and requires systems approach... Attempts to deal with each pollutant as a problem in its own right are ineffective - they only transfer the problem from one place to another.

If in the next decade it is not possible to restrain the process of deterioration of the quality of the environment, then it is likely that not a shortage of natural resources, but the impact of harmful substances will become a factor limiting the development of civilization.

Similar information.

Anthropogenic factors- various forms of activity human society that lead to a change in the habitat of other species or directly affect their life.

Man has begun to influence the natural environment around him since he moved from gathering to hunting and farming. The result of the hunt was the disappearance of a number of species of large mammals and birds (mammoths, bison, sea cows, etc.). Many species have become rare and are on the verge of extinction. The development of agriculture led to the development of more and more territories for cultivation cultivated plants... Forests and other natural biocenoses were replaced by agrocenoses - plantations of agricultural crops poor in species composition.

From the middle of the XIX century, all greater importance begin to acquire impacts on nature associated with the development of industry, accompanied by changes in the landscape due to the extraction of minerals and the release of pollutants into the environment.

Pollution is the introduction of new, non-typical substances into any environment or the excess of the natural level of these substances in the environment. We can also say that pollution is an undesirable change in the physical, chemical or biological characteristics of air, earth and water, which can now or in the future have an adverse effect on the life of a person himself, the plants and animals he needs, on different kinds production processes and living conditions.

Influence of human production activity on his environment

Influence on the atmosphere

Automobiles and industrial plants are the main sources of air pollution. According to scientists, more than 200 million tons of carbon oxide and dioxide, 150 million tons of sulfur dioxide, more than 50 million tons of nitrogen oxides, about the same amount of hydrocarbons, enter the atmospheric air annually. In addition, a large number of fine particles are emitted into the atmosphere, forming the so-called atmospheric aerosol (from 200 to 400 million tons annually). Due to the combustion of coal in power plants, mercury, arsenic, uranium, cadmium, lead and other elements are released into the environment in quantities that exceed the possibilities of their involvement in the natural cycle of substances. The work of vehicles and environmentally dirty enterprises in industrial centers leads to the fact that the air above them contains 150 times more dust than over the ocean, and extends to a height of 1.5-2 km, delaying a significant (20 to 50%) part of solar rays. It should be borne in mind that part of the gases emitted by cars (CO, CO 2, etc.) are heavier than air and accumulate at the surface of the earth.

It is necessary to pay special attention to the consequences of an increase in the concentration of CO 2 in the atmosphere. As a result of the continuously increasing combustion of fossil fuels over the past 100 years, the CO 2 content has increased by 10%. CO 2 prevents thermal radiation into outer space, creating the so-called "greenhouse effect". According to scientists' calculations, a further increase in the concentration of CO 2 in the atmosphere will create conditions for an increase in planetary temperature, retreat of the polar ice border to the north and an increase in the level of the World Ocean.

In rural areas, air pollutants include ammonia, hydrogen sulfide and pesticides.

Influence on the hydrosphere

The waters of the Earth are in continuous motion. The water cycle binds together all parts of the hydrosphere, forming unified system: ocean - atmosphere - land. For human life, industry and agriculture, fresh river waters are of the greatest importance due to their easy accessibility and renewability.

The main reason for the pollution of water basins is the discharge of untreated or insufficiently treated wastewater into water bodies by industrial and municipal enterprises. Mineral fertilizers and toxic chemicals are washed off from agricultural land and enter the rivers. In recent decades, the traditional mineral, organic and bacterial pollutants of water bodies have been supplemented with increasing amounts of surfactant synthetic substances that make up detergents and petroleum products. More than 10% of the total flow of rivers in the world is spent on wastewater treatment.

Pollution causes deterioration in the quality of drinking water and the death of spawning grounds for valuable commercial fish.

The level of pollution of the waters of the World Ocean is increasing. With river runoff, from the atmosphere with rain, when washing oil tankers, when extracting oil on the ocean shelf, a huge amount of lead (up to 50 thousand tons), oil (up to 10 million tons), mercury, pesticides, household waste and etc. This leads to the death of many organisms, especially in the coastal zone and in the areas of traditional routes of sea vessels. Oil has a particularly harmful effect on marine life. Oil films on the surface of seas and oceans not only poison living organisms living in the surface layer, but also reduce the saturation of water with oxygen. As a result, the reproduction of plankton, the first link in the food chain in the seas and oceans, slows down. Many kilometers of oil films on the surface of the water reduce its evaporation and thereby disrupt water exchange between the ocean and land.

Impact on the soil

The fertile soil layer in natural conditions is formed for a very long time. At the same time, tens of millions of tons of nitrogen, potassium, phosphorus - the main components of plant nutrition - are removed annually from the huge areas occupied by agricultural crops. Soil depletion does not occur only because organic and mineral fertilizers are annually applied to the fields in cultural agriculture. The preservation of soil fertility is also facilitated by crop rotations aimed at creating conditions for the accumulation of nitrogen in the soil (crops of legumes) and hindering the reproduction of pests of cultivated plants. Adverse changes in the soil occur when sowing the same crops for a long time, salinization with artificial irrigation, waterlogging with improper reclamation.

Overuse chemicals protection of plants from pests and diseases, the use of herbicides leads to soil contamination with compounds that, due to their synthetic origin and toxicity, are very slowly rendered harmless by the microbial and fungal population of the soil. Recently, many countries are abandoning the use of synthetic potent drugs and are switching to biological methods of protecting plants and animals.

Erosion is one of the anthropogenic changes in the soil. Erosion is the destruction and demolition of soil cover by water currents or wind. Water erosion is especially destructive. It develops on slopes with improper tillage. With melt and rainwater, millions of tons of soil are carried away from the fields into gullies and ravines.

Radioactive contamination of the biosphere

The problem of radioactive contamination arose in 1945 after the explosion of atomic bombs dropped by the Americans on the Japanese cities of Hiroshima and Nagasaki. Until 1962, all nuclear powers tested nuclear weapons in the atmosphere, which caused global radioactive contamination. A great danger is posed by accidents at nuclear power plants, as a result of which vast territories are contaminated with radioactive isotopes with a long half-life. Strontium-90 is especially dangerous due to its proximity to calcium and cesium-137, which is similar to potassium. Accumulating in the bones and muscles of the affected organisms, they serve as a source of long-term radioactive irradiation of tissues.

Despite the fact that humanity makes up an insignificant part of the biomass of our planet, its activities are immense. She has become one of the most important forces that change the processes in the biosphere.

Before our eyes, a transition is taking place from evolution, which is controlled by spontaneous biological factors (the period of biogenesis), to evolution, controlled by human consciousness - to the period of noogenesis, the period of conscious control of the biosphere on the basis of perfect technology.

A new state of the biosphere, in which labor activity turned out to be very significant, V.I. Vernadsky called the noosphere, as a kind of new geological phenomenon on our planet, a new stage in the development of the biosphere, when for the first time mankind becomes the greatest natural force. The high rates of development of the industry necessitated the protection of nature resources.

Human environmental protection

Security inanimate nature and environments

To protect water sources of the environment, the construction of facilities for the neutralization and purification of wastewater has become a prerequisite for the construction of enterprises. Technological cycles that require a large amount of water began to improve. Systems with a multi-turn or closed cycle using the same volume of water are increasingly used. Waste-free technologies are being developed, work is being carried out on the reasonable regulation of the number of algae in water bodies, causing "water bloom", which significantly deteriorates its quality.

The most effective measures are those that eliminate the causes of the massive development of algae - thorough cleaning of the bottom of the future sea from organic residues (trees, shrubs, humus layer of the soil), limiting the leaching of fertilizers from the shelves and getting them into the reservoir, reducing the inflow of nutritious mineral salts with household waste and industrial wastewater (primarily phosphorus, nitrogen) and other elements that cause the eutrophication of water bodies and watercourses, i.e., their enrichment with nutritious mineral elements.

To protect the air from a significant amount of impurities (chemical and mechanical) emitted by industrial enterprises, systems of chemical, mechanical and electrostatic treatment facilities and filters are used.

Wildlife protection

Excessive hunting and human destruction of the natural environment have led to the fact that a significant number of animals (especially commercial) and plants have become rare and even endangered. Over the past 200 years, over 150 species of animals have disappeared from the face of the Earth, and this happened with the direct participation of humans. Among the species that have been lost forever, of course, there were economically valuable: tours, tarpans (wild European horses), sea (Steller's) cow, wingless auk, wandering pigeon, etc. Humanity has lost many representatives of the animal world for selection and genetic work with them , a significant part of the genetic stock for modern animal husbandry. In many cases, only the crossing of wild and domestic animals makes it possible to increase the productivity of the latter, despite the fact that they are under constant human care, incomparably better conditions cultivation.

The number of some species of animals and plants has decreased so much that there was a threat to their further existence. Currently, on our planet, about a thousand species of animals belong to this category. In this regard, the "Red Book" was created, which includes the most valuable species that are under the threat of destruction or extinction and therefore require careful protection.

The fauna independently and rather effectively regulates the number of certain species. Human intervention, not always deliberate, interferes with this. Not so long ago, birds of prey and animals were destroyed. In Norway, at one time, hawks (enemies of ptarmigan) were almost completely exterminated, but the number of partridges still did not increase; the destruction of sparrows in China did not give the expected positive results. Regular shooting of wolves in many hunting farms in our country led, oddly enough, to a decrease in the number of wild ungulates - elk, deer due to diseases and weakening of offspring. A small number of wolves performed the function of orderlies, destroying first of all sick and weakened animals, as a result of which there was an effective biological rejection of genetically undesirable specimens.

To control the preservation of the ecological situation from further destruction, for the continuation in the biosphere of the persistent cycle of substances formed during evolution, ensuring the harmonious interaction and self-renewal of its most important elements, at the 16th session of the UNESCO General Conference in October 1970, the International Coordinating Committee for Implementation a new long-term program "Man and the Biosphere".

The main task of the program was to preserve the values ​​of ecosystems through in-depth study of the basic laws of interaction between nature and society. The program includes 14 projects covering various aspects of environmental protection and rational use of biosphere resources, as well as combating its pollution.

The projects of the program focus on the selection of new highly productive plants and animals in order to eliminate the deficiency of food protein, the use of fertilizers and land reclamation, and the control of pests and diseases; better study of replacing natural ecosystems with artificial ones and assessing the future performance of such systems. The productivity of different biocenoses, the prospects and consequences of a possible overpopulation of the planet, the prospects for the development of cities, industrial, hydraulic structures, etc., are thoroughly studied. Particular attention is paid to the need to teach environmental sciences in schools and universities in order to deeply understand the urgency of this problem by the public.

Within the framework of one of the projects of the "Man and the Biosphere" program, the creation of biosphere reserves is being carried out. UN experts have proposed a zoning concept for biosphere reserves, which consists in the creation of three special zones: a core, a buffer zone and a transition zone, or a zone of cooperation with the local population. In 1974, the first biological reserve was founded in the United States, the main activity of which was the conduct of long-term research.

In our country, there are reserves in almost every natural area, which makes it possible to preserve the animals and plants characteristic of this zone. The XX session of the UNESCO General Conference classified seven reserves as biosphere in our country: Berezinsky, Prioksko-Terrasny, Central Black Earth, Caucasian, Repeteks, Sary-Cheleksky, Sikhote-Allnsky, and since 1985 - two reserves and on the territory of Ukraine - Askania-Nova and Black Sea. The largest and most famous reserves, besides the listed biosphere reserves, are: Altai, Astrakhan, Barguzinsky, Darvinsky, Ilmensky, Suputinsky, Teberdinsky (RSFSR); Carpathian, Polessky (Ukrainian SSR); Berezinsky (BSSR); Alma-Ata (KazSSR); Issyk-Kul (Kyrgyz SSR); Borzhomsky, Pontinsky (GSSR) and others. In addition, there are numerous nature reserves, hunting grounds, several thousand landscape, zoological, botanical and geological reserves and individual protected natural objects.

An important role is played by school forestry departments, which harvest seeds of valuable species of trees and shrubs, hang artificial nests for birds, monitor the cleanliness of lakes and rivers, protect fish resources, save fry from drying up reservoirs, carry out certification of small rivers and springs.

Active participation in the campaign "For the protection of nature native land"accept student construction teams. Students check the sanitary condition of rivers and lakes, promote the idea of ​​nature conservation and rational use of natural resources among the population.

Due to the limited and non-renewable mineral resources, at present, serious attention is paid to the protection and rational use of organic and mineral resources, the protection of land resources, including the improvement and directional change of land tracts. Environmental protection is strictly regulated in the development of mineral resources by mining enterprises.

There is a system of state bodies for the protection of nature and its resources. These include bodies of state standard control, water protection, mining supervision, forest protection, quarantine service, fish supervision, the State Committee for Hydrometeorology, etc. Any activity that may lead to undesirable changes in the natural environment is limited or stopped.

A number of decrees have been adopted aimed at improving the environment and improving the use of natural resources. These are measures to preserve the wealth of lakes Baikal and Sevan, the Caspian Sea, the Volga and Ural basins, the Donetsk basin. Many new reserves and sanctuaries have been created as a kind of reference samples of nature, including biosphere and national parks.

We have every opportunity to preserve for ourselves and subsequent generations clean, reservoirs, air, soil with their fauna and flora. All these are important and irreplaceable parts of a single mechanism - the Earth's biosphere, of which man himself is a part and outside of which he cannot exist.

The scale of human activity has increased immeasurably over the past several hundred years, which means that new anthropogenic factors have appeared. Examples of the impact, the place and role of humanity in changing the habitat - all this will be discussed later in the article.

life?

Part of the nature of the Earth in which organisms live is their habitat. The resulting relationships, lifestyle, productivity, the number of creatures are studied by ecology. The main components of nature are distinguished: soil, water and air. There are organisms that are adapted to live in one environment or three, for example, coastal plants.

Individual elements interacting with living things and among themselves are environmental factors. Each of them is irreplaceable. But in recent decades, anthropogenic factors have acquired planetary significance. Although half a century ago, the influence of society on nature was not paid enough attention, but 150 years ago the science of ecology itself was in its infancy.

What are environmental factors?

All the diversity of the impact of society on the environment - these are anthropogenic factors. Examples of negative influences:

• reduction in mineral reserves;
• clearing of forests;
• soil pollution;
• hunting and fishing;
• extermination of wild species.

The positive influence of man on the biosphere is associated with environmental protection measures. Reforestation and afforestation, landscaping and beautification are underway settlements, acclimatization of animals (mammals, birds, fish).

What is being done to improve the relationship between man and the biosphere?

The above examples of anthropogenic environmental factors, human intervention in nature indicate that the impact can be positive and negative. These characteristics are conditional, because a positive influence under changed conditions often becomes its opposite, that is, it acquires a negative connotation. The activities of the population are more likely to harm nature than benefit. This fact is explained by the violation of natural laws that have been in effect for millions of years.

Back in 1971, the United Nations Educational, Scientific and Cultural Organization (UNESCO) approved the International Biological Program called "Man and the Biosphere". Its main task was to study and prevent adverse changes in the habitat. In recent years, adult and children's environmental organizations, scientific institutions are very concerned about the preservation of biological diversity.

How to improve the health of the environment?

We found out what the anthropogenic factor is in ecology, biology, geography and other sciences. Note that the well-being of human society, the life of the present and future generations of people depend on the quality and degree of influence of economic activity on the environment. It is necessary to reduce the environmental risk associated with the ever-increasing negative role of anthropogenic factors.

Not even enough to keep the environment healthy, the researchers say. It can be unfavorable for human life with its former biodiversity, but strong radiation, chemical and other types of pollution.

The link between health and the degree of influence of anthropogenic factors is obvious. To reduce their negative impact, it is required to form a new attitude towards the environment, responsibility for the prosperous existence of wildlife and the preservation of biodiversity.

Environmental factors environments by origin are subdivided into:

1. Biotic.

2. Abiotic.

3. Anthropogenic.

Changes in the natural environment that have occurred as a result of economic and other human activities are due to anthropogenic factors. Trying to remake nature in order to adapt it to his needs, man transforms the natural habitat of living organisms, influencing their life.

Anthropogenic factors include the following types:

1. Chemical.

2. Physical.

3. Biological.

4. Social.

Chemical anthropogenic factors include the use of mineral fertilizers and toxic chemicals for the treatment of fields, as well as the pollution of all earth's shells with transport and industrial waste. Physical factors include the use of nuclear energy, increased noise and vibration levels as a result of human activities, in particular when using a variety of vehicles. Biological factors are food. They also include organisms that can inhabit the human body or those for which a person is potentially food. Social factors are determined by the coexistence of people in society and their relationships.

Human influence on the environment can be direct, indirect and complex. The direct influence of anthropogenic factors is carried out with a strong short-term effect of any of them. For example, when arranging a highway or laying railway tracks through a forest, seasonal commercial hunting in a certain area, etc. An indirect impact is manifested by a change in natural landscapes during human economic activities of low intensity for a long period of time. At the same time, the climate, the physical and chemical composition of water bodies are affected, the structure of soils, the structure of the Earth's surface, the composition of fauna and flora change. This happens, for example, during the construction of a metallurgical plant next to the railway without the use of the necessary treatment facilities, which entails the pollution of the surrounding nature with liquid and gaseous waste. In the future, trees in the surrounding area die, animals are threatened with heavy metal poisoning, etc. The complex impact of direct and indirect factors entails the gradual appearance of pronounced changes in the environment, which may be due to the rapid growth of the population, an increase in the number of livestock and animals living near human habitation (rats, cockroaches, crows, etc.), plowing of new lands, ingress of harmful impurities into water bodies, etc. In such a situation, only those living organisms that are able to adapt to new conditions of existence can survive in the altered landscape.

In the twentieth and eleventh centuries, anthropogenic factors acquired great importance in changing climatic conditions, the structure of soils and the composition of atmospheric air, salt and fresh water bodies, in reducing the area of ​​forests, in the extinction of many representatives of flora and fauna.