Anthropogenic impact on nature. Coursework: Anthropogenic impact on the biosphere

Anthropogenic impact on the biosphere.

Anthropogenic impact is understood as activities related to the implementation of economic, military, recreational, cultural and other human interests, introducing physical, chemical, biological and other changes into the natural environment.

The American ecologist B. Commoner identified five main types of human intervention in environmental processes:

Simplifying the ecosystem and breaking biological cycles (plowing land, deforestation, etc.);

The concentration of dissipated energy in the form of thermal pollution;

The growth of toxic waste;

Introduction to the ecosystem of new species;

The appearance of genetic changes in plants and animals.

The depth of the environmental consequences of human impact on nature depends on several variables: population, lifestyle and environmental consciousness. The vast majority of impacts are purposeful, i.e. carried out by a person consciously in the name of achieving specific goals. So, according to WHO, out of more than 6 million known chemical compounds, about 500 thousand are practically used by humans in economic activities. Of these, about 40 thousand have properties that are harmful to humans, and 12 thousand are toxicants.

But there are also spontaneous (involuntary) anthropogenic impacts that have negative consequences. Example: the processes of flooding of the territory that occur after its development; exposure to pesticides and fertilizers used in agriculture.

As a result of human impact on the components of the biosphere, the natural environment is destabilized. The main factors of destabilization include:

Growth in consumption of natural resources and their reduction;

The growth of the world's population with a reduction in areas for habitation;

Degradation of the main components of the biosphere and a decrease in the ability of nature to self-sustain;

Climate change and the depletion of the Earth's ozone layer;

Reduction of biological diversity.

Pollution is the main and most widespread factor of human impact on the biosphere.

by pollution refers to the entry into the environment or the occurrence in it of any solid, liquid and gaseous substances, microorganisms or energies (in the form of sounds, noise, radiation) in quantities harmful to human health, animals, plants and ecosystems.

Pollution can occur as a result of natural causes (natural pollution ) or under the influence of human activity ( anthropogenic pollution ).

Natural pollutants can be dust storms, volcanic ash, mudflows, etc.

Sources of anthropogenic pollution, the most dangerous for populations of any organisms that are part of ecosystems, are industrial enterprises (chemical, metallurgical, pulp and paper, building materials, etc.), thermal power engineering, transport, agricultural production and other technologies. Under the influence of urbanization, the territories of large cities and industrial agglomerations are most polluted.

According to the objects of pollution, pollution of surface and ground waters, atmospheric air pollution, soil pollution, etc. are distinguished. In recent years, the problems associated with the pollution of near-Earth space have also become topical.

According to the types of pollution chemical (heavy metals, surfactants, pesticides, etc.) , physical (thermal, noise, electromagnetic, etc.) and biological ( pathogens, genetic engineering products, etc.) pollution.

At the same time, chemical pollution is divided into primary and secondary. Primary pollution - these are the pollutants that enter the environment from land-based sources of emissions (natural or anthropogenic). Secondary pollution is the result of physical and chemical transformations of primary pollution in the natural environment.

In terms of scale and distribution, pollution can be local ( local), regional and global.

One of the pollution classifications, based on a systematic approach, was made by G. V. Stadnitsky and A. I. Rodionov (1988). The authors understand pollution as any undesirable anthropogenic changes for ecosystems and divide it into

- ingredient (mineral and organic) pollution as a set of substances alien to natural biogeocenoses (for example, domestic wastewater, pesticides, combustion products in internal combustion engines, etc.);

- parametric pollution associated with changes in the qualitative parameters of the environment (thermal, noise, radiation, electromagnetic);

- biocenotic pollution causing a disturbance in the composition and structure of populations of living organisms (overfishing, directed introduction and acclimatization of species, etc.);

- stationary-destructive pollution (station - population habitat, destruction - destruction) associated with the violation and transformation of landscapes and ecosystems in the process of nature management (regulation of watercourses, urbanization, deforestation, etc.).

When investigating environmental pollution, it is necessary to take into account the type and source of pollution and the environmental consequences that they cause.

MINISTRY OF EDUCATION OF THE RUSSIAN FEDERATION

STATE EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

"KUZBAS STATE TECHNICAL UNIVERSITY"

Department of Chemical Technology of Solid Fuels and Ecology

TEST

By discipline

"Ecology"

Completed by: group student

OPz-08 Vasiliev S. S.

Checked:

Kemerovo, 2009

Introduction

2.1 Air pollution

2.2 Soil pollution

2.3 Pollution of natural waters

Conclusion

Used Books

Introduction

Man has always used the environment mainly as a source of resources, but for a very long time his activity did not have a noticeable impact on the biosphere. Only at the end of the last century, changes in the biosphere under the influence of economic activity attracted the attention of scientists. In the first half of this century, these changes have been growing and are now like an avalanche hitting human civilization. In an effort to improve the conditions of his life, a person constantly increases the pace of material production, without thinking about the consequences. With this approach, most of the resources taken from nature are returned to it in the form of waste, often poisonous or unsuitable for disposal. This poses a threat to the existence of the biosphere, and of man himself. The purpose of the abstract is to highlight: the current state of the natural environment; characterize the main sources of pollution of the biosphere; identify ways to protect the environment from pollution.

1. Current state of the natural environment

Let us consider some features of the current state of the biosphere and the processes taking place in it.

The global processes of formation and movement of living matter in the biosphere are connected and accompanied by the circulation of huge masses of matter and energy. Unlike purely geological processes, biogeochemical cycles involving living matter have a much higher intensity, speed, and amount of matter involved in the circulation.

With the advent and development of mankind, the process of evolution has noticeably changed. In the early stages of civilization, cutting down and burning forests for agriculture, grazing, fishing and hunting for wild animals, wars devastated entire regions, led to the destruction of plant communities, and the extermination of certain animal species. With the development of civilization, especially the rapid after the industrial revolution of the end of the Middle Ages, mankind seized ever greater power, an ever greater ability to involve and use huge masses of matter to satisfy their growing needs - both organic, living, and mineral, inert.

Population growth and the expanding development of agriculture, industry, construction, and transport caused massive deforestation in Europe and North America. Livestock grazing on a large scale led to the death of forests and grass cover, to erosion (destruction) of the soil layer (Central Asia, North Africa, southern Europe and the USA). Exterminated dozens of animal species in Europe, America, Africa.

Scientists suggest that soil depletion in the territory of the ancient Central American Mayan state as a result of slash-and-burn agriculture was one of the reasons for the death of this highly developed civilization. Similarly, in ancient Greece, vast forests disappeared as a result of deforestation and immoderate grazing. This increased soil erosion and led to the destruction of the soil cover on many mountain slopes, increased the aridity of the climate and worsened agricultural conditions.

The construction and operation of industrial enterprises, mining have led to serious violations of natural landscapes, pollution of soil, water, air with various wastes.

Real shifts in biospheric processes began in the 20th century as a result of another industrial revolution. The rapid development of energy, mechanical engineering, chemistry, and transport has led to the fact that human activity has become comparable in scale with the natural energy and material processes occurring in the biosphere. The intensity of mankind's consumption of energy and material resources grows in proportion to the population and even outstrips its growth.

Warning about the possible consequences of the expanding human intervention in nature, half a century ago, Academician V. I. Vernadsky wrote: “Man becomes a geological force capable of changing the face of the Earth.” This warning was prophetically justified. The consequences of anthropogenic (man-made) activities are manifested in the depletion of natural resources, pollution of the biosphere with production waste, destruction of natural ecosystems, changes in the structure of the Earth's surface, and climate change. Anthropogenic impacts lead to disruption of almost all natural biogeochemical cycles.

As a result of the combustion of various fuels, about 20 billion tons of carbon dioxide are released into the atmosphere every year and a corresponding amount of oxygen is absorbed. The natural reserve of CO2 in the atmosphere is about 50,000 billion tons. This value fluctuates and depends, in particular, on volcanic activity. However, anthropogenic emissions of carbon dioxide exceed natural ones and currently account for a large share of its total amount. An increase in the concentration of carbon dioxide in the atmosphere, accompanied by an increase in the amount of aerosol (fine particles of dust, soot, suspensions of solutions of some chemical compounds), can lead to noticeable climate changes and, accordingly, to a violation of the equilibrium relationships that have developed over millions of years in the biosphere.

The result of a violation of the transparency of the atmosphere, and, consequently, of the thermal balance, may be the occurrence of a "greenhouse effect", that is, an increase in the average temperature of the atmosphere by several degrees. This can cause the melting of glaciers in the polar regions, an increase in the level of the World Ocean, a change in its salinity, temperature, global climate disturbances, flooding of coastal lowlands, and many other adverse consequences.

The release of industrial gases into the atmosphere, including compounds such as carbon monoxide CO (carbon monoxide), oxides of nitrogen, sulfur, ammonia and other pollutants, leads to inhibition of the vital activity of plants and animals, metabolic disorders, poisoning and death of living organisms.

Uncontrolled influence on the climate in combination with irrational agriculture can lead to a significant decrease in soil fertility, large fluctuations in crop yields. According to UN experts, in recent years, fluctuations in agricultural production have exceeded 1%. But a decrease in food production even by 1% can lead to the death of tens of millions of people from starvation.

Catastrophically reducing forests on our planet, irrational deforestation and fires have led to the fact that in many places, once completely covered with forests, by now they have survived only on 10-30% of the territory. The area of tropical forests in Africa has decreased by 70%, in South America by 60%, in China only 8% of the territory is covered with forest.

1.1 Environmental pollution

The appearance in the natural environment of new components caused by human activity or any grandiose natural phenomena (for example, volcanic activity) is characterized by the term pollution. In general, pollution is the presence in the environment of harmful substances that disrupt the functioning of ecological systems or their individual elements and reduce the quality environment in terms of human habitation or economic activity. This term characterizes all bodies, substances, phenomena, processes that in a given place, but not at the time and not in the amount that is natural for nature, appear in the environment and can bring its systems out of equilibrium.

The environmental impact of polluting agents can manifest itself in different ways; it can affect either individual organisms (manifested at the organismal level), or populations, biocenoses, ecosystems, and even the biosphere as a whole.

At the organismic level, there may be a violation of individual physiological functions of organisms, a change in their behavior, a decrease in the rate of growth and development, a decrease in resistance to the effects of other adverse environmental factors.

At the level of populations, pollution can cause changes in their numbers and biomass, fertility, mortality, structural changes, annual migration cycles, and a number of other functional properties.

At the biocenotic level, pollution affects the structure and functions of communities. The same pollutants affect different components of communities in different ways. Accordingly, the quantitative ratios in the biocenosis change, up to the complete disappearance of some forms and the appearance of others. The spatial structure of communities is changing, the chains of decomposition (detrital) begin to prevail over pastures, dying off - over production. Ultimately, there is degradation of ecosystems, their deterioration as elements of the human environment, a decrease in the positive role in the formation of the biosphere, and economic depreciation.

There are natural and anthropogenic pollution. Natural pollution occurs as a result of natural causes - volcanic eruptions, earthquakes, catastrophic floods and fires. Anthropogenic pollution is the result of human activity.

At present, the total capacity of anthropogenic pollution sources in many cases exceeds the capacity of natural ones. Thus, natural sources of nitrogen oxide emit 30 million tons of nitrogen per year, and anthropogenic - 35-50 million tons; sulfur dioxide, respectively, about 30 million tons and more than 150 million tons. As a result of human activity, lead enters the biosphere almost 10 times more than in the process of natural pollution.

Pollutants resulting from human activities and their impact on the environment are very diverse. These include: compounds of carbon, sulfur, nitrogen, heavy metals, various organic substances, artificially created materials, radioactive elements, and much more.

Thus, according to experts, about 10 million tons of oil enter the ocean every year. Oil on water forms a thin film that prevents gas exchange between water and air. Settling to the bottom, oil enters bottom sediments, where it disrupts the natural processes of life of bottom animals and microorganisms. In addition to oil, there has been a significant increase in the release into the ocean of domestic and industrial wastewater containing, in particular, such dangerous pollutants as lead, mercury, and arsenic, which have a strong toxic effect. Background concentrations of such substances in many places have already been exceeded by dozens of times.

Each pollutant has a certain negative impact on nature, so their entry into the environment must be strictly controlled. The legislation establishes for each pollutant the maximum allowable discharge (MPD) and the maximum allowable concentration (MPC) of it in the natural environment.

Maximum allowable discharge (MPD) is the mass of a pollutant emitted by individual sources per unit of time, the excess of which leads to adverse effects on the environment or is dangerous to human health. The maximum allowable concentration (MAC) is understood as the amount of a harmful substance in the environment that does not adversely affect human health or its offspring through permanent or temporary contact with it. Currently, when determining MPC, not only the degree of influence of pollutants on human health is taken into account, but also their impact on animals, plants, fungi, microorganisms, as well as on the natural community as a whole.

Special environmental monitoring (surveillance) services monitor compliance with the established standards for MPCs and MPCs for harmful substances. Such services have been established in all regions of the country. Their role is especially important in large cities, near chemical plants, nuclear power plants and other industrial facilities. Monitoring services have the right to apply the measures provided by law, up to the suspension of production and any work, if environmental protection standards are violated.

In addition to environmental pollution, anthropogenic impact is expressed in the depletion of the natural resources of the biosphere. The huge scale of the use of natural resources has led to a significant change in landscapes in some regions (for example, in the coal basins). If at the dawn of civilization, man used only about 20 chemical elements for his needs, at the beginning of the XX 60 flowed in, now more than 100 - almost the entire periodic table. Annually, about 100 billion tons of ore, fuel, mineral fertilizers are mined (extracted from the geosphere).

The rapid growth in demand for fuel, metals, minerals and their extraction led to the depletion of these resources. Thus, according to experts, while maintaining current rates of production and consumption, explored oil reserves will be exhausted in 30 years, gas - in 50 years, coal - in 200. A similar situation has developed not only with energy resources, but also with metals (depletion of aluminum reserves is expected in 500-600 years, iron - 250 years, zinc - 25 years, lead - 20 years) and mineral resources such as asbestos, mica, graphite, sulfur.

This is a far from complete picture of the ecological situation on our planet at the present time. Even individual successes in environmental protection activities cannot noticeably change the general course of the process of the harmful influence of civilization on the state of the biosphere.

2. Atmosphere - the outer shell of the biosphere

2.1 Air pollution

Various negative changes in the Earth's atmosphere are mainly associated with changes in the concentration of minor components of atmospheric air.

There are two main sources of air pollution: natural and anthropogenic.

The natural source is volcanoes, dust storms, weathering, forest fires, decomposition processes of plants and animals.

The main anthropogenic sources of air pollution include enterprises of the fuel and energy complex, transport, and various machine-building enterprises.

In addition to gaseous pollutants, a large amount of particulate matter enters the atmosphere. These are dust, soot and soot. A great danger is the pollution of the natural environment with heavy metals. Lead, cadmium, mercury, copper, nickel, zinc, chromium, vanadium have become almost constant components of the air in industrial centers. Lead air pollution is a particularly acute problem.

Global air pollution affects the state of natural ecosystems, especially the green cover of our planet. One of the most obvious indicators of the state of the biosphere is forests and their well-being.

Acid rains, caused mainly by sulfur dioxide and nitrogen oxides, cause great harm to forest biocenoses. It has been established that conifers suffer from acid rain to a greater extent than broad-leaved ones.

Only on the territory of our country the total area of forests affected by industrial emissions has reached 1 million hectares. A significant factor in forest degradation in recent years is environmental pollution with radionuclides. Thus, as a result of the accident at the Chernobyl nuclear power plant, 2.1 million hectares of forests were affected.

Especially severely affected are green spaces in industrial cities, the atmosphere of which contains a large amount of pollutants.

The air environmental problem of ozone depletion, including the appearance of ozone holes over Antarctica and the Arctic, is associated with the excessive use of freons in production and everyday life.

2.2 Soil pollution

Under normal natural conditions, all processes occurring in the soil are in balance. But often a person is to blame for the violation of the equilibrium state of the soil. As a result of the development of human economic activity, pollution, a change in the composition of the soil, and even its destruction occur. At present, there is less than one hectare of arable land for every inhabitant of our planet. And these insignificant areas continue to shrink due to inept human activities.

Enormous areas of fertile lands are destroyed in the mining industry, during the construction of enterprises and cities. The destruction of forests and natural grass cover, repeated plowing of the land without observing the rules of agricultural technology leads to soil erosion - the destruction and washing away of the fertile layer by water and wind (Fig. 58). Erosion has now become a worldwide evil. It is estimated that in the last century alone, as a result of water and wind erosion, 2 billion haploferous lands of active agricultural use have been lost on the planet.

One of the consequences of the intensification of human production activity is the intense pollution of the soil cover. The main soil pollutants are metals and their compounds, radioactive elements, as well as fertilizers and pesticides used in agriculture.

Mercury and its compounds are among the most dangerous soil pollutants. Mercury enters the environment with pesticides, industrial waste containing metallic mercury and its various compounds.

Lead pollution of soils is even more widespread and dangerous. It is known that during the smelting of one ton of lead, up to 25 kg of lead is released into the environment with waste. Lead compounds are used as additives to gasoline, so motor vehicles are a serious source of lead pollution. Especially a lot of lead in soils along major highways.

Near large centers of ferrous and non-ferrous metallurgy, soils are contaminated with iron, copper, zinc, manganese, nickel, aluminum and other metals. In many places, their concentration is tens of times higher than the MPC.

Radioactive elements can get into the soil and accumulate in it as a result of precipitation from atomic explosions or during the removal of liquid and solid waste from industrial enterprises, nuclear power plants or research institutions associated with the study and use of atomic energy. Radioactive substances from soils get into plants, then into animal and human organisms, accumulate in them.

Modern agriculture, which widely uses fertilizers and various chemicals to control pests, weeds and plant diseases, has a significant impact on the chemical composition of soils. At present, the amount of substances involved in the cycle in the process of agricultural activity is approximately the same as in the process of industrial production. At the same time, the production and use of fertilizers and pesticides in agriculture is increasing every year. Inept and uncontrolled use of them leads to disruption of the circulation of substances in the biosphere.

Of particular danger are persistent organic compounds used as pesticides. They accumulate in the soil, input, bottom sediments of reservoirs. But most importantly, they are included in ecological food chains, move from soil and water to plants, then animals, and ultimately enter the human body with food.

2.3 Pollution of natural waters

Pollution of water bodies is understood as a decrease in their biospheric functions and economic significance as a result of the entry of harmful substances into them.

One of the main water pollutants is oil and oil products. Oil can get into the water as a result of its natural outflows in the areas of occurrence. But the main sources of pollution are associated with human activities: oil production, transportation, processing and use of oil as fuel and industrial raw materials.

Other pollutants include metals (eg mercury, lead, zinc, copper, chromium, tin, manganese), radioactive elements, pesticides from agricultural fields, and runoff from livestock farms. A small danger to the aquatic environment from metals is mercury, lead and their compounds.

Expanded production (without treatment facilities) and the use of pesticides in the fields lead to severe pollution of water bodies with harmful compounds. Pollution of the aquatic environment occurs as a result of the direct introduction of pesticides during the treatment of water bodies for pest control, the entry into water bodies of water flowing from the surface of treated agricultural land, when waste from manufacturing enterprises is discharged into water bodies, as well as as a result of losses during transportation, storage and partially with precipitation.

Along with pesticides, agricultural effluents contain a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields. In addition, large amounts of organic compounds of nitrogen and phosphorus enter with runoff from livestock farms, as well as sewage. An increase in the concentration of nutrients in the soil leads to a violation of the biological balance in the reservoir.

Initially, in such a reservoir, the number of microscopic algae increases sharply. With an increase in the food supply, the number of crustaceans, fish and other aquatic organisms increases. Then there is the death of a huge number of organisms. It leads to the consumption of all reserves of oxygen contained in the water, and the accumulation of hydrogen sulfide. The situation in the water changes so much that it becomes unsuitable for the existence of any forms of organisms. The reservoir gradually "dies".

One of the types of water pollution is thermal pollution. Power plants, industrial enterprises often dump heated water into a reservoir. This leads to an increase in the temperature of the water in it. With an increase in temperature in the reservoir, the amount of oxygen decreases, the toxicity of impurities polluting the water increases, and the biological balance is disturbed.

In polluted water, as the temperature rises, pathogenic microorganisms and viruses begin to multiply rapidly. Once in drinking water, they can cause outbreaks of various diseases.

In a number of regions, groundwater was an important source of fresh water. Previously, they were considered the purest. But at present, as a result of human activities, many groundwater sources are also being polluted. Often this pollution is so great that the water from them has become undrinkable.

Mankind consumes a huge amount of fresh water for its needs. Its main consumers are industry and agriculture. The most water-intensive industries are mining, steel, chemical, petrochemical, pulp and paper, and food. Nanih wastes up to 70% of all water used in industry. The main consumer of fresh water is agriculture: 60-80% of all fresh water is used for its needs.

Already at the present time, not only the territories that nature has deprived of water resources are experiencing a lack of fresh water, but also many regions that until recently were considered prosperous in this regard. Currently, the need for fresh water is not met by 20% of the urban and 75% of the rural population of the planet.

Human intervention in natural processes has affected even large rivers (such as the Volga, Don, Dnieper), changing in the direction of decreasing the volume of transported water masses (river runoff). Most of the water used in agriculture is spent on evaporation and the formation of plant biomass and, therefore, is not returned to the rivers. Already now, in the most populated areas of the country, the flow of rivers has decreased by 8%, and in such rivers as the Don, Terek, Ural - by 11-20%. The fate of the Aral Sea, which in fact ceased to exist due to the excessive intake of the waters of the Syr Darya and Amu Darya rivers for irrigation, is very dramatic.

The limited supply of fresh water is further reduced due to pollution. Wastewater (industrial, agricultural and domestic) poses the main hazard, since a significant part of the used water is returned to water basins in the form of wastewater.

3. Radiation and environmental problems in the biosphere

Radiation pollution have a significant difference from others. Radioactive nuclides are the nuclei of unstable chemical elements that emit charged particles and short-wave electromagnetic radiation. It is these particles and radiation that destroy cells when they enter the human body, as a result of which various diseases can occur, including radiation.

There are natural sources of radioactivity everywhere in the biosphere, and man, like all living organisms, has always been exposed to natural radiation. External exposure occurs due to radiation of cosmic origin and radioactive nuclides in the environment. Internal exposure is created by radioactive elements that enter the human body with air, water and food.

To quantify the impact of radiation on a person, units are used - the biological equivalent of a roentgen (rem) or a sievert (Sv): 1 Sv \u003d 100 rem. Since radioactive radiation can cause serious changes in the body, each person must know the permissible doses.

As a result of internal and external exposure, a person receives an average dose of 0.1 rem per year and, consequently, about 7 rem throughout his life. In these doses, radiation does not harm a person. However, there are areas where the annual dose is above average. So, for example, people living in high-mountainous regions, due to cosmic radiation, can receive a dose several times greater. Large doses of radiation can be in areas where the content of natural radioactive sources is high. For example, in Brazil (200 km from Sao Paulo) there is a hill where the annual dose is 25 rem. This area is uninhabited.

The greatest danger is the radioactive contamination of the biosphere as a result of human activities. Currently, radioactive elements are widely used in various fields. Negligence in the storage and transportation of these elements leads to serious radioactive contamination. Radioactive contamination of the biosphere is associated, for example, with the testing of atomic weapons.

In the second half of our century, nuclear power plants, icebreakers, nuclear-powered submarines began to be put into operation. During normal operation of nuclear facilities and industry, environmental pollution with radioactive nuclides is an insignificant fraction of the natural background. A different situation develops in case of accidents at nuclear facilities.

At present, the problem of warehousing and storage of radioactive waste from the military industry and nuclear power plants is becoming more and more acute. Every year they pose an increasing danger to the environment. Thus, the use of nuclear energy has posed new serious problems for mankind.

Human economic activity, acquiring an increasingly global character, begins to have a very tangible impact on the processes taking place in the biosphere. You have already learned about some of the results of human activity and their impact on the biosphere. Fortunately, up to a certain level, the biosphere is capable of self-regulation, which makes it possible to minimize the negative consequences of human activity. But there is a limit when the biosphere is no longer able to maintain balance. Irreversible processes begin, leading to ecological disasters. Humanity has already encountered them in a number of regions of the planet.

Mankind has significantly changed the course of a number of processes in the biosphere, including the biochemical cycle and migration of a number of elements. At present, although slowly, a qualitative and quantitative restructuring of the entire biosphere of the planet is taking place. A number of the most complex environmental problems of the biosphere have already arisen, which must be resolved in the near future.

"Greenhouse effect". Climate warming can lead to intense melting of glaciers and rising sea levels. The changes that may result from this are simply difficult to predict.

This problem could be solved by reducing carbon dioxide emissions into the atmosphere and establishing a balance in the carbon cycle.

Depletion of the ozone layer. In recent years, scientists have noted with increasing concern the depletion of the ozone layer of the atmosphere, which is a protective screen against ultraviolet radiation. Especially quickly this process takes place over the poles of the planet, where the so-called ozone holes have appeared. The danger lies in the fact that ultraviolet radiation is detrimental to living organisms.

The main reason for the depletion of the ozone layer is the use by people of chlorofluorocarbons (freons), which are widely used in production and everyday life as refrigerants, foaming agents, and solvents. aerosols. Freons intensively destroy ozone. They themselves are destroyed very slowly, within 50-200 years. In 1990, more than 1300 thousand tons of ozone-depleting substances were produced in the world.

Under the action of ultraviolet radiation, oxygen molecules (O2) decompose into free atoms, which in turn can attach to other oxygen molecules to form ozone (O3). Free oxygen atoms can also react with ozone molecules, forming two oxygen molecules. Thus, a balance is established and maintained between oxygen and ozone.

However, freon-type pollutants catalyze (accelerate) the process of ozone decomposition, upsetting the balance between it and oxygen towards a decrease in ozone concentration.

Given the danger hanging over the planet, the international community has taken the first step towards solving this problem. An international agreement has been signed, according to which the production of freons in the world by 1999 should be reduced by about 50%.

Mass deforestation is one of the most important global environmental problems of our time.

You already know that forest communities play an essential role in the normal functioning of natural ecosystems. They absorb atmospheric pollution of anthropogenic origin, protect the soil from erosion, regulate the normal flow of surface water, prevent the decrease in the level of groundwater and the silting of rivers, canals and reservoirs.

Reducing the area of forests disrupts the cycle of oxygen and carbon in the biosphere.

The reduction of forests entails the death of their richest flora and fauna. Man impoverishes the appearance of his planet.

However, it seems that humanity is already aware that its existence on the planet is inextricably linked with the life and well-being of forest ecosystems. The serious warnings of scientists, sounded in the declarations of the United Nations and other international organizations, began to find a response. In recent years, artificial afforestation and the organization of highly productive forest plantations have begun to be successfully carried out in many countries of the world.

Waste production. Waste from industrial and agricultural production has become a serious environmental problem. You already know what harm they do to the environment. Currently, attempts are being made to reduce the amount of waste that pollutes the environment. For this purpose, the most complex filters are being developed and installed, expensive treatment facilities and settling tanks are being built. But practice shows that even though they reduce the risk of pollution, they still do not solve the problem. It is known that even with the most advanced treatment, including biological, all dissolved minerals and up to 10% of organic pollutants remain in treated wastewater. Waters of this quality can become suitable for consumption only after repeated dilution with clean water.

Obviously, the solution to the problem is possible with the development and introduction into production of completely new, closed, waste-free technologies. When they are used, water will not be discharged, but will be reused in a closed cycle. All by-products will not be thrown away as waste, but will be subjected to deep processing. This will create conditions for obtaining additional products that people need and will protect the environment.

Agriculture. In agricultural production, it is important to strictly follow the rules of agricultural technology and monitor the norms of fertilizing. Since chemical pest and weed control products lead to significant ecological imbalances, a search is underway for ways to overcome this crisis in several directions.

Work is underway to breed plant varieties that are resistant to agricultural pests and diseases: selective bacterial and viral preparations are being created that affect, for example, only pests. Highly selective drugs are being developed from among hormones, antihormones and other substances that can act on the biochemical systems of certain insect species and not have a noticeable effect on other insect species or other organisms.

Energy production. Very complex environmental problems are associated with the production of energy at heat and power enterprises. The need for energy is one of the basic vital human needs. Energy is needed not only for the normal activity of modern, complexly organized human society, but also for the simple physical existence of every human organism. Currently, electricity is mainly produced at hydroelectric power plants, thermal and nuclear power plants.

Hydroelectric power plants at first glance are environmentally friendly enterprises that do not harm nature. So thoughtmany decades. In our country, many of the largest hydroelectric power plants have been built on the great rivers. Now it became clear that this construction caused great damage to both nature and people.

First of all, the construction of dams on large flat rivers leads to the flooding of vast areas for reservoirs. This is due to the resettlement of a large number of people and the loss of pasture land.

Secondly, blocking the river, the dam creates insurmountable obstacles on the migration routes of migratory and semi-anadromous fish rising to spawn in the upper reaches of the rivers.

Thirdly, the water in the reservoirs stagnates, its flow slows down, which affects the lives of all living creatures that live in the river and ureki.

Fourthly, the local increase in water affects groundwater, leads to flooding, waterlogging, bank erosion and landslides.

This list of negative consequences of the construction of hydroelectric power stations on lowland rivers can be continued. Large high-altitude dams on mountain rivers are also sources of danger, especially in areas with high seismicity. In world practice, there are several cases when the breakthrough of such dams led to huge destruction and death of hundreds and thousands of people.

From an environmental point of view, nuclear power plants are the cleanest among other currently operating energy complexes. The danger of radioactive waste is fully recognized, therefore, both the design and operating standards of nuclear power plants provide for reliable isolation from the environment of at least 99.999% of all resulting radioactive waste.

Not everyone knows that coal has a small natural radioactivity. Since TPPs burn huge volumes of fuel, their total radioactive emissions are higher than those of nuclear power plants. But this factor is secondary in comparison with the main disaster from the installation on organic fuel, applied to nature and people - emissions into the atmosphere of chemical compounds that are products of combustion.

Although nuclear power plants are more environmentally friendly than simple power plants, they carry a greater potential hazard in the event of a serious reactor accident. We were convinced of this by the example of the Chernobyl disaster. Thus, the energy industry poses seemingly insoluble environmental problems. The search for a solution to the problem is carried out in several directions.

Scientists are developing new safe reactors for nuclear power plants. The second direction is connected with the use of non-traditional renewable energy sources. This is, first of all, the energy of the Sun and wind, the heat of the earth's interior, the thermal and mechanical energy of the ocean. In many countries, including ours, not only experimental, but also industrial installations have already been created using these energy sources. They are still relatively underpowered. But many scientists believe that they have a great future.

Conclusion

Due to the increase in the scale of anthropogenic impact (human economic activity), especially in the last century, the balance in the biosphere is disturbed, which can lead to irreversible processes and raise the question of the possibility of life on the planet. This is due to the development of industry, energy, transport, agriculture and other human activities without taking into account the possibilities of the Earth's biosphere. Serious environmental problems have already arisen before mankind, requiring an immediate solution.

Used Books

1. A. M. Vladimirov, environmental protection / - L .: Gidrometeoizdat, 1991

2. G. A. Bogdanovsky "Chemical Ecology" Moscow University Publishing House 1994

3. E. A. Kriksunov and V.V. Pasechnik, A.P. Sidorin "Ecology" Publishing House "Drofa" 2005

4. N. A. Agadzhanyan, V.I. Torshin "Human Ecology" MMP "Ecocenter", KRUK2004

MINISTRY OF EDUCATION OF THE RUSSIAN FEDERATION

STATE EDUCATIONAL INSTITUTION

HIGHER PROFESSIONAL EDUCATION

"KUZBAS STATE TECHNICAL UNIVERSITY"

Department of Chemical Technology of Solid Fuels and Ecology

TEST

By discipline

"Ecology"

Completed by: group student

OPz-08 Vasiliev S. S.

Checked:

Kemerovo, 2009

Introduction

1. Current state of the natural environment

2. Atmosphere - the outer shell of the biosphere

2.1 Air pollution

2.2 Soil pollution

2.3 Pollution of natural waters

3. Radiation and environmental problems in the biosphere

Conclusion

Used Books

Let us consider some features of the current state of the biosphere and the processes taking place in it.

With the advent and development of mankind, the process of evolution has noticeably changed. In the early stages of civilization, cutting down and burning forests for agriculture, grazing, hunting and hunting for wild animals, wars devastated entire regions, led to the destruction of plant communities, and the extermination of certain animal species. As civilization developed, especially the end of the Middle Ages, which was turbulent after the industrial revolution, humanity seized ever greater power, an ever greater ability to involve and use huge masses of matter to satisfy its growing needs - both organic, living, and mineral, inert.

Construction and operation of industrial enterprises, mining have led to serious violations of natural landscapes, pollution of soil, water, air with various wastes.

Real shifts in biospheric processes began in the 20th century. as a result of the next industrial revolution. The rapid development of energy, mechanical engineering, chemistry, and transport has led to the fact that human activity has become comparable in scale with the natural energy and material processes occurring in the biosphere. The intensity of human consumption of energy and material resources is growing in proportion to the population and even ahead of its growth.

Warning about the possible consequences of the expanding intrusion of man into nature, half a century ago, Academician V. I. Vernadsky wrote: "Man is becoming a geological force capable of changing the face of the Earth." This warning was prophetically justified. The consequences of anthropogenic (man-made) activities are manifested in the depletion of natural resources, pollution of the biosphere with industrial waste, destruction of natural ecosystems, changes in the structure of the Earth's surface, and climate change. Anthropogenic impacts lead to disruption of almost all natural biogeochemical cycles.

As a result of the combustion of various fuels, about 20 billion tons of carbon dioxide and a corresponding amount of oxygen is absorbed. natural reserve CO2 in the atmosphere is about 50,000 billion m. This value fluctuates and depends, in particular, on volcanic activity. However anthropogenic emissions of carbon dioxide exceed natural ones and currently account for a large proportion of its total. An increase in the concentration of carbon dioxide in the atmosphere, accompanied by an increase in the amount of aerosol (fine particles of dust, soot, suspensions of solutions of some chemical compounds), can lead to noticeable climate changes and, accordingly, to disruption of the equilibrium relationships that have developed over millions of years in the biosphere.

The result of the violation of the transparency of the atmosphere, and, consequently, the heat balance may be the occurrence greenhouses th effect”, that is, an increase in the average temperature of the atmosphere by several degrees. This can cause the melting of glaciers in the polar regions, an increase in the level of the World Ocean, a change in its salinity, temperature, global climate disturbances, flooding of coastal lowlands and many other adverse consequences.

Air emissions of industrial gases, including compounds such as carbon monoxide CO (carbon monoxide gas nitrogen oxides sulfur, ammonia and other pollutants, leads to inhibition of plant life and animals, metabolic disorders, poisoning and death of living organisms.

Forests on our planet are catastrophically shrinking, irrational deforestation and fires have led to the fact that in many places, once completely covered with forests, by now they have survived only on 10-30% of the territory. The area of tropical forests in Africa has decreased by 70%, in South America - by 60%, in China only 8% of the territory is covered with forest.

1.1 Environmental pollution

The appearance in the natural environment of new components caused by human activity or some grandiose natural phenomena (for example, volcanic activity) is characterized by the term

On the organismic level may occur violation individual physiological functions of organisms, change their behavior, slowdown in growth and development, reduced resistance to the effects of other adverse environmental factors.

At the level of populations, pollution can cause changes in their numbers and biomass, fertility, mortality, structural changes, annual migration cycles, and a number of other functional properties.

At the biocenotic level, pollution affects the structure and functions of communities. The same pollutants affect different components of communities in different ways. Accordingly, the quantitative ratios in the biocenosis change, up to the complete disappearance of some forms and the appearance of others. The spatial structure of communities is changing, chains of decomposition (detrital) begin to prevail over pastures, dying off - over production. Ultimately, there is degradation of ecosystems, their deterioration as elements of the human environment, a decrease in the positive role in the formation of the biosphere, and economic depreciation.

Abstract completed by student: group №382 Papin Oleg Sergeevich

Surgut State University

Department of Biology

Surgut 1998

Introduction.

On the current state of the natural environment;

On the main sources of pollution of the biosphere;

On the ways of protecting the environment from pollution.

1. CURRENT STATE OF THE ENVIRONMENT

Let us consider some features of the current state of the biosphere and the processes taking place in it.

As already mentioned, with the advent and development of mankind, the process of evolution has noticeably changed. In the early stages of civilization, cutting down and burning forests for agriculture, grazing, hunting and hunting for wild animals, wars devastated entire regions, led to the destruction of plant communities, and the extermination of certain animal species. As civilization developed, especially the end of the Middle Ages, which was turbulent after the industrial revolution, humanity seized ever greater power, an ever greater ability to involve and use huge masses of matter to satisfy its growing needs - both organic, living, and mineral, inert.

Population growth and the expanding development of agriculture, industry, construction, and transport caused massive deforestation in Europe, North America. Grazing on a large scale led to the death of forests and grass cover, to erosion (destruction) of the soil layer (Central Asia, North Africa, south of Europe and the USA). Exterminated dozens of animal species in Europe, America, Africa.

Construction and operation of industrial enterprises, mining have led to serious violations of natural landscapes, pollution of soil, water, air with various wastes.

As a result of the combustion of various fuels, about 20 billion tons of carbon dioxide are emitted into the atmosphere annually and a corresponding amount of oxygen is absorbed. The natural supply of CO2 in the atmosphere is about 50,000 billion tons. This value fluctuates and depends, in particular, on volcanic activity. However, anthropogenic emissions of carbon dioxide exceed natural ones and currently account for a large proportion of its total amount. An increase in the concentration of carbon dioxide in the atmosphere, accompanied by an increase in the amount of aerosol (fine particles of dust, soot, suspensions of solutions of some chemical compounds), can lead to noticeable climate changes and, accordingly, to disruption of the equilibrium relationships that have developed over millions of years in the biosphere.

The result of the violation of the transparency of the atmosphere, and hence the heat balance, may be the emergence of a "greenhouse effect", that is, an increase in the average temperature of the atmosphere by several degrees. This can cause the melting of glaciers in the polar regions, an increase in the level of the World Ocean, a change in its salinity, temperature, global climate disturbances, flooding of coastal lowlands and many other adverse consequences.

The forests on our planet are catastrophically reduced. Irrational deforestation and fires have led to the fact that in many places, once completely covered with forests, by now they have survived only on 10-30% of the territory. The area of tropical forests in Africa has decreased by 70%, in South America - by 60%, in China only 8% of the territory is covered with forest.

Pollution of the natural environment. The appearance of new components in the natural environment, caused by human activity or some grandiose natural phenomena (for example, volcanic activity), is characterized by the term pollution. In general, pollution is the presence in the environment of harmful substances that disrupt the functioning of ecological systems or their individual elements and reduce the quality of the environment in terms of human habitation or economic activity. This term characterizes all bodies, substances, phenomena, processes that in a given place, but not at the time and not in the amount that is natural for nature, appear in the environment and can bring its systems out of equilibrium.

The environmental impact of polluting agents can manifest itself in different ways; it can affect either individual organisms (manifested at the organism level), or populations, biocenoses, ecosystems, and even the biosphere as a whole.

At the level of populations, pollution can cause changes in their numbers and biomass, fertility, mortality, structural changes, annual migration cycles, and a number of other functional properties.

At the biocenotic level, pollution affects the structure and functions of communities. The same pollutants affect different components of communities in different ways. Accordingly, the quantitative ratios in the biocenosis change, up to the complete disappearance of some forms and the appearance of others. The spatial structure of communities is changing, chains of decomposition (detrital) begin to prevail over pastures, dying off - over production. Ultimately, there is degradation of ecosystems, their deterioration as elements of the human environment, a decrease in the positive role in the formation of the biosphere, and economic depreciation.

At present, the total power of anthropogenic pollution sources in many cases exceeds the power of natural ones. Thus, natural sources of nitric oxide emit 30 million tons of nitrogen per year, and anthropogenic - 35-50 million tons; sulfur dioxide, respectively, about 30 million tons and more than 150 million tons. As a result of human activity, lead enters the biosphere almost 10 times more than in the process of natural pollution.

Thus, according to experts, about 10 million tons of oil enters the ocean every year. Oil on water forms a thin film that prevents gas exchange between water and air. Settling to the bottom, oil enters bottom sediments, where it disrupts the natural life processes of bottom animals and microorganisms. In addition to oil, there has been a significant increase in the release of domestic and industrial wastewater into the ocean, containing, in particular, such dangerous pollutants as lead, mercury, and arsenic, which have a strong toxic effect. Background concentrations of such substances in many places have already been exceeded by dozens of times.

Each pollutant has a certain negative impact on nature, so their entry into the environment must be strictly controlled. The legislation establishes "for each pollutant the maximum allowable discharge (MPD) and the maximum allowable concentration (MPC) of it in the natural environment.

Maximum allowable discharge (MPD) is the mass of a pollutant emitted by individual sources per unit of time, the excess of which leads to adverse effects in the environment or is dangerous to human health. The maximum allowable concentration (MAC) is understood as the amount of a harmful substance in the environment that does not adversely affect human health or its offspring through permanent or temporary contact with it. Currently, when determining MPC, not only the degree of influence of pollutants on human health is taken into account, but also their impact on animals, plants, fungi, microorganisms, as well as on the natural community as a whole.

Special environmental monitoring (surveillance) services monitor compliance with the established standards for MPC and MPC of harmful substances. Such services have been established in all regions of the country. Their role is especially important in large cities, near chemical plants, nuclear power plants and other industrial facilities. Monitoring services have the right to apply measures provided by law, up to the suspension of production and any work, if environmental protection standards are violated.

In addition to environmental pollution, anthropogenic impact is expressed in the depletion of the natural resources of the biosphere. The enormous use of natural resources has led to a significant change in landscapes in some regions (for example, in the coal basins). If at the dawn of civilization a person used only about 20 chemical elements for his needs, at the beginning of the 20th century 60 flowed in, now more than 100 - almost the entire periodic table. About 100 billion tons of ore, fuel, and mineral fertilizers are annually mined (extracted from the geosphere).

The rapid growth in demand for fuel, metals, minerals and their extraction led to the depletion of these resources. Thus, according to experts, while maintaining current rates of production and consumption, proven reserves of oil will be exhausted in 30 years, gas - in 50 years, coal - in 200. A similar situation has developed not only with energy resources, but also with metals (depletion of reserves aluminum is expected in 500-600 years, iron - 250 years, zinc - 25 years, lead - 20 years) and mineral resources, such as asbestos, mica, graphite, sulfur.

2. ATMOSPHERE - THE OUTER SHELL OF THE BIOSPHERE. AIR POLLUTION.

The mass of the atmosphere of our planet is negligible - only one millionth of the mass of the Earth. However, its role in the natural processes of the biosphere is enormous. The presence of the atmosphere around the globe determines the general thermal regime of the surface of our planet, protects it from harmful cosmic and ultraviolet radiation. Atmospheric circulation has an impact on local climatic conditions, and through them - on the regime of rivers, soil and vegetation cover and the processes of relief formation.

The modern gas composition of the atmosphere is the result of a long historical development of the globe. It is mainly a gas mixture of two components - nitrogen (78.09%) and oxygen (20.95%). Normally, it also contains argon (0.93%), carbon dioxide (0.03%) and small amounts of inert gases (neon, helium, krypton, xenon), ammonia, methane, ozone, sulfur dioxide and other gases. Along with gases, the atmosphere contains solid particles coming from the Earth's surface (for example, products of combustion, volcanic activity, soil particles) and from space (cosmic dust), as well as various products of plant, animal or microbial origin. In addition, water vapor plays an important role in the atmosphere.

The three gases that make up the atmosphere are of greatest importance for various ecosystems: oxygen, carbon dioxide and nitrogen. These gases are involved in the main biogeochemical cycles.

Oxygen plays an essential role in the life of most living organisms on our planet. It is necessary for everyone to breathe. Oxygen has not always been part of the earth's atmosphere. It appeared as a result of the vital activity of photosynthetic organisms. Under the influence of ultraviolet rays, it turns into ozone. As ozone accumulated, an ozone layer formed in the upper atmosphere. The ozone layer, like a screen, reliably protects the Earth's surface from ultraviolet radiation, which is fatal to living organisms.

The modern atmosphere contains hardly a twentieth of the oxygen available on our planet. The main reserves of oxygen are concentrated in carbonates, organic substances and iron oxides, part of the oxygen is dissolved in water. In the atmosphere, apparently, there was an approximate balance between the production of oxygen in the process of photosynthesis and its consumption by living organisms. But recently there has been a danger that, as a result of human activity, oxygen reserves in the atmosphere may decrease. Of particular danger is the destruction of the ozone layer, which has been observed in recent years. Most scientists attribute this to human activity.

The oxygen cycle in the biosphere is extremely complex, since a large number of organic and inorganic substances, as well as hydrogen, react with it, combining with which oxygen forms water.

Carbon dioxide (carbon dioxide) is used in the process of photosynthesis to form organic substances. It is thanks to this process that the carbon cycle in the biosphere closes. Like oxygen, carbon is a part of soils, plants, animals, and participates in various mechanisms of the circulation of substances in nature. The content of carbon dioxide in the air we breathe is about the same in different parts of the world. The exception is large cities in which the content of this gas in the air is above the norm.

Some fluctuations in the content of carbon dioxide in the air of the area depend on the time of day, the season of the year, and the biomass of vegetation. At the same time, studies show that since the beginning of the century, the average content of carbon dioxide in the atmosphere, although slowly, but constantly increases. Scientists associate this process mainly with human activity.

Nitrogen is an indispensable biogenic element, since it is part of proteins and nucleic acids. The atmosphere is an inexhaustible reservoir of nitrogen, but most living organisms cannot directly use this nitrogen: it must first be bound in the form of chemical compounds.

Part of the nitrogen comes from the atmosphere to ecosystems in the form of nitric oxide, which is formed under the action of electrical discharges during thunderstorms. However, the main part of nitrogen enters the water and soil as a result of its biological fixation. There are several types of bacteria and blue-green algae (fortunately, very numerous) that are able to fix atmospheric nitrogen. As a result of their activities, as well as due to the decomposition of organic residues in the soil, autotrophic plants are able to absorb the necessary nitrogen.

The nitrogen cycle is closely related to the carbon cycle. Although the nitrogen cycle is more complex than the carbon cycle, it tends to be faster.

Other constituents of the air do not participate in biochemical cycles, but the presence of a large amount of pollutants in the atmosphere can lead to serious violations of these cycles.

Air pollution. Various negative changes in the Earth's atmosphere are mainly associated with changes in the concentration of minor components of atmospheric air.

There are two main sources of air pollution: natural and anthropogenic. The natural source is volcanoes, dust storms, weathering, forest fires, decomposition processes of plants and animals.

The main anthropogenic sources of air pollution include enterprises of the fuel and energy complex, transport, and various machine-building enterprises.

According to scientists (1990s), every year in the world as a result of human activity, 25.5 billion tons of carbon oxides, 190 million tons of sulfur oxides, 65 million tons of nitrogen oxides, 1.4 million tons of chlorofluorocarbons (freons), organic lead compounds, hydrocarbons, including carcinogenic (causing cancer).

In addition to gaseous pollutants, a large amount of particulate matter enters the atmosphere. These are dust, soot and soot. Contamination of the natural environment with heavy metals poses a great danger. Lead, cadmium, mercury, copper, nickel, zinc, chromium, vanadium have become almost constant components of the air in industrial centers. The problem of air pollution with lead is particularly acute.

Only on the territory of our country, the total area of forests affected by industrial emissions has reached 1 million hectares. A significant factor in forest degradation in recent years is environmental pollution with radionuclides. Thus, as a result of the accident at the Chernobyl nuclear power plant, 2.1 million hectares of forests were affected.

Particularly affected are green spaces in industrial cities, the atmosphere of which contains a large amount of pollutants.

3. SOIL IS AN IMPORTANT COMPONENT OF THE BIOSPHERE. SOIL POLLUTION.

Soil - the top layer of land, formed under the influence of plants, animals, microorganisms and climate from the parent rocks on which it is located. This is an important and complex component of the biosphere, closely related to its other parts.

The following main components interact in a complex way in the soil:

Mineral particles (sand, clay), water, air;

Detritus - dead organic matter, the remains of the vital activity of plants and animals;

Many living organisms - from detritus feeders to decomposers, decomposing detritus to humus.

Thus, the soil is a bioinert system based on the dynamic interaction between mineral components, detritus, detritus feeders and soil organisms.

Soils go through several stages in their development and formation. Young soils are usually the result of weathering of parent rocks or the transport of sedimentary deposits (eg alluvium). Microorganisms, pioneer plants - lichens, mosses, grasses, small animals settle on these substrates. Gradually, other species of plants and animals are introduced, the composition of the biocenosis becomes more complicated, a whole series of relationships arise between the mineral substrate and living organisms. As a result, a mature soil is formed, the properties of which depend on the original parent rock and climate.

The process of soil development ends when equilibrium is reached, the correspondence of the soil with the vegetation cover and climate, that is, a climax state occurs. Thus, the changes in the soil that occur during its formation resemble the successional changes in ecosystems.

Each type of soil corresponds to certain types of plant communities. Thus, pine forests, as a rule, grow on light sandy soils, while spruce forests prefer heavier and nutrient-rich loamy soils.

The soil is like a living organism, within which various complex processes take place. In order to maintain the soil in good condition, it is necessary to know the nature of the metabolic processes of all its constituents.

The surface layers of the soil usually contain many remains of plant and animal organisms, the decomposition of which leads to the formation of humus. The amount of humus determines the fertility of the soil.

A great many different living organisms live in the soil - edaphobionts, which form a complex food detritus network: bacteria, microfungi, algae, protozoa, mollusks, arthropods and their larvae, earthworms and many others. All these organisms play a huge role in the formation of the soil and changing its physical and chemical characteristics.

Plants absorb the necessary minerals from the soil, but after the death of plant organisms, the removed elements return to the soil. Soil organisms gradually process all organic residues. Thus, under natural conditions, there is a constant cycle of substances in the soil.

In artificial agrocenoses, such a cycle is disrupted, since a person withdraws a significant part of agricultural products, using it for their own needs. Due to the non-participation of this part of the production in the cycle, the soil becomes barren. To avoid this and increase soil fertility in artificial agrocenoses, a person makes organic and mineral fertilizers.

Soil pollution. Under normal natural conditions, all processes occurring in the soil are in balance. But often a person is to blame for the violation of the equilibrium state of the soil. As a result of the development of human activities, pollution, changes in the composition of the soil and even its destruction occur. Currently, there is less than one hectare of arable land for every inhabitant of our planet. And these insignificant areas continue to shrink due to inept human activities.

Enormous areas of fertile lands are lost during mining operations, during the construction of enterprises and cities. The destruction of forests and natural grass cover, repeated plowing of the land without observing the rules of agricultural technology leads to soil erosion - the destruction and washing away of the fertile layer by water and wind (Fig. 58). Erosion has now become a worldwide evil. It is estimated that in the last century alone, as a result of water and wind erosion, 2 billion hectares of fertile lands of active agricultural use have been lost on the planet.

One of the consequences of increased human production activity is the intense pollution of the soil cover. The main soil pollutants are metals and their compounds, radioactive elements, as well as fertilizers and pesticides used in agriculture.

Mercury and its compounds are among the most dangerous soil pollutants. Mercury enters the environment with pesticides, industrial waste containing metallic mercury and its various compounds.

Lead contamination of soils is even more widespread and dangerous. It is known that during the smelting of one ton of lead, up to 25 kg of lead is released into the environment with waste. Lead compounds are used as additives to gasoline, so motor vehicles are a serious source of lead pollution. Especially a lot of lead in soils along major highways.

Radioactive elements can enter the soil and accumulate in it as a result of precipitation from atomic explosions or during the removal of liquid and solid waste from industrial enterprises, nuclear power plants or research institutions associated with the study and use of atomic energy. Radioactive substances from soils get into plants, then into the organisms of animals and humans, accumulate in them.

Of particular danger are persistent organic compounds used as pesticides. They accumulate in the soil, in water, bottom sediments of reservoirs. But most importantly, they are included in ecological food chains, pass from soil and water to plants, then to animals, and ultimately enter the human body with food.

WATER IS THE BASIS FOR LIFE PROCESSES IN THE BIOSPHERE. POLLUTION OF NATURAL WATER.

Water is the most common inorganic compound on our planet. Water is the basis of all life processes, the only source of oxygen in the main driving process on Earth - photosynthesis. Water is present throughout the biosphere: not only in water bodies, but also in the air, and in the soil, and in all living beings. The latter contain up to 80-90% water in their biomass. Losses of 10-20% of water by living organisms lead to their death.

In its natural state, water is never free from impurities. Various gases and salts are dissolved in it, there are suspended solid particles. 1 liter of fresh water can contain up to 1 g of salts.

Most of the water is concentrated in the seas and oceans. Fresh water accounts for only 2%. Most of the fresh water (85%) is concentrated in the ice of the polar zones and glaciers. Renewal of fresh water occurs as a result of the water cycle.

With the advent of life on Earth, the water cycle became relatively complex, since more complex processes associated with the vital activity of living organisms were added to the simple phenomenon of physical evaporation (turning water into steam). In addition, the role of man, as he develops, becomes more and more significant in this cycle.

The water cycle in the biosphere occurs as follows. Water falls to the Earth's surface as precipitation from atmospheric water vapor. A certain part of the precipitation evaporates directly from the surface, returning to the atmosphere as water vapor. The other part penetrates the soil, is absorbed by the roots of plants and then, after passing through the plants, evaporates in the process of transpiration. The third part seeps into the deep layers of the subsoil to impervious horizons, replenishing groundwater. The fourth part in the form of surface, river and underground runoff flows into water bodies, from where it also evaporates into the atmosphere. Finally, a part is used by animals and consumed by humans for their needs. All the water evaporated and returned to the atmosphere condenses and falls again as precipitation.

Thus, one of the main ways of the water cycle - transpiration, that is, biological evaporation, is carried out by plants, supporting their vital activity. The amount of water released as a result of transpiration depends on the plant species, the type of plant communities, their biomass, climatic factors, seasons, and other conditions.

The intensity of transpiration and the mass of water evaporating in this case can reach very significant values. In communities such as forests (with a large phytomass and leaf surface) or swamps (with a water-saturated moss surface), transpiration is generally quite comparable with the evaporation of open water bodies (ocean) and often even exceeds it. On average, for plant communities of a temperate climate, transpiration is from 2000 to 6000 m of water per year.

The value of total evaporation (from the soil, from the surface of plants and through transpiration) depends on the physiological characteristics of plants and their biomass, therefore it serves as an indirect indicator of the vital activity and productivity of communities. Vegetation as a whole plays the role of a grandiose evaporator, while significantly influencing the climate of the territory. The vegetation cover of landscapes, especially forests and swamps, is also of great water-protective and water-regulating importance, mitigating runoff fluctuations (floods), contributing to moisture retention, and preventing soil drying and erosion.

Pollution of natural waters. Pollution of water bodies is understood as a decrease in their biospheric functions and economic significance as a result of the entry of harmful substances into them.

Among industrial products, toxic synthetic substances occupy a special place in terms of their negative impact on the aquatic environment and living organisms. They are increasingly being used in industry, in transport, and in public utilities. The concentration of these compounds in wastewater, as a rule, is 5-15 mg/l at MPC - 0.1 mg/l. These substances can form a layer of foam in reservoirs, which is especially noticeable on rapids, rifts, locks. The ability to foam in these substances appears already at a concentration of 1-2 mg / l.

Other contaminants include metals (eg mercury, lead, zinc, copper, chromium, tin, manganese), radioactive elements, pesticides from agricultural fields, and runoff from livestock farms. A small danger to the aquatic environment from metals is mercury, lead and their compounds.

Expanded production (without treatment facilities) and the use of pesticides in the fields lead to severe pollution of water bodies with harmful compounds. Pollution of the aquatic environment occurs as a result of the direct introduction of pesticides during the treatment of water bodies for pest control, the ingress of water flowing down from the surface of cultivated agricultural land into water bodies, when waste from manufacturing enterprises is discharged into water bodies, as well as as a result of losses during transportation, storage and partially with atmospheric precipitation.

Along with pesticides, agricultural effluents contain a significant amount of fertilizer residues (nitrogen, phosphorus, potassium) applied to the fields. In addition, large amounts of organic compounds of nitrogen and phosphorus enter with runoff from livestock farms, as well as with sewage. An increase in the concentration of nutrients in the soil leads to a violation of the biological balance in the reservoir.

Initially, in such a reservoir, the number of microscopic algae sharply increases. With an increase in the food supply, the number of crustaceans, fish and other aquatic organisms increases. Then there is the death of a huge number of organisms. It leads to the consumption of all the reserves of oxygen contained in the water, and the accumulation of hydrogen sulfide. The situation in the reservoir changes so much that it becomes unsuitable for the existence of any forms of organisms. The reservoir gradually "dies".

One of the types of water pollution is thermal pollution. Power plants, industrial enterprises often discharge heated water into a reservoir. This leads to an increase in the temperature of the water in it. With an increase in temperature in the reservoir, the amount of oxygen decreases, the toxicity of impurities polluting the water increases, and the biological balance is disturbed.

In polluted water, as the temperature rises, pathogenic microorganisms and viruses begin to multiply rapidly. Once in drinking water, they can cause outbreaks of various diseases.

In a number of regions, groundwater was an important source of fresh water. Previously, they were considered the purest. But at present, as a result of human activities, many sources of groundwater are also being polluted. Often this pollution is so great that the water from them has become undrinkable.

Mankind consumes a huge amount of fresh water for its needs. Its main consumers are industry and agriculture. The most water-intensive industries are mining, steel, chemicals, petrochemicals, pulp and paper, and food. They take up to 70% of all water used in industry. The main consumer of fresh water is agriculture: 60-80% of all fresh water is used for its needs.

In modern conditions, human needs for water for household needs are greatly increasing. The volume of water consumed for these purposes depends on the region and standard of living, ranged from 3 to 700 liters per person. In Moscow, for example, about 650 liters per inhabitant, which is one of the highest rates in the world.

From the analysis of water use over the past 5-6 decades, it follows that the annual increase in irretrievable water consumption, in which the used water is irretrievably lost to nature, is 4-5%. Forward-looking calculations show that if such rates of consumption are maintained and taking into account population growth and production volumes, by 2100 mankind can exhaust all fresh water reserves.

Human intervention in natural processes has affected even large rivers (such as the Volga, Don, Dnieper), changing the volume of transported water masses (river runoff) downward. Most of the water used in agriculture is used for evaporation and the formation of plant biomass and therefore is not returned to the rivers. Already now, in the most populated areas of the country, the flow of rivers has decreased by 8%, and in such rivers as the Don, Terek, Ural - by 11-20%. The fate of the Aral Sea is very dramatic, which, in fact, ceased to exist due to the excessive intake of the waters of the Syrdarya and Amudarya rivers for irrigation.

Limited fresh water supplies are further reduced due to pollution. Wastewater (industrial, agricultural and domestic) poses the main hazard, as a significant part of the used water is returned to water basins in the form of wastewater.

5. RADIATION IN THE BIOSPHERE.

Radiation pollution have a significant difference from others. Radioactive nuclides are the nuclei of unstable chemical elements that emit charged particles and short-wave electromagnetic radiation. It is these particles and radiation that, when entering the human body, destroy cells, as a result of which various diseases can occur, including radiation.

To quantify the impact of radiation on a person, units are used - the biological equivalent of a roentgen (rem) or sievert (Sv): 1 Sv \u003d 100 rem. Since radioactive radiation can cause serious changes in the body, each person must know its permissible doses.

As a result of internal and external exposure, a person receives an average dose of 0.1 rem during the year and, consequently, about 7 rem throughout his life. In these doses, radiation does not harm a person. However, there are areas where the annual dose is above average. So, for example, people living in high-mountainous regions, due to cosmic radiation, can receive a dose several times greater. Large doses of radiation can be in areas where the content of natural radioactive sources is high. So, for example, in Brazil (200 km from Sao Paulo) there is a hill where the annual dose is 25 rem. This area is uninhabited.

The greatest danger is the radioactive contamination of the biosphere as a result of human activities. At present, radioactive elements are widely used in various fields. Negligence in the storage and transportation of these elements leads to serious radioactive contamination. Radioactive contamination of the biosphere is associated, for example, with the testing of atomic weapons.

In the second half of our century, nuclear power plants, icebreakers, and submarines with nuclear power plants began to be put into operation. During the normal operation of nuclear power facilities and industry, environmental pollution with radioactive nuclides is a negligible fraction of the natural background. A different situation develops in case of accidents at nuclear facilities.

So, during the explosion at the Chernobyl nuclear power plant, only about 5% of nuclear fuel was released into the environment. But this led to the exposure of many people, large areas were so polluted that they became hazardous to health. This required the relocation of thousands of residents from the contaminated areas. An increase in radiation as a result of radioactive fallout was noted hundreds and thousands of kilometers from the accident site.

6. ENVIRONMENTAL PROBLEMS OF THE BIOSPHERE

Mankind has significantly changed the course of a number of processes in the biosphere, including the biochemical cycle and migration of a number of elements. Currently, although slowly, a qualitative and quantitative restructuring of the entire biosphere of the planet is taking place. A number of the most complex ecological problems of the biosphere have already arisen, which must be resolved in the near future.

"Greenhouse effect". According to the latest data of scientists, for the 80s. the average air temperature in the northern hemisphere has increased compared to the end of the 19th century. by 0.5-0.6 "C. According to forecasts, by the beginning of 2000 the average temperature on the planet may increase by 1.2°C compared to the pre-industrial era. Scientists attribute this increase in temperature primarily to an increase in the content of carbon dioxide (carbon dioxide) and aerosols in the atmosphere. This leads to excessive absorption of the Earth's thermal radiation by the air. Obviously, a certain role in creating the so-called "greenhouse effect" is played by the heat released from thermal power plants and nuclear power plants.

Climate warming can lead to intensive melting of glaciers and an increase in the level of the World Ocean. The changes that may result from this are simply difficult to predict.

This problem could be solved by reducing carbon dioxide emissions into the atmosphere and establishing a balance in the carbon cycle.

Depletion of the ozone layer. In recent years, scientists have noted with increasing alarm the depletion of the ozone layer of the atmosphere, which is a protective screen against ultraviolet radiation. This process occurs especially quickly over the poles of the planet, where the so-called ozone holes have appeared. The danger lies in the fact that ultraviolet radiation is detrimental to living organisms.

The main reason for the depletion of the ozone layer is the use by people of chlorofluorohydrocarbons (freons), which are widely used in production and everyday life as refrigerants, foaming agents, and solvents. aerosols. Freons intensively destroy ozone. They themselves are destroyed very slowly, within 50-200 years. In 1990, more than 1300 thousand tons of ozone-depleting substances were produced in the world.

Under the action of ultraviolet radiation, oxygen molecules (O2) decompose into free atoms, which in turn can join other oxygen molecules to form ozone (O3). Free oxygen atoms can also react with ozone molecules to form two oxygen molecules. Thus, an equilibrium is established and maintained between oxygen and ozone.

However, freon-type pollutants catalyze (accelerate) the process of ozone decomposition, breaking the balance between it and oxygen in the direction of reducing the ozone concentration.

Given the danger looming over the planet, the international community has taken the first step towards solving this problem. An international agreement has been signed, according to which the production of freons in the world by 1999 should be reduced by about 50%.

Mass deforestation is one of the most important global environmental problems of our time.

You already know that forest communities play an essential role in the normal functioning of natural ecosystems. They absorb atmospheric pollution of anthropogenic origin, protect the soil from erosion, regulate the normal runoff of surface water, prevent the decrease in the level of groundwater and the silting of rivers, canals and reservoirs.

Reducing the area of forests disrupts the cycle of oxygen and carbon in the biosphere.

Despite the fact that the catastrophic consequences of deforestation are already widely known, their destruction continues. Currently, the total forest area on the planet is about 42 million km2, but it is decreasing by 2% annually. Tropical rainforests are being destroyed especially intensively in Asia, Africa, America and some other regions of the world. So, in Africa, forests used to occupy about 60% of its territory, and now - only about 17%. The areas of forests in our country have also significantly decreased.

The reduction of forests entails the death of their richest flora and fauna. Man impoverishes the appearance of his planet.

However, it seems that humanity is already aware that its existence on the planet is inextricably linked with the life and well-being of forest ecosystems. The serious warnings of scientists, sounded in the declarations of the United Nations and other international organizations, began to find a response. In recent years, artificial afforestation and the organization of highly productive forest plantations have been successfully carried out in many countries of the world.

Waste production. Waste from industrial and agricultural production has become a serious environmental problem. You already know what harm they do to the environment. Efforts are currently being made to reduce the amount of waste polluting the environment. For this purpose, the most complex filters are being developed and installed, expensive treatment facilities and settling tanks are being built. But practice shows that although they reduce the risk of pollution, they still do not solve the problem. It is known that even with the most advanced treatment, including biological treatment, all dissolved minerals and up to 10% of organic pollutants remain in the treated wastewater. Waters of this quality can become suitable for consumption only after repeated dilution with clean water.

Calculations show that 2,200 km3 of water per year is spent on all types of water use. Almost 20% of the world's fresh water resources are used to dilute effluents. Calculations for the year 2000 show that even if the treatment covers all wastewater, it will still require 30-35 thousand km3 of fresh water to dilute them. This means that the resources of the total world river flow will be close to exhaustion. But in many areas such resources are already in acute shortage,

Obviously, the solution to the problem is possible with the development and introduction into production of completely new, closed, non-waste technologies. When applied, water will not be discharged, but will be reused in a closed cycle. All by-products will not be thrown away as waste, but will be subjected to deep processing. This will create conditions for obtaining additional products that people need and will protect the environment.

Agriculture. In agricultural production, it is important to strictly observe the rules of agricultural technology and monitor the norms of fertilization. Since chemical pest and weed control products lead to significant ecological imbalances, there are several ways to overcome this crisis.

Work is underway to develop plant varieties that are resistant to agricultural pests and diseases: selective bacterial and viral preparations are being created that affect, for example, only insect pests. Ways and methods of biological control are being sought, that is, a search is underway for a hydroelectric power station and the reproduction of natural enemies that destroy harmful insects. Highly selective drugs are being developed from among hormones, antihormones and other substances that can act on the biochemical systems of certain insect species and not have a noticeable effect on other insect species or other organisms.

Energy production. Very complex environmental problems are associated with the production of energy at thermal power plants. The need for energy is one of the basic human needs. Energy is needed not only for the normal activity of today's complexly organized human society, but also for the simple physical existence of every human organism. Currently, electricity is mainly obtained from hydroelectric power plants, thermal and nuclear power plants.

Hydroelectric power plants at first glance are environmentally friendly enterprises that do not harm nature. It has been thought so for many decades. In our country, many of the largest hydroelectric power plants have been built on the great rivers. Now it became clear that this construction caused great damage to both nature and people.

Secondly, by blocking the river, the dam creates insurmountable obstacles on the migration routes of anadromous and semi-anadromous fish rising to spawn in the upper reaches of the rivers.

Thirdly, the water in the reservoirs stagnates, its flow slows down, which affects the lives of all living creatures that live in the river and near the river.

Fourthly, local water rise affects groundwater, leads to flooding, waterlogging, bank erosion and landslides.

It should be taken into account that the actual volumes of radioactive waste are relatively small. For a standard nuclear power unit with a capacity of 1 million kW, this is 3-4m per year. It is clear that even a cubic meter of a very harmful and hazardous substance is still easier to handle than a million cubic meters of simply harmful and dangerous, such as, for example, waste from thermal power plants, which almost entirely enters the environment.

Not everyone knows that coal has a small natural radioactivity. Since TPPs burn huge volumes of fuel, their total radioactive emissions are higher than those of nuclear power plants. But this factor is secondary in comparison with the main disaster from the installation on fossil fuels, applied to nature and people - emissions of chemical compounds into the atmosphere, which are products of combustion.

Although nuclear power plants are more environmentally friendly than mere power plants, they carry great potential hazards in the event of serious reactor accidents. We were convinced of this by the example of the Chernobyl disaster. Thus, energy poses seemingly insoluble environmental problems. The search for a solution to the problem is carried out in several directions.

Scientists are developing new safe reactors for nuclear power plants. The second direction is connected with the use of non-traditional renewable energy sources. This is primarily the energy of the Sun and wind, the heat of the earth's interior, the thermal and mechanical energy of the ocean. In many countries, including ours, not only experimental, but also industrial installations have already been created using these energy sources. They are still relatively underpowered. But many scientists believe that they have a great future.

Conclusion.

Bibliography

E. A. Kriksunov, V. V. Pasechnik, A.P. Sidorin "Ecology" Publishing House "Drofa" 1995

G. A. Bogdanovsky "Chemical Ecology" Moscow University Publishing House 1994

ON THE. Agadzhanyan, V.I. Torshin "Human Ecology" MMP "Ecocenter", KRUK 1994

Branch of NOU HPE "Moscow Institute of Entrepreneurship and Law" in Novosibirsk

TEST

By discipline: Ecology and environmental protection

Subject: Biosphere. Anthropogenic impact on the environment

Specialty: Economics

Student: Telina E.S.

Gradebook code: 05751

Lecturer: Lyapina O.P.

Novosibirsk

year 2009

Introduction ……………………………………………………………………......................3

I. Biosphere ………………………………………………………………………………...4

1. The biosphere as a global ecosystem ………………………………………………………………………………………………………………………………4

2. Properties of the biosphere …………………………………………………………………..5

3. The boundaries and structure of the biosphere ……………………………………………………..7

3.1 Atmosphere ……………………………………………………………………...8

3.2 Hydrosphere ……………………………………………………………..............9

3.3 Lithosphere ……………………………………………………………..............10

II. Anthropogenic impact on the environment …………………………………...................................12

1. Impact on the biosphere………………………………………………......................12

2. Impact on the atmosphere………………………………………………………….13

3. Impact on the hydrosphere………………………………………………………………………………..15

4. Impact on the lithosphere…………………………………………………………..17

Conclusion ……………………………………………………………………………… 19

References ……………………………………………………………………...20

Task number 2 ……………………………………………………………………………...21

Introduction

Man and nature are inseparable from each other and are closely interconnected. For a person, as well as for society as a whole, nature is the environment of life and the only source of resources necessary for existence. Nature and natural resources are the basis on which human society lives and develops, the primary source of meeting the material and spiritual needs of people. Man is a part of nature and, as a living being, with his elementary vital activity, has a tangible impact on the natural environment.

I . Biosphere

1. Biosphere as a global ecosystem.

Biosphere (from the Greek. bios - life, sphaira - ball) - the area of systemic interaction between the living and bone matter of the planet. It is a global ecosystem - the totality of all biogeocenoses (ecosystems) of our planet. The first ideas about the biosphere as an "area of life" and the outer shell of the Earth were expressed at the beginning of the 19th century. J. Lamarck. In 1875, the Austrian geologist E. Suess first introduced the modern term "biosphere" into scientific literature, meaning by it the area of interaction between the main shells of the Earth: the atmosphere, hydro- and lithosphere, where living organisms meet. The merit of creating the integrity of the doctrine of the biosphere belongs to VI Vernadsky. Using these terms, he created the science of the "biosphere", introduced the concept of "living matter" - the totality of all living organisms, and assigned living organisms the role of the main transforming force on the planet Earth, taking into account the activity of organisms not only at the present time, but also in the past. Therefore, the biosphere is the entire space where life exists or has ever existed, i.e. where living organisms or products of their vital activity meet.

Life in the biosphere depends on the flow of energy and the circulation of substances between the biotic and abiotic components. The cycles of matter are called biogeochemical cycles. The existence of these cycles is provided by the energy of the Sun. A visual representation of the pathways for the passage of energy is provided by food chains. Each of their links is a certain trophic level. The first trophic level is occupied by autotrophs, or producers. Organisms of the second trophic level are called primary consumers, the third - secondary consumers, etc. Producers are plants, cyanobacteria (blue-green "algae") and some other types of bacteria. Part of the energy associated with producers in the process of photosynthesis is consumed during their own respiration, the other part is stored in their cells and tissues and is available to consumers. Organisms that are not capable of photosynthesis or chemosynthesis are heterotrophs, or consumers. These include animals, fungi, most bacteria, and a few plants that have lost the ability to photosynthesize. Consumers depend directly (herbivores) or indirectly (predators) on the value of net primary production as a source of energy and substances. The passage of energy through living matter is a path from light to producers, then to consumers, and from both to heat. This path is a flow, not a cycle, since energy is dissipated in the form of heat in the environment and cannot be used again for photosynthesis. Thus, the energy flow through living matter is a process of loss of energy accumulated by organisms. Maintaining a dynamic balance between the biotic and abiotic components of the biosphere is a necessary condition for the existence of all forms of life. Human impact on the biosphere, accompanied by the deterioration of water quality, deforestation or the release of pollutants into the atmosphere, can threaten life on Earth.

2. Properties of the biosphere.

The biosphere, as well as other lower-ranking ecosystems that make it up, has a system of properties that ensure its functioning, self-regulation, stability, and other parameters. Let's consider the main ones.

· The biosphere is a centralized system. Living organisms (living matter) act as its central link. This property is comprehensively disclosed by V.I. Vernadsky, but, unfortunately, is often underestimated by man at the present time: only one species is placed at the center of the biosphere or its links - man (anthropocentrism).

· The biosphere is an open system. Its existence is unthinkable without energy from outside. It is affected by cosmic forces, primarily solar activity. For the first time ideas about the influence of solar activity on living organisms (heliobiology) were developed by A. L. Chizhevsky (1897-1964), who showed that many phenomena on Earth and in the biosphere are closely related to the activity of the sun.

· The biosphere is a self-regulating system, for which, as noted by V.I. Vernadsky, characteristic organization. Currently, this property is called homeostasis, meaning by it the ability to return to its original state, to dampen emerging perturbations by turning on a number of mechanisms. Homeostatic mechanisms are mainly associated with living matter, its properties and functions discussed above.

· The biosphere is a system characterized by great diversity. Diversity is the most important property of all ecosystems. The biosphere as a global ecosystem is characterized by the maximum diversity among other systems. The latter is due to many reasons and factors. These are different environments of life (water, ground-air, soil, organismic); and the diversity of natural zones, differing in climatic, hydrological, soil, biotic and other properties; and the presence of regions that differ in chemical composition (geochemical provinces); and, most importantly, the unification within the biosphere of a large number of elementary ecosystems with their characteristic species diversity.

An important property of the biosphere is the presence in it of mechanisms that ensure the circulation of substances and the associated inexhaustibility of individual chemical elements and their compounds. In the absence of circulation, for example, in a short time the main "building material" of living things would be exhausted - carbon, which is practically the only one capable of forming interelemental (carbon) bonds and creating a huge amount of organic compounds. Only thanks to the cycles and the presence of an inexhaustible source of solar energy is the continuity of processes in the biosphere and its potential immortality ensured.

3. Borders and structure of the biosphere.

The boundaries of the neo- and paleobiosphere are different.

Upper border. In most cases, the ozone layer is indicated as the upper theoretical boundary of the biosphere without specifying its boundaries, which is quite acceptable if one does not discuss the difference between the neo- and paleobiosphere. Otherwise, it should be taken into account that the ozone screen was formed only about 600 million years ago, after which the organisms were able to reach land. In practice, the maximum height above sea level at which a living organism can exist is limited by the level up to which positive temperatures remain and chlorophyll-containing plants - producers can live (6200m in the Himalayas). Above, up to the “snow line”, only spiders, springtails and some mites live, feeding on grains of plant pollen, plant spores, microorganisms and other organic particles blown by the wind. Even higher, living organisms can come across only by chance.

Bottom line. The lower boundary of the existence of active life is traditionally determined by the ocean floor at 11,022 m (the maximum depth of the Mariana Trench) and the depth of the lithosphere, characterized by a temperature of 100 ° C (about 6000 m, according to ultra-deep drilling on the Kola Peninsula). Basically, life in the lithosphere is distributed only a few meters deep, limited to the soil layer. However, through individual cracks and caves, it extends to hundreds of meters, reaching depths of 3000-4000 m. Perhaps the limits of the biosphere are much wider, since organisms have been found in the ocean floor hydrotherms at depths of about 3000 m at a temperature of 250 ° C. Theoretically, at a depth of 25,000 m relative to sea level, there should be a critical temperature of 460 ° C, at which, at any pressure, water exists only in the form of steam, and therefore life is impossible. Sedimentary rocks, almost all of which have undergone processing by living organisms, determine the lower boundary of the former biospheres, which, however, does not fall on the continents below the deepest depths of the ocean.

Portal for the student. Self-training

Anthropogenic impact on the biosphere.

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