On a global scale, biochemical water cycles and carbon dioxide are, in our opinion, the most important for humanity. Biochemical cycles are characterized by the presence of small but mobile funds in the atmosphere.

Atmospheric pool of CO 2 in the cycle, compared to carbon stocks in the oceans, fossil fuels and other reservoirs earth's crust, is relatively small.

With the advent of scientific and technological progress, previously balanced carbon flows between the atmosphere, continents and oceans begin to enter the atmosphere in quantities that cannot be fully absorbed by plants.

There are different estimates of the impact of human activity on the enrichment of the atmosphere with CO 2, but all authors agree that the main carbon accumulators are forests, since forest biomass contains 1.5 times more, and humus contained in the soil contains 4 times more CO 2 than in the atmosphere.

Plants are a good regulator of CO 2 content in the atmosphere. Most plants are characterized by an increase in the intensity of photosynthesis with an increased content of carbon dioxide in the air

Photosynthetic" green belt"The earth and the carbonate system of the sea maintain a constant level of CO 2 in the atmosphere. However, the rapid increase in the consumption of fossil fuels, as well as a decrease in the absorption capacity of the “green belt” lead to the fact that the content of CO 2 in the atmosphere is gradually increasing. It is assumed that if the level of CO 2 in the atmosphere will be doubled (before the onset of active human influence on the environment it was 0.29%), then it is possible that the global temperature will increase by 1.5 - 4.5 °C. This can lead to the melting of glaciers and, as a consequence, to. rising sea levels, as well as adverse consequences in agriculture. Currently, the United States has a national research program on agricultural management in the event of a warming or cooling climate.

In addition to CO 2, carbon monoxide CO is present in small quantities in the atmosphere - 0.1 parts per million and methane CH 4 - 1.6 parts per million. These carbon compounds are actively included in the cycle and therefore have a short residence time in the atmosphere: CO - about 0.1 year, CH 4 - 3.6 years, and CO 2 - 4 years. Carbon monoxide and methane are formed during incomplete or aerobic decomposition of organic matter and are oxidized to CO 2 in the atmosphere.

The accumulation of CO on a global scale does not seem to be realistic, but in cities where the air stagnates, there is an increase in the concentration of this compound, which negatively affects people's health.

Methane is produced by the decomposition of organic matter in marshy areas and shallow seas. According to some scientists, methane performs useful function- it maintains the stability of the ozone layer, which protects all life on Earth from the harmful effects of ultraviolet radiation.

The pool of water in the atmosphere, as shown in Figure 11, is small, and its turnover rate is higher and its residence time is shorter than CO 2. Like the CO 2 cycle, human activities affect the water cycle.

From an energy point of view, two parts of the CO 2 cycle can be distinguished: the “upper” part, which is driven by the Sun, and the “lower” part, in which energy is released. As already noted, about 30% of all the solar energy arriving at the Earth’s surface is spent on setting the water cycle in motion.

In ecological terms, special attention should be paid to two aspects of the water cycle. Firstly, the sea loses more water through evaporation than it receives through precipitation, that is, a significant part of the precipitation that supports land ecosystems, including agroecosystems, consists of water that has evaporated from the surface of the sea. Secondly, as a result of human activity, surface runoff increases and the replenishment of the fund decreases. groundwater. There are already areas where groundwater accumulated in the previous century is used. Therefore, in this case, water is a non-renewable resource. After groundwater is depleted, it will be delivered from other territories, which will require the investment of additional energy.

The role of water in the processes occurring in the biosphere is enormous. Without water, metabolism in living organisms is impossible. With the advent of life on Earth, the water cycle became relatively complex, since the simple phenomenon of physiological evaporation was supplemented by the more complex process of biological evaporation (transpiration), associated with the life of plants and animals.

Briefly describe the water cycle in nature in the following way. Water reaches the Earth's surface in the form of precipitation, which is formed mainly from water vapor entering the atmosphere as a result of physical evaporation and evaporation of water by plants. One part of this water evaporates directly from the surface of water bodies or indirectly through plants and animals, while the other feeds groundwater (Figure 1.13).

The nature of evaporation depends on many factors. Thus, significantly more water evaporates from a unit area in a forest area than from the surface of a water body. With a decrease in vegetation cover, transpiration also decreases, and, consequently, the amount of precipitation.

The flow of water in the hydrological cycle is determined by evaporation, not precipitation. The atmosphere's ability to hold water vapor is limited. An increase in evaporation rates leads to a corresponding increase in precipitation. The water contained in the air in the form of vapor at any moment corresponds to an average layer 2.5 cm thick, evenly distributed over the surface of the Earth. The amount of precipitation that falls per year averages 65 cm. Consequently, water vapor from the atmospheric front circulates approximately 25 times annually (once every two weeks).

Water content in water bodies and soil hundreds of times more than in the atmosphere, but it flows through the first two funds at the same speed. The average time of transport of water in its liquid phase across the Earth's surface is about 3650 years, 10,000 times longer than the time of its transport in the atmosphere. Humans in the process of economic activity have a strong impact on the basis of the hydrological cycle - water evaporation.

Pollution of water bodies and, first of all, seas and oceans with petroleum products sharply worsens the process of physical evaporation, and a decrease in forest area - transpiration. This cannot but affect the nature of the water cycle in nature.

Figure 1.13 - Water cycle

Global cycles of vitally important nutrients break up in the biosphere into many small cycles confined to the local habitats of various biological communities. They can be more or less complex and to varying degrees sensitive to various types of external influences. But nature has decreed that under natural conditions these biochemical cycles are “exemplary waste-free technologies.” Cycling covers 98-99% of nutrients and only 1-2% goes not even to waste, but to the geological reserve (Figure 1.14).

1.8 Fundamentals of biosphere sustainability

The stability of ecosystems and their entire biosphere depends on many factors (Figure 1.15), the essence of the most important of which is as follows:

Figure 1.15- Factors of biosphere stability

1. The biosphere uses external sources energy: solar energy and the energy of heating the earth’s interior to streamline its organization, effective use free energy without causing pollution environment. The constant use of a certain amount of energy and its dissipation in the form of heat has created an evolutionarily established heat balance in the biosphere.

Biocenoses are characterized by the law (principle) of “energy conductivity”: the through flow of energy, passing through the trophic levels of the biocenosis, is constantly extinguished.

In 1942, R. Lindeman formulated the law of the energy pyramid or the law (rule) of 10%, according to which from one trophic level ecological pyramid moves to another higher level (“on the ladder” producer - consumer - decomposer) on average about 10% of the energy received at the previous level of the ecological pyramid.

2. The biosphere uses substances (mainly light nutrients) mainly in the form of cycles. Biogeochemical cycles of elements have been worked out evolutionarily and do not lead to the accumulation of waste.

3. There is a huge diversity of species and biological communities in the biosphere. Competitive and predatory relationships between species contribute to the establishment of equilibrium between them. At the same time, there are practically no dominant species with excessive numbers, which protects the biosphere from severe danger from internal factors.

Species diversity is a factor in increasing the resilience of ecosystems to impacts external factors. Gene pool wildlife- an invaluable gift, the potential of which has so far been used only to a small extent.

4. Almost all patterns characteristic of living matter have adaptive significance. Biosystems are forced to adapt to continuously changing living conditions. In the ever-changing environment of life, each type of organism is adapted in its own way. This is expressed by the rule of ecological individuality: no two species are identical.

The ecological specificity of species is emphasized by the so-called axiom of adaptability: each species is adapted to a strictly defined set of existence conditions specific to it - an ecological niche.

5. Self-regulation or maintenance of population size depends on a combination of abiotic and biotic factors. Each population interacts with nature as an integral system.

Population maximum rule: the size of natural populations is limited by the depletion of food resources and breeding conditions, the insufficiency of these resources and the too short period of acceleration of population growth.

Any population has a strictly defined genetic, phenotic, sex-age and other structure. It cannot consist of fewer individuals than is necessary to ensure its resistance to environmental factors.

The principle of minimum size is not a constant for any species; it is strictly specific for each population. Going beyond the minimum threatens the population with death: it will no longer be able to regenerate itself.

The destruction of each of these factors can lead to a decrease in the stability of both individual ecosystems and the biosphere as a whole.

Related information.

Topic No. 5. Global cycles of basic nutrients

Questions:

Global and local water cycle.

Carbon cycle. Changes in the carbon dioxide balance over time: long-term trends and seasonal variations.

Oxygen cycle.

Nitrogen cycle. The role of microorganisms in maintaining the nitrogen cycle: ammonifying bacteria, nitrifying bacteria.

Phosphorus cycle, its low isolation. Phosphorus as a limiting factor.

Sulfur cycle. The role of microorganisms in maintaining the sulfur cycle. Pollution of water bodies with hydrogen sulfide.

Target: formation of ideas about the transboundary transfer of basic nutrients (water, carbon, oxygen, nitrogen, sulfur, phosphorus).

1. Global and local water cycle

Solar energy on Earth causes two cycles of substances: large, or geological, most clearly manifested in the water cycle and atmospheric circulation, and small, biological (biotic), developing on the basis of the large one and consisting of a continuous, cyclical, but uneven in time and space, and accompanied by more or less significant losses in the natural redistribution of matter, energy and information within ecological systems of various levels of organization.

The most significant cycle on Earth in terms of transferred masses and energy consumption is the planetary hydrological cycle - the water cycle.

In liquid, solid and vapor states, water is present in all three main components of the biosphere: the atmosphere, the hydrosphere, and the lithosphere. All the waters unite general concept"hydrosphere". The components of the hydrosphere are interconnected by constant exchange and interaction. 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. When water vapor is carried by air currents to land, the cycle becomes much more complex. In this case, part of the precipitation evaporates and enters back into the atmosphere, the other feeds rivers and reservoirs, but ultimately returns to the ocean through river and underground runoff, thereby completing the large cycle.

The biotic (biological) cycle refers to the circulation of substances between soil, plants, animals and microorganisms. According to the definition of N.P. Remezov, L.E. Rodin and N.I. Bazilevich, the biotic (biological) cycle is the flow of chemical elements from soil, water and atmosphere into living organisms, the transformation of incoming elements into new complex compounds and their return back in the process of life activity with the annual fall of part of the organic matter or with completely dead organisms that are part of the ecosystem.

2. Carbon cycle. Changes in the carbon dioxide balance over time: long-term trends and seasonal variations

Migration of CO 2 in the biosphere occurs in two ways.

The first way is to absorb it during photosynthesis with the formation of glucose and other organic substances from which all plant tissues are built. They are subsequently transported through food chains and form the tissues of all other living beings in the ecosystem. It should be noted that the probability of a single carbon “being” in the composition of many organisms during one cycle is small, because with each transition from one trophic level to another, there is a high probability that the organic molecule containing it will be broken down during cellular respiration to obtain energy. The carbon atoms then re-enter the environment as carbon dioxide, thus completing one cycle and preparing to begin the next. On land where there is vegetation, atmospheric carbon dioxide is absorbed during the daytime through the process of photosynthesis. At night, part of it is released by plants into the external environment. With the death of plants and animals on the surface, oxidation of organic substances occurs with the formation of CO 2.

Carbon atoms are also returned to the atmosphere when organic matter is burned. An important and interesting feature of the carbon cycle is that in distant geological epochs, hundreds of millions of years ago, a significant part of the organic matter created in the processes of photosynthesis was not used by either consumers or decomposers, but accumulated in the lithosphere in the form of fossil fuels: oil, coal, oil shale, peat, etc. These fossil fuels are mined in huge quantities to meet the energy needs of our industrial society. By burning it, we, in a sense, complete the carbon cycle.

In the second way, carbon migration is carried out by creating a carbonate system in various reservoirs, where CO 2 turns into H 2 CO 3, HCO 3, CO 2. With the help of calcium (or magnesium) dissolved in water, carbonates (CaCO 3) are precipitated through biogenic and abiogenic pathways. Thick layers of limestone are formed. According to A. B. Ronov, the ratio of buried carbon in photosynthetic products to carbon in carbonate rocks is 1:4. Along with the large carbon cycle, there are a number of small carbon cycles on the land surface and in the ocean.

Definitions
The CO2 and water cycles on a global scale are probably the most important biogeochemical cycles for humanity. Both are characterized by small but highly mobile funds in the atmosphere, highly sensitive to disturbances caused by human activity and which can influence weather and climate. A network of measuring stations has now been created around the world to identify significant changes in the CO2 and H2O cycles, on which the future of man on Earth literally depends.
Explanations
In the CO2 cycle (Fig. 4.9,.4), the atmospheric fund is very small in comparison with carbon reserves in the oceans, in fossil fuels and other reservoirs of the earth's crust. It is believed that before the onset of the industrial era, carbon flows between the atmosphere, continents and oceans were balanced (solid lines in Fig. 4.9, A). Ho, over the past hundred years, the CO2 content has been constantly increasing as a result of new anthropogenic inputs (dashed lines in Fig. 4.9, A). The main source of these revenues is considered to be the combustion of fossil fuels, but agricultural development and deforestation also contribute.
It may seem surprising that Agriculture ultimately results in the loss of CO2 from the soil (i.e., it contributes more to the atmosphere than it takes out), but the fact is that CO2 fixation by crops (many of which are active only part of the year) does not compensate for the amounts of CO2 released from soil, especially as a result of frequent plowing. Deforestation, of course, can release the carbon stored in the wood, especially if it is immediately burned. Destruction of forests, especially with the subsequent use of these lands for agriculture or urban construction, leads to the oxidation of humus in the soil.
About the “CO2 problem” and its impact various types human activity to enrich the atmosphere with this compound, there is Order No. 1383

Rice. 4.9. A. Carbon dioxide cycle. The numbers represent the CO2 content (in billion tons) in the main parts of the biosphere and in the fluxes between HIiMiTs (at the arrows). (Data from the 1981 US Council on Environmental Quality report) B. Water cycle. The H2O content in the main parts of the biosphere and in the flows between them (with arrows) is indicated in geograms (1020) (Data from Hutchinson, 1957.)

many different points of view. According to one extreme point of view (Woodwell et al., 1978), the destruction of biotic reservoirs produces as much as burning fossil fuels. According to the opposite point of view (Broecker et al., 1979), the first of the mentioned sources plays a very minor role. Bolin (1977) takes an intermediate position. All,

However, we agree that forests are important carbon accumulators, since forest biomass contains 1.5 times more carbon, and forest humus contains 1 times more carbon than in the atmosphere.
The rapid oxidation of humus and the release of gaseous CO2, normally retained by the soil, also manifests itself in other, more subtle and only recently discovered effects. Among them is the influence of CO on the cycle of other nutrients. For example, Nelson (19(7)), studying the shells of bivalve mollusks, showed that as a result of deforestation and plowing of land, the amount of some trace elements in soil waters decreased. He discovered that bivalve shells from Indian kitchen middens 1000-2000 years old contain 50-100% more manganese and barium than shells of modern mollusks. By process of elimination, Nelson concluded that the rate of leaching of manganese and barium from the underlying rocks decreased due to a decrease in the flow of CO2-rich acidic water circulating deep in the soil. In other words, water now tends to flow quickly over the soil surface rather than filter through humus layers. An ecologist will say that modern human modification of the landscape has noticeably affected the flow of substances from the reserve fund to the exchange fund. If we understand what is happening and know how to correct the situation, then such changes do not have to be destructive. Agronomists have concluded that in many areas, to maintain crop yields, it is now necessary to add trace amounts of certain mineral elements (microelements) to fertilizers, since agroecosystems are not as good as natural ones at retaining these elements in circulation.
Let us remember how the modern earth's atmosphere with its low CO2 content and very high O2 content. The evolution of the atmosphere is briefly discussed in Chap. 2, section 4, in connection with the Gaia hypothesis (see also Fig. 8.11). When life appeared on Earth more than 2 billion years ago, the atmosphere, like the modern atmosphere of Jupiter, consisted of volcanic gases (as a geologist would say, the atmosphere was formed due to the “degassing of the earth’s crust”), it had a lot of CO2 and little oxygen (and be maybe there was none at all), and the first organisms were anaerobic. As a result of the fact that production (P) on average slightly exceeded respiration (/?), oxygen accumulated in the atmosphere over geological time and the CO2 content decreased. The accumulation of oxygen is also believed to have been facilitated by geological and purely chemical processes, such as the release of O2 from iron oxides or the formation of reduced nitrogen compounds and the splitting of water by ultraviolet radiation to release oxygen (Cloud, 1980). Both low CO2 and high O2 concentrations now serve as limiting factors for photosynthesis;
Most plants are characterized by an increase in the intensity of photosynthesis if the CO2 content increases or the O2 content decreases in the experiment. Thus, green plants turn out to be very sensitive regulators of the content of these gases.
The Earth's photosynthetic "green belt" and the carbonate system of the sea maintain a constant level of CO2 in the atmosphere. But the rapidly increasing consumption of fossil fuels (imagine what a huge amount of CO2 would be released if at least half of the huge fund of fossil fuels marked in Fig. 4.9, A) were burned, together with a decrease in the absorption capacity of the “green belt”, begins to exceed the capabilities natural control, so the CO2 content in the atmosphere is now gradually increasing. Remember that the flows of substances at the input and output of small exchange funds are subject to the greatest changes. It is believed that at the beginning of the Industrial Revolution (around 1800), the Earth's atmosphere contained about 290 parts per million (0.29%) of CO2. In 1958, when accurate measurements were first taken, the CO2 content was 315, and in 1980 it rose to 335 parts per million. If CO2 concentrations double the pre-industrial level, which could happen by the middle of the next century, the Earth's climate will likely warm; Temperatures will rise on average by 1.5-4.5 °C, and this, along with rising sea levels (as a result of melting polar caps) and changes in precipitation patterns, could destroy agriculture. As has recently been shown (Gornitze et al., 1982; Etkins and Epstein, 1982), mean sea level has already begun to rise, rising by approximately 12 cm this century. These threats (climate change and coastal flooding) must be taken into account when planning national and international energy policy. Reviews of the “CO2 problem” can be found in Baes et al. (1977) and in the reports of the commissions of the Council on Environmental Quality (1981) and the National Academy of Sciences (1979). .
In the next century, a new but precarious balance will be established between increasing levels of CO2 (which helps warm the Earth) and increasing atmospheric pollution with dust and other particles that reflect radiation and thereby cool the Earth. Any significant resulting change in the Earth's heat budget will affect the climate [good review possible consequences changes in the Earth's climate gives Bryson (Bryson,
1974)].
In addition to CO2, two more carbon compounds are present in small quantities in the atmosphere: carbon monoxide (CO) - about 0.1 parts per million and methane (CH4) - about 1.6 parts per million.

million. Like CO2, these compounds are in rapid circulation and therefore have a short residence time - about 1 year for CO, 3.6 years for CH4 and 4 years for CO2. Both CO and CH4 are formed from incomplete or anaerobic decomposition of organic matter; in the atmosphere both are oxidized to CO2. The same amount of CO that enters the atmosphere as a result of natural decomposition is now introduced into it at incomplete combustion fossil fuels, especially with exhaust gases. The accumulation of carbon monoxide, a deadly poison for humans, does not pose a threat on a global scale, but in cities where the air stagnates, the increase in the concentration of this gas in the atmosphere begins to become alarming. Concentrations of up to 100 ppm are not uncommon in areas with heavy traffic (a smoker consuming a pack of cigarettes a day receives up to 400 ppm, which reduces the amount of sxyhemoglobin in his blood by 3%, and this can lead to anemia and other diseases of the cardiovascular system associated with a lack of oxygen).
Methane is believed to have a beneficial function: it maintains the stability of the ozone layer in the upper atmosphere, which blocks deadly ultraviolet radiation Sun (see p. 113). Methane production is one of the important functions of the world's wetlands and shallow seas. Good review of the carbon cycle as a whole is given by Garrels, Mackenzie, and Hunt (1975; Chapter 6).
- As shown in the diagram of the hydrological cycle (Fig. 4.9Т/?) Т^ the water fund in the atmosphere is small, its turnover rate Bbinie1 and its storage time is less than that of UO2. The water cycle, like the CO2 cycle, is beginning to be affected by the global impacts of human activity. While rainfall and river flows are now being monitored around the world, we need to quickly gain greater control over all major pathways through which water moves through the cycle.
In Fig. 4.10 the water cycle is shown from an energy point of view, highlighting its “upper” part, driven by the Sun, and the “lower” part, in which energy is released that can be used by ecosystems and hydroelectric power plants. As shown in table. 3.3, about a third of all coming to Earth solar energy spent on setting the water cycle in motion. This is another example of the free service that solar energy provides us. Too often we undervalue services that we don't have to pay for. But if a person violates this system, then he will have to pay dearly for it!
Particular attention should be paid to two aspects of the water cycle: "
The sea loses more water due to evaporation than it receives through precipitation; on land the situation is opposite. In other words, much of the sediment that supports terrestrial ecosystems, including most agroecosystems that produce human food, consists of water evaporated from the sea. In many areas

Rice. 4.10. The energy of the hydrological cycle, presented in the form of two paths: the upper one is driven by solar energy, and the lower one gives energy to lakes, rivers, wetlands and performs work that is directly useful to humans (for example, at a hydroelectric power station). Surface runoff replenishes and is replenished by groundwater reservoirs, although in many dry areas these reservoirs are now being pumped by humans faster than they are replenished.

In areas such as the Mississippi Valley, 90% of precipitation is believed to come from the sea (Benton et al., 1950). It is estimated that freshwater lakes and rivers contain 0.25 geograms of water (I geogram - IO20 g, or IO14 t), and the annual flow is 0.2 geograms, so the turnover time is approximately I year. The difference between annual precipitation (1.0 geograms) and runoff (0.2 geograms) is 0.8; this is the amount of annual water flow into subsoil aquifers. As already indicated, as a result of human activity (covering the earth's surface impermeable to water

materials, creating reservoirs on rivers, building irrigation systems, compacting arable land, clearing forests, etc.) flow increases and replenishment is very important fund groundwater is decreasing. In the US, about half drinking water, most of the water for irrigation and in many parts of the country most of the water for industry comes from groundwater. In arid areas, such as the western Great Plains, underground aquifers are filled primarily with “fossil” water that accumulated there in previous, wetter geological periods and is no longer replenished. Therefore, water here is a non-renewable resource, like oil. This is evident in the heavily irrigated grain growing region of western Nebraska, Oklahoma, Texas and Kansas, where the Ogallala Formation aquifers, the main source of water, will be depleted within 30 to 40 years. After that, the land will have to be used as pasture or to grow drought-resistant crops on it, unless they begin to supply water from the major rivers of the Mississippi Valley - a very expensive and energy-intensive project that will have to pay for all taxpayers in the country. In 1982 it was impossible to predict what decision would be made, but one thing was clear: political differences would be sharp; many will suffer the economic collapse that is inevitable when a non-renewable resource is exploited without thought for the future.
In Fig. Figure 4.11 presents a graphical model of the “lower” part of the water cycle, showing how biotic communities adapt to changing conditions in the so-called river continuum (gradient from small to large rivers; see Vannote et al., 1980). In the upper reaches, rivers are small and often completely shaded, so that the aquatic community receives little light. Consumers depend mainly on leaf and other organic detritus brought from the drainage basin. The detritus is dominated by large organic particles, such as leaf fragments, and the fauna is represented mainly by aquatic insects and other primary consumers, which ecologists who study river ecosystems classify as mechanical destroyers. The upper reaches ecosystem is heterotrophic; the P/R ratio is much less than one.
In the middle reaches, rivers are wider, unshaded, and less dependent on organic matter from their drainage basins, as autotrophic algae and aquatic macrophytes provide primary products. Finely ground organic matter predominates here, and among the fauna there are filter feeders with appropriate food-collecting devices (catchers and filters). The metabolism of the community is autotrophic, the P/R ratio is equal to I or higher (Fig. 4.11). In the middle reaches of the river, a maximum of species diversity and daily temperature fluctuations are usually observed. In the lower reaches of a large river, the flow is slow, the water is usually cloudy, as a result of which the depth of light penetration is reduced and the water photo is weakened.

Rice. 4.11. River continuum. Change in community metabolism, in the diversity of organic matter particle sizes from headwater streams to large rivers. (Vannote et a!., 1980.)

synthesis. Here the river again becomes heterotrophic, and at most trophic levels species diversity is decreasing"
In rivers, as elsewhere in the biosphere, organisms are not limited to passive adaptation to a gradient of change physical factors environment. Acting together, river animals, for example, return nutrients to the cycle and reduce their removal into the ocean. Aquatic insects, fish and other organisms collect suspended and dissolved substances, retain them, pass them through the food chain, and more mobile species during their life cycle can move these substances up against the current or from the river to the drainage basin. Limnologists called this process “spiral movement of substances” (Elwood and Nelson, 1975).
An excellent overview of the water cycle is given by Hutchinson (1957) in Chap. 4 of "Treatise on Limnology" and Garrels, Mackenzie and Hunt (Garrels, Mackenzie, Hunt, 1975, ch. 5) in the book "Chemical Cycles and the Global External Environment".

As you know, everything structural components biospheres are closely interconnected by complex biogeochemical cycles migration of substances and energy. Processes of mutual exchange and interaction take place on different levels: between geospheres (atmosphere, hydro, lithosphere), between natural areas, individual landscapes, their morphological parts, etc. However, a single general process of exchange of matter and energy dominates everywhere, a process that generates phenomena of different scales - from atomic to planetary. Many elements, having gone through a chain of biological and chemical transformations, return to the composition of the same chemical compounds in which they were at the initial moment. At the same time, the main driving force in the functioning of both global and small (as well as local) cycles are living organisms themselves.
The role of biogeochemical cycles in the development of the biosphere is extremely great, since they ensure the repetition of the same organic forms with a limited volume of the initial substance participating in the cycles. Humanity can only be amazed at how wisely nature is structured, which itself tells the “unlucky Homo sapiens* how to organize the so-called waste-free production. Let us note, however, that in nature there are no completely closed cycles: any of them is simultaneously closed and open. An elementary example of a partial cycle is water that, having evaporated from the surface of the ocean, partially returns there.
There are complex relationships between individual small cycles, which ultimately leads to a constant redistribution of matter and energy between them, to the elimination of a kind of asymmetric phenomena in the development of cycles. Thus, in the lithosphere, oxygen and silicon appeared in excess in a bound state, in the atmosphere in a free state - nitrogen and oxygen, in the biosphere - hydrogen, oxygen and carbon. It should also be noted that the bulk of carbon was concentrated in sedimentary rocks lithosphere, where carbonates accumulated the bulk of carbon dioxide released into the atmosphere with volcanic eruptions.
We must not forget that there is a very close connection between space and the Earth, which, with a certain degree of convention, should be considered within the framework of the global circulation (since, as already noted, it is not closed). From space, our planet receives radiant energy (solar and cosmic rays), corpuscles of the Sun and other stars, meteorite dust, etc. The role of solar energy is especially important. In turn, the Earth gives back some of the energy, dissipates hydrogen into space, etc.
Many scientists, starting with V.I. Vernadsky, considering the global biogeochemical cycle elements in nature as one of the most important factors in maintaining dynamic equilibrium in nature, two stages were distinguished in the process of its evolution: ancient and modern. There is reason to believe that at the ancient stage the cycle was different, however, due to the absence of many unknowns (names of elements, their mass, energy, etc.), it is almost impossible to simulate the cycles of past geological eras (“former biospheres”).
To this it should be added that the main part of living matter consists of C, O, H, N, the main sources of plant nutrition are CO2, NO and other minerals. Taking into account the importance of carbon, oxygen, hydrogen, nitrogen for the biosphere, as well as the specific role of phosphorus, we will briefly consider their global cycles, called “private” or “small”. (There are also local circulations associated with individual landscapes.)