Anthropogenic features. Anthropogenic factors and their impact on the natural environment

Anthropogenic factors, their influence on organisms.

Anthropogenic factors- these are forms of human activity that affect living organisms and the conditions of their habitat: felling, plowing, irrigation, grazing, construction of reservoirs, water, oil and gas pipelines, laying roads, power lines, etc. The impact of human activity on living organisms and their environmental conditions habitats can be direct and indirect. For example, when cutting down trees in the forest during timber harvesting, it has a direct impact on the cut down trees (felling, debranching, sawing, removal, etc.) and at the same time has an indirect impact on the plants of the tree canopy, changing the conditions of their habitat: lighting, temperature, air circulation, etc. Due to changes in environmental conditions, shade-loving plants and all organisms associated with them will no longer be able to live and develop in the cutting area. Among the abiotic factors, there are climatic (lighting, temperature, humidity, wind, pressure, etc.) and hydrographic (water, current, salinity, stagnant flow, etc.) factors.

Factors affecting organisms and their habitat conditions change during the day, season and year (temperature, rainfall, lighting, etc.). Therefore, they distinguish regularly changing And arising spontaneously ( unexpected) factors. Regularly changing factors are called periodic factors. These include the change of day and night, seasons, tides, etc. Living organisms have adapted to the effects of these factors as a result of long evolution. Factors that arise spontaneously are called non-periodic. These include volcanic eruptions, floods, fires, mudflows, predator attacks on prey, etc. Living organisms are not adapted to the impact of non-periodic factors and do not have any adaptations. Therefore, they lead to death, injury and disease of living organisms, destroy their habitats.

A person often uses non-periodic factors to his advantage. For example, in order to improve the regeneration of the herbage of pastures and hayfields, he arranges a fall in the spring, i.e. sets fire to old vegetation; using pesticides and herbicides destroys pests of agricultural crops, weeds of fields and gardens, destroys pathogens, bacteria and invertebrates, etc.

A set of factors of the same kind constitutes the upper level of concepts. The lower level of concepts is associated with the knowledge of individual environmental factors (Table 3).

Table 3 - Levels of the concept of "environmental factor"

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

Law of Optimum. Each factor has only certain limits of positive influence on organisms. The beneficial effect is called zone of optimum ecological factor or simply optimum for organisms of this species (Fig. 5).

Figure 5 - Dependence of the results of the environmental factor on its intensity

The stronger the deviation from the optimum, the more pronounced the inhibitory effect of this factor on organisms ( pessimum zone). The maximum and minimum tolerated values ​​of the factor are critical points, beyond which existence is no longer possible, death occurs. The endurance limits between critical points are called environmental valency living beings in relation to a specific environmental factor. The points that bound it, i.e. the maximum and minimum temperatures suitable for life are the limits of stability. Between the optimum zone and the limits of stability, the plant experiences increasing stress, i.e. we are talking about stress zones, or zones of oppression within the range of stability. As you move away from the optimum, eventually, upon reaching the limits of the organism's stability, its death occurs.

Species whose existence requires strictly defined environmental conditions, low-hardy species are called stenobiont(narrow ecological valence) , and those that are able to adapt to different environmental conditions are hardy - eurybiontic(broad ecological valency) (Fig. 6).

Figure 6 - Ecological plasticity of species (according to Yu. Odum, 1975)

Eurybiontic contributes to the wide distribution of species. Stenobiontness usually limits ranges.

The ratio of organisms to the fluctuations of one or another specific factor is expressed by adding the prefix eury- or stheno- to the name of the factor. For example, in relation to temperature, eury- and stenothermal organisms are distinguished, in relation to salt concentration - eury- and stenohaline, in relation to light - eury- and stenophotic, etc.

J. Liebig's law of the minimum. The German agronomist J. Liebig in 1870 was the first to establish that the crop (product) depends on the factor that is in the environment at a minimum, and formulating the law of the minimum, which says: “the substance that is at a minimum controls the crop and determines the size and stability last in time."

When formulating Liebig's law, he had in mind the limiting effect on plants of vital chemical elements present in their habitat in small and intermittent quantities. These elements are called trace elements. These include: copper, zinc, iron, boron, silicon, molybdenum, vanadium, cobalt, chlorine, iodine, sodium. Trace elements, like vitamins, act as catalysts, the chemical elements phosphorus, potassium, calcium, magnesium, sulfur, which are required by organisms in a relatively high honor, are called macroelements. But, if these elements in the soil contain more than necessary for the normal life of organisms, then they are also limiting. Thus, micro- and macroelements in the habitat of living organisms should be contained as much as is necessary for their normal existence and vital activity. A change in the content of micro- and macroelements in the direction of decreasing or increasing from the required amount limits the existence of living organisms.

Environmental limiting factors determine the geographic range of a species. The nature of these factors may be different. Thus, the movement of a species to the north can be limited by a lack of heat, and to desert regions by a lack of moisture or too high temperatures. Biotic relations can also serve as a limiting factor for distribution, for example, the occupation of a given territory by a stronger competitor, or the lack of pollinators for plants.

W. Shelford's law of tolerance. Any organism in nature is able to endure the impact of periodic factors both in the direction of decrease and in the direction of their increase up to a certain limit for a certain time. Based on this ability of living organisms, the American zoologist W. Shelford in 1913 formulated the law of tolerance (from the Latin “tolerantica” - patience: the ability of an organism to endure the influence of environmental factors up to a certain limit), which reads: “The absence or impossibility of developing an ecosystem is determined not only by a lack (quantitatively or qualitatively), but also an excess of any of the factors (light, heat, water), the level of which may be close to the limits tolerated by this organism. These two limits: the ecological minimum and the ecological maximum, the impact of which a living organism can withstand, are called tolerance (tolerance) limits, for example, if a certain organism is able to live at temperatures from 30 ° C to - 30 ° C, then its tolerance limit lies within these limits. temperatures.

Eurobionts, due to their wide tolerance, or wide ecological amplitude, are widespread, more resistant to environmental factors, i.e., more resilient. Deviations of the influence of factors from the optimum depresses the living organism. Ecological valence in some organisms is narrow (for example, snow leopard, walnut, within the temperate zone), in others it is wide (for example, wolf, fox, hare, reed, dandelion, etc.).

After the discovery of this law, numerous studies were carried out, thanks to which the limits of existence for many plants and animals became known. One such example is the impact of air pollutants on the human body. At concentration values ​​of C years, a person dies, but irreversible changes in his body occur at much lower concentrations: C lim. Therefore, the true range of tolerance is determined precisely by these indicators. This means that they must be experimentally determined for each polluting or any harmful chemical compound, and not to exceed its content in a particular environment. In sanitary protection environment it is not the lower limits of resistance to harmful substances that are important, but the upper limits, because environmental pollution - this is an excess of the body's resistance. The task or condition is set: the actual concentration of the pollutant C fact should not exceed C lim. Fact< С лим. С ¢ лим является предельно допустимой концентрации С ПДК или ПДК.

Interaction of factors. The optimal zone and limits of endurance of organisms in relation to any environmental factor can be shifted depending on the strength and combination of other factors acting simultaneously. For example, heat is easier to bear in dry but not humid air. The threat of freezing is much higher in frost with strong winds than in calm weather . Thus, the same factor in combination with others has an unequal environmental impact. The effect of partial mutual substitution of factors is created. For example, wilting of plants can be stopped by both increasing the amount of moisture in the soil and lowering the air temperature, which reduces evaporation.

However, the mutual compensation of the action of environmental factors has certain limits, and it is impossible to completely replace one of them with another. The extreme lack of heat in the polar deserts cannot be compensated for either by an abundance of moisture or round-the-clock illumination. .

Groups of living organisms in relation to environmental factors:

Light or solar radiation. All living organisms need energy from outside to carry out life processes. Its main source is solar radiation, which accounts for about 99.9% of the total energy balance of the Earth. Albedo is the fraction of reflected light.

The most important processes occurring in plants and animals with the participation of light:

Photosynthesis. On average, 1-5% of the light falling on plants is used for photosynthesis. Photosynthesis is the source of energy for the rest of the food chain. Light is essential for the synthesis of chlorophyll. All adaptations of plants in relation to light are associated with this - leaf mosaic (Fig. 7), the distribution of algae in aquatic communities over water layers, etc.

According to the requirement for lighting conditions, it is customary to divide plants into the following ecological groups:

Light-loving or heliophytes- plants of open, constantly well-lit habitats. Their light adaptations are as follows - small leaves, often dissected, at noon can turn edge to the sun; leaves are thicker, may be covered with cuticle or waxy coating; cells of the epidermis and mesophyll are smaller, the palisade parenchyma is multilayered; internodes are short, etc.

Shade-loving or sciophytes- plants of the lower tiers of shady forests, caves and deep-sea plants; they do not tolerate strong light from direct sunlight. They can photosynthesize even in very low light; the leaves are dark green, large and thin; the palisade parenchyma is single-layered and is represented by larger cells; leaf mosaic is pronounced.

shade-tolerant or facultative heliophytes- can tolerate more or less shading, but grow well in the light; they are easier than other plants to rebuild under the influence of changing lighting conditions. This group includes forest and meadow grasses, shrubs. Adaptations are formed depending on the lighting conditions and can be rebuilt when the light regime changes (Fig. 8). An example is coniferous trees that have grown in open spaces and under the forest canopy.

transpiration- the process of evaporation of water by the leaves of plants to reduce the temperature. Approximately 75% of the solar radiation falling on plants is spent on the evaporation of water and thus enhances transpiration; this is important in connection with the problem of water conservation.

photoperiodism. It is important for synchronizing the vital activity and behavior of plants and animals (especially their reproduction) with the seasons. Phototropism and photonasts in plants are important for providing plants with sufficient light. Phototaxis in animals and unicellular plants is essential for finding a suitable habitat.

Vision in animals. One of the most important sensory functions. The concept of visible light is different for different animals. Rattlesnakes see in the infrared part of the spectrum; bees are closer to the ultraviolet region. In animals living in places where light does not penetrate, the eyes can be completely or partially reduced. Animals leading a nocturnal or twilight lifestyle do not distinguish colors well and see everything in black and white; in addition, in such animals, the size of the eyes is often hypertrophied. Light as a means of orientation plays an important role in the life of animals. Many birds during flights are guided with the help of vision by the sun or stars. Some insects, such as bees, have the same ability.

Other processes. Synthesis of vitamin D in humans. However, prolonged exposure to ultraviolet rays can cause tissue damage, especially in animals; in connection with this, protective devices have developed - pigmentation, behavioral avoidance reactions, etc. A certain signal value in animals is played by bioluminescence, that is, the ability to glow. Light signals emitted by fish, mollusks, and other aquatic organisms serve to attract prey, individuals of the opposite sex.

Temperature. The thermal regime is the most important condition for the existence of living organisms. The main source of heat is solar radiation.

The boundaries of the existence of life are temperatures at which the normal structure and functioning of proteins is possible, on average from 0 to +50 ° C. However, a number of organisms have specialized enzyme systems and are adapted to active existence at body temperatures that go beyond these limits (Table . five). The lowest at which living beings are found is -200°C, and the highest is up to +100°C.

Table 5 - Temperature indicators of various living environments (0 C)

In relation to temperature, all organisms are divided into 2 groups: cold-loving and heat-loving.

Cold-loving (cryophiles) able to live in conditions of relatively low temperatures. Bacteria, fungi, mollusks, worms, arthropods, etc. live at a temperature of -8°C. From plants: trees in Yakutia can withstand a temperature of -70°C. In Antarctica, at the same temperature, lichens, certain types of algae, and penguins live. Under laboratory conditions, seeds, spores of some plants, nematodes tolerate absolute zero temperatures of -273.16°C. Suspension of all life processes is called suspended animation.

thermophilic organisms (thermophiles) - inhabitants of hot regions of the Earth. These are invertebrates (insects, arachnids, mollusks, worms), plants. Many species of organisms are able to tolerate very high temperatures. For example, reptiles, beetles, butterflies can withstand temperatures up to +45-50°C. In Kamchatka, blue-green algae live at a temperature of + 75-80 ° C, camel thorn tolerates a temperature of + 70 ° C.

Invertebrates, fish, reptiles, amphibians lack the ability to maintain a constant body temperature within narrow limits. They are called poikilothermic or cold-blooded. They depend on the level of heat coming from outside.

Birds and mammals are able to maintain a constant body temperature regardless of the ambient temperature. This - homoiothermic or warm-blooded organisms. They do not depend on external heat sources. Due to the high metabolic rate, they produce a sufficient amount of heat that can be stored.

Temperature adaptations of organisms: Chemical thermoregulation - an active increase in heat production in response to a decrease in temperature; physical thermoregulation- change in the level of heat transfer, the ability to retain heat or, on the contrary, dissipate heat. Hairline, distribution of fat reserves, body size, organ structure, etc.

Behavioral responses- movement in space allows you to avoid adverse temperatures, hibernation, torpor, huddling, migration, burrowing, etc.

Humidity. Water is an important environmental factor. All biochemical reactions take place in the presence of water.

Table 6 - Water content in various organisms (% of body weight)

Anthropogenic factors - a set of environmental factors caused by accidental or intentional human activities during the period of its existence.

Types of anthropogenic factors:

· physical - the use of atomic energy, movement in trains and planes, the impact of noise and vibration, etc.;

· chemical - the use of mineral fertilizers and pesticides, pollution of the Earth's shells by industrial and transport waste; smoking, alcohol and drug use, excessive use of drugs;

· social - associated with human relations and life in society.

· In recent decades, the impact of anthropogenic factors has increased dramatically, which has led to the emergence of global environmental problems: the greenhouse effect, acid rain, deforestation and desertification of territories, pollution of the environment with harmful substances, and a reduction in the biological diversity of the planet.

Human habitat. Anthropogenic factors affect the human environment. Since he is a biosocial creature, they distinguish natural and social habitats.

natural habitat gives a person health and material for labor activity, is in close interaction with him: a person constantly changes the natural environment in the course of his activity; the transformed natural environment, in turn, affects a person.

A person communicates with other people all the time, entering into relationships with them. interpersonal relationships, which determines social habitat . Communication can be favorable(promoting personal development) and unfavorable(leading to psychological overload and breakdowns, to the acquisition of addictions - alcoholism, drug addiction, etc.).

Abiotic environment (environmental factors) - This is a complex of conditions of the inorganic environment that affect the body. (Light, temperature, wind, air, pressure, humidity, etc.)

For example: the accumulation of toxic and chemical elements in the soil, the drying up of water bodies during a drought, an increase in the length of daylight hours, intense ultraviolet radiation.

ABIOTIC FACTORS, various factors not related to living organisms.

Light - the most important abiotic factor with which all life on Earth is connected. There are three biologically unequal regions in the spectrum of sunlight; ultraviolet, visible and infrared.

All plants in relation to light can be divided into the following groups:

■ photophilous plants - heliophytes(from the Greek "helios" - the sun and fiton - a plant);

■ shade plants - sciophytes(from the Greek "scia" - a shadow, and "phyton" - a plant);

■ shade-tolerant plants - facultative heliophytes.

Temperature on the earth's surface depends on the geographical latitude and height above sea level. In addition, it changes with the seasons of the year. In this regard, animals and plants have various adaptations to temperature conditions. In most organisms, vital processes proceed within the range from -4°С to +40…45°С

The most perfect thermoregulation appeared only in higher vertebrates - birds and mammals, providing them with a wide settlement in all climatic zones. They received the name of homoiothermal (Greek h o m o y o s - equal) organisms.

7. The concept of a population. Structure, system, characteristics and dynamics of populations. population homeostasis.

9. The concept of an ecological niche. Law of competitive exclusion G. F. Gause.

ecological niche- this is the totality of all connections of the species with the habitat, which ensure the existence and reproduction of individuals of this species in nature.
The term ecological niche was proposed in 1917 by J. Grinnell to characterize the spatial distribution of intraspecific ecological groups.
Initially, the concept of an ecological niche was close to the concept of a habitat. But in 1927, C. Elton defined an ecological niche as the position of a species in a community, emphasizing the particular importance of trophic relationships. Domestic ecologist G.F. Gause expanded this definition: an ecological niche is the place of a species in an ecosystem.
In 1984, S. Spurr and B. Barnes identified three components of a niche: spatial (where), temporal (when) and functional (how). This concept of a niche emphasizes the importance of both the spatial and temporal components of the niche, including its seasonal and diurnal changes, taking into account circannian and circadian biorhythms.

A figurative definition of an ecological niche is often used: a habitat is the address of a species, and an ecological niche is its profession (Yu. Odum).

The principle of competitive exclusion; (=Gause's Theorem; =Gause's Law)
Gause's exclusion principle - in ecology - the law according to which two species cannot exist in the same locality if they occupy the same ecological niche.

In connection with this principle, when the possibilities of space-time separation are limited, one of the species develops a new ecological niche or disappears.
The principle of competitive exclusion contains two general provisions related to sympatric species:

1) if two species occupy the same ecological niche, then almost certainly one of them outperforms the other in this niche and will eventually displace the less adapted species. Or, in a shorter form, "coexistence between complete competitors is impossible" (Hardin, 1960*). The second proposition follows from the first;

2) if two species coexist in a state of stable equilibrium, then they must be ecologically differentiated so that they can occupy different niches. ,

The principle of competitive exclusion can be treated in different ways: as an axiom and as an empirical generalization. If we consider it as an axiom, then it is logical, consistent and turns out to be very heuristic. If we consider it as an empirical generalization, it is valid within wide limits, but is not universal.
Add-ons
Interspecific competition can be observed in mixed laboratory populations or in natural communities. To do this, it is enough to artificially remove one species and see if there are changes in the abundance of another sympatric species with similar ecological needs. If the number of this other species increases after the removal of the first species, then we can conclude that it was previously suppressed under the influence of interspecific competition.

This result was obtained in mixed laboratory populations of Paramecium aurelia and P. caudatum (Gause, 1934*) and in natural littoral communities of barnacles (Chthamalus and Balanus) (Connell, 1961*), as well as in a number of relatively recent studies, for example, on saccular jumpers and lungless salamanders (Lemen and Freeman, 1983; Hairston, 1983*).

Interspecies competition manifests itself in two broad aspects, which can be called consumption competition and interference competition. The first aspect is the passive use of the same resource by different species.

For example, passive or non-aggressive competition between different shrub species in a desert community for limited soil moisture resources is highly likely. Species of Geospiza and other ground finches in the Galápagos compete for food, and this competition is an important factor in determining their ecological and geographical distribution across several islands (Lack, 1947; B. R. Grant and PR Grant, 1982; PR Grant, 1986* ).

The second aspect, often overlapping with the first, is the direct suppression of one species by another competing species.

The leaves of some plant species produce substances that enter the soil and inhibit the germination and growth of neighboring plants (Muller, 1966; 1970; Whittaker and Feeny, 1971*). In animals, the suppression of one species by another can be achieved through aggressive behavior or assertion of superiority based on threats of attack. In the Mojave Desert (California and Nevada), native bighorn sheep (Ovis canadensis) and feral donkey (Equus asinus) compete for water and food. In direct confrontations, donkeys dominate sheep: when donkeys approach water sources occupied by sheep, the latter give way to them, and sometimes even leave the area (Laycock, 1974; see also Monson and Summer, 1980*).

Exploitative competition has received much attention in theoretical ecology, but as Hurston (1983*) points out, interference competition is probably more favorable for any given species.

10. Food chains, food webs, trophic levels. ecological pyramids.

11. The concept of an ecosystem. Cyclic and directed changes in ecosystems. Structure and biological productivity of ecosystems.

12. Agroecosystems and their features. Stability and instability of ecosystems.

13. Ecosystems and biogeocenoses. Theory of biogeocenology VN Sukacheva.

14. Dynamics and problems of ecosystem stability. Ecological succession: classification and types.

15. Biosphere as the highest level of organization of living systems. The boundaries of the biosphere.

Biosphere-organized, defined shell earth's crust associated with life." The basis of the concept of the biosphere is the idea of ​​living matter. More than 90% of all living matter is found in terrestrial vegetation.

The main source of biochemical The activities of organisms - solar energy used in the process of photosynthesis is green. Plants and some microorganisms. To create an organic a substance that provides food and energy to other organisms. Photosynthesis led to the accumulation of free oxygen in the atmosphere, the formation of an ozone layer that protects against ultraviolet and cosmic radiation. It maintains the modern gas composition of the atmosphere. Living organisms and their habitat form integral systems-biogeocenoses.

The highest level of organization of life on planet Earth is the biosphere. This term was introduced in 1875. It was first used by the Austrian geologist E. Suess. However, the doctrine of the biosphere as a biological system appeared in the 20s of this century, its author is the Soviet scientist V.I. Vernadsky. The biosphere is that shell of the Earth in which living organisms existed and still exist, and in the formation of which they played and play the main role. The biosphere has its own boundaries, determined by the spread of life. V.I. Vernadsky distinguished three spheres of life in the biosphere:

The atmosphere is the gaseous shell of the Earth. It is not all inhabited by life, its spread is prevented by ultraviolet radiation. The boundary of the biosphere in the atmosphere is located at an altitude of approximately 25-27 km, where the ozone layer is located, which absorbs about 99% of ultraviolet rays. The most populated is the surface layer of the atmosphere (1-1.5 km, and in the mountains up to 6 km above sea level).
The lithosphere is the solid shell of the Earth. It is also not completely inhabited by living organisms. Distribution
The existence of life here is limited by temperature, which gradually increases with depth and, upon reaching 100°C, causes the transition of water from a liquid to a gaseous state. The maximum depth at which living organisms have been found in the lithosphere is 4-4.5 km. This is the boundary of the biosphere in the lithosphere.
3. The hydrosphere is the liquid shell of the Earth. She is full of life. Vernadsky drew the boundary of the biosphere in the hydrosphere below the ocean floor, because the bottom is a product of the vital activity of living organisms.
The biosphere is a gigantic biological system, which includes a huge variety of constituent components, which are extremely difficult to characterize separately. Vernadsky proposed to unite everything that is part of the biosphere into groups depending on the nature of the origin of the substance. He singled out seven groups of matter: 1) living matter is the totality of all producers, consumers and decomposers inhabiting the biosphere; 2) inert matter is a set of substances in the formation of which living organisms did not participate, this substance was formed before the appearance of life on Earth (mountainous, rocky rocks, volcanic eruptions); 3) biogenic substance is a set of substances that are formed by organisms themselves or are products of their vital activity (coal, oil, limestone, peat and other minerals); 4) bioinert substance is a substance that is a system of dynamic balance between living and inert matter (soil, weathering crust); 5) a radioactive substance is a collection of all isotopic elements that are in a state of radioactive decay; 6) the substance of scattered atoms is the totality of all elements that are in the atomic state and are not part of any other substance; 7) cosmic matter is a set of substances that enter the biosphere from space and are of cosmic origin (meteorites, cosmic dust).
Vernadsky believed that living matter plays the main transforming role in the biosphere.

16. The role of man in the evolution of the biosphere. Influence human activity on modern processes in the biosphere.

17. Living matter of the biosphere according to V.I. Vernadsky, its characteristics. The concept of the noosphere according to V. I. Vernadsky.

18. The concept, causes and main trends of the current environmental crisis.

19. Reducing genetic diversity, loss of the gene pool. Population growth and urbanization.

20. Classification of natural resources. Exhaustible and inexhaustible natural resources.

Natural resources are: --- exhaustible - are divided into non-renewable, relatively renewable (soil, forests), renewable (animals). --- inexhaustible - air, solar energy, water, soil

21. Sources and extent of air pollution. Acid precipitation.

22. Energy resources of the world. Alternative energy sources.

23. Greenhouse effect. The state of the ozone layer.

24. Brief description of the carbon cycle. Cycle stagnation.

25. Nitrogen cycle. Nitrogen fixers. A brief description of.

26. The water cycle in nature. A brief description of.

27. Determination of the biogeochemical cycle. List of main cycles.

28. The flow of energy and cycles of biogenic elements in the ecosystem (scheme).

29. List of the main soil-forming factors (according to Dokuchaev).

30. "Ecological succession". "Climax Community". Definitions. Examples.

31. Basic principles of the natural structure of the biosphere.

32. International "Red Book". Types of natural areas.

33. The main climatic zones of the globe (a short list according to G. Walter).

34. Pollution of ocean waters: scale, composition of pollutants, consequences.

35. Deforestation: scale, consequences.

36. The principle of dividing human ecology into human ecology as an organism and social ecology. Human ecology as autecology of the organism.

37. Biological pollution of the environment. MPC.

38. Classification of pollutants discharged into water bodies.

39. Environmental factors that cause diseases of the digestive system, circulatory system, capable of causing malignant neoplasms.

40. Rationing: concept, types, MPC. "Smog": concept, reasons for its formation, harm.

41. Population explosion and its danger to state of the art biosphere. Urbanization and its negative consequences.

42. The concept of "sustainable development". Prospects for the concept of "sustainable development" for the "golden billion" of the population of economically developed countries.

43. Reserves: functions and values. Types of reserves and their number in the Russian Federation, USA, Germany, Canada.

All processes occurring in the biosphere are inextricably linked, and humanity is only a small fraction, or rather, just one species of organic life. Throughout his existence, man has striven and continues to strive not to adapt to the environment, but to use it with maximum benefit for himself. But now comes the realization that the deterioration of the biosphere is dangerous for us. According to statistics, up to 85% of human diseases are associated with negative environmental conditions.

Human impact on the environment

Let's start by explaining what anthropogenic factors are. It is a human activity that has an impact on the environment.

Types of anthropogenic factors

1. Chemical - the use of pesticides, mineral fertilizers, as well as pollution of the earth's shells with industrial and transport waste. This category includes alcohol, smoking, drugs.

2. Physical environmental factors - movement in airplanes, trains, nuclear energy, noise and vibration.

4. Social anthropogenic factors are associated with society.

Main negative impact

In just the past few years, only in Russia, the birth rate has decreased by 30%, and the death rate has increased by 15%. Half of the young people of draft age are unfit for military service due to health reasons. Since the 1970s, the frequency of cardiovascular and oncological diseases has increased by 50%. In many regions, the occurrence of allergies occurs in more than half of the children. This is not a complete list of what anthropogenic factors lead to.

Atmospheric implications

As you know, today around the world there is great amount industrial enterprises that emit pollutants into the atmosphere around the clock. As a result, sanitary violations in many areas exceed all permissible figures by dozens of times. This leads to the fact that in cities the number of patients with bronchitis, allergies, asthma, and ischemia is steadily growing.

the greenhouse effect

If we talk about whether anthropogenic factors affect climate change, then we can assure that in such a global sense, a person does not have such an effect. Forests are cut down, the atmosphere is polluted, cities are built up, and so on, but one active large volcano is able to fill the air with carbon dioxide in such a large volume that all of humanity does not produce in five years. We know that the Eyjafjallajokull volcano woke up not so long ago, due to which flights were canceled in many countries. So in this sense, anthropogenic environmental factors play only a small role.

Flora and fauna

Much worse is the situation with the animal and plant world. Although, as has been repeatedly proven, in the old days there were completely different flora and fauna, but as a result of global catastrophes, everything changed dramatically and quickly. Of course, now a person is contributing to the destruction of many species, although there is no urgent need for food. Huge tracts of land are polluted by man, so living conditions for animals become unsuitable.

Conclusion

In conclusion, it can be said that more Anthropogenic activity is negative not so much for nature as for man himself. This means that we ourselves create negative conditions for existence for ourselves, slowly destroying each other. Man-made disasters, an increase in the number of diseases, the emergence of new viruses, an excess of mortality and a decrease in the birth rate in developed countries are proof of this.

The influence of man as an ecological factor is extremely strong and versatile. Not a single ecosystem on the planet has escaped this influence, and many ecosystems have been completely destroyed. Even entire biomes, such as the steppes, have almost completely disappeared from the face of the earth. Anthropogenic means "born of man", and anthropogenic refers to those factors that owe their origin to any human activity. In this they fundamentally differ from natural factors that arose even before the appearance of man, but still exist and operate.

Anthropogenic factors (AF) arose only with the advent of man during the ancient stage of its interaction with nature, but then they were still very limited in scope. The first significant AF was the impact on nature with the help of fire; the set of AFs spread significantly with the development of animal husbandry, crop production, and the emergence of large settlements. Of particular importance for the organisms of the biosphere were such APs, which had no analogues in nature before, since in the course of evolution these organisms could not develop certain adaptations to them.

Now the influence of man on the biosphere has reached gigantic proportions: there is a total pollution of the natural environment, geographical envelope saturated with technical structures (cities, factories, pipelines, mines, reservoirs, etc.); technical items (i.e., spacecraft remnants, containers with toxic substances, landfills) new substances that are not assimilated by biota; new processes - chemical, physical, biological and mixed (thermonuclear fusion, bioengineering, etc.).

Anthropogenic factors - bodies, substances, processes and phenomena that arise as a result of economic and other human activities and act on nature together with natural factors. The whole variety of anthropogenic factors is divided into the following main subgroups:

o Body factors are, for example, artificial relief (mounds, cockroaches), reservoirs (reservoirs, canals, ponds), structures and buildings, and the like. The factors of this subgroup are characterized by a clear spatial certainty and long-term action. Produced before, they often exist for centuries and even millennia. Many of them are distributed over large areas.

o Factors-substances are conventional and radioactive chemicals, artificial chemical compounds and elements, aerosols, wastewater, and the like. They, unlike the first subgroup, do not have a specific spatial definition, constantly change concentration and move, changing the degree of impact on the elements of nature, respectively. Some of them are destroyed over time, others can be present in the environment for tens, hundreds and even thousands of years (for example, some radioactive substances), which makes it possible for them to accumulate in nature.

o Process factors - this is a subgroup of AF, which includes the impact on the nature of animals and plants, the destruction of harmful and breeding of beneficial organisms, the random or purposeful movement of organisms in space, mining, soil erosion, and the like. These factors often occupy limited areas of nature, but sometimes they can cover large spaces. In addition to the direct impact on nature, they often cause a number of indirect changes. All processes are highly dynamic and often unidirectional.

o Factors-phenomena are, for example, heat, light, radio waves, electrical and electromagnetic field, vibration, pressure, sound effects, etc. Unlike other AF subgroups, the phenomena mostly have precise parameters. As a rule, as they move away from the source, their influence on nature decreases.

Based on the foregoing, anthropogenic factors can be called only those bodies, substances, processes and phenomena produced by man that did not exist in nature before the appearance of man. In the event that certain AF did not exist before the appearance of man only in some (certain) region, they are called regional anthropogenic factors; if they were absent only for a certain season, then they are called seasonal anthropogenic factors.

In those cases when a body, substance, process or phenomenon produced by a person is similar in its qualities and properties to a natural factor, then it can be considered an anthropogenic factor only when it quantitatively prevails over the natural one. For example, heat, which is a natural factor, becomes anthropogenic if its amount, which the enterprise releases into the environment, causes an increase in the temperature of this environment. Such factors are called quantitative-anthropogenic.

Sometimes, under the influence of a person, the transition of bodies, processes, substances or phenomena into a new quality is carried out. In this case, we are talking about qualitative anthropogenic factors, for example, sands become mobile due to the destruction of vegetation by humans, they are fixed, or water that is formed from a glacier when it melts under the influence of anthropogenic warming.

Consider such a simple anthropogenic impact as grazing. Firstly, this immediately leads to the suppression in the biocenosis of a number of species that are eaten by domestic animals. Secondly, as a result of this, groups are formed on the territory with a relatively small number of species that livestock do not accept, so each of them has a significant number. Thirdly, the biogeocenosis that has arisen in this way becomes unstable, easily amenable to fluctuations in the number of populations, and therefore, if the effect of the factor (livestock grazing) intensifies, this can lead to profound changes and even complete degradation of the biogeocenosis.

When identifying and studying AF, the main attention is paid not to the means by which they are made, but to those of their elements that cause changes in nature. From the point of view of the doctrine of factors, anthropogenic impact on nature can be defined as a conscious and unconscious influence through man-made AF. This influence is carried out not only in the process of human activity, but also after its completion. The influence of a person, which is classified by type of activity, is a complex factor. For example, if we analyze the plowing of a field by a tractor as an effect of a complex anthropogenic factor, we can cite the following components: 1) soil compaction; 2) crushing soil organisms; 3) loosening the soil; 4) turning the soil; 5) cutting organisms with a plow; 6) soil vibration; 7) soil contamination with fuel residues; 8) pollution of the atmosphere by exhausts; 9) sound effects, etc.

There are many classifications of AF according to various criteria. By nature, AF is divided into:

Mechanical - pressure from the wheels of cars, deforestation, obstacles to the movement of organisms, and the like;

Physical - heat, light, electric field, color, humidity changes, etc.;

Chemical - the action of various chemical elements and their compounds;

Biological - the influence of introduced organisms, breeding of plants and animals, forest plantations, and the like.

Landscape - artificial rivers and lakes, beaches, forests, meadows, etc.

It should be noted that any type of human activity cannot be defined simply as the sum of AF, since this activity involves elements that can in no way be considered factors in the natural sense, for example, technical means, products, people themselves, their production relations Technological processes and v. Only in some cases, technical means (for example, dams, communication lines, buildings) can be called factors if they directly cause changes in nature by their presence, for example, they are an obstacle to the movement of animals, a barrier to air flows, etc.

According to the time of origin and duration of action, anthropogenic factors are divided into the following groups:

Factors produced in the past: a) those that have ceased to operate, but its consequences are still being felt now (destruction of certain types of organisms, overgrazing, etc.); b) those that continue to operate in our time (artificial relief, reservoirs, introductions, etc.);

Factors that are produced in our time: a) those that act only at the time of production (radio waves, noise, light); b) those that are valid for a certain time and after the end of production (persistent chemical pollution, cut down forest, etc.).

Most AFs are distributed in areas of intensive development of industry and agriculture. However, some produced in limited areas can be found in any region of the world due to their ability to migrate (for example, radioactive substances with a long decay period, persistent pesticides). Even those APs that are very widespread on the planet or in a separate "and" region are distributed unevenly in nature, creating zones of high and low concentrations, as well as zones of their complete absence. So soil plowing and livestock grazing are carried out only in certain areas, you need to know for sure.

So, the main quantitative indicator of AF is the degree of saturation of space with them, called the concentration of anthropogenic factors. The concentration of AP in a particular area is determined, as a rule, by the intensity and nature of AP production; the degree of ability of these factors to migrate; the property of accumulation (accumulation) in nature and the general conditions of a particular natural complex. Therefore, the quantitative features of AF change significantly in time and space.

According to the degree of ability to migrate, anthropogenic factors are divided into those that:

They do not migrate - they act only at the place of production and at some distance from it (relief, vibration, pressure, sound, light, motionless organisms introduced by man, etc.);

Migrate with streams of water and air (dust, heat, chemicals, gases, aerosols, etc.);

They migrate with the means of production (ships, trains, planes, etc.);

They migrate independently (mobile organisms introduced by humans, feral domestic animals).

Not all AFs are continuously produced by humans; they have different frequency. So, haymaking takes place in a certain period, but annually; Atmospheric pollution by industrial enterprises is carried out either at certain hours or around the clock. The study of the dynamics of the production of factors is very important for a correct assessment of their impact on nature. With an increase in the number of periods and their duration, the impact on nature intensifies due to a decrease in the possibilities for self-healing of the quantitative and qualitative features of the elements of nature.

The dynamics of the number and set of various factors is clearly expressed throughout the year, due to the seasonality of many production processes. Identification of the AF dynamics is carried out for a certain territory for a selected time (for example, for a year, season, day). This is of great importance for comparing them with the dynamics of natural factors and for determining the degree of influence on the nature of AF. Wind erosion of soils is most dangerous in summer, and water erosion is most dangerous in spring when snow melts, when there is still no vegetation; wastewater of the same volume and composition changes the chemistry of the river more in winter than in spring, due to the small volume of winter runoff.

According to such an important indicator as the ability to accumulate in nature, AF are divided into:

Existing only at the moment of production, therefore by their nature they are not capable of accumulation (light, vibration, etc.);

Those that are able to persist in nature for a long time after their production, which leads to their accumulation - accumulation - and increased impact on nature.

The second group of AF includes artificial relief, reservoirs, chemical and radioactive substances, and the like. These factors are very dangerous, as their concentrations and areas grow over time, and, accordingly, the intensity of the impact on the elements of nature. Some radioactive substances obtained by man from the bowels of the Earth and introduced into the active circulation of substances can exhibit radioactivity for hundreds and thousands of years, while exerting a negative impact on nature. The ability to accumulate sharply enhances the role of AF in the development of nature, and in some cases even is decisive in determining the possibility of the existence of individual species and organisms.

During the migration process, some factors can move from one environment to another and act in all environments that are in a particular region. Thus, in the event of an accident at a nuclear power plant, radioactive substances spread in the atmosphere, and also pollute soils, penetrate into groundwater and settle in water bodies. And solid emissions from industrial enterprises from the atmosphere fall onto the soil and into water bodies. This feature is inherent in many AF from a subgroup of factors-substances. Some sustainable chemical factors in the process of cycling, substances are carried out of water bodies with the help of organisms onto land, and then they are again washed away into water bodies - this is how long-term circulation and the effect of the factor in a number of natural environments occur.

The effect of the anthropogenic factor on living organisms depends not only on its quality, but also on the quantity per unit of space, called the dose of the factor. The dose of a factor is a quantitative characteristic of a factor in a certain space. The dose of the grazing factor will be the number of animals of a certain species per hectare of pasture per day or grazing season. The determination of its optimum is closely related to the dose of the factor. AF, depending on their dose, can affect organisms in different ways or be indifferent to them. Some doses of the factor cause a maximum of positive changes in nature and practically do not cause negative (direct and indirect) changes. they are called optimal, or optimum.

Some AF continuously affect nature, others - periodically or sporadically. Therefore, according to the frequency, they are divided into:

Continuously acting - pollution of the atmosphere, water and soil by emissions from industrial enterprises and the extraction of minerals from the bowels;

periodic factors - plowing the soil, growing and harvesting agricultural crops, grazing domestic animals, etc. These factors directly affect nature only at certain hours, therefore they are associated with the seasonal and daily frequency of AF action;

Sporadic factors - vehicle accidents that lead to environmental pollution, explosions of nuclear and thermonuclear devices, forest fires, etc. They operate at any time, although in some cases they can be tied to a specific season.

It is very important to distinguish between anthropogenic factors according to the changes in which they have or can have an impact on nature and living organisms. Therefore, they are also divided according to the stability of zooming changes in nature:

AF causing temporary reverse changes - any temporary impact on nature does not lead to the complete destruction of species; pollution of water or air by unstable chemicals, etc.;

AF causing relatively irreversible changes - individual cases of the introduction of new species, the creation of small reservoirs, the destruction of some water bodies, etc.;

AF that cause absolutely irreversible changes in nature - the complete destruction of which species of plants and animals, the complete withdrawal from mineral deposits, etc.

The action of some AF can cause the so-called anthropogenic stress of ecosystems, which can be of two types:

Acute stress, which is characterized by a sudden onset, a rapid rise in intensity and a short duration of disturbances in ecosystem components;

Chronic stress, which is characterized by disturbances of low intensity, but they continue for a long time or often recur.

Natural ecosystems are able to withstand acute stress or recover from it. Potential stressors include, for example, industrial waste. Particularly dangerous among them are those that include man-made new chemicals in which ecosystem components do not yet have adaptations. The chronic action of these factors can lead to significant changes in the structure and functions of communities of organisms in the process of acclimatization and genetic adaptation to them.

In the process of social metabolism (that is, the metabolism in the process of nature management), substances and energy appear in the environment, created with the help of technological processes(anthropogenic factors). Some of them have long been called "pollution". So, pollution should be considered those AP, which negatively affect the organisms and resources of inanimate nature that are valuable for humans. In other words, pollution is everything that appears in the environment and in the wrong place, at the wrong time and in the wrong quantities that are usually inherent in nature, and brings it out of balance. In general, there are a huge number of forms of pollution (Fig. 3.5).

The whole variety of forms of human pollution of the natural environment can be reduced to the following main types (Table 3.2):

o Mechanical pollution - pollination of the atmosphere, the presence of solid particles in water and soil, as well as in outer space.

o Physical pollution - radio waves, vibration, heat and radioactivity, etc.

o Chemical - pollution by gaseous and liquid chemical compounds and elements, as well as their solid fractions.

o Biological contamination includes pathogens, pests, dangerous competitors, some predators.

o Radiation - excess of the natural level of content in the environment of radioactive substances.

o Information pollution - changes in the properties of the environment, impairs its function as a carrier of information.

Table 3.2. Characteristics of the main types of environmental pollution

Type of pollution		Characteristic
1. Mechanical		Clogging the environment with agents that have only a mechanical effect without physico-chemical consequences (for example, garbage)
2. Chemical		Changing the chemical properties of the environment, which negatively affects ecosystems and technological devices
3. Physical	Changes in the physical parameters of the environment: temperature and energy (thermal or thermal), wave (light, noise, electromagnetic), radiation (radiation or radioactive), etc.
3.1. Thermal (thermal)	Increase in ambient temperature, mainly as a result of industrial emissions of heated air, gases and water; may also occur as a secondary result of change chemical composition environments
3.2. light	Violation of the natural illumination of the area as a result of the action of artificial light sources; can lead to anomalies in the life of plants and animals
3.3. Noise	Increasing the noise intensity to a more natural level; causes increased fatigue in a person, a decrease in mental activity, and when 90-130 dB is reached, a gradual loss of hearing
3.4. electromagnetic	Changes in the electromagnetic properties of the environment (cause power lines, radio and television, the operation of some industrial and domestic installations, etc.); leads to global and local geographic anomalies and changes in subtle biological structures
4. Radiation	Exceeding the natural level of content in the environment of radioactive substances
5. Biological	Penetration into ecosystems and technological devices various kinds animals and plants that disturb the ecological balance or cause socio-economic losses
5.1. Biotic	Distribution of certain, as a rule, undesirable for people, biogenic substances (excretions, dead bodies, etc.) or those that disturb the ecological balance
5.2. Microbiological	o Appearance extremely a large number microorganisms as a result of their mass reproduction on anthropogenic substrates or in environments modified by man in the course of economic activity. o The acquisition of a previously harmless form of microorganism with pathogenic properties or the ability to suppress other organisms in the community
6. Informational	Changing the properties of the environment, worsens the functions of the storage medium

Rice. 3.5.

One of the indicators characterizing one or another degree of environmental pollution is the specific ability to pollute, that is, the numerical ratio of a ton of products passing through one of the systems of social metabolism to the weight of substances emitted into nature and falls on this ton. For example, for agricultural production, the substances emitted into nature per ton of products include undeveloped and washed away fertilizers and pesticides, organic substances from livestock complexes, etc. For industrial enterprises, these are all solid, gaseous and liquid substances released into nature. For different types transport calculations are carried out per ton of transported products, and pollution should include not only vehicle emissions, but also those goods that were dispersed during transportation.

The concept of "specific capacity for pollution" should be distinguished from the concept of "specific pollution"1, that is, the degree of pollution of the environment, has already been implemented. This degree is determined separately for conventional chemicals, thermal and radiation pollution, which is associated with their different quality. Also, specific pollution must be calculated separately for soil, water and air. For soil, this will be the total weight of all pollution per 1 m2 per year, for water and air - per 1 m3 per year. For example, specific thermal pollution is the number of degrees by which the environment is heated by anthropogenic factors at a certain moment or on average per year.

The impact of anthropogenic factors on ecosystem components is not always negative. Positive will be such an anthropogenic impact that causes changes in nature that are favorable for humans in the existing nature of the interaction between society and nature. But at the same time, for individual elements of nature, it can also be negative. For example, the destruction of harmful organisms is positive for humans, but at the same time harmful to these organisms; the creation of reservoirs is beneficial to humans, but harmful to nearby soils, etc.

AF differ in the results in the natural environment, which leads or can lead to their action. Therefore, according to the nature of the aftereffect of the influence of AF, the following possible groups of consequences in nature are distinguished:

Destruction or complete destruction of individual elements of nature;

Changes in the properties of these elements (for example, a sharp decrease in income sun rays to Earth as a result of atmospheric dustiness, which leads to climate change and worsens the conditions for photosynthesis by plants)

An increase in those that already exist, and the creation of new elements of nature (for example, the increase and creation of new forest belts, the creation of reservoirs, etc.);

Movement in space (many species of plants and animals, including pathogens, move with vehicles).

When studying the consequences of AF exposure, one should take into account the fact that these consequences may manifest themselves not only in our time, but also in the future. Thus, the consequences of the introduction of new species into ecosystems by man appear only after decades; ordinary chemical pollution often cause serious impairment of vital functions only when they accumulate in living organisms, that is, some time after the direct impact of the factor. Modern nature, when many of its elements are direct or indirect results of human activity, bears very little resemblance to the previous one as a result of changes made by man. All these changes at the same time are anthropogenic factors that can be considered elements of modern nature. However, there are a number of AFs that cannot be called elements of nature, because they belong exclusively to the activities of society, for example, the influence of vehicles, cutting down trees, etc. At the same time, reservoirs, artificial forests, relief and other works of man should be considered anthropogenic elements of nature. , which are also secondary AFs.

It is important to show all types of anthropogenic activities and their scale in each region. For this purpose, a qualitative and quantitative characterization of anthropogenic factors is carried out. Qualitative assessment of AF is carried out in accordance with the usual methods of natural sciences; evaluate the main quality indicators of AF: general character - Chemical substance, radio waves, pressure, etc.; basic parameters - wavelength, intensity, concentration, speed of movement, etc.; the time and duration of the factor - continuously during the day, in the summer season, and the like; as well as the nature of the influence of AF on the object under study - movement, destruction or change in properties, etc.

Quantitative characterization of AF is carried out to determine the scale of their impact on the components of the natural environment. At the same time, the following main quantitative indicators of AF are studied:

The size of the space in which the factor is detected and operates;

The degree of saturation of space with this factor;

The total number of elementary and complex factors in this space;

The degree of damage to objects;

The degree of coverage by the action of the factor of all objects on which it affects.

The size of the space in which the anthropogenic factor is found is based on expeditionary research and the determination of the area of ​​action of this factor. The degree of saturation of space by a factor is the percentage of the space actually occupied by it to the area of ​​the factor's action. The total number of factors (elementary and complex) is an important complex indicator of the degree of human impact as an anthropogenic factor on nature. To solve many issues related to nature protection, it is important to have general idea about the power and breadth of the effect of AF on nature, which is called the intensity of the anthropogenic impact. An increase in the intensity of anthropogenic impact should be accompanied by a corresponding increase in the scale of environmental protection measures.

All of the above indicates the urgency of the tasks of production management and the nature of the action of various anthropogenic factors. In other words, the management of AF is the regulation of their set, distribution in space, qualitative and quantitative features in order to ensure optimal conditions for the development of society in its interaction with nature. Today, there are many ways to control AF, but all of them require improvement. One of these ways is the complete cessation of the production of a certain factor, the other is a decrease or, conversely, an increase in the production of certain factors. Another effective way is the neutralization of one factor by another (for example, deforestation is neutralized by their re-planting, the destruction of landscapes by their reclamation, etc.). Man's ability to control the action of AF on nature will eventually make rational control of all social metabolism.

Summing up, it should be emphasized that for any impact of natural abiotic and biotic factors in living organisms, certain adaptive (adaptive) properties produced in the process of evolution, while for most anthropogenic factors that act predominantly suddenly (unpredictable impact), there are no such adaptations in living organisms. . It is this feature of the action of anthropogenic factors on nature that people must constantly remember and take into account in any activity related to the natural environment.

In the course of the historical process of interaction between nature and society, there is a continuous increase in the influence of anthropogenic factors on the environment.

In terms of scale and degree of impact on forest ecosystems, one of the most important places among anthropogenic factors is occupied by final fellings. (The felling of the forest within the allowable cutting area and in compliance with ecological and forestry requirements is one of the necessary conditions for the development of forest biogeocenoses.)

The nature of the impact of final felling on forest ecosystems largely depends on the applied logging equipment and technology.

IN last years new heavy multi-operational logging equipment came to the forest. Its implementation requires strict adherence to the technology of logging operations, otherwise undesirable environmental consequences are possible: the death of undergrowth of economically valuable species, a sharp deterioration in the water-physical properties of soils, an increase in surface runoff, the development of erosion processes, etc. This is confirmed by the data of a field survey conducted by Soyuzgiproleskhoz specialists in some areas of our country. At the same time, there are many facts when the reasonable use of new technology in compliance with the technological schemes of logging operations, taking into account forestry and environmental requirements, ensured the necessary preservation of undergrowth and created favorable conditions for the restoration of forests with valuable species. In this regard, noteworthy is the experience of working with new equipment of loggers of the Arkhangelsk region, who, using the developed technology, achieve the preservation of 60% of viable undergrowth.

Mechanized logging significantly changes the microrelief, soil structure, its physiological and other properties. When using fellers (VM-4) or fellers and skidders (VTM-4) in the summer, up to 80-90% of the cutting area is mineralized; in conditions of hilly and mountainous terrain, such impacts on the soil increase surface runoff by a factor of 100, increase soil erosion, and, consequently, reduce its fertility.

Clearcutting can cause especially great harm to forest biogeocenoses and the environment in general in areas with an easily vulnerable ecological balance (mountainous regions, tundra forests, permafrost regions, etc.).

Industrial emissions have a negative impact on vegetation and especially on forest ecosystems. They affect plants directly (through the assimilation apparatus) and indirectly (change the composition and forest-growing properties of the soil). Harmful gases affect the above-ground organs of the tree and impair the vital activity of the microflora of the roots, as a result of which growth is sharply reduced. The predominant gaseous toxicant is sulfur dioxide - a kind of indicator of air pollution. Significant harm is caused by ammonia, carbon monoxide, fluorine, hydrogen fluoride, chlorine, hydrogen sulfide, nitrogen oxides, sulfuric acid vapors, etc.

The degree of damage to plants by pollutants depends on a number of factors, and above all on the type and concentration of toxicants, the duration and time of their exposure, as well as on the state and nature of forest plantations (their composition, age, density, etc.), meteorological and other conditions.

More resistant to the action of toxic compounds are middle-aged, and less resistant - mature and overmature plantations, forest crops. Hardwoods are more resistant to toxicants than conifers. High-density with abundant undergrowth and undisturbed tree structure is more stable than sparse artificial plantations.

The action of high concentrations of toxicants on the stand in a short period leads to irreversible damage and death; long-term exposure to low concentrations causes pathological changes in forest stands, and low concentrations cause a decrease in their vital activity. Forest damage is observed in almost any source of industrial emissions.

More than 200 thousand hectares of forests have been damaged in Australia, where up to 580 thousand tons of SO 2 falls annually with precipitation. In the FRG, 560,000 hectares were affected by harmful industrial emissions, in the GDR, 220, Poland, 379, and Czechoslovakia, 300,000 hectares. The action of gases extends over fairly considerable distances. Thus, in the United States, latent damage to plants was noted at a distance of up to 100 km from the emission source.

The harmful effect of emissions from a large metallurgical plant on the growth and development of forest stands extends to a distance of up to 80 km. Observations of the forest in the area of ​​the chemical plant from 1961 to 1975 showed that, first of all, pine plantations began to dry out. Over the same period, the average radial increment fell by 46% at a distance of 500 m from the emission source and by 20% at 1000 m from the emission site. In birch and aspen, the foliage was damaged by 30-40%. In the 500-meter zone, the forest completely dried up 5-6 years after the onset of damage, in the 1000-meter zone - after 7 years.

In the affected area from 1970 to 1975, there were 39% of dried trees, 38% of severely weakened and 23% of weakened trees; at a distance of 3 km from the plant, there was no noticeable damage to the forest.

The greatest damage to forests from industrial emissions into the atmosphere is observed in areas of large industrial and fuel and energy complexes. There are also smaller-scale lesions, which also cause considerable harm, reducing the environmental and recreational resources of the region. This applies primarily to sparsely forested areas. To prevent or sharply reduce the damage to forests, it is necessary to implement a set of measures.

The allocation of forest lands for the needs of a particular sector of the national economy or their redistribution according to their purpose, as well as the acceptance of lands into the state forest fund, are one of the forms of influencing the state of forest resources. Relatively large areas are allocated for agricultural land, for industrial and road construction, significant areas are used by mining, energy, construction and other industries. Pipelines for pumping oil, gas, etc. stretch for tens of thousands of kilometers through forests and other lands.

The impact of forest fires on environmental change is great. The manifestation and suppression of the vital activity of a number of components of nature is often associated with the action of fire. In many countries of the world, the formation of natural forests is to some extent associated with the influence of fires, which have a negative impact on many forest life processes. Forest fires cause serious injuries to trees, weaken them, cause the formation of windblows and windbreaks, reduce the water protection and other useful functions of the forest, and promote the reproduction of harmful insects. Influencing all components of the forest, they make serious changes in forest biogeocenoses and ecosystems as a whole. True, in some cases, under the influence of fires, favorable conditions are created for the regeneration of the forest - the germination of seeds, the appearance and formation of self-seeding, especially pine and larch, and sometimes spruce and some other tree species.

On the globe, forest fires annually cover an area of ​​up to 10-15 million hectares or more, and in some years this figure more than doubles. All this puts the problem of combating forest fires in the category of priorities and requires great attention to it from forestry and other bodies. The severity of the problem is increasing due to the rapid development of the national economic development of poorly inhabited forest areas, the creation of territorial production complexes, population growth and migration. This applies primarily to the forests of the West Siberian, Angara-Yenisei, Sayan and Ust-Ilim industrial complexes, as well as to the forests of some other regions.

Serious tasks for the protection of the natural environment arise in connection with the increase in the scale of the use of mineral fertilizers and pesticides.

Despite their role in increasing the yield of agricultural and other crops, high economic efficiency, it should be noted that if scientifically based recommendations for their use are not followed, negative consequences may also occur. With careless storage of fertilizers or poor incorporation into the soil, cases of poisoning of wild animals and birds are possible. Of course, the chemical compounds used in forestry and especially in agriculture in the fight against pests and diseases, unwanted vegetation, in the care of young plantations, etc., cannot be classified as completely harmless to biogeocenoses. Some of them have a toxic effect on animals, some, as a result of complex transformations, form toxic substances that can accumulate in the body of animals and plants. This obliges to strictly monitor the implementation of the approved rules for the use of pesticides.

The use of chemicals in the care of young forest plantations increases the risk of fire, often reduces the resistance of plantations to forest pests and diseases, and can have a negative impact on plant pollinators. All this should be taken into account when managing the forest with the use of chemicals; special attention should be paid in this case to water protection, recreational and other categories of forests for protective purposes.

Recently, the scale of hydrotechnical measures has been expanding, water consumption is increasing, and settling tanks are being installed in forest areas. Intensive water intake affects the hydrological regime of the territory, and this, in turn, leads to the violation of forest plantations (often they lose their water protection and water regulation functions). Flooding can cause significant negative consequences for forest ecosystems, especially during the construction of a hydroelectric power plant with a system of reservoirs.

The creation of large reservoirs leads to the flooding of vast territories and the formation of shallow waters, especially in flat conditions. The formation of shallow waters and swamps worsens the sanitary and hygienic situation and adversely affects the natural environment.

Livestock grazing causes particular damage to the forest. Systematic and unregulated grazing leads to soil compaction, destruction of herbaceous and shrubby vegetation, damage to undergrowth, thinning and weakening of the forest stand, decrease in current growth, damage to forest plantations by pests and diseases. When undergrowth is destroyed, insectivorous birds leave the forest, since their life and nesting are most often associated with the lower tiers of forest plantations. Grazing causes the greatest danger in mountainous regions, since these territories are most susceptible to erosion processes. All this requires special attention and caution when using forest areas for pastures, as well as for haymaking. An important role in the implementation of measures for a more efficient and rational use of forest areas for these purposes is called upon to play the new rules for haymaking and grazing in the forests of the USSR, approved by the Decree of the Council of Ministers of the USSR of April 27, 1983 No.

Serious changes in the biogeocenosis are caused by the recreational use of forests, especially unregulated ones. In places of mass recreation, a strong compaction of the soil is often observed, which leads to a sharp deterioration in its water, air and thermal regimes, and a decrease in biological activity. As a result of excessive trampling of the soil, entire plantations or individual groups of trees can die (they are weakened to such an extent that they become victims of harmful insects and fungal diseases). Most often, the forests of green areas located 10-15 km from the city, in the vicinity of recreation centers and places of mass events, suffer from the recreational press. Some damage is caused to forests by mechanical damage, various kinds of waste, garbage, etc. Coniferous plantations (spruce, pine) are the least resistant to anthropogenic impact, deciduous plantations (birch, linden, oak, etc.) suffer to a lesser extent.

The degree and course of digression are determined by the resistance of the ecosystem to the recreational load. The resistance of the forest to recreation determines the so-called capacity of the natural complex (the maximum number of vacationers that can withstand the biogeocenosis without damage). An important measure aimed at preserving forest ecosystems, increasing their recreational properties is the comprehensive improvement of the territory with exemplary management of the economy here.

Negative factors act, as a rule, not in isolation, but in the form of certain interrelated components. At the same time, the action of anthropogenic factors often enhances the negative impact of natural ones. For example, the impact of toxic emissions from industry and transport is most often combined with an increased recreational load on forest biogeocenoses. In turn, recreation and tourism create conditions for the occurrence of forest fires. The action of all these factors sharply reduces the biological resistance of forest ecosystems to pests and diseases.

When studying the influence of anthropogenic and natural factors on the forest biogeocenosis, it must be taken into account that the individual components of the biogeocenosis are closely related both to each other and to other ecosystems. quantitative change one of them inevitably causes a change in all the others, and a significant change in the entire forest biogeocenosis inevitably affects each of its components. So, in the areas of constant action of toxic emissions from industry, the species composition of vegetation and wildlife is gradually changing. Of tree species, conifers are the first to be damaged and die. Due to the premature death of needles and a decrease in the length of shoots, the microclimate in the plantation changes, which affects the change in the species composition of herbaceous vegetation. Grasses begin to develop, contributing to the reproduction of field mice, systematically damaging forest crops.

Certain quantitative and qualitative characteristics of toxic emissions lead to disruption or even complete cessation of fruiting in most tree species, which adversely affects the species composition of birds. There are species of forest pests resistant to the action of toxic emissions. As a result, degraded and biologically unstable forest ecosystems are formed.

The problem of reducing the negative impact of anthropogenic factors on forest ecosystems through a whole system of protective and protective measures is inextricably linked with measures for the protection and rational use of all other components based on the development of an intersectoral model that takes into account the interests of the rational use of all environmental resources in their relationship.

Reduced a brief description of The ecological interconnection and interaction of all components of nature shows that the forest, like no other of them, has powerful properties to positively influence the natural environment and regulate its condition. Being an environment-forming factor and actively influencing all the processes of evolution of the biosphere, the forest is also affected by the relationship between all other components of nature unbalanced by anthropogenic impact. This gives grounds to consider the plant world and the natural processes occurring with its participation as a key factor that determines the general direction of the search for integral means of rational nature management.

Environmental schemes and programs should become an important means of identifying, preventing and solving problems in the relationship between man and nature. Such developments will help to solve these problems both in the country as a whole and in its individual territorial units.