§ 44. What is the biosphere and how it works

Remember

• How do living bodies differ from nonliving ones? How are plants different from animals? What is the ozone layer? What altitude is it at?

Our planet is the only one of all the cosmic bodies of the Solar System that is inhabited by living organisms. The area of ​​their settlement forms the biosphere (from the Greek “bios” - life and “sphere” - ball).

The biosphere is the outer shell of the Earth, inhabited by living organisms and transformed by them.

Now living organisms populate the troposphere, the land surface, the upper part of the earth's crust and the hydrosphere (Fig. 156). Therefore, the upper boundary of the biosphere is drawn at the level of the ozone layer, the lower - in the earth's crust at a depth of about 5 km.

However, the boundaries of the biosphere were not always like this. They have changed over time. Life on our planet originated in water about 3.5 billion years ago. About 500 million years ago it spread to land and then into the atmosphere. With the development of the Earth, the conditions for the existence of organisms changed. Some died out, others adapted to new conditions. But the total number of species was constantly increasing. An important stage in the development of the biosphere is associated with the emergence and settlement of humans on Earth.

The modern biosphere is home to about 2.5 million species of plants and animals, as well as fungi and bacteria. They all form living matter planets. In terms of mass, it is dominated by microscopic organisms, and among large forms - plants.

Rice. 156. Distribution of organisms in the biosphere

Everything that surrounds a living organism is called its habitat. These are bodies of living and inanimate nature: rocks, water, air and other living organisms. Organisms interact with their environment. They take from there the substances necessary for life, process them, and excrete the unnecessary ones. Consequently, organisms exchange substances with their environment. At the same time, life both adapts to the environment and changes and transforms it.

Questions and tasks

1. What is the biosphere and how does it differ from other layers of the Earth?
2. Where are the upper and lower boundaries of the biosphere?
3. What is living matter and what does it consist of?

My son’s questions sometimes take me by surprise... Yesterday he suddenly asked about what the biosphere is. I was even confused, not knowing how to answer. This is the case when you seem to understand what it’s about, but you can’t tell it clearly. I had to sit down at the computer and find out everything about this shell of the Earth.

What shells does the Earth have?

Our planet is complex, although this is somehow forgotten in everyday life. We breathe, drink, eat and go about our daily activities without thinking. That is, we constantly interact with the planet and its shells:

• gaseous (atmosphere);
• solid (lithosphere);
• liquid (hydrosphere).

What is the biosphere

The fourth shell of the Earth is called the biosphere, or “living shell”. It consists of two components: living and non-living. All living organisms on the planet make up the living matter of the biosphere, which captures parts of the other three shells. After all, living organisms are common in air, water, soil and sediment. We can say that where life ends, the biosphere ends.

The difference between the biosphere and other shells

The main difference is living matter, its enormous diversity, ability for self-regulation, reproduction and restoration.

This happens thanks to the following features:

• the constant circulation of substances, which is regulated by living organisms;
• the openness of this sphere to cosmic energies and the energy of the Sun;
• the ability of living beings to convert solar energy into other types of energy;
• maintaining balance in the biosphere through the species diversity of living organisms and their relationships.

Simply put, living beings themselves take care of creating conditions for their life on the planet. It is their merit that water and air have the composition that is necessary for life; they form soil and minerals through interactions with each other and nonliving matter.

Man is also part of the biosphere. He actively intervenes in all the processes occurring in it and uses the result of the “work” of living organisms for his own needs, often harming nature, and therefore the biosphere.

The biosphere is the environment of our life, this is the nature that surrounds us, which we talk about in colloquial language. A person - first of all - with his breathing, the manifestation of his functions, is inextricably linked with this “nature”, even if he lives in a city or in a secluded house.

V. I. Vernadsky

Biosphere(Greek bios - life, sphere - ball, sphere) - the complex outer shell of the Earth, inhabited by organisms that together make up the living matter of the planet. This is one of the most important geospheres of the Earth, which is the main component of the natural environment surrounding humans.

The term “biosphere” was first introduced into science by the Austrian geologist Eduard Suess in 1875. He understood the biosphere as a thin film of life on the earth’s surface. The role and importance of the biosphere for the development of life on our planet turned out to be so great that already in the first third of the 20th century. a new fundamental scientific direction in natural science has emerged - doctrine of the biosphere , the founder of which is the great Russian scientist V.I. Vernadsky.

The Earth and its environment were formed as a result of the natural development of the entire solar system. About 4.7 billion years ago, planet Earth was formed from gas and dust matter scattered in the protosolar system. Like other planets, the Earth receives energy from the Sun, which reaches the earth's surface in the form of electromagnetic radiation. Solar heat is one of the main components of the Earth's climate, the basis for the development of many geological processes. A huge heat flow comes from the depths of the Earth.

According to the latest data, the mass of the Earth is 6x10 21 tons, volume - 1.083x10 12 km 3, surface area - 510.2 million km 2. The size, and therefore all the natural resources of our planet are limited.

Our planet has a heterogeneous structure and consists of concentric shells (geospheres) - internal and external. The internal ones include the core, the mantle, and the external ones include the lithosphere (earth's crust), hydrosphere, atmosphere and the complex shell of the Earth - the biosphere.

Lithosphere(Greek “lithos” - stone) - the stone shell of the Earth, including the earth’s crust with a thickness (thickness) from 6 (under the oceans) to 80 km (mountain systems). The earth's crust is composed of rocks. The share of various rocks in the earth's crust is not the same - more than 70% is basalts, granites and other igneous rocks, about 17% is rocks transformed by pressure and high temperature, and only a little more than 12% is sedimentary.

The earth's crust is the most important resource for humanity. It contains combustible minerals (coal, oil, oil shale), ore (iron, aluminum, copper, tin, etc.) and non-metallic (phosphorites, apatites, etc.) minerals, natural building materials (limestones, sands, gravel and etc.).

Hydrosphere(Greek “gidorah” - water) - the watery shell of the Earth. It is divided into surface and underground.

Surface hydrosphere- the water shell of the surface part of the Earth. It includes the waters of oceans, seas, lakes, rivers, reservoirs, swamps, glaciers, snow covers, etc. All these waters are permanently or temporarily located on the earth's surface and are called surface water.

The surface hydrosphere does not form a continuous layer and intermittently covers the earth's surface by 70.8%.

Underground hydrosphere- includes waters located in the upper part of the earth's crust. They are called underground. The underground hydrosphere is limited from above by the surface of the earth; its lower boundary cannot be traced, since the hydrosphere penetrates very deeply into the thickness of the earth's crust.

In relation to the volume of the globe, the total volume of the hydrosphere does not exceed 0.13%. The main part of the hydrosphere (96.53%) is the World Ocean. Groundwater accounts for 23.4 million km 2, or 1.69% of the total volume of the hydrosphere, the rest is water from rivers, lakes and glaciers.

More than 98% of all water resources of the Earth are salty waters of the oceans, seas, etc. The total volume of fresh water on Earth is 28.25 million km 3, or about 2% of the total volume of the hydrosphere. The bulk of fresh water is concentrated in glaciers, the waters of which are still used very little. The rest of the fresh waters suitable for water supply account for 4.2 million km3 of water, or only 0.3% of the volume of the hydrosphere.

The hydrosphere plays a huge role in shaping the natural environment of our planet. It also very actively influences atmospheric processes (heating and cooling of air masses, saturating them with moisture, etc.).

Atmosphere(Greek “atmos” - steam) - the gaseous envelope of the Earth, consisting of a mixture of various gases, water vapor and dust. The total mass of the atmosphere is 5.15-10 15 tons. At an altitude of 10 to 50 km, with a maximum concentration at an altitude of 20-25 km, there is a layer of ozone that protects the Earth from excessive ultraviolet irradiation, which is fatal to organisms.

The atmosphere physically, chemically and mechanically affects the lithosphere, regulating the distribution of heat and moisture. Weather and climate on Earth depend on the distribution of heat, pressure and water vapor content in the atmosphere. Water vapor absorbs solar radiation, increases air density, and is the source of all precipitation. The atmosphere supports various forms of life on Earth.

In the formation of the Earth's natural environment, the role of the troposphere (the lower layer of the atmosphere up to a height of 8-10 km in polar, 10-12 km in temperate and 16-18 km in tropical latitudes) and, to a lesser extent, the stratosphere, a region of cold rarefied dry air with a thickness of approximately 20 km. Meteorite dust continuously falls through the stratosphere, volcanic dust is ejected into it, and in the past, products of nuclear explosions in the atmosphere.

In the troposphere, global vertical and horizontal movements of air masses occur, which largely determine the water cycle, heat exchange, and transboundary transport of dust particles and pollution.

Atmospheric processes are closely related to processes occurring in the lithosphere and water shell.

Atmospheric phenomena include: precipitation, clouds, fog, thunderstorm, ice, dust (sand) storm, squall, blizzard, frost, dew, hoarfrost, icing, aurora, etc.

The atmosphere, hydrosphere and lithosphere interact closely with each other. Almost all surface exogenous geological processes are caused by this interaction and usually take place in the biosphere.

Biosphere- the outer shell of the Earth, which includes part of the atmosphere up to a height of 25-30 km (up to the ozone layer), almost the entire hydrosphere and the upper part of the lithosphere to a depth of approximately 3 km. The peculiarity of these parts is that they are inhabited by living organisms that make up the living matter of the planet. The interaction of the abiotic part of the biosphere - air, water and rocks and organic matter - biota determined the formation of soils and sedimentary rocks. The latter, according to V.I. Vernadsky, bear traces of the activity of ancient biospheres that existed in past geological eras.

The biosphere is understood as the totality of all living organisms on the planet. They inhabit every corner of the Earth: from the depths of the oceans, the bowels of the planet to the airspace, which is why many scientists call this shell the sphere of life. The human race itself lives in it.

Composition of the biosphere

The biosphere is considered the most global ecosystem on our planet. It consists of several spheres. It includes, that is, all water resources and reservoirs of the Earth. These are the World Ocean, underground and surface waters. Water is both the living space of many living creatures and a necessary substance for life. It ensures the flow of many processes.

The biosphere contains an atmosphere. There are various organisms in it, and it itself is saturated with various gases. Of particular value is oxygen, which is necessary for life for all organisms. The atmosphere also plays a vital role in nature, influencing weather and climate.

The lithosphere, namely the upper layer of the earth's crust, is part of the biosphere. It is inhabited by living organisms. Thus, insects, rodents and other animals live in the depths of the Earth, plants grow, and people live on the surface.

The world and are the most important inhabitants of the biosphere. They occupy a huge space not only on the ground, but also shallowly in the subsoil, inhabit bodies of water and are found in the atmosphere. Plant forms vary: from mosses, lichens and herbs to shrubs and trees. As for animals, the smallest representatives are single-celled microbes and bacteria, and the largest are terrestrial and sea creatures (elephants, bears, rhinoceroses, whales). They all have a wide variety, and each species is important to our planet.

The importance of the biosphere

The biosphere has been studied by various scientists in all historical eras. V.I. paid a lot of attention to this shell. Vernadsky. He believed that the biosphere is defined by the boundaries within which living matter lives. It is worth noting that all its components are interconnected, and changes in one area will lead to changes in all shells. The biosphere plays a vital role in the distribution of energy flows on the planet.

Thus, the biosphere is the living space of people, animals and plants. It contains essential substances and natural resources such as water, oxygen, earth and others. People have a significant influence on her. In the biosphere there is a cycle of elements in nature, life is in full swing and the most important processes are carried out.

Human influence on the biosphere

Human influence on the biosphere is ambiguous. With each century, anthropogenic activity becomes more intense, destructive and large-scale, so people contribute to the emergence of not only local environmental problems, but also global ones.

One of the results of human influence on the biosphere is a reduction in the number of flora and fauna on the planet, as well as the disappearance of many species from the face of the earth. For example, plant ranges are shrinking due to agricultural activities and deforestation. Many trees, shrubs, and grasses are secondary, that is, new species were planted instead of the primary vegetation cover. In turn, animal populations are destroyed by hunters not only for food, but also for the purpose of selling valuable skins, bones, shark fins, elephant tusks, rhino horns, and various body parts on the black market.

Anthropogenic activity quite strongly influences the process of soil formation. Thus, plowing fields leads to wind and water erosion. A change in the composition of the vegetation cover leads to the fact that other species participate in the process of soil formation, and, therefore, a different type of soil is formed. Due to the use of various fertilizers in agriculture and the discharge of solid and liquid waste into the ground, the physical and chemical composition of the soil changes.

Demographic processes have a negative impact on the biosphere:

• the planet's population is growing, consuming more and more natural resources;
• the scale of industrial production is increasing;
• there is more waste;
• The area of ​​agricultural land is increasing.

It is worth noting that people contribute to the pollution of all layers of the biosphere. There are a huge variety of sources of pollution today:

• vehicle exhaust gases;
• particles released during fuel combustion;
• radioactive substances;
• petroleum products;
• releases of chemical compounds into the air;
• municipal solid waste;
• pesticides, mineral fertilizers and agrochemicals;
• dirty wastewater from both industrial and municipal enterprises;
• electromagnetic devices;
• nuclear fuel;
• viruses, bacteria and foreign microorganisms.

All this leads not only to changes in ecosystems and a reduction in biodiversity on earth, but also to climate change. Due to the influence of the human race on the biosphere, melting of glaciers and changes in the level of oceans and seas, acid precipitation, etc. occur.

Over time, the biosphere becomes more and more unstable, which leads to the destruction of many ecosystems on the planet. Many scientists and public figures advocate reducing the impact of the human community on nature, in order to preserve the Earth's biosphere from destruction.

Material composition of the biosphere

The composition of the biosphere can be viewed from various points of view. If we talk about the material composition, then it includes seven different parts:

• Living matter is the totality of living beings that inhabit our planet. They have an elementary composition, and in comparison with other shells they have a small mass, they feed on solar energy, distributing it in their environment. All organisms constitute a powerful geochemical force, distributed unevenly across the earth's surface.
• Biogenic substance. These are those mineral-organic and purely organic components that were created by living beings, namely fossil fuels.
• Inert substance. These are inorganic resources that are formed without the participation of living beings, on their own, that is, quartz sand, various clays, as well as water resources.
• Bioinert substance obtained through the interaction of living and inert components. These are soil and rocks of sedimentary origin, the atmosphere, rivers, lakes and other surface waters.
• Radioactive substances such as the elements uranium, radium, thorium.
• Scattered atoms. They are formed from substances of terrestrial origin when they are influenced by cosmic radiation.
• Cosmic matter. Bodies and substances formed in outer space fall onto the earth. These can be either meteorites or fragments of cosmic dust.

Layers of the biosphere

It is worth noting that all the shells of the biosphere are in constant interaction, so sometimes it is difficult to distinguish the boundaries of a particular layer. One of the most important shells is the aerosphere. It reaches a level of approximately 22 km above the ground, where there are still living beings. In general, this is the air space where all living organisms live. This shell contains moisture, solar energy and atmospheric gases:

• oxygen;
• ozone;
• argon;
• nitrogen;
• water vapor

The number of atmospheric gases and their composition depends on the influence of living beings.

The geosphere is an integral part of the biosphere; it includes the totality of living beings that inhabit the earth's surface. This sphere includes the lithosphere, the world of flora and fauna, groundwater and the gas envelope of the earth.

A significant layer of the biosphere is the hydrosphere, that is, all bodies of water without groundwater. This shell includes the World Ocean, surface waters, atmospheric moisture and glaciers. The entire aquatic sphere is inhabited by living beings - from microorganisms to algae, fish and animals.

If we talk in more detail about the solid shell of the Earth, it consists of soil, rocks and minerals. Depending on the location environment, there are different types of soil, which differ in chemical and organic composition and depend on environmental factors (vegetation, water bodies, wildlife, anthropogenic influence). The lithosphere consists of a huge number of minerals and rocks, which are present in unequal quantities on earth. At the moment, more than 6 thousand minerals have been discovered, but only 100-150 species are most common on the planet:

• quartz;
• feldspar;
• olivine;
• apatites;
• gypsum;
• carnallite;
• calcite;
• phosphorites;
• sylvinite, etc.

Depending on the quantity of rocks and their economic use, some of them are valuable, especially fossil fuels, metal ores and precious stones.

As for the world of flora and fauna, this is a shell that includes, according to various sources, from 7 to 10 million species. Presumably, about 2.2 million species live in the waters of the World Ocean, and about 6.5 million live on land. There are approximately 7.8 million representatives of the animal world on the planet, and about 1 million plants. Of all known species of living beings, no more than 15% have been described, so it will take humanity hundreds of years to explore and describe all existing species on the planet.

Connection of the biosphere with other shells of the Earth

All components of the biosphere are in close relationship with other shells of the Earth. This manifestation can be seen in the biological cycle, when animals and people release carbon dioxide, it is absorbed by plants, which release oxygen during photosynthesis. Thus, these two gases are constantly regulated in the atmosphere due to the interrelationships of various spheres.

One example is soil - the result of the interaction of the biosphere with other shells. Living beings (insects, rodents, reptiles, microorganisms), plants, water (groundwater, precipitation, reservoirs), air mass (wind), soil-forming rocks, solar energy, climate take part in this process. All these components slowly interact with each other, which contributes to the formation of soil at an average rate of 2 millimeters per year.

When components of the biosphere interact with living shells, rocks are formed. As a result of the influence of living beings on the lithosphere, deposits of coal, chalk, peat and limestone are formed. During the mutual influence of living beings, the hydrosphere, salts and minerals, and a certain temperature, corals are formed, and from them, in turn, coral reefs and islands appear. This also makes it possible to regulate the salt composition of the waters of the World Ocean.

Various types of relief are a direct result of the connection of the biosphere with other layers of the earth: the atmosphere, hydrosphere and lithosphere. This or that form of relief is influenced by the water regime of the area and precipitation, the nature of air masses, solar radiation, air temperature, what types of flora grow here, what animals inhabit this territory.

The importance of the biosphere in nature

The importance of the biosphere as a global ecosystem of the planet cannot be overestimated. Based on the functions of the shell of all living things, one can understand its significance:

• Energy. Plants are intermediaries between the Sun and the Earth, and, receiving energy, part of it is distributed between all elements of the biosphere, and part is used to form nutrients.
• Gas. Regulates the amount of different gases in the biosphere, their distribution, transformation and migration.
• Concentration. All creatures selectively extract biogenic components, so they can be both beneficial and dangerous.
• Destructive. This is the destruction of minerals and rocks, organic substances, which contributes to a new turnover of elements in nature, during which new living and nonliving substances appear.
• Environment-forming. It affects environmental conditions, the composition of atmospheric gases, rocks of sedimentary origin and the soil layer, the quality of the aquatic environment, as well as the balance of substances on the planet.

For a long time, the role of the biosphere was underestimated, since in comparison with other spheres the mass of living matter on the planet is very small. Despite this, living beings are a powerful force of nature, without which many processes, as well as life itself, would be impossible. In the process of the activity of living beings, their interactions with each other, and their influence on inanimate matter, the natural world itself and the appearance of the planet are formed.

The role of Vernadsky in the study of the biosphere

The theory of the biosphere was first developed by Vladimir Ivanovich Vernadsky. He isolated this shell from other earthly spheres, updated its meaning and presented that it is a very active sphere that changes and influences all ecosystems. The scientist became the founder of a new discipline - biogeochemistry, on the basis of which the doctrine of the biosphere was substantiated.

Studying living matter, Vernadsky concluded that all forms of relief, climate, atmosphere, rocks of sedimentary origin are the result of the activity of all living organisms. One of the key roles in this is given to people who have a huge influence on the course of many earthly processes, being a certain element that possesses a certain force that can change the face of the planet.

Vladimir Ivanovich presented the theory of all living things in his work “Biosphere” (1926), which contributed to the emergence of a new scientific branch. In his work, the academician presented the biosphere as an integral system, showed its components and their relationships, as well as the role of humans. When living matter interacts with inert matter, a number of processes are affected:

• geochemical;
• biological;
• biogenic;
• geological;
• migration of atoms.

Vernadsky outlined that the boundaries of the biosphere are the field of existence of life. Its development is influenced by oxygen and air temperature, water and mineral elements, soil and solar energy. The scientist also identified the main components of the biosphere, discussed above, and identified the main one - living matter. He also formulated all the functions of the biosphere.

Among the main provisions of Vernadsky’s teaching on the living environment, the following theses can be distinguished:

• the biosphere covers the entire aquatic environment to ocean depths, includes the surface layer of the earth up to 3 kilometers and airspace to the boundary of the troposphere;
• showed the difference between the biosphere and other shells in its dynamism and constant activity of all living organisms;
• the specificity of this shell lies in the continuous circulation of elements of living and inanimate nature;
• the activity of living matter has led to significant changes throughout the planet;
• the existence of the biosphere is determined by the astronomical position of the Earth (distance from the Sun, tilt of the planet’s axis), which determines the climate and the course of life cycles on the planet;
• Solar energy is the source of life for all creatures in the biosphere.

Perhaps these are the key concepts about the living environment that Vernadsky laid down in his teaching, although his works are global and require further understanding, they are still relevant today. They became the basis for the research of other scientists.

Conclusion

To summarize, it is worth noting that life in the biosphere is distributed differently and unevenly. A large number of living organisms live on the earth's surface, be it aquatic or land. All beings come into contact with water, minerals and the atmosphere, being in continuous communication with them. This is what provides optimal conditions for life (oxygen, water, light, heat, nutrients). The deeper into the ocean water or underground, the more monotonous life is. Living matter also spreads over an area, and it is worth noting the diversity of life forms throughout the earth's surface. To understand this life, we will need more than a dozen years, or even hundreds, but we need to value the biosphere and protect it from our harmful human influence today.