Types of communities of organisms (ecosystem, biogeocenosis, biosphere). Goal setting of the main biological systems: organism, population, community and biosphere The role of the human factor in the development of the biosphere
The upper layer of the lithosphere and in the soil cover. In other words, the biosphere is a single dynamic system on the surface of the Earth, created and regulated by life. Biosphere is the habitat of living organisms.
The biosphere, as a specific shell of the earth, unites the lower part of the air shell (atmosphere) - the so-called troposphere, where active life can exist up to a height of 10-15 km; the entire water shell (hydrosphere), in which life penetrates to the greatest depths exceeding 11 km; the upper part of the solid shell (lithosphere) is the weathering crust, usually having a thickness of 30 - 60 m, and sometimes 100 - 200 m or more. (Weathering crust is a collection of geological deposits formed by the products of decomposition and leaching of rocks of various compositions, which remains at the place of its origin or moves a short distance, but does not lose connection with the “parent” rock.) Outside the weathering crust, life can only be detected in some cases. Thus, microorganisms were found in oil-bearing waters at a depth of more than 4500 m. If we include in the biosphere and, in which the existence of resting rudiments of organisms is possible, then vertically it will reach 25 - 40 km. Special traps installed on rockets detected the presence of microorganisms at altitudes of up to 85 km.
Life processes influence not only the areas where active life occurs, but also the upper layers of the lithosphere - the stratosphere, the mineralogical and elemental composition of which is formed by the geological past. The thickness of the stratosphere, according to V.I. Vernadsky, is 5 - 6 km. The stratosphere is created mainly by organisms, water and, which process and move sedimentary rocks after they are raised above the water.
There are areas within the biosphere where active life is impossible. Thus, in the upper layers of the troposphere, as well as in the coldest and hottest regions of the globe, organisms can only exist in a state of rest. The totality of these regions of the biosphere is called the parabiosphere. However, even in those areas of the biosphere where organisms can exist in an active state, life is unevenly distributed.
“A continuous layer of living matter,” as V.I. Vernadsky called it, occupies the water column and extends in a narrow strip between the troposphere, including the soil and subsoil with plant roots, fungi, microorganisms and soil animals located in them, and the ground part of the troposphere where the above-ground parts of plants are located and the bulk of their pollen, spores and seeds are transferred. This “continuous layer of living matter” is called the phytosphere (or phytogeosphere), since plants are the main energy storage units in it. The thickness of the phytosphere is great only in the oceans, where it is slightly higher than 11 km, and on land it is measured in meters or tens of meters and only in certain, small regions it increases to 100 - 150 m. Moreover, in the lithosphere and hydrosphere, as well as on On the border with the troposphere, organisms carry out the entire development cycle, while in the troposphere itself living beings can only stay temporarily, since they cannot reproduce here.
What are the main features of the biosphere as the shell of the Earth?
The first sign: the chemical composition created by the vital activity of living organisms.
The second sign: the presence of liquid water in significant quantities.
Third sign: a powerful flow of energy from the Sun.
The fourth sign: the presence of an interface between substances in liquid, solid and gaseous states. The presence of free oxygen is also very important for the modern biosphere.
V.I. Vernadsky considered life, the total activity of all organisms on Earth, to be the most powerful geochemical factor transforming the surface of the Earth, an energy factor of planetary scale and significance, about which he wrote: “Whatever the phenomena of life consist of, the energy released by organisms there is in its main part, and perhaps entirely, the radiant energy of the Sun. Through organisms, it regulates the chemical manifestations of the earth’s crust.” V.I. Vernadsky understood the biosphere as all those layers of the earth’s crust that throughout geological history were influenced by the activity of organisms. And it is no coincidence that V.I. Vernadsky opens his work “Essays on Geochemistry” (1934) with the chapter “Science of the Twentieth Century”: only in the 20th century. ideas about the earth's geospheres, the structure of atoms of chemical elements, cyclic or organogenic elements, and the mechanisms of geochemical transformations were formed. This allowed the scientist to assert: “The vortex of atoms entering and leaving a living organism is established by a certain organization of the living environment, a geologically determined mechanism of the planet - the biosphere.”
ABOUT THE CHAPTER
1. Introduction
2. Analytical part
2.1. Structure of the biosphere......................................................... ............................. 4
2.2. Evolution of the biosphere................................................... ........................... 6
2.3. Natural resources and their use................................................................. 8
2.4. Stability of the biosphere................................................... ....................... 10
2.5. Bioproductivity of ecosystems................................................... ............. 12
2.6. Biosphere and man. Noosphere........................................................ ........... 15
2.7. The role of the human factor in the development of the biosphere.................................... 16
2.8. Ecological problems of the biosphere................................................................... ....
2.9. Nature conservation and prospects for rational environmental management.................................................. ........................................................ .................................... 17
3. Conclusion
INTRODUCTION
Literally translated, the term “biosphere” means the sphere of life and in this sense it was first introduced into science in 1875 by the Austrian geologist and paleontologist Eduard Suess (1831 – 1914). However, long before this, under other names, in particular “space of life”, “picture of nature”, “living shell of the Earth”, etc., its content was considered by many other naturalists.
Initially, all these terms meant only the totality of living organisms living on our planet, although sometimes their connection with geographical, geological and cosmic processes was indicated, but at the same time, attention was rather drawn to the dependence of living nature on the forces and substances of inorganic nature. Even the author of the term “biosphere” itself, E. Suess, in his book “The Face of the Earth,” published almost thirty years after the introduction of the term (1909), did not notice the reverse effect of the biosphere and defined it as “a set of organisms limited in space and in time and living on the surface of the Earth."
The first biologist who clearly pointed out the enormous role of living organisms in the formation of the earth's crust was J.B. Lamarck (1744 - 1829). He emphasized that all the substances located on the surface of the globe and forming its crust were formed due to the activity of living organisms.
The biosphere (in the modern sense) is a kind of shell of the Earth that contains the entire totality of living organisms and that part of the planet’s substance that is in continuous exchange with these organisms.
The biosphere covers the lower part of the atmosphere, the hydrosphere and the upper part of the lithosphere.
All living organisms inhabiting our planet do not exist on their own; they depend on the environment and experience its influence. This is a precisely coordinated complex of many environmental factors, and the adaptation of living organisms to them determines the possibility of the existence of all kinds of forms of organisms and the most varied formation of their life.
Living nature is a complexly organized, hierarchical system. There are several levels of organization of living matter.
1.Molecular. Any living system manifests itself at the level of interaction of biological macromolecules: nucleic acids, polysaccharides, and other important organic substances.
2. Cellular. The cell is the structural and functional unit of reproduction and development of all living organisms living on Earth. There are no non-cellular forms of life, and the existence of viruses only confirms this rule, because they can exhibit the properties of living systems only in cells.
3. Organic. An organism is an integral unicellular or multicellular living system capable of independent existence. A multicellular organism is formed by a collection of tissues and organs specialized to perform various functions.
4. Population-species. A species is understood as a set of individuals that are similar in structural and functional organization, have the same karyotype and a single origin and occupy a certain habitat, freely interbreed with each other and produce fertile offspring, characterized by similar behavior and certain relationships with other species and factors of inanimate nature.
A set of organisms of the same species, united by a common habitat, creates a population as a system of supraorganismal order. In this system, the simplest, elementary evolutionary transformations are carried out.
5. Biogeocenotic. Biogeocenosis is a community, a set of organisms of different species and varying complexity of organization with all the factors of their specific habitat - components of the atmosphere, hydrosphere and lithosphere.
6.Biosphere. The biosphere is the highest level of organization of life on our planet. It contains living matter - the totality of all living organisms, non-living or inert matter and bio-inert matter (soil).
ANALYTICAL PART.
1. Structure of the biosphere.
The biosphere includes: living matter, formed by a collection of organisms; nutrient, which is created in the process of vital activity of organisms (atmospheric gases, coal, oil, peat, limestone, etc.); inert matter, which is formed without the participation of living organisms; bioinert substance, which is a joint result of the vital activity of organisms and non-biological processes (for example, soil).
Inert matter of the biosphere.
The boundaries of the biosphere are determined by environmental factors that make the existence of living organisms impossible. The upper boundary passes at an altitude of approximately 20 km from the surface of the planet and is limited by a layer of ozone, which blocks the life-destructive short-wavelength ultraviolet radiation of the Sun. Thus, living organisms can exist in the troposphere and lower stratosphere. In the hydrosphere of the earth's crust, organisms penetrate the entire depth of the World Ocean - up to 10-11 km. In the lithosphere, life is found at a depth of 3.5-7.5 km, which is determined by the temperature of the earth’s interior and the condition of penetration of liquid water.
Atmosphere.
The predominant elements of the chemical composition of the atmosphere: N 2 (78%), O 2 (21%), CO 2 (0.03%). The state of the atmosphere has a great influence on physical, chemical and biological processes on the Earth's surface and in the aquatic environment. For biological processes, the most important are: oxygen, used for respiration and mineralization of dead organic matter, carbon dioxide, involved in photosynthesis, and ozone, which shields the earth's surface from hard ultraviolet radiation. Nitrogen, carbon dioxide, and water vapor were formed largely due to volcanic activity, and oxygen as a result of photosynthesis.
Hydrosphere.
The predominant elements of the chemical composition of the hydrosphere: Na +, Mg 2+, Ca 2+, Cl -, S, C. Water is the most important component of the biosphere and one of the necessary factors for the existence of living organisms. Its main part (95%) is located in the World Ocean, which occupies about 70% of the surface of the globe and contains 1300 million km 3. Surface waters (lakes, rivers) include only 0.182 million km 3, and the amount of water in living organisms is only 0.001 million km 3. Glaciers contain significant water reserves (24 million km 3). Gases dissolved in water are of great importance: oxygen and carbon dioxide. Their quantity varies widely depending on temperature and the presence of living organisms. There is 60 times more carbon dioxide in water than in the atmosphere. The hydrosphere was formed in connection with the development of the lithosphere, which during the geological history of the Earth released large amounts of water vapor.
Lithosphere.
The predominant elements of the chemical composition of the hydrosphere: O, Si, Al, Fe, Ca, Mg, Na, K. The bulk of organisms living within the lithosphere are located in the soil layer, the depth of which does not exceed several meters. Soil includes minerals formed during the destruction of rocks, and organic substances - waste products of organisms.
Living organisms (living matter).
Although the boundaries of the biosphere are quite narrow, living organisms within them are distributed very unevenly. At high altitudes and in the depths of the hydrosphere and lithosphere, organisms are relatively rare. Life is concentrated mainly on the surface of the Earth, in the soil and in the near-surface layer of the ocean. The total mass of living organisms is estimated at 2.43x10 12 tons. The biomass of organisms living on land is 99.2% represented by green plants and 0.8% by animals and microorganisms. In contrast, in the ocean, plants account for 6.3%, and animals and microorganisms account for 93.7% of the total biomass. Life is focused mainly on land. The total biomass of the ocean is only 0.03x10 12 tons, or 0.13% of the biomass of all creatures living on Earth.
An important pattern is observed in the distribution of living organisms by species composition. Of the total number of species, 21% are plants, but their contribution to the total biomass is 99%. Among animals, 96% of species are invertebrates and only 4% are vertebrates, of which a tenth are mammals. The mass of living matter is only 0.01-0.02% of the inert matter of the biosphere, but it plays a leading role in geochemical processes. Organisms obtain substances and energy necessary for metabolism from the environment. Limited amounts of living matter are recreated, transformed and decomposed. Every year, thanks to the vital activity of plants and animals, about 10% of the biomass is reproduced.
2. Evolution of the biosphere.
All components of the biosphere closely interact with each other, forming an integral, complexly organized system, developing according to its own internal laws and under the influence of external forces, including cosmic ones (solar radiation, gravitational forces, magnetic fields of the Sun, Moon and other celestial bodies)
According to modern ideas, the development of a lifeless geosphere, i.e. shell formed by the Earth's substance occurred in the early stages of the existence of our planet, billions of years ago. Changes in the appearance of the Earth were associated with geological processes occurring in the earth's crust, on the surface and in the deep layers of the planet and were manifested in volcanic eruptions, earthquakes, crustal movements, and mountain building. Such processes are still taking place on the lifeless planets of the solar system and their satellites - Mars, Venus, and the Moon.
With the emergence of life (self-developing stable forms), at first slowly and weakly, then increasingly faster and more significantly, the influence of living matter on the geological processes of the Earth began to manifest itself.
The activity of living matter, which has penetrated into all corners of the planet, has led to the emergence of a new formation - the biosphere - a closely interconnected unified system of geological and biological bodies and processes of transformation of energy and matter. The extent of transformations carried out by living matter has reached planetary proportions, significantly changing the appearance and evolution of the Earth.
So, for example, as a result of the process of photosynthesis - the activity of green plants, the modern gas composition of the atmosphere was formed, oxygen appeared in it. In turn, the activity of photosynthesis is significantly affected by the concentration of carbon dioxide in the atmosphere, the presence of moisture and heat.
Soil is entirely the result of the activity of living matter in an inert (non-living) environment. The decisive role in this process belongs to climate, topography, activity of microorganisms and plants, and parent rocks. The biosphere, having emerged and formed 1-2 billion years ago (the first discovered remains of living organisms date back to this time), is in constant dynamic balance and development.
In the biosphere, as in any ecosystem, there is a water cycle, planetary movements of air masses, as well as a biological cycle, characterized by capacity - the number of chemical elements that are simultaneously part of living matter in a given ecosystem, and speed - the amount of living matter formed and decomposed in unit of time. As a result, a large geological cycle of substances is maintained on Earth, where each element is characterized by its own migration rate in large and small cycles. The speeds of all cycles of individual elements in the biosphere are closely related to each other.
The cycles of energy and matter established over many millions of years in the biosphere are self-sustaining on a global scale, although local changes in the structure and characteristics of individual ecosystems (biogeocenoses) that make up the biosphere can be significant.
Even in the early stages of evolution, living matter spread across the lifeless spaces of the planet, occupying all places potentially accessible to life, changing them and turning them into habitats. And already in ancient times, various life forms and species of plants, animals, microorganisms, and fungi occupied the entire planet. Living organic matter can be found in the depths of the ocean, and on the tops of the highest mountains, and in the eternal snows of the polar region, and in the hot waters of springs in volcanic regions.
V.I. Vernadsky called this ability to distribute living matter “the ubiquity of life.”
The evolution of the biosphere followed the path of complicating the structure of biological communities, multiplying the number of species and improving their adaptability. The evolutionary process was accompanied by an increase in the efficiency of conversion of energy and matter by biological systems: organisms, populations, communities.
The pinnacle of the evolution of life on Earth was man, who, as a biological species, based on numerous changes, acquired not only consciousness (the perfect form of displaying the surrounding world), but also the ability to make and use tools in his life.
Through tools of labor, humanity began to create a virtually artificial environment for its habitat (settlements, homes, clothing, food, cars and much more). Since then, the evolution of the biosphere has entered a new phase, where the human factor has become a powerful natural driving force.
Natural resources and their use.
Biological, including food, resources of the planet determine the possibilities of human life on Earth, and mineral and energy resources serve as the basis for the material production of human society. Among the natural resources of the planet there are exhaustible And inexhaustible resources.
Inexhaustible resources.
Inexhaustible resources are divided into space, climate and water. This is the energy of solar radiation, sea waves, and wind. Taking into account the huge mass of air and water on the planet, atmospheric air and water are considered inexhaustible. Selection is relative. For example, fresh water can already be considered a finite resource, since acute water shortages have arisen in many regions of the globe. We can talk about the unevenness of its distribution and the impossibility of using it due to pollution. Atmospheric oxygen is also conventionally considered an inexhaustible resource.
Modern environmental scientists believe that with the current level of technology for using atmospheric air and water, these resources can be considered inexhaustible only when developing and implementing large-scale programs aimed at restoring their quality.
Exhaustible resources.
Exhaustible resources are divided into renewable and non-renewable.
Renewable resources include flora and fauna and soil fertility. Among the renewable natural resources, forests play a major role in human life. The forest is of no small importance as a geographical and environmental factor. Forests prevent soil erosion and retain surface water, i.e. serve as moisture accumulators and help maintain groundwater levels. Forests are home to animals of material and aesthetic value to humans: ungulates, fur-bearing animals and game. In our country, forests occupy about 30% of its total landmass and are one of the natural resources.
Non-renewable resources include minerals. Their use by humans began in the Neolithic era. The first metals to find use were native gold and copper. They were able to extract ores containing copper, tin, silver, and lead already 4000 BC. At present, man has brought into the sphere of his industrial activity the predominant part of known mineral resources. If at the dawn of civilization a person used only about 20 chemical elements for his needs, at the beginning of the 20th century - about 60, but now more than 100 - almost the entire periodic table. About 100 billion tons of ore, fuel, and mineral fertilizers are mined (extracted from the geosphere) annually, which leads to the depletion of these resources. More and more various ores, coal, oil and gas are being extracted from the bowels of the earth. In modern conditions, a significant part of the Earth's surface is plowed or represents fully or partially cultivated pastures for domestic animals. The development of industry and agriculture required large areas for the construction of cities, industrial enterprises, the development of mineral resources, and the construction of communications. Thus, to date, about 20% of the land has been transformed by humans.
Significant areas of the land surface are excluded from human economic activity due to the accumulation of industrial waste on it and the impossibility of using areas where mining and mineral resources are being mined.
Man has always used the environment mainly as a source of resources, however, for a very long time, his activities 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. These changes have been increasing and are currently affecting human civilization. Striving to improve their living conditions, humanity is constantly increasing 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 toxic or not suitable for disposal. This poses a threat to both the existence of the biosphere and man himself.
4. Stability of the biosphere.
What is the stability of the biosphere, that is, its ability to return to its original state after any disturbing influences? It's very big. The biosphere has existed for about 3.8 billion years (the Sun and planets are about 4.6 billion) and during this time its evolution has not been interrupted: this follows from the fact that all living organisms, from viruses to humans, have the same genetic a code written in a DNA molecule, and their proteins are built from 20 amino acids, the same in all organisms. And no matter how great the disturbing influences were, and some of them can be classified as global catastrophes that led to the extinction of many species, there were always internal reserves in the biosphere for restoration and development.
In the last 570 million years alone, there have been six major catastrophes. As a result of one of them, the number of families of marine animals decreased by more than 40%. The largest catastrophe on the border of the Permian and Triassic periods (240 million years ago) led to the extinction of about 70% of species, and the catastrophe on the border of the Cretaceous and Tertiary periods (67 million years ago) led to the extinction of almost half of the species (then dinosaurs also became extinct).
The reasons for such cataclysms could be different: climate cooling, large volcanic eruptions with extensive outpourings of lava, ocean retreats, impacts of large meteorites - the biota still developed, adapting to the environment and at the same time exerting a powerful transformative influence on the latter. The formation of atmospheric oxygen and the increase in its concentration, by the way, also turned out to be catastrophic for some species - they became extinct, while at the same time the development of others accelerated. The carbon dioxide content in the atmosphere has decreased accordingly. Carbon began to accumulate in biota and detritus (dead organic matter: leaf litter, dried trees, peat, coal, oil) and be converted into coal, oil and gas. In the oceans, thick marine deposits of carbonates (limestone, chalk, marble) and silicates were formed from the shells and skeletons of marine organisms. Banded iron ores, which make up the main industrial reserves of iron, including the reserves of the Kursk magnetic anomaly, were formed about 2 billion years ago under the influence of oxygen released by photosynthetic bacteria (only after that oxygen began to accumulate in the atmosphere). A number of organisms that accumulate certain elements participated in the creation of deposits of other minerals.
Biota has gone through a huge evolutionary path from the simplest organisms to animals and plants and has reached species diversity, which researchers estimate at 2-10 million species of animals, plants and microorganisms, each of which has occupied its own ecological niche.
The state of the biota is determined mainly by the physicochemical characteristics of the environment. We call the set of average long-term characteristics of the atmosphere, hydrosphere and land climate. The main climatic characteristic - temperature at the Earth's surface - has changed relatively little during the evolution of biota (with the current value of the average global temperature 288 0 K (the Kelvin scale counts degrees from absolute zero, 288 0 = 15 0) changes, taking into account the ice ages, did not exceed 10-20 0).
Although physical and chemical processes in the environment have a certain influence on the state of ecosystems and the biosphere as a whole, the opposite influence of biota on the environment is also strong. Moreover, it affects both positive and negative feedbacks, so its development sometimes accelerates and sometimes slows down.
But this cycle is not closed, not stationary, as shown by geological data and theoretical models containing CO 2 in the atmosphere (and the associated O 2 content) over the past 570 million years has fluctuated repeatedly, and the amount of CO 2 each time decreased or increased several times once. In some cases this contributed to the development of biota, while in others it interfered.
The slow geochemical cycle is also not closed: CO 2 enters the atmosphere through volcanoes, and is spent on weathering rocks and the formation of biota. Some of the atmospheric carbon is deposited and buried for a long time, creating reserves of fossil fuels, and the released oxygen enters the atmosphere. As a result, over 4 billion years, the concentration of CO 2 in the atmosphere decreased by 100 - 1000 times (due to the weakening of volcanism, as a result of the consumption of radioactive elements in the bowels of the Earth), which negatively affected plant nutrition. At the same time, the accumulation of oxygen in the atmosphere sharply accelerated the development of biota, but was not beneficial to the most anaerobic (oxygen-free) organisms, as a result of whose vital activity oxygen appeared. They were almost completely replaced by newly emerging aerobic organisms.
The great influence of biota on the environment has led some researchers to the conclusion that biota could maintain conditions in the environment that were favorable for its life. But this hypothesis contradicts a number of factors (mass extinctions, disappearance of billions of species), as well as Darwin’s theory of evolution. The biota did not maintain environmental conditions optimal for living organisms, so many organisms and species could not survive changes in geographic and climatic conditions. There are estimates that several billion species have disappeared during the existence of the biosphere, while several million now exist. But organisms that managed to survive changing conditions gave rise to new species. It was adaptation to changing environmental conditions that created numerous and adapted species, that is, it drove evolution, as Darwin first showed. If the assumption were correct that the biota existing at a certain moment could maintain environmental parameters within their optimal limits, then the climate and rich vegetation of the Carboniferous period could now exist, but the evolution of the biota would cease.
There is evidence that the emergence of humans as a species was facilitated by the difficult environmental conditions in which our ancestors lived. When he learned to maintain favorable conditions for his existence, his evolution as a biological species ceased, replaced by the evolution of society.
So, in the process of biota development there were periods of sustainable development and periods of disasters.
Bioproductivity of ecosystems.
The rate at which ecosystem producers fix solar energy in the chemical bonds of synthesized organic matter determines productivity communities. The organic mass created by plants per unit of time is called primary production of the community. Products are expressed quantitatively in the wet or dry mass of plants or in energy units - the equivalent number of joules.
Gross primary production- the amount of substance created by plants per unit of time at a given rate of photosynthesis. Part of this production goes to maintaining the vital activity of the plants themselves (spending on respiration). This part can be quite large; it ranges from 40 to 70% of gross output. The remaining part of the created organic mass characterizes the net primary production, which represents the amount of plant growth, the energy reserve for consumers and decomposers. Being processed in food chains, it is used to replenish the mass of heterotrophic organisms. The increase in the mass of consumers per unit time is community secondary products. It is calculated separately for each trophic level, because The increase in mass on each of them occurs due to the energy coming from the previous one. Heterotrophs, being included in trophic chains, ultimately live off the net primary production of the community. In different ecosystems they consume it to different completeness. If the rate of primary production in food chains lags behind the rate of plant growth, this leads to a gradual increase in the total biomass of producers. Biomass is understood as the total mass of organisms in a given group or the entire community as a whole. Biomass is often expressed in equivalent energy units.
Insufficient utilization of litter products in decomposition chains results in the accumulation of organic matter, which occurs, for example, when bogs become peaty and shallow water bodies become overgrown. The biomass of a community with a balanced cycle of substances remains relatively constant, because Almost all primary production is spent for the purposes of nutrition and reproduction.
The most important practical result of the energy approach to the study of ecosystems was the implementation of research under the International Biological Program, conducted by scientists from around the world since 1969 in order to study the potential biological productivity of the Earth.
The global distribution of primary biological products is extremely uneven. The largest absolute increase in plant life reaches an average of 25 g per day in very favorable conditions. Over large areas, productivity does not exceed 0.1 g/m (hot deserts and polar deserts). The total annual production of dry organic matter on Earth is 150-200 billion tons. About a third of it is formed in the oceans, about two thirds on land. Almost all of the Earth's net primary production serves to support the life of all heterotrophic organisms. Energy that is underutilized by consumers is stored in their bodies, organic sediments of water bodies and soil humos.
The efficiency of solar radiation binding by vegetation decreases with a lack of heat and moisture, with unfavorable physical and chemical properties of the soil, etc. Vegetation productivity changes not only during the transition from one climatic zone to another, but also within each zone.
For the five continents of the world, average productivity varies relatively little. The exception is South America, in most of which conditions for the development of vegetation are very favorable.
People's nutrition is provided mainly by agricultural crops, which occupy approximately 10% of the land area (about 1.4 billion hectares). The total annual increase in cultivated plants is about 16% of the total land productivity, most of which is in forests. Approximately 1/2 of the harvest goes directly to human nutrition, the rest is used to feed domestic animals, is used in industry and is lost in waste. In total, humans consume about 0.2% of the Earth's primary production.
Plant food is energetically cheaper for people than animal food. Agricultural areas, with rational use and distribution of products, could support approximately twice the current population of the Earth. But this requires a lot of labor and capital investment. It is especially difficult to provide the population with secondary products. A person's diet should include at least 30 g of protein per day. The resources available on Earth, including livestock products and the results of fishing on land and in the ocean, can annually provide about 50% of the needs of the modern population of the Earth. The majority of the world's population is thus in a state of protein starvation, and a significant proportion of people also suffer from general malnutrition.
Thus, increasing the bioproductivity of ecosystems, and especially secondary products, is one of the main challenges facing humanity.
6. Biosphere and man. Noosphere.
Vernadsky, analyzing the geological history of the Earth, argues that there is a transition of the biosphere into a new state - into the noosphere under the influence of a new geological force, the scientific thought of mankind. However, in the works of Vernadsky there is no complete and consistent interpretation of the essence of the material noosphere as a transformed biosphere. In some cases, he wrote about the noosphere in the future tense (it has not yet arrived), in others in the present (we are entering it), and sometimes he associated the formation of the noosphere with the appearance of Homo sapiens or with the emergence of industrial production. It should be noted that when, as a mineralogist, Vernadsky wrote about the geological activity of man, he had not yet used the concepts of “noosphere” and even “biosphere”. He wrote in most detail about the formation of the noosphere on Earth in his unfinished work “Scientific Thought as a Planetary Phenomenon,” but mainly from the point of view of the history of science.
So, what is the noosphere: a utopia or a real survival strategy? Vernadsky’s works make it possible to more substantively answer the question posed, since they indicate a number of specific conditions necessary for the formation and existence of the noosphere. We list these conditions:
1. human settlement of the entire planet;
2. a dramatic transformation in the means of communication and exchange between countries;
3. strengthening ties, including political ones, between all countries of the Earth;
4. the beginning of the predominance of the geological role of man over other geological processes occurring in the biosphere;
5. expansion of the boundaries of the biosphere and access to space;
6. discovery of new energy sources;
7. equality of people of all races and religions;
8. increasing the role of the people in resolving issues of foreign and domestic policy;
9. freedom of scientific thought and scientific research from the pressure of religious, philosophical and political constructs and the creation in the state system of conditions favorable to free scientific thought;
10. a well-thought-out system of public education and an increase in the well-being of workers. Creating a real opportunity to prevent malnutrition and hunger, poverty and greatly reduce disease;
11.reasonable transformation of the primary nature of the Earth in order to make it capable of satisfying all the material, aesthetic and spiritual needs of a numerically increasing population;
12.exclusion of wars from the life of society.
7. The role of the human factor in the development of the biosphere.
The central theme of the doctrine of the noosphere is the unity of the biosphere and humanity. Vernadsky in his works reveals the roots of this unity, the importance of the organization of the biosphere in the development of mankind. This allows us to understand the place and role of the historical development of mankind in the evolution of the biosphere, the patterns of its transition to the noosphere.
One of the key ideas underlying Vernadsky’s theory of the noosphere is that man is not a self-sufficient living being, living separately according to his own laws, he coexists within nature and is part of it. This unity is due primarily to the functional continuity of the environment and man, which Vernadsky tried to show as a biogeochemist. Humanity itself is a natural phenomenon and it is natural that the influence of the biosphere affects not only the environment of life but also the way of thinking.
But not only nature has an impact on humans, there is also feedback. Moreover, it is not superficial, reflecting the physical impact of man on the environment, it is much deeper. This is proven by the fact that planetary geological forces have recently become noticeably more active. “...we see the geological forces around us more and more clearly in action. This coincided, hardly by chance, with the penetration into scientific consciousness of the conviction about the geological significance of Homo sapiens, with the identification of a new state of the biosphere - the noosphere - and is one of the forms of its expression. It is connected, of course, primarily with the clarification of natural scientific work and thought within the biosphere, where living matter plays the main role.” Thus, recently the reflection of living beings on the surrounding nature has changed dramatically. Thanks to this, the process of evolution is transferred to the field of minerals. Soil, water and air are changing dramatically. That is, the evolution of species itself turned into a geological process, since in the process of evolution a new geological force appeared. Vernadsky wrote: “The evolution of species passes into the evolution of the biosphere.”
Vernadsky saw the inevitability of the noosphere, prepared both by the evolution of the biosphere and by the historical development of mankind. From the point of view of the noospheric approach, modern pain points in the development of world civilization are seen differently. The barbaric attitude towards the biosphere, the threat of global environmental catastrophe, the production of means of mass destruction - all this should have a passing significance. The question of a radical turn to the origins of life, to the organization of the biosphere in modern conditions should sound like an alarm bell, a call to think and act in the biosphere - planetary aspect.
Ecological problems of the biosphere.
Environmental problems of the biosphere are the greenhouse effect, depletion of the ozone layer, massive deforestation, which disrupts the process of oxygen and carbon cycling in the biosphere, waste from production, agriculture, energy production (hydroelectric power plants cause damage to nature and people - flooding of vast areas for reservoirs, insurmountable obstacles on the migration routes of anadromous and semi-anadromous fish that rise to spawn in the upper reaches of rivers, there is stagnation of water, a slowdown in flow, which affects the life of all living creatures living in the river and near the river; a local increase in water affects the soil of the reservoir, leading to flooding, swamping, coastal erosion and landslides; there is a danger from dams in areas with high seismicity). All this leads to a global environmental crisis and requires an immediate transition to rational environmental management.
Nature conservation and prospects for rational environmental management.
Rational use of natural resources is the only way out of the situation.
The overall goal of natural resource management is to find the best or optimal ways to exploit natural and artificial (eg, agricultural) ecosystems. Exploitation refers to harvesting and the impact of certain types of economic activity on the conditions of existence of biogeocenoses.
Solving the problem of creating an optimal natural resource management system is significantly complicated by the presence of not one, but many optimization criteria. These include: obtaining maximum yield, reducing production costs, preserving natural landscapes, maintaining species diversity of communities, ensuring a clean environment, maintaining the normal functioning of ecosystems and their complexes.
Environmental protection and restoration of natural resources should include:
A rational strategy for pest control, knowledge and compliance with agrotechnical practices, dosage of mineral fertilizers, good knowledge of ecological agrocenoses and the processes occurring in them, as well as at their boundaries with natural systems;
Improving technology and extraction of natural resources;
Maximum complete and comprehensive extraction of all useful components from the deposit;
Reclamation of land after the use of deposits;
Economical and waste-free use of raw materials in production;
Deep cleaning and technologies for using production waste;
Recycling of materials after products are no longer in use;
Use of technologies that allow the extraction of dispersed minerals;
Use of natural and fossil substitutes for scarce mineral compounds;
Closed production cycles (development and application);
Application of energy saving technologies;
Development and use of new environmentally friendly energy sources.
In general, environmental protection and natural resource restoration objectives should include:
Local and global logical monitoring, i.e. measurement and control of the state of the most important characteristics of the environment, the concentration of harmful substances in the atmosphere, water, soil;
Restoration and preservation of forests from fires, pests, diseases;
Expansion and increase in the number of reserves, zones of reference ecosystems, unique natural complexes;
Protection and breeding of rare species of plants and animals;
Broad education and environmental education of the population;
International cooperation in environmental protection.
Such active work in all areas of human activity to form an attitude towards nature, the development of rational use of natural resources, and environmentally friendly technologies of the future will be able to solve the environmental problems of today and move on to harmonious cooperation with Nature.
Nowadays, the consumer attitude towards nature, the withdrawal of its resources without taking measures to restore them, are becoming a thing of the past. The problem of rational use of natural resources and the protection of nature from the destructive consequences of human economic activity is acquiring national importance.
Nature conservation and rational environmental management is a complex problem, and its solution depends both on the consistent implementation of government measures aimed at preserving ecosystems, and on the expansion of scientific knowledge, which is cost-effective and profitable for society to finance for its own well-being.
For harmful substances in the atmosphere, maximum permissible concentrations are legally established that do not cause noticeable consequences for humans. In order to prevent air pollution, measures have been developed to ensure proper combustion of fuel, the transition to gasified central heating, and the installation of treatment facilities at industrial enterprises. In addition to protecting air from pollution, treatment facilities allow you to save raw materials and return many valuable products to production. For example, capturing sulfur from released gases makes it possible to increase the production of sulfuric acid; capturing cement saves production equal to the productivity of several factories. In aluminum smelters, installing filters on pipes prevents the release of fluoride into the atmosphere. In addition to the construction of treatment facilities, a search is underway for a technology in which waste generation would be minimized. The same goal is served by improving car designs and switching to other types of fuel (liquefied gas, ethyl alcohol), the combustion of which produces fewer harmful substances. A car with an electric motor is being developed for movement within the city. The correct layout of the city and green spaces is of great importance. Trees clean the air from liquid and solid particles (aerosols) suspended in it and absorb harmful gases. For example, sulfur dioxide is well absorbed by poplar, linden, maple, horse chestnut, phenols - by lilac, mulberry, and elderberry.
Domestic and industrial wastewater is subjected to mechanical, physical and biological treatment. Biological treatment involves the destruction of dissolved organic substances by microorganisms. Water is passed through special tanks containing only the so-called activated sludge, which includes microorganisms that oxidize phenols, fatty acids, alcohols, hydrocarbons, etc.
Wastewater treatment does not solve all problems. Therefore, more and more enterprises are switching to a new technology - a closed cycle, in which purified water is re-entered into production. New technological processes make it possible to reduce the amount of water required for industrial purposes by tens of times.
Subsoil protection consists primarily of preventing unproductive waste of organic resources in their integrated use. For example, a lot of coal is lost in underground fires, and flammable gas burns in flares in oil fields. The development of technology for the complex extraction of metals from ores makes it possible to obtain additional valuable elements such as titanium, cobalt, tungsten, molybdenum, etc.
To increase agricultural productivity, correct agricultural technology and the implementation of special soil protection measures are of great importance. For example, the fight against ravines is successfully carried out by planting plants - trees, shrubs, grasses. Plants protect soils from being washed away and reduce the speed of water flow. The cultivation of ravines allows them to be used for economic purposes. Sowing amorpha imported from America, which has a powerful root system, not only effectively prevents soil loss: the plant itself produces beans with high feed value. The diversity of plantings and crops along the ravine contributes to the formation of persistent biocenoses. Birds settle in the thickets, which is of no small importance for pest control. Protective forest plantations in the steppes prevent water and wind erosion of fields. The development of biological methods of pest control makes it possible to reduce the use of pesticides in agriculture. Currently, 2,000 plant species, 236 mammal species, and 287 bird species need protection. The International Union for Conservation of Nature has established a special Red Book, which provides information about endangered species and provides recommendations for their conservation. Many endangered animal species have now recovered their numbers. This applies to elk, saiga, egret, and eider.
The conservation of flora and fauna is facilitated by the organization of nature reserves and sanctuaries. In addition to protecting rare and endangered species, reserves serve as a base for the domestication of wild animals with valuable economic properties. Nature reserves are also centers for the resettlement of animals that have disappeared in the area and help enrich the local fauna. The North American muskrat has successfully taken root in Russia, providing valuable fur. In the harsh conditions of the Arctic, musk ox imported from Canada and Alaska successfully reproduces. The number of beavers, which almost disappeared at the beginning of the century, has been restored.
Similar examples are numerous. They show that caring for nature, based on deep knowledge of the biology of plants and animals, not only preserves it, but also provides a significant economic effect.
Many people believe that nature should be protected only because of its actual or potential benefits to people, an approach called an anthropocentric (human-centered) view of the world. Some people adhere to a biocentric worldview and are convinced that it is unworthy of man to hasten the extinction of any species, since man is no more important than other species on earth. “Man has no superiority over other species, for everything is vanity of vanities,” they believe. Others take an ecocentric (center-ecosystem) view and believe that only those actions that are aimed at maintaining the earth's life support systems are justified.
CONCLUSION.
Thus, we see that all those specific signs are present, all or almost all the conditions that V.I. Vernadsky indicated in order to distinguish the noosphere from the previously existing states of the biosphere. The process of its formation is gradual, and it will probably never be possible to accurately indicate the year or even decade from which the transition of the biosphere to the noosphere can be considered complete. Of course, opinions on this issue may differ. F.T. Yanshina writes: “The teaching of Academician V.I. Vernadsky about the transition of the biosphere to the noosphere is not a utopia, but a real strategy for survival and achieving a reasonable future for all humanity.” R.K. Balandin’s opinion is somewhat different: “The biosphere does not move to a higher level of complexity, perfection, but is simplified, polluted, degraded (an unprecedented rate of extinction of species, destruction of forest zones, terrible land erosion...). It moves to a lower level, i.e. in it the most active transformative and regulating force becomes techno-substance, a set of technical systems through which a person - mostly involuntarily - changes the entire area of life." Vernadsky himself, noticing the undesirable, destructive consequences of human management on Earth, considered them to be some costs. He believed in the human mind, the humanism of scientific activity, the triumph of goodness and beauty. He foresaw some things brilliantly, but perhaps he was wrong about others. The noosphere should be accepted as a symbol of faith, as an ideal of reasonable human intervention in biosphere processes under the influence of scientific achievements. We must believe in it, hope for its coming, and take appropriate measures.
BIBLIOGRAPHY:
1. Chernova N.M., Bylova A.M., Ecology. Textbook for pedagogical institutes, M., Prosveshchenie, 1988;
2. Kriksunov E.A., Pasechnik V.V., Sidorin A.P., Ecology, M., Bustard Publishing House, 1995;
3. General biology. Reference materials, Compiled by V.V. Zakharov, M., Bustard Publishing House, 1995.
4. “Vernadsky V.I.: On the fundamental material and energy difference between living and inert bodies of the biosphere.” // “Vladimir Vernadsky: Biography. Selected works. Memoirs of contemporaries. Judgments of descendants.” Comp. G.P.Aksenov. - M.: Sovremennik, 1993.
5. V.I. Vernadsky "Reflections of a naturalist. - Scientific thought as a planetary phenomenon." M., Nauka, 1977. “Study of life phenomena and new physics”, 1931; Biogeochemical essays. M.-L., publishing house of the USSR Academy of Sciences, 1940
6. Sat. "Biosphere" Art. “A few words about the noosphere” M., Mysl, 1967.
7. "V.I. Vernadsky. Materials for the biography" M., publishing house "Young Guard", 1988.
8. Lapo A.V. “Traces of past biospheres.” – Moscow, 1979.
The concept of the biosphere. Biosphere is the shell of life that includes plants, animals and microorganisms. In a certain sense, humans as a biological species and soil as a product of the activity of living organisms can be classified as the biosphere.
The term “biosphere” was first used by E. Suess (Austrian geologist) in 1875, and the doctrine of the biosphere was created only at the beginning of the 20th century by the works of V.I. Vernadsky.
Currently, the term “biosphere” is interpreted in two ways: in a broad sense – the biosphere is identified with the geographical envelope (with the only difference that the geographical envelope is older than the biosphere); in the narrow sense, the biosphere is a film, a “clump of life”, and is considered in parallel with other shells of the Earth.
The upper boundary of the biosphere is taken to be the ozone screen, located at an altitude of 25-27 km (this is the altitude at which some spores and bacteria can still be found). The lower boundary of the biosphere passes in the lithosphere at a depth of 3-5 km (where organogenic rocks occur and bacteria can exist). These boundaries are determined for the biosphere, understood in a broad sense.
The greatest concentration of life is found within relatively narrow limits, in the contact zone of three media: water, air and land (soil). Most
The hydrosphere, lower part of the troposphere and soil are populated. This thin horizon with the highest concentration of living matter is called biostroma (live cover).
It is believed that the origin of life occurred approximately 3 billion years ago (at the end of the Archean) in shallow water bodies, from which life spread to the ocean, and only then to land (in the absence of an ozone screen, water was good at blocking harmful ultraviolet radiation). During the period of the origin of life, the climate on Earth was warm and humid.
For a long time, life was “located” in the geographical shell in spots, i.e. the biosphere was poorly developed and very discontinuous. Over the course of geological history, the diversity of living organisms has increased, their organization has become more complex, and their total mass has increased. The development of life was uneven. Some species have survived from the Archean to the present day (for example, blue-green algae), the development of other lines led to the emergence of complex forms of life (primates, humans), the development of others ended with their extinction (dinosaurs, mammoths, etc.).
Throughout the history of the biosphere, there have been about 500 million species, but currently there are only about 2 million species.
The wide distribution of living organisms on Earth was helped by their ability to adapt to a wide variety of environmental conditions and their high ability to reproduce. Thus, microorganisms were found in Icelandic geysers at a temperature of +93 o C, and even in permafrost soils at very low temperatures. Spores of some bacteria remain viable at temperatures of +100 o C and below –200 o C. The offspring of one of the bacteria, under appropriate favorable conditions, could fill the entire World Ocean in 5 days, and clover could cover the entire surface of the Earth in 11 years.
Currently, the composition of the biosphere is dominated by animals - there are about 1.7 million species. There are about 400 thousand species of plants on Earth, but the mass of plant substances is many times greater than the mass of animals. Plants account for almost 97% of the total biomass of the Earth and only 3% - the mass of animals and microorganisms. The overwhelming majority of biomass is concentrated on land; it exceeds the biomass of the ocean by 1000 times. The species diversity in the ocean is much poorer.
Vegetation on land forms an almost continuous cover - the phytosphere. The plant mass consists of aboveground (trunks with branches, leaves, needles; shrubs, herbaceous and moss-lichen cover) and underground (plant roots). For example, for a mixed forest, the plant mass is almost 400 t/ha, of which the above-ground part accounts for about 300 t/ha, and the underground part accounts for 100 t/ha. On land, biomass generally increases from the poles to the equator, and the number of plant and animal species increases in the same direction. In the tundra, biomass is approximately 12 t/ha, in the taiga - about 320 t/ha, in mixed and deciduous forests - 400 t/ha, in the steppes it decreases to 25 t/ha, and in deserts even to 12 t/ha, in in savannas it again increases to 100 t/ha or more, in tropical forests it reaches a maximum of 500 t/ha. The smallest number of plant and animal species is in the Arctic deserts and tundras, the largest in equatorial forests.
Plants on land contain more than 99% of all land biomass, while animals and microorganisms contain only less than 1%. In the ocean, this ratio is reversed: plants make up more than 6%, and animals and microorganisms make up about 94%. The total biomass of the ocean is only 0.13% of the biomass of the entire biosphere, although the ocean occupies an area equal to 71%. Thus, the open ocean is essentially a water desert.
Let us take a closer look at the components of the biosphere and their role in the geographic envelope of the Earth.
Microorganisms (germs) is the smallest of life forms and all-pervasive. Microbes were discovered in the 17th century. A. Levenguk. The following groups of microbes are distinguished:
a) by structure: unicellular organisms (algae, fungi, unicellular protozoa) - they have a relatively large cell of a complex type (eukaryotes); bacteria are structurally simpler organisms (prokaryotes);
b) according to chemical characteristics (energy source for biochemical processes): photosynthetic microorganisms - use the radiant energy of the Sun as an energy source and convert carbon dioxide into organic carbon (primary producers); heterotrophic microorganisms - obtain energy by decomposing organic carbon molecules (molecular predators); photosynthetic and heterotrophic microorganisms play a huge role in the geographic envelope: they maintain the carbon available on Earth in constant movement;
c) on the use of oxygen: aerobic - consume oxygen; anaerobic - do not consume oxygen.
The number of types of microorganisms is huge, and they are distributed everywhere on Earth. They decompose organic matter, assimilate atmospheric nitrogen, etc.
Plants - one of the kingdoms of the organic world. Their main difference from other living organisms is the ability to create organic substances from inorganic ones, which is why they are called autotrophs . At the same time, green plants carry out photosynthesis - the process of converting solar energy into organic matter. Plants are the main primary source of food and energy for all other life forms on Earth.
Plants are a source of oxygen on Earth (equatorial forests are called the “lungs” of our planet). Plants are considered primary producers - producers. Plants feed all of humanity and are ultimately sources of energy and raw materials. Plants protect the soil from erosion, regulate runoff and gas composition in the atmosphere.
Currently, almost 400 thousand species of plants are known, which are divided into lower and higher. From the middle of the 20th century. From the plant kingdom, an independent kingdom is distinguished - mushrooms, which were previously classified as lower.
Of the 40 thousand plant species on Earth, 25 thousand species are angiosperms (flowering plants). The richest flora on Earth is the flora of the tropics.
Animals - organisms that make up one of the kingdoms of the organic world. Animals are heterotrophs , i.e. feed on ready-made organic compounds. Almost all animals are actively mobile. There are more than 1.7 million species of animals on Earth, of which the largest number of species are insects (about 1 million)
Animals create secondary products, influence vegetation cover, soil, and destroy and mineralize organic matter. Animals, like plants, play a huge role in human life.
In a certain sense, soil can also be a component of the biosphere. The soil – the upper loose fertile layer of the earth’s crust in which plant roots are distributed. Soil is a complex formation consisting of two main parts: mineral (destroyed rocks) and organic (humus). Soils cover most of the Earth's surface with a thin layer - from 0 to 2 m.
An important property of the soil is its fertility, i.e. the ability of the soil to produce plants. Soil is the basis for plant growth and the habitat of a large number of living beings. Soils regulate water balance and influence the formation of the landscape. The famous Russian soil scientist V.V. Dokuchaev called soils a “mirror of the landscape.”
Soils accumulate and convert solar energy. Soil is the basis of agricultural production.
The biological (small) cycle continuously occurs in the biosphere. The interaction of living organisms with the atmosphere, hydrosphere, and lithosphere occurs through the biological cycle of substances and energy.
The biological cycle consists of two processes:
– formation of living matter from non-living matter due to solar energy;
– decomposition and transformation of organic matter into simple mineral (inert).
The first process is associated with photosynthesis, carried out by green plants on land and in the ocean (water). In the green leaf of a plant, due to sunlight with the participation of chlorophyll, organic matter is formed from carbon dioxide and water and free oxygen is released. In addition, plants with their root system absorb soluble mineral substances from the soil: nitrogen, potassium, calcium, sulfur, phosphorus salts - and also convert these substances into organic ones.
The decomposition of organic matter occurs mainly under the influence of microorganisms. Microorganisms use organic matter for their life processes, and although part of it goes to the formation of new organic matter (the body of the microorganism), a significant part of the organic matter is mineralized, i.e. organic matter decomposes to its simplest compounds.
The formation and destruction of organic matter are opposite, but inseparable processes. The absence of one of them will inevitably lead to the extinction of life. Modern life exists on Earth thanks to the biological cycle.
Thanks to the biological cycle, living organisms influence all the shells of the Earth. Thus, almost all the oxygen in the Earth's atmosphere is of biogenic origin. If the process of photosynthesis stops, free oxygen will quickly disappear.
The role of living beings in the hydrosphere is also great. Organisms continuously consume and excrete water. The process of transpiration (evaporation of water by plants) is especially intense. The gas and salt composition of ocean waters is also determined by the activity of living organisms. Land waters also become chemically active largely under the influence of living organisms.
The influence of living organisms on the lithosphere is especially profound and diverse. It manifests itself in the destruction of rocks (biological weathering), in the formation of organogenic rocks: limestone, peat, brown and hard coal, oil, gas, oil shale. The reserves of organic matter accumulated in the earth's crust are enormous. They are many times superior to living organic matter. Iron and manganese ores and phosphorites can also be of biogenic origin. Their formation is associated with the activity of special bacteria.
Only under the influence of living organisms did soils form on Earth. Soils are considered a complex bio-inert formation, which is formed in the process of interaction of living matter with non-living matter. The basis for the formation of soils are mountain soil-forming rocks, and the main factors of soil formation are microorganisms and plants, and to a lesser extent, soil animals.
Biosphere (from Greek bios - life, sphaira - sphere)- the shell of planet Earth in which life is present. The development of the term “biosphere” is associated with the English geologist Eduard Suesse and the Russian scientist V.I. Vernadsky. The biosphere, together with the lithosphere, hydrosphere and atmosphere, forms the four main shells of the Earth.
Origin of the term "biosphere"
The term "biosphere" was first coined by geologist Eduard Suess in 1875 to refer to the space on the Earth's surface where life exists. A more complete definition of the concept “biosphere” was proposed by V.I. Vernadsky. He was the first to assign life the dominant role of the transformative force of our planet, taking into account the vital activity of organisms both in the present and in the past. Geochemists define the term "biosphere" as the total sum of living organisms ("biomass" or "biota" as biologists and ecologists call it).
Boundaries of the biosphere
Every part of the planet, from the polar ice caps to the equator, is inhabited by living organisms. Recent advances in the field of microbiology have shown that microorganisms live deep under the earth's surface and perhaps their total biomass exceeds the biomass of all flora and fauna on the Earth's surface.
At present, the actual boundaries of the biosphere cannot be measured. Typically, most bird species fly at altitudes between 650 and 1,800 meters, and fish have been found as deep as 8,372 meters in the Puerto Rico Trench. But there are also more extreme examples of life on the planet. The African vulture, or Rüppel's vulture, has been seen at altitudes of over 11,000 meters, mountain geese usually migrate to altitudes of at least 8,300 meters, wild yaks live in the mountainous regions of Tibet at an altitude of about 3,200 - 5,400 meters above sea level, and mountain goats live at altitudes up to 3000 meters.
Microscopic organisms are capable of living in more extreme conditions, and if we take them into account, the thickness of the biosphere is much greater than we imagined. Some microorganisms have been discovered in the upper layers of the Earth's atmosphere at an altitude of 41 km. It is unlikely that microbes are active at altitudes where temperature and air pressure are extremely low and ultraviolet radiation is very intense. Most likely, they were transported to the upper atmosphere by winds or volcanic eruptions. Also, single-celled life forms were found in the deepest part of the Mariana Trench at a depth of 11,034 meters.
Despite all the above examples of the extremes of life, in general the layer of the Earth's biosphere is so thin that it can be compared to the peel of an apple.
Structure of the biosphere
The biosphere is organized into a hierarchical structure in which individual organisms form populations. Several interacting populations make up a biocenosis. Communities of living organisms (biocenosis) living in certain physical habitats (biotope) form an ecosystem. is a group of animals, plants and microorganisms that interact with each other and with their environment in such a way as to ensure their existence. Therefore, the ecosystem is the functional unit of sustainability of life on Earth.
Origin of the biosphere
The biosphere has existed for about 3.5-3.7 billion years. The first forms of life were prokaryotes - single-celled living organisms that could live without oxygen. Some prokaryotes have developed a unique chemical process that we know as . They were able to use sunlight to make simple sugar and oxygen from water and carbon dioxide. These photosynthetic microorganisms were so numerous that they radically transformed the biosphere. Over a long period of time, an atmosphere formed from a mixture of oxygen and other gases that could support new life.
The addition of oxygen to the biosphere allowed more complex life forms to rapidly develop. Millions of different plants and animals appeared that ate plants and other animals. evolved to decompose dead animals and plants.
Thanks to this, the biosphere has made a huge leap in its development. The decomposed remains of dead plants and animals released nutrients into the soil and ocean, which were reabsorbed by plants. This exchange of energy allowed the biosphere to become a self-sustaining and self-regulating system.
The role of photosynthesis in the development of life
The biosphere is unique in its kind. Until now, there have been no scientific facts confirming the existence of life in other places in the Universe. Life on Earth exists thanks to the Sun. When exposed to energy from sunlight, a process called photosynthesis occurs. As a result of photosynthesis, plants, some types of bacteria and protozoa convert carbon dioxide into oxygen and organic compounds such as sugar under the influence of light. The vast majority of animal, fungal, plant and bacterial species depend directly or indirectly on photosynthesis.
Factors influencing the biosphere
There are many factors influencing the biosphere and our life on Earth. There are global factors such as the distance between the Earth and the Sun. If our planet were closer or further away from the Sun, then the Earth would be too hot or cold for life to arise. The angle of inclination of the earth's axis is also an important factor influencing the planet's climate. Seasons and seasonal climate changes are direct results of the Earth's tilt.
Local factors also have an important impact on the biosphere. If you look at a certain area of the Earth, you can see the influence of climate, daily weather, erosion and life itself. These small factors constantly change space and living organisms must respond accordingly, adapting to changes in their environment. Even though people can control most of their immediate environment, they are still vulnerable to natural disasters.
The smallest of the factors influencing the appearance of the biosphere are changes occurring at the molecular level. Oxidation and reduction reactions can change the composition of rocks and organic matter. There is also biological degradation. Tiny organisms such as bacteria and fungi are capable of processing both organic and inorganic materials.
Biosphere reserves
People play an important role in maintaining the energy exchange of the biosphere. Unfortunately, our impact on the biosphere is often negative. For example, oxygen levels in the atmosphere are decreasing and carbon dioxide levels are rising due to people over-burning fossil fuels, and oil spills and industrial waste discharges into the ocean cause enormous damage to the hydrosphere. The future of the biosphere depends on how people interact with other living things.
In the early 1970s, the United Nations established a project called Man and the Biosphere (MAB), which promotes sustainable, balanced development. There are currently hundreds of biosphere reserves around the world. The first biosphere reserve was established in Yangambi, Democratic Republic of the Congo. Yangambi is located in the fertile Congo River Basin and is home to some 32,000 species of trees and animals, including endemic species such as the forest elephant and brush-eared pig. Yangambi Biosphere Reserve supports important activities such as sustainable agriculture, hunting and extraction.
Extraterrestrial biospheres
Until now, the biosphere has not been discovered outside the Earth. Therefore, the existence of extraterrestrial biospheres remains hypothetical. On the one hand, many scientists believe that life on other planets is unlikely, and if it exists somewhere, it is most likely in the form of microorganisms. On the other hand, there can be a lot of analogues of the Earth, even in our galaxy - the Milky Way. Given the limitations of our technology, it is currently unknown what percentage of these planets are capable of having a biosphere. It is also impossible to exclude the possibility that artificial biospheres will be created by humans in the future, for example, on Mars.
The biosphere is a very fragile system in which every living organism is an important link in a huge chain of life. We must realize that man, as the most intelligent creature on the planet, is responsible for preserving the miracle of life on our planet.
The interaction of populations determines the nature of the functioning of the next, higher level of organization of living things - the biotic community, or biocenosis. Under biocenosis refers to a biological system that is a collection of populations of different species coexisting in space and time. The study of communities aims to find out how their sustainable existence is maintained and what impact biotic interactions and environmental conditions have on changes in communities.
Community, ecosystem, biogeocenosis, biosphere
A community (biocenosis) is a collection of organisms of various species that coexist for a long time in a certain space and represent an ecological unity. Like a population, a community has its own properties (and indicators) inherent to it as a whole. The properties of the community are stability (the ability to withstand external influences), productivity (the ability to produce living matter). Indicators of a community are the characteristics of its composition (diversity of species, structure of the food web), the ratio of individual groups of organisms. One of the main tasks of ecology is to clarify the relationships between the properties and composition of a community, which appear regardless of what species are included in it.
Ecosystem is another ecological category; it is any community of living beings, together with its physical habitat, functioning as a single whole. An example of an ecosystem is a pond, including a community of hydrobionts, the physical properties and chemical composition of water, features of the bottom topography, the composition and structure of the soil, atmospheric air interacting with the surface of the water, and solar radiation. In ecosystems, there is a constant exchange of energy and matter between living and inanimate nature. This exchange is sustainable. Elements of living and inanimate nature are in constant interaction.
Ecosystem is a very broad concept and applies to both natural complexes (for example, tundra, ocean) and artificial ones (for example, an aquarium). Therefore, to designate an elementary natural ecosystem in ecology, the term “biogeocenosis” is used.
Biogeocenosis is a historically established set of living organisms (biocenosis) and the abiotic environment, together with the area of the earth’s surface they occupy. The border of the biogeocenosis is established along the border of the plant community (phytocenosis) - the most important component of any biogeocenosis. Each biogeocenosis is characterized by its own type of material and energy exchange.
Biogeocenosis is an integral part of the natural landscape and an elementary bioterritorial unit of the biosphere. Often, the classification of natural ecosystems is based on the characteristic ecological characteristics of habitats, highlighting communities of sea coasts or shelves, lakes or ponds, floodplain or upland meadows, rocky or sandy deserts, mountain forests, estuaries (mouths of large rivers), etc. All natural ecosystems (biogeocenoses) ) are interconnected and together form the living shell of the Earth, which can be considered as the largest ecosystem - the biosphere.
Ecosystem functioning
Energy in ecosystems. An ecosystem is a collection of living organisms that continuously exchange energy, matter and information with each other and with the environment. Let us first consider the process of energy exchange. Energy is defined as the ability to produce work. The properties of energy are described by the laws of thermodynamics.
The first law (law) of thermodynamics or the law of conservation of energy states that energy can change from one form to another, but it does not disappear or be created anew. The second law (law) of thermodynamics or the law of entropy states that in a closed system entropy can only increase. In relation to energy in ecosystems, the following formulation is convenient: processes associated with energy transformations can occur spontaneously only if the energy passes from a concentrated form to a dispersed one, that is, it degrades.
The measure of the amount of energy that becomes unavailable for use, or otherwise the measure of the change in order that occurs during the degradation of energy, is entropy. The higher the order of the system, the lower its entropy. Thus, any living system, including an ecosystem, maintains its vital activity thanks to, firstly, the presence in the environment of an excess of free energy (the energy of the Sun); secondly, the ability, due to the design of its components, to capture and concentrate this energy, and when used, to dissipate it into the environment. Thus, first capturing and then concentrating energy with the transition from one trophic level to another ensures an increase in the orderliness and organization of a living system, that is, a decrease in its entropy.
Energy and productivity of ecosystems. So, life in an ecosystem is maintained due to the continuous passage of energy through living matter, transferred from one trophic level to another; At the same time, there is a constant transformation of energy from one form to another. In addition, during energy transformations, part of it is lost in the form of heat. Then the question arises: in what quantitative relationships and proportions should members of the community of different trophic levels in the ecosystem be among themselves in order to meet their energy needs?The entire energy supply is concentrated in the mass of organic matter - biomass, therefore the intensity of the formation and destruction of organic matter at each level is determined by the passage of energy through the ecosystem (biomass can always be expressed in energy units). The rate of formation of organic matter is called productivity. There are primary and secondary productivity. In any ecosystem, biomass is formed and destroyed, and these processes are entirely determined by the life of the lower trophic level - the producers. All other organisms only consume the organic matter already created by plants and, therefore, the overall productivity of the ecosystem does not depend on them. High rates of biomass production are observed in natural and artificial ecosystems where abiotic factors are favorable, and especially when additional energy is supplied from outside, which reduces the system’s own costs of maintaining life.
This additional energy can come in different forms: for example, in a cultivated field - in the form of fossil fuel energy and work done by humans or animals. Thus, to provide energy to all individuals of a community of living organisms in an ecosystem, a certain quantitative relationship between producers, consumers of different orders, detritivores and decomposers is necessary. However, for the life activity of any organisms, and therefore the system as a whole, energy alone is not enough; they must receive various mineral components, trace elements, and organic substances necessary for the construction of molecules of living matter.
Cycle of elements in an ecosystem
Where do the components necessary to build an organism initially come from in living matter? They are supplied to the food chain by the same producers. They extract inorganic minerals and water from the soil, CO2 from the air, and from glucose formed during photosynthesis, with the help of nutrients, they further build complex organic molecules - carbohydrates, proteins, lipids, nucleic acids, vitamins, etc. In order for the necessary elements to be available to living organisms, they must be available at all times. In this relationship, the law of conservation of matter is realized. It is convenient to formulate it as follows: atoms in chemical reactions never disappear, are not formed or transform into each other; they only rearrange to form various molecules and compounds (at the same time, energy is absorbed or released).
Because of this, atoms can be used in a wide variety of compounds and their supply is never depleted. This is exactly what happens in natural ecosystems in the form of cycles of elements. In this case, two cycles are distinguished: large (geological) and small (biotic). The water cycle is one of the grandest processes on the surface of the globe. It plays a major role in linking geological and biotic cycles. In the biosphere, water, continuously moving from one state to another, makes small and large cycles. The evaporation of water from the surface of the ocean, the condensation of water vapor in the atmosphere and the precipitation on the surface of the ocean form a small cycle. If water vapor is carried by air currents to land, the cycle becomes much more complicated. In this case, part of the precipitation evaporates and goes back into the atmosphere, the other feeds rivers and reservoirs, but ultimately returns to the ocean again by river and underground runoff, thereby completing the large cycle.
An important property of the water cycle is that, interacting with the lithosphere, atmosphere and living matter, it links together all parts of the hydrosphere: the ocean, rivers, soil moisture, groundwater and atmospheric moisture. Water is the most important component of all living things. Groundwater, penetrating through plant tissue during the process of transpiration, introduces mineral salts necessary for the life of the plants themselves. Summarizing the laws of ecosystem functioning, let us formulate once again their main provisions: 1) natural ecosystems exist due to free solar energy, which does not pollute the environment, the amount of which is excessive and relatively constant;
2) the transfer of energy and matter through the community of living organisms in the ecosystem occurs along the food chain; all species of living things in an ecosystem are divided according to the functions they perform in this chain into producers, consumers, detritivores and decomposers - this is the biotic structure of the community; the quantitative ratio of the number of living organisms between trophic levels reflects the trophic structure of the community, which determines the rate of passage of energy and matter through the community, that is, the productivity of the ecosystem; 3) natural ecosystems, due to their biotic structure, maintain a stable state indefinitely, without suffering from resource depletion and pollution by their own waste; obtaining resources and getting rid of waste occur within the cycle of all elements.
The human impact on the natural environment can be considered in different aspects, depending on the purpose of studying this issue. From an ecological point of view, it is of interest to consider the human impact on ecological systems from the point of view of compliance or contradiction of human actions with the objective laws of the functioning of natural ecosystems. Based on the view of the biosphere as a global ecosystem, all the diversity of human activities in the biosphere leads to changes in: the composition of the biosphere, the cycles and balance of its constituent substances; energy balance of the biosphere; biota. The direction and extent of these changes are such that man himself gave them the name of an ecological crisis.
The modern environmental crisis is characterized by the following manifestations: gradual change in the planet's climate due to changes in the balance of gases in the atmosphere, general and local (over the poles, individual land areas); destruction of the biosphere ozone screen; pollution of the World Ocean with heavy metals, complex organic compounds, petroleum products, radioactive substances; saturation of waters with carbon dioxide. gas disruption of natural ecological connections between the ocean and land waters as a result of the construction of dams on rivers, leading to changes in solid runoff, spawning routes, etc. atmospheric pollution with the formation of acid precipitation, highly toxic substances as a result of chemical and photochemical reactions; pollution of land waters, including river waters, used for drinking water supply, with highly toxic substances, including dioxins, heavy metals, phenols; desertification of the planet; degradation of the soil layer; reduction in the area of fertile lands; suitable for agriculture; radioactive contamination of certain territories due to the disposal of radioactive waste, man-made accidents, etc. accumulation of household garbage and industrial waste on the land surface, especially practically non-degradable plastics; reduction in the area of tropical and northern forests, leading to an imbalance of atmospheric gases, including a reduction in the concentration of oxygen in the planet’s atmosphere; pollution of underground space, including groundwater, which makes them unsuitable for water supply and threatens the still little studied life in the lithosphere; massive and rapid, avalanche-like disappearance of species of living matter; deterioration of the living environment in populated areas, especially urbanized areas; general depletion and lack of natural resources for the development of humanity; change in the size, energetic and biogeochemical role of organisms; reorganization of food chains, mass reproduction of individual species of organisms, disruption of the hierarchy of ecosystems, increasing systemic uniformity on the planet.
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