IX. Biosphere and landscapes of the Earth: the impact of human activities
The surface of the globe in all its diversity existed in the past and is now the subject of study of many natural sciences (geology, physical geography, biology, soil science, etc.). In the process of development of these sciences, as knowledge accumulated, the surface of the globe began to be understood as the result of a complex interaction of its four constituent spheres: lithosphere(hard, stone), atmosphere(air), hydrosphere(water) and biosphere(living matter). As a result, a new concept emerged - geographical envelope of the Earth as the most extensive complex natural formation, consisting of four interpenetrating private physical-geographical shells.
Planet Earth is characterized by a shell structure (shell is a three-dimensional, volumetric concept). One of the shells - geographical - has a number of distinctive features indicating its more complex structure compared to others. Distinctive features of the geographical shell of the Earth: the presence in its composition of matter in three states of aggregation (solid, liquid and gaseous), the simultaneous presence of cosmic and terrestrial energy sources, the presence of organic matter - life. For the first time, the Russian naturalist P. I. Brounov pointed out the geographical shell of the Earth, consisting of four parts (shells, or spheres). He wrote that all these spheres (lithosphere, atmosphere, hydrosphere and biosphere), penetrating one into another, determine by their interaction the external appearance of the Earth. The study of these interactions is one of the most important tasks of modern natural sciences.
The main property of the geographical shell of the earth is the constant exchange of matter and energy not only between it and the outside world - outer space, but also between the main parts of the shell itself: substrate, air, water, biomass. This exchange determines the constant development of the geographical shell, and the variability of its composition and structure makes the organization of natural components and their complexes increasingly higher and more complex (complex translated from Latin is a plexus, that is, a close connection of parts of the whole).
The geographic envelope of the Earth has significant power, but there are different views regarding its boundaries. According to the most common opinion, its upper limit lies in the atmosphere at the upper limit of the distribution of life at an altitude of approximately 25-30 km. Up to this limit, the thermal effect of the earth's surface is felt and the atmosphere is enriched with ozone (0 3). The ozone layer intercepts excess ultraviolet radiation from the Sun, thereby protecting life on the earth's surface.
The composition of the geographical shell of the Earth includes the entire thickness of ocean waters. The lower limit of the penetration of life on the continents apparently runs along the lower limit of the layer of the earth's crust, which is in continuous exchange of matter and energy with the hydrosphere and atmosphere, which is expressed in tectonic movements, including earthquakes and volcanic eruptions. The total thickness of the geographical shell of the Earth covered by life is 35 - 40 km.
A characteristic feature of the geographical shell of the Earth is the heterogeneity and contrast of its constituent parts - the spheres. The layer of direct interaction between them stands out as a special landscape sphere, which serves as a place for the transformation of solar energy into various types of earthly energy, an environment most favorable for the development of life. Its thickness ranges from several tens to 250 m above the oceans and the earth's surface (both over plains and over mountains). Within these limits, landscapes are formed on land and in the oceans as a result of direct contact and active interaction of the lithosphere, atmosphere, and hydrosphere. The landscape sphere on land includes the modern weathering crust 1, soil, vegetation, living organisms and ground layers of air. In other words, The landscape sphere is a collection of natural complexes on the earth's surface.
In the landscape sphere of the Earth, which occupies the central part of the geographical envelope, there is a biological focus (according to V.I. Vernadsky) - the most vigorous manifestation of life on land and in water. As part of the geographical envelope, this sphere is global in nature and is the subject of study of a special science - landscape science. The landscape sphere is distinguished from other geospheres of our planet by the exceptional complexity of the external and internal structure, the existence and activities of human society. The properties of the geocomplexes that make up the landscape sphere are determined by processes occurring both directly in the landscape and occurring in the bowels of the Earth and the World Space.
In scientific and educational literature, terms are used that are synonymous, or complement each other, or have completely different content. Thus, the actual synonyms for the term “geographical envelope” are the geographic sphere, landscape envelope, and epigeosphere. There are works that equate the concepts of landscape envelope and geographic environment. This is incorrect, since the geographical - landscape - shell became the geographical environment of human society after its emergence, and then only in the space where this society worked. For ancient man of the Paleolithic period, the geographic environment was only a small part of the landscape envelope. Now human activity has gone beyond the geographic envelope (cosmonaut flights, deep drilling). The geographical environment is understood as that part of the earth's natural environment of man, which at a given historical moment is most connected with his production activities.
Preface
Based on the works of V.I. Vernadsky uses the definition of the biosphere as a planetary shell, the composition of which includes the lower layers of the atmosphere, the hydrosphere, and the upper layers of the lithosphere. Its composition and structure are determined by the modern and past life activity of the entire set of living organisms. Due to the interaction of its living and nonliving components, the accumulation and redistribution of a huge amount of energy in it, it is a thermodynamically open, self-organized, self-regulating, dynamically balanced, stable, global system.
The French biologist J.B. came close to the concept of “biosphere”. Lamarck (1802). But the term “biosphere” itself was first used by the Australian geologist E. Zuss (1875). He also identified the biosphere as a separate shell of the Earth, covered by life, which includes parts of the atmosphere, hydrosphere and lithosphere. Living beings (plants, animals, microorganisms) exist on the surface of the Earth, in its atmosphere, hydrosphere and upper part of the lithosphere, and as a whole make up the film of life (sphere) on our planet. The upper boundary of the biosphere reaches 85 km above the Earth's surface. At such altitudes (in the stratosphere), during the launch of geophysical rockets, microorganism spores were detected in air samples. The lower boundary of the biosphere reaches the depths of the lithosphere, where the temperature reaches 100 0 C (in young folded areas this is approximately 1.5 - 2 km and on crystalline shields - 7 - 8 km).
The upper boundary of the biosphere, according to V.I. Vernadsky, is radial, and the lower is thermal. The radial boundary is due to the presence of hard short-wave radiation, from which life on Earth is protected by the ozone layer, the thermal boundary is due to the presence of high temperatures and is located on land at an average depth of 3 - 3.5 km from the earth's surface. Thus, the total thickness of this earth's shell would have to be several tens of kilometers.
1. Geographic shell - a complex shell of the Earth, formed as a result of the interpenetration and interaction of substances of individual geospheres - the lithosphere, the hydrosphere of the atmosphere and the biosphere. The geographical envelope is the environment of human society, and in turn is subject to significant transformative influence from it.
The geographic envelope is the largest natural complex, the development of which has certain patterns:
o Integrity - all components of the geographical shell represent a single whole, interact with each other, and substances and energy are in constant circulation;
o Rhythmicity - periodic repetition of similar natural phenomena that last a day (day and night), a year (spring, summer, autumn, winter) or millions of years (mountain building), etc.;
o Zoning - a change in the nature and properties of natural complexes from the equator to the pole, associated with the uneven distribution of solar heat depending on geographic latitude;
o Altitudinal zonation - a change in relief, climate, water, vegetation depending on the absolute height of the area, the exposure of the slopes and the extent of mountainous countries relative to superior air masses.
Atmospheric air is one of the main sources of life on the planet. A person cannot live without air for more than 5 minutes. A person’s need for air depends on his condition, working conditions and ranges from 15 to 150 thousand. L per day.
The atmosphere is the outer gaseous shell of the Earth, reaching from its surface into outer space approximately 3000 km and is divided into the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
It surrounds the earth and rotates with it under the influence of gravity. The composition of the atmosphere includes nitrogen - 78%, oxygen - 21%, argon, helium, krypton and some other permanent components. It is believed that the composition and properties of the atmosphere have stabilized over the past 50 million years. Among the changing components of the atmosphere - water vapor, ozone, carbon dioxide, are of great importance for atmospheric processes. The bulk of water vapor is concentrated in the lower layers of the atmosphere (from 0.1 - 0.2% in polar latitudes to 3% in equatorial latitudes), with height its amount decreases significantly - by 90% at an altitude of about 5 km. The content of water vapor in the atmosphere is determined by the relationship between the processes of evaporation, condensation and horizontal transport. The ozone layer absorbs most of the sun's ultraviolet radiation, protecting life on Earth. This is the main ecological significance of the atmosphere.
The lithosphere is the outer solid shell of the earth, which includes the entire crust of the earth with part of the upper mantle of the earth, and consists of sedimentary, igneous and metamorphic rocks.
Man influences most of all the earth's crust - the thin upper shell of the Earth, 40 - 80 km thick on the continents, 5 - 10 km under the oceans and makes up only about 1% of the Earth's mass. The elements of the lithosphere - oxygen, silicon, hydrogen, aluminum, iron, magnesium, calcium, sodium - form 99.5% of the earth's crust.
The earth's crust is inhabited by living organisms only in the upper layers of the soil (pedosphere) to a depth of 5 m. The rocks that make up the lithosphere are susceptible to cyclic processes, under the influence of exogenous and endogenous forces. Endogenous forces act through weathering, depositing weathered material into deeper layers or transporting it to new deposit locations (sedimentation).
Through cementation or pressure, sediments can harden (diagenesis). 8% of sediments cover 75% of the Earth's surface. After a long (from a geological point of view) time, the sedimentary cover, which has already become very thick and very heavy, can sink, and then it is subject to the action of endogenous forces. They lead to the formation of folds, and due to pressure and high temperatures, the rocks can change, melt and harden again.
The hydrosphere is the water sphere of our planet, the totality of oceans, seas, continental waters, and ice sheets. Our planet contains about 16 billion cubic meters. m. of water, which is 0.25% of its mass. The main part of this water (more than 80%) resides in the deep zones of the Earth - its mantle. The underground part of the hydrosphere covers ground, subsoil, interstratal, free-flow and pressure waters, fissure waters and waters of karst cavities in easily soluble rocks (limestone, gypsum).
For a huge number of living organisms, especially at different stages of development of the biosphere, water was the medium of birth and development. Water in the biosphere is in constant motion, originating in the geological and biological circulation of substances. Water is the basis for the existence of life on Earth. Without water, human civilization cannot exist, because water is used by people not only for drinking, but also to provide sanitary, hygienic and household needs.
2.1. The biosphere (the space inhabited by living organisms) covers only a thin belt of the Earth, a layer about 20 km thick. In the earth's space, the depth of penetration of living organisms (pedosphere) depends on the climate, the degree of weathering of rocks, etc.
Due to the difficulties of transporting water due to the action of the Earth's gravitational field, plants rarely rise above the ground above 50 m. The most important factors limiting the distribution of living organisms in the atmosphere and hydrosphere are the oxygen content and temperature conditions.
In the atmosphere, due to the passive transfer of pollen and bacterial spores by wind, organic matter reaches a height of up to 10 km.
In deep-sea depressions, anaerobic bacteria have been found at depths of 10,000 m.
From the ecological side, the biosphere can be divided into subbiospheres (Schubert), and the atmosphere, as soon as the temporarily inhabited space is not taken into account:
Geobiosphere - inhabited space of the lithosphere and pedosphere (soil, etc.);
Hydrobiosphere - the inhabited space of the hydrosphere (seas, freshwater lakes, rivers);
Anthropobiosphere is a space with human dominance (cultural landscapes, cities).
2.2 The formation of living substances and their decay are two sides of a single process, which is called the biological circulation of chemical elements. Life is the circulation of elements between organisms and the environment.
The reason for the circulation is the limited nature of the elements that make up the body. Biological circulation is the repeated participation of chemical elements in processes occurring in the biosphere. In this regard, the biosphere is defined as the region of the Earth where three main processes occur: the cycle of hydrogen, nitrogen, sulfur, in which five elements (H, O 2, C, N, S) moving through the atmosphere, hydrosphere, and lithosphere take part. In nature, the circulation is carried out not by substances, but by chemical elements.
Carbon cycling. There are more than 12,000 billion tons of carbon in the biosphere. This is because carbon compounds are constantly being created, changed and broken down. The carbon cycle actually occurs between substances and carbon dioxide. In the process of photosynthesis carried out by plants, carbon dioxide and water are converted into various organic compounds using the energy of sunlight. The complete cycle of atmospheric carbon exchange occurs within 300 years. But some of the carbon is excluded in the form of peat, oil, coal, marble, etc.
Oxygen cycle. Every year forests produce 55 billion tons of oxygen. It is used by living organisms for respiration and takes part in oxidative reactions in the atmosphere, lithosphere and hydrosphere. Circulating through the biosphere, oxygen is converted either into organic matter, then into water, or into molecular oxygen. Nowadays, a large amount of oxygen is spent annually on the combustion of carbon, oil products and gas. The intensity of this process increases every year.
Cycle of nitrogen, phosphorus, sulfur. Human activity accelerates the circulation of these elements. The main reason for the acceleration is the use of phosphorus in fertilizers, which leads to eutrification - fertilization. During eutrification, rapid proliferation of algae occurs - “blooming” of water. This leads to a decrease in the amount of oxygen dissolved in water. Algae metabolic products destroy fish and other organisms. The formed ecosystems are destroyed. Industry and internal combustion engines emit a lot of nitrates and sulfates into the atmosphere every year. Falling to the ground with rain, they are absorbed by plants.
Water cycle. Water covers * the surface of the Earth. In one minute, under the influence of solar heat, 1 billion tons of water evaporates from the surface of the Earth's reservoirs. After the vapor cools, clouds form and return to the Earth's surface in the form of rain and snow. Precipitation partially penetrates into the soil. Groundwater returns to the surface of the earth through plant roots, springs, pumps, etc.
The rate of water circulation is very high: ocean water is replenished in 2 million years, groundwater in 1 year, river water in 12 days, steam in the atmosphere in 10 days.
Every year, to create the primary production of the biosphere, 1% of the water that falls in the form of precipitation is used during photosynthesis. People only use 20 mm of precipitation for domestic and industrial needs - 2.5% of the total amount for the year. The permanent annual catchment is now 55 cubic meters. m. annually it increases by 4 - 5%.
On the other hand, living organisms adapt to different chemical conditions of the environment and can tolerate high concentrations of those elements that are usually found in large quantities here. Elements that are rarely found in nature and in small concentrations become toxic to living organisms when accumulated.
3. 3.5 billion years ago, in the primary ocean of the Earth, under the influence of ultraviolet and penetrating radiation, as well as electrical lightning discharges, the formation of the first organic compounds began - “organic broth” (A.I. Oparin). With increasing concentration of this solution, some organic molecules, combining, began to form coacervate droplets, isolated from their environment and which used the substances included in its composition to increase their size. This is how molecules capable of self-reproduction arose, which meant the origin of Life.
The first organisms fed on the organic solution surrounding them, but the time came when its reserves began to deplete, and there was practically no free oxygen, and the first organisms were forced to obtain energy through the fermentation process. But this process is ineffective and required a large amount of food. Therefore, life was doomed to starvation. The only way to transform a final substance into a non-final one is to include it in the circulation. As a result of natural selection, photosynthetic organisms appeared that did not feed on ready-made organic matter, but created it themselves, using sunlight to convert carbon dioxide, mineral salts and water. The waste product of this method of nutrition was oxygen, which, firstly, made possible the emergence of multicellular representatives of the animal world, consuming energy from ready-made organic substances through their oxidation, and, secondly, created protection from the influence of ultraviolet radiation, which was destructive for protein compounds, since some Some of the free oxygen turned into ozone, which is a powerful absorber.
This is how a closed circle of interdependent and mutually adapted organisms and processes was created, among which there is not a single one that is superfluous, since each performs its own function: the waste of one is the condition for the life of the other.
Animals could not eat and breathe without the help of plants. But plants without animals would die very quickly, since there would be no one to process the created organic matter into water, carbon dioxide and mineral salts, preventing the planet from being polluted by extinct remains and restoring nutrient reserves for new generations of plants. Living organisms also take part in the general cycle of substances in nature and the formation of the planet.
So, animal and plant organisms, through their activity during life and biomass after death, created and improved conditions favorable for life for billions of years, that is, the biosphere, before man appeared, who after several hundred thousand years began to destroy it with his irrational activities.
Conclusion
The approximate mass of the biosphere is 3 10 24 g, and the volume is 10 10 24 cm 3, including the lithosphere - 0.6 10 24 cm 3, the hydrosphere - 1.4 10 24 cm 3 and the troposphere - 8 10 24 cm 3. The approximate mass of the biosphere is 0.05% of the mass of the Earth, and the volume is 0.4% of the volume of the Earth, including the latter atmosphere 2000 km thick from the geoid level. The mass of living matter is only (3...5) 10 -8% of the mass of the Earth and about (0.7 - 1.0) 10 -8% of the mass of the biosphere.
Interesting generalizations about the parameters of the biosphere are given by F. Ya. Shipunov (1980). According to his data, the greatest thickness of the biosphere is located at tropical latitudes - 22 km, the smallest - at polar latitudes - 12 km.
The processes that occur in the biosphere and in the surrounding planetary environment originate and are supported, on the one hand, by cosmic, and on the other, by terrestrial factors associated with the characteristics of the Earth as a planet (tension of gravitational and magnetic fields, characteristics of its substance, radiation, etc. .). the interaction of these two factors creates a single creation - the Earth system (Shipunov). The biosphere is a structural part of this complex planetary system. And if its living matter forms for itself an unfavorable habitat and development - the biosphere, then the latter transforms its planetary environment in such a way and in such a size as to have maximum stability of its structural organization. Therefore, the biosphere must be considered not only as an area of development of living matter on Earth, but also as an area that transforms its immediate environment into an inseparable ecological planetary matter.
LIST OF REFERENCES USED
Biosphere: pollution, degradation, protection. - Dictionary. 2003
Vernadsky V.I. Biosphere - Leningrad, 1972
Korsak K.V., Plakhovnik O.V. Fundamentals of ecology. Scientific manual - K., 2002.
Fundamentals of Ecology - ed. E. N. Meshechko 2002
Myakushko V.V., Volvach F.V. Ecology. - K., 2000
Sytnik K. M., Brion A. V., Gordetsky A. V. Biosphere, ecology, nature conservation. - K., 1987
Dieter Heinrich, Manfred Gergt. Ecology - ed. V.V. Serebryakova - 2001
Bilyavsky T. D., Padun M. M. Fundamentals of general ecology. Textbook - K., 1996
Vernadsky V.I. Biosphere and noosphere 1989
Biosphere and its resources - ed. N. Fillipovsky 1982
Biosphere. Evolution, space, time. - ed. R.W. Sims 1988
The biosphere is a unique shell of our planet. All the previous shells we considered exist to one degree or another on other planets, but, apparently, they do not exist on any of them except the Earth. It is possible that since there is life on our planet, it also exists in other corners of the Universe, it is also likely that this is a very common phenomenon, but so far scientists are still looking for life beyond our planet and the only one where life has been discovered is Earth. Who knows, maybe this is the only planet where life originated in some unknown way?
Where it came from on Earth, no one really has any idea yet. Life is too complex a phenomenon to arise by chance, and we still know nothing about the processes that can lead to its appearance. But the fact remains that life exists and thrives on Earth. Scientists have divided the entire history of the existence of our planet, which lasts 4.5 billion years, into two large parts - two eons: Cryptozoic and Phanerozoic. The Cryptozoic eon is the eon of “hidden life.” In the geological layers of this period, no traces of life on the planet are found. This cannot clearly indicate that it did not exist at all at that time, but no evidence of its presence is noted; perhaps it was too primitive for a long time - at the level of single-celled organisms that are not preserved in the form of fossils. The Phanerozoic eon began 570 million years ago, marked by the so-called “Cambrian Explosion”. During this period, the Precambrian or Archean geological era ends and the Paleozoic begins. The Paleozoic era is the era of “ancient life.” At this moment, almost all types of living beings appear: mollusks, brachiopods, worms, echinoderms, arthropods, chordates and others - which is why this moment was called the “explosion”. Within 100 million years, the first vertebrates appeared, and 400 million years ago, life began to make its way onto land—amphibians appeared. I would like to note that life arose in the ocean and for a long time could not get to land, since until the oxygen and ozone layers were formed, protecting all living things from deadly solar radiation, the land was unsuitable for life. During the same period, terrestrial plants began to flourish - mosses, horsetails, ferns appeared, and soil appeared after the plants. The Paleozoic era ends 251 million years ago with the largest mass extinction of living creatures in its entire history. What happened during this period remains unknown; obviously, colossal climate changes occurred on the planet. Some paleontologists believe that a major ice age occurred on Earth, covering the entire planet. However, after the Paleozoic came the Mesozoic, and life on the planet was restored again. The Mesozoic was the era of dinosaurs, who reigned on the planet for about 200 million years. But 65 million years ago, mass extinction occurred again. All dinosaurs disappeared from the face of the planet. Presumably, a large meteorite crashed into the Earth, radically changing its climate. From this moment the Cenozoic era began, which continues to this day. The Cenozoic became the era, and about 2 million years ago man emerged among them.
Today, life has penetrated into all corners of the globe; it is found at the very bottom of the oceans, in hot springs, on the highest mountains, in volcanoes and under ice. It has penetrated everywhere, where life disappears for some reason, it is soon restored again, adapting to increasingly new and difficult environmental conditions. The diversity of living organisms on the planet is enormous; it numbers millions of animals, plants, fungi and microorganisms. The biosphere itself is essentially a continuous space in which all these species are located. They interact with each other through a huge number of biological connections, forming a single, global ecosystem. Of course, different living organisms have adapted to different natural conditions, which is why several natural zones have formed on Earth, characterized by special natural conditions and the species inhabiting them.
Ecology has significantly expanded the scope of its research and now considers the patterns of the ecosystem in close connection with geography and human activity. This gives rise to general geoecological patterns at the biosphere level.
The basis of geographical patterns is relief, unity (integrity) of the biosphere, preservation of balance in nature, zonality and azonality, polar asymmetry and metabolism.
In 1974, the famous American ecologist B. Commoner combined the listed patterns into four laws:
1. Everything is connected to everything. A small shift in one place in an ecological system leads to unintended consequences for the entire ecosystem.
2. Nothing disappears without a trace and disappears into nowhere. The substance enters into metabolism and passes from one form to another.
3. Nature knows best. Man does not know that, while “improving” nature, he can disrupt the laws of development in it.
4. You have to pay for everything. Man, using natural resources freely and illiterately, pollutes the air, water, and soil. There must be a limit to human mismanagement. All human actions should be decided on equal terms in favor of nature. The future of the biosphere directly depends on the intelligence of the people living in it. Only by preserving the quality of the environment can humans protect themselves as a species.
The second way to preserve humanity is the ability to adapt to unfavorable environmental conditions. According to the biological laws of nature, in the absence of these two conditions, human society will gradually disappear. Therefore, maintaining balance on the planet and studying the patterns of unity of the geographical envelope help to carry out life processes within the biosphere.
Biosphere- field of study of ecology, the largest ecological system on the globe. For a deeper study of the geographic envelope and biosphere, let us dwell on some geoecological concepts.
Biosphere- a favorable environment for the existence of living organisms on Earth. Its areas extend from small burrows, bird nests and anthills to large valleys, biocenoses and ecosystems (Fig. 64).
Rice. 64. A flower is the habitat of a butterfly
Geographical envelope- a single territorial system that occupies the entire outer layer of the globe. It covers all components of the biosphere. The total depth of the geographic shell is 35-40 km.
The structure, characteristics and area of study of the geographical envelope and the biosphere are similar; these are mutually complementary systems. Although the biosphere is inferior to the geographical envelope in volume and size, all organisms currently living on Earth are concentrated in it. Two large ecosystems are the subject of ecology research. The term “geographical envelope” was introduced into science by A. A. Grigoriev (1932), and “biosphere” by E. Suess (1875).
One of the main properties of the geographic shell is the heterogeneity of space. The spatial distribution of the earth's crust is the result of long-term and complex geobiological processes. For example, the main indicator of the geographic envelope is geosystems, or natural landscapes.
Ecosystems- a natural complex formed by a collection of living organisms and a continuous flow of substances and energy on Earth.
The size and biomass of an ecosystem can vary greatly - from small to huge areas. They cover aboveground (atmosphere), underground (lithosphere) and aquatic (hydrosphere) living environments. For example, the concept of “ecosystem” is applicable from a drop of water to the ocean. By their nature, ecosystems are divided into natural and anthropogenic.
One of the main properties of an “ecosystem” is its diversity of sizes. The highest, global scale ecosystem is the biosphere. Simple ecosystems (biogeocenoses) are characterized by relative homogeneity. As a single ecosystem, plant communities, fauna, physical and geographical conditions, as well as a constant flow of energy and metabolism interact in it.
Biogeocenosis corresponds to the geographical concept of "facies". For example: ecosystems of birches, valleys, steppes, etc.
The main properties characteristic of an ecosystem are the circulation of substances and the stability of biological productivity.
Geosystem (geographical system)- a single complex of natural components that develop in close relationship in time and space and complement each other as a material system. Although the geosystem and the ecosystem are close to each other, geosystems, compared to ecosystems, cover production, territorial complexes and the area of distribution of production sites.
The highest natural system of the geographic envelope is landscape (Fig. 65, 66).
Rice. 65. Mountain meadows
Rice. 66. Okzhetpes. Mountain landscape
Landscape- territories that are homogeneous in origin and history of development, with a single geographical period of formation, uniform soil, topography, climate, hydrothermal conditions, and biocenosis.
There are similarities and differences between ecosystems and geosystems (landscapes). It is based on concepts that describe natural complexes. But the ecosystem does not have firm territorial boundaries; they are arbitrary. For example, the forests of Charyn, Ili, the ecosystem of Zhetysu (Dzhungar) Alatau, etc.
Within the geographical envelope, the landscape environment is distinguished. This is a layer of earth that covers flora and fauna, the lower layers of air, above-ground and underground waters. Only in this layer is a favorable environment created for all living organisms. If the landscape environment in the tundra zone occupies 5-10 m, then in tropical zones it reaches 100-150 m. The main reasons for this are related to the development of relief and the thickness of the organic layer.
Thus, what are the main differences between a geosystem and an ecosystem? The geosystem performs a polycentral function, and the ecosystem performs a biocentral function, where the basis is made up of living organisms.
A complete scientific definition of geographical landscapes was given and described by the famous Russian scientist P. P. Semenov-Tyan-Shansky.
According to its taxonomy, primary, partially natural, cultural and restorative landscapes are distinguished.
If we take modern landscapes using the example of Kazakhstan, we can find natural, anthropogenic and cultural landscapes.
Natural landscapes- virgin natural complexes, where perhaps no human has set foot. Such landscapes in Kazakhstan can be found in the region of high mountains, in steppe desert and semi-desert natural zones.
Anthropogenic landscapes- these are altered lands associated with human impact on natural complexes directly and indirectly, for example, the appearance of pastures in the place of cleared forests. Sometimes such anthropogenic landscapes can be restored. But illiterate use of landscapes by humans turns them into deserts and takyrs. According to scientific data, the largest desert ecosystems of the planet - the Sahara, Gobi, Taklamakan, and Central Asia - are the result of direct or indirect human influence. This includes thousands of hectares of unsuitable land in Central Kazakhstan, regions of the Aral Sea, and Southern Kazakhstan with soils susceptible to erosion (Fig. 67).
Rice. 67. Aral lands subject to erosion
The largest ecosystem on earth is the biosphere (sphere of life). Its developmental evolution and future are connected only with the Earth. The merit of creating a holistic doctrine of the biosphere belongs to Academician V.I. Vernadsky (1863-1945).
The foundations of his doctrine of the biosphere, set out in 1926 in the book “Biosphere,” retain their significance in modern science.
In the book, the scientist explored the development, formation and future of life in the biosphere, where the main driving force of life is the energy of the Sun. In general, the formation, development and metabolism in the biosphere are considered from the point of view of the emergence of organic substances.
Geographical envelope. Ecosystem. Geosystem. Landscape.
1. The geographical envelope and the biosphere are mutually complementary single ecosystems.
2. There are natural patterns of development of the geographical envelope and the biosphere.
3. B. Commoner's laws.
1. What are geographical patterns?
2. What is the significance of V. Commoner’s laws?
3. What is natural balance?
1. What is the general description of the biosphere and its driving force?
2. What does the geographical envelope include?
3. What types of ecosystems do you know?
1. What are the similarities and differences between geo- and ecosystems?
2. Name the types of landscape and its functions.
3. Is there a future for unusable land?
Concepts: geographic envelope, landscape space, landscape envelope, natural territorial complex, biosphere, noosphere, vitasphere
One of the most important properties of our planet as a cosmic body is its clearly defined shell structure. Starting from the center of the Earth to the periphery (near and far Space), the inner and outer cores, the lower and upper mantle, the earth's crust with basalt, granite and sedimentary layers, the hydrosphere with abyssal, bathyal and littoral zones, the biosphere with a soil layer ( pedosphere) and biostrome (a zone of concentration of plants and animals near the Earth's surface), the landscape sphere, which includes the weathering crust, soils, biostrome and ground layers of air, the geographic envelope extending from the asthenosphere to the ozone screen, and, finally, the atmosphere with the troposphere , stratosphere, mesosphere, thermosphere and exosphere.
The entire diversity of spheres that form planet Earth has developed during a long evolution and is divided into two large groups (Table 1).
Table. 1
Elements of structural and functional groups that form planet Earth.
The second group arose as a result of the interaction of the first, which is why it is called functional. A characteristic feature of this group is that all its elements are formed in contact zones and form their internal structure at the expense of natural bodies of other spheres located near one or another contact zone.
The geographic envelope of the Earth is a complex natural complex that arises in the zone of interpenetration and interaction of the lithosphere, atmosphere and hydrosphere. The geographic envelope is formed under the influence of solar energy and is characterized by the development of organic life. It includes the lower part of the atmosphere (troposphere) (10 km), the entire hydrosphere, the upper layer of the lithosphere (on continents - 4 - 5 km, on oceans 11 - 12 km), corresponding to the shell of sedimentary rocks and the biosphere. The total thickness of the geographical shell is 20 – 35 km.
The criterion for the isolation of landscape space is the integration observed in it and characteristic only of it of all states of matter characteristic of the earth's surface: abiogenic - solid, liquid, gaseous and living. Landscape space occupies that contact position in the geographic shell in which the lithosphere, atmosphere, hydrosphere and biosphere most closely interlock, penetrate each other, and carry out mutual exchange of matter and energy. If the first three components for the most part extend far beyond the boundaries of the contact landscape space, then the biosphere, with its bulk, is concentrated precisely in it. Landscape space envelops our entire planet. Being a three-dimensional (volumetric) formation, it at the same time has a “film”, borderline character, that is, it is spread out over the earth’s surface.
For the first time, the landscape shell (sphere) was identified as an independent natural body by the Voronezh geographer Fyodor Nikolaevich Milkov in 1959. The landscape shell is a thin layer of direct contact and energetic interaction of the upper layers of the earth's crust, the lower layers of the troposphere and the water shell of the Earth. All of it (from its upper border to the lower) is permeated with life and can be defined as the biological focus of the geographical envelope.
The landscape shell is the place of transformation of solar energy into various types of earthly energy, the environment most favorable for the development of life. The landscape envelope is a set of landscape complexes lining land, oceans and ice sheets.
The landscape shell includes:
Modern weathering crust;
Ground layers of air;
Vegetation;
Animal organisms.
With the direct participation or under the control of living organisms, many energy and mass exchange processes take place here, the result of which are specific landscape bodies that cannot arise and exist in any other conditions.
The landscape envelope is a relatively small part of the geographic envelope, but it is the most complexly organized, heterogeneous, energetically the most active and the most important in ecological terms. In a generalized form, its definition can be as follows: landscape shell - a thin ground layer of the geographical shell, representing the zone of contact and active energy and mass exchange of the lithosphere, atmosphere, hydrosphere and biosphere, powered by the radiant energy of the Sun and energy of intraterrestrial origin, the sphere of the highest concentration of life on Earth, the origin, development and modern existence of humanity and earthly civilization.
The landscape shell is one of the most ancient functional shells. It arose at the beginning of the geological stage of the Earth's development and was represented by an abiogenic weathering crust in contact with a fairly thin layer of the surface atmosphere. In the course of its evolution, and especially with the appearance of living matter on Earth, the landscape sphere acquired a complex internal structure, moving into the category of bioinert systems, i.e. systems in the structure of which both organic and inorganic matter play an equal role.
Two main functions of the landscape shell can be distinguished.
1. Within its boundaries, solar energy is converted into other types, as well as the dissipation of this energy not only within the boundaries of the landscape envelope, but also the entire geographic envelope as a whole.
2. Within the landscape envelope, the most favorable conditions are created for the emergence and existence of life.
What are the vertical boundaries of the landscape envelope? The upper boundary of the landscape shell coincides with the upper boundary of the surface layers of air. These layers, with an average thickness of 30-50 m, are under the direct influence of the underlying surface of the Earth. Their thickness is characterized by daily fluctuations in temperature and air humidity, well-developed thermal convection, in addition, increased air dustiness and the presence of spores and plant pollen are observed here. The thickness of the layer is determined by the nature of the underlying surface. In high latitudes, where this surface is quite homogeneous (snow, ice), the upper boundary is located at an altitude of the first tens of meters. In low latitudes, the underlying surface is represented by tropical rainforests, where the height of the tree layer alone reaches 70-80 m, and therefore the boundary is already located at an altitude of the first hundreds of meters.
The lower boundary coincides with the lower boundary of the weathering crust, which is the products of the direct action of air, water, vegetation and animals on rocks. Weathering crust is ubiquitous and varies from a few meters in high latitudes to several tens of meters, and sometimes hundreds, in the tropics.
Thus, the average thickness of the landscape shell is several tens of meters, and its thickness decreases when moving from the equator to the poles.
The landscape shell, in the course of its long evolution, gave birth to humanity, for thousands of years it was the cradle of its civilization and is now the sphere of human habitation and the object of its work. Over time, the landscape shell became anthropogenic, technogenic and intellectual and spiritual.
The integrity of the landscape shell is ensured by its internal structure, i.e. the totality of its parts, the nature of their relationships and interactions. There are three main structural levels of its organization:
1. Real (geocomponent);
2. Vertical (radial);
3. Lateral (complex).
The material level plays an important role in isolating individual parts (geocomponents) of the landscape sphere. Geocomponents are a set of substances that are homogeneous in their chemical, physical, and biological composition. The following components are distinguished:
Rocks (minerals);
Plants;
Animals.
Behind each of the components there is a certain type of substance. In addition, the components include relief and climate (microclimate), which do not have any underlying material content.
The geocomponents in the landscape shell form four contrasting environments: the earth's crust (rocks and minerals), the air troposphere (air) and the hydrosphere - in solid (ice) and liquid (water) states. Not all environments take part simultaneously in the formation of the internal structure of the landscape shell, but only individual combinations of them, separated territorially.
Five combinations of direct contact of contrasting media are observed on Earth. The combinations differ from each other in the intensity and forms of mutual exchange of matter and energy, and, therefore, in each of them a special landscape environment is formed, fundamentally different from the others. As a result, special variants of it are formed within the landscape shell (Table 2).
table 2
Combinations of direct contact of contrasting landscape environments
The terrestrial variant is formed in land conditions, where there is contact between lithogenic and air environments. This is the currently most studied variant of the landscape sphere.
The aquatic, or water-surface, option covers the surface part of the waters of the World Ocean and has the maximum area among all other options. In addition to the ground layers of air, it also includes the upper layer of ocean waters to a depth of 200 m, since it is within these limits that the process of photosynthesis is possible.
The bottom version is very unique. Here the atmosphere is replaced by water and the soil by silt. There is no light at all. It arises at the bottom of the World Ocean, covering its bathyal and abyssal zones.
The amphibian variant is the most complex in terms of the totality of its constituent components. It covers all surface waters (rivers, lakes, etc.), shallow marine waters (up to a depth of 200 m), as well as the littoral zone itself, which is the core of this option.
The ice variant includes land glaciers and multi-year sea ice. Both are derivatives of climatic conditions. Their main distribution area is the high latitudes of both hemispheres and the highlands of the Earth.
The vertical structure of the landscape shell is expressed through a set of its tiers, replacing each other from bottom to top (from the center of the Earth to its periphery). When moving in this direction, within the boundaries of the landscape sphere the following horizons, or tiers, are well separated, but at the same time actively interact:
1) lithogenic, coinciding mainly with the weathering crust;
2) soil;
3) biogenic, formed by plants and animals;
4) airy, with organic inclusions: spores, pollen, insects, birds, etc.
This vertical structure is characteristic only of the ground version of the landscape sphere. In other versions, it has a different, sharply different character from the one presented.
3. The horizontal structure of the landscape shell is associated with the uneven distribution of solar radiation over the Earth's surface, as well as the complex material and hypsometric structure of its surface. This nature of the horizontal structure is expressed in the formation of various landscapes.
In addition to the concept of “landscape envelope”, the concept of a natural territorial complex (NTC) has been established in landscape science. It is defined as a spatio-temporal system of geographical components, interdependent in their placement and developing as a single whole. NTC is characterized by conjugation with a certain territory within the framework of spatial threshold criteria and denotes a class of natural geographical systems of local and regional dimensions (Fig. 2).
PTC is a landscape concept, unambiguously interpreted in almost all works of landscape scientists as a set of interconnected natural components (lithogenic base, air masses, natural waters, soils, vegetation and wildlife) in the form of territorial formations of various hierarchical ranks.
Landscape PTCs are self-regulating and self-healing systems of interconnected components and complexes that function under the influence of one or more components that act as a leading factor.
Figure 2. Geosystem (I) and natural territorial complex (landscape) (II) of the mountain range
The term “biosphere” was first used by E. Suess in his classic work “The Face of the Earth” (1875), and after him by a number of other researchers, but there was no sufficiently strict formulation of this concept, no precise definition of the boundaries of the biosphere, no study of the significance of the biosphere in general energy and these authors did not do any geochemical work on the Earth. Only V.I. Vernadsky, who, on the basis of his geochemical research, came to the conclusion about the exceptionally great importance of living organisms in the course of geochemical processes on the earth’s surface and in the formation of the face of the Earth, formulated a general doctrine of the biosphere in his 1926 work “Biosphere”.
According to Vernadsky, the biosphere is the shell of the earth, the composition of which is mainly predetermined by the activities of living beings: the entire troposphere, hydrosphere, lithosphere: up to 30–40 km thick, inhabited by living organisms, as well as the region of “former biospheres”, outlined by the distribution of biogenic sedimentary rocks on Earth ; in which the total activity of living organisms manifests itself as a geochemical factor on a planetary scale. This is an area of systemic interaction between living and inert matter on the planet.
The biosphere is not only the so-called area of life. Its substance consists of seven deeply diverse parts:
1) living matter;
2) biogenic;
3) inert;
4) bioinert;
5) radioactive;
6) scattered atoms;
7) substance of cosmic origin.
Consequently, the biosphere is a planetary concept, broad, much larger in scope than the field of study of the forester, biologist and soil scientist, which is limited to the “area of life”. Therefore, the term vitasphere is used to designate the “region of life” or biogeocenotic shell. The particle “vita” emphasizes the fact that this layer is inhabited by living organisms. Thus, the vitasphere (epigenema, phytogeosphere, biogeocenotic shell) is a layer of the biosphere, or area of life, including currently living organisms and parts of the atmosphere, hydrosphere, and lithosphere that they involve in the biological cycle; thickness on land up to hundreds of meters.
The noosphere (noos - mind) is the sphere of the earth covered by human activity. Now, in connection with space flights, the boundaries of the noosphere have gone beyond the Earth's biosphere.