The cycle of the most important chemical elements in nature. Chemical elements in nature - cycle and migration

Introduction

1 The cycle of the most important chemical elements in nature

1.1 The water cycle.

1.2. Carbon cycle.

1.3. Nitrogen cycle

1.4. The sulfur cycle.

1.5. Phosphorus cycle

3 Ecological role of the main abiotic factors

3.1. Solar radiation

3.2. Temperature.

3.3 Humidity

3.4. Air-gas mode

4 Basic laws of action of abiotic factors

4.1. The concept of optimum

4.2. The concept of tolerance

4.3. Liebig's law, or the "law of the minimum", or the law of the limiting factor

4.5. Rule of advance V.V. Alekhine

4.6. The principle of static fidelity G.Ya. Bay Bienko

4.7. The rule of zonal tiers M.S. Gilyarova

5 Ecological significance of abiotic factors

6 Adaptation of living organisms to environmental conditions.

7 Biotic factors and their description.

8 Biosphere

8.1. Biosphere: functions of living matter.

8.3. Biosphere: protective screens

9. Sustainability of the natural environment (ecosystems) in Russia.

Conclusion

List of references

Annex 1

The value of nitrogen for living organisms is determined mainly by its content in proteins and nucleic acids. Nitrogen, like carbon, is part of organic compounds, the cycles of these elements are closely related. The main source of nitrogen is atmospheric air. Thanks to fixation by living organisms, nitrogen enters from the air into the soil and water. Blue-green bind about 25 kg / ha of nitrogen annually. Effectively fix nitrogen and nodule bacteria.

Plants absorb nitrogen compounds from the soil and synthesize organic matter. Organics spreads along food chains up to reducers, which break down proteins with the release of ammonia, which is further converted by other bacteria to nitrites and nitrates. A similar nitrogen circulation occurs between benthos and plankton organisms. Denitrifying bacteria reduce nitrogen to free molecules that return to the atmosphere. A small amount of nitrogen is fixed in the form of oxides by lightning discharges and enters the soil with precipitation, and also comes from volcanic activity, compensating for the decrease in deep-sea deposits. Nitrogen also enters the soil in the form of fertilizers after industrial fixation from the atmosphere.

The nitrogen cycle is a more closed cycle than the carbon cycle. Only a small amount is washed away by rivers or into the atmosphere, leaving the boundaries of ecosystems.

1.4. The sulfur cycle.

Sulfur is part of a number of amino acids and proteins. Sulfur compounds enter the cycle mainly in the form of sulfides from the weathering products of land and seabed rocks. A number of microorganisms (for example, chemosynthetic bacteria) are able to convert sulfides into a form accessible to plants - sulfates. Plants and animals die off, the mineralization of their residues by reducers returns sulfur compounds to the soil. So, sulfur bacteria bacteria oxidize to sulfates hydrogen sulfide formed during the decomposition of proteins. Sulfates facilitate the conversion of sparingly soluble phosphorus compounds to soluble ones. The amount of mineral compounds available to plants is increasing, the conditions for their nutrition are improving.

The resources of sulfur-containing minerals are very significant, and the excess of this element in the atmosphere, leading to acid rain and disrupting the processes of photosynthesis near industrial enterprises, is already worrying scientists. The amount of sulfur in the atmosphere increases significantly when burning natural fuels.

1.5. The phosphorus cycle.

This element is contained in a number of vital molecules. Its cycle begins by leaching of phosphorus-containing compounds from rocks and their entry into the soil. Part of the phosphorus is carried to rivers and seas, the other is absorbed by plants. The biogenic cycle of phosphorus occurs according to the general scheme: reducers. ® consumables ® producers

Significant amounts of phosphorus are applied to the fertilizer fields. About 60 thousand tons of phosphorus annually returns to the mainland with fish catch. In the human protein diet, fish make up from 20% to 80%, some low-value fish varieties are processed into fertilizers rich in useful elements, including phosphorus.

The annual production of phosphorus-containing rocks is 1-2 million tons. The resources of phosphorus-containing rocks are still large, but in the future, humanity will probably have to solve the problem of the return of phosphorus to the biogenic cycle.

Organisms in the ecosystem are connected by a commonality of energy and nutrients, and it is necessary to clearly distinguish between these two concepts. The entire ecosystem can be likened to a single mechanism that consumes energy and nutrients to do the job. Nutrients originally originate from the abiotic component of the system, into which they eventually return either as waste products, or after the death and destruction of organisms. Thus, in the ecosystem there is a constant cycle of nutrients, in which both the living and non-living components participate. Such cycles are called biogeochemical cycles.

At a depth of tens of kilometers, rocks and minerals are exposed to high pressures and temperatures. As a result, metamorphism (change) of their structure, mineral, and sometimes chemical composition occurs, which leads to the formation of metamorphic rocks.

Sinking even deeper into the Earth, metamorphic rocks can melt and form magma. Earth's internal energy (i.e. endogenous forces) raises magma to the surface. With molten rocks, i.e. magma, chemical elements are carried to the surface of the Earth during volcanic eruptions, freeze in the crust in the form of intrusions. The processes of mountain building raise deep rocks and minerals to the surface of the Earth. Here, rocks are exposed to the sun, water, animals and plants, i.e. are destroyed, transported and deposited in the form of precipitation in a new place. As a result, sedimentary rocks are formed. They accumulate in the movable zones of the earth's crust and, when bent, again fall to great depths (over 10 km).

The processes of metamorphism, crossing, crystallization begin again, and the chemical elements return to the surface of the Earth. Such a “route” of chemical elements is called a large geological cycle. The geological cycle is not closed, because part of the chemical elements goes out of the cycle: carried away into space, fixed by strong bonds on the earth's surface, and part comes from outside, from space, with meteorites.

The geological cycle is a global journey of chemical elements within the planet. They make shorter trips on the Earth within its individual sections. The main initiator is living matter. Organisms intensively absorb chemical elements from the soil, water air. But at the same time they are returned. Chemical elements are washed out of plants by rainwater, released into the atmosphere when breathing, and deposited in the soil after the death of organisms. Returned chemical elements are again and again involved in living matter in "travel". All together, it makes up the biological, or small, cycle of chemical elements. He is not closed either.

Some of the “travelers” elements are carried out beyond its borders with surface and ground waters, some at different times “turn off” from the cycle and linger in trees, soil, and peat.

Another route of chemical elements runs from top to bottom from peaks and watersheds to valleys and riverbeds, hollows, and depressions. Chemical elements enter the watersheds only with atmospheric precipitation, and are carried down with water and under the influence of gravity. The consumption of the substance prevails over the intake, as evidenced by the very name of the landscapes of the watershed eluvial.

On the slopes, the life of chemical elements is changing. The speed of their movement increases sharply, and they "pass" the slopes, like passengers comfortably settled in the train compartment. The landscapes of the slopes are called transit.

Chemical elements are able to "rest" from the road only in accumulative (accumulating) landscapes located in depressions. In these places, they often remain, creating good nutritional conditions for vegetation. In some cases, vegetation has to deal with an excess of chemical elements.

Many years ago, man intervened in the distribution of chemical elements. Since the beginning of the twentieth century, human activity has become the main way of their journey. During mining, a huge amount of substances is removed from the earth's crust. Their industrial processing is accompanied by emissions of chemical elements with industrial wastes into the atmosphere, water, and soil. This pollutes the living environment of living organisms. On the earth, new areas with a high concentration of chemical elements appear man-made geochemical anomalies. They are common around mines of non-ferrous metals (copper, lead). These sites sometimes resemble lunar landscapes, because they are practically deprived of life due to the high content of harmful elements in soils and waters. It is impossible to stop scientific and technological progress, but a person must remember that there is a threshold in environmental pollution, which cannot be crossed, beyond which human diseases and even the extinction of civilization are inevitable.

Having created biogeochemical "dumps", nature, perhaps, wanted to warn a person from ill-conceived, immoral activities, to show him with a good example what the violation of the distribution of chemical elements in the earth's crust and on its surface leads to.

The possibility of our life, its conditions are dependent on natural resources. Biological and especially food resources serve as the material basis of life. Mineral and energy resources, including in production, serve as the basis for a stable standard of living.

Intensively consuming natural resources, a person needs to maintain a natural balance. The balance of resources in the cycle of matter determines the stability of the biosphere.

2 Environmental factors and their description.

2.1. Habitat and classification of environmental factors.

Under habitat  they understand the totality of external environmental conditions and phenomena in which living organisms are immersed, and with which these organisms are in constant interaction.

In bioecology, it is usually a natural environment that has not been altered by humans. Applied (social) ecology speaks of the environment, one way or another mediated by man.

Individual elements of the environment to which organisms respond with adaptive reactions (adaptations) are called environmental factors or environmental factors. Among environmental factors, usually three groups of factors are distinguished: abiotic, biotic and anthropogenic.

1. Abiotic environmental factors called conditions that are not directly related to the vital activity of organisms. The most important abiotic factors include temperature, light, water, composition of atmospheric gases, soil structure, composition of nutrients in it, topography, etc. These factors can affect organisms either directly, for example, light or heat, or indirectly, for example, the terrain, which determines the effect of direct factors, light, wind, moisture, etc. Perhaps, among the abiotic factors there are also those that we still don’t even we guess. So, for example, we recently discovered the influence of changes in solar activity on processes in the biosphere.

2. Biotic environmental factors  called the totality of the effects of some organisms on others. Living creatures can serve as a source of food for other organisms, be their habitat, contribute to their reproduction, etc. The effect of biotic factors can be not only direct, but also indirect, expressed in the correction of abiotic factors, for example, changes in soil composition, microclimate under the forest canopy, etc.

ABIOTIC	Biotic
Physicalclimatic - moisture, light, temperature, wind, pressure, currents, day length	The influence of plants on each other and on other organisms in the biocenosis (directly or indirectly)
Physical edaphic- moisture capacity, heat supply, mechanical composition and permeability of the soil	The influence of animals on each other and on other organisms in the biocenosis
Chemical- composition of air, content of nutrients in soil or water, salinity of air and water, pH reaction	Anthropic factors - all types of human activity

3. Anthropogenic environmental factorscalled the totality of human influences on living organisms. This influence can also be direct, for example, when a person cuts down a forest or shoots animals, or indirect, manifested in a person’s impact on abiotic and biotic environmental factors, for example, a change in the composition of the atmosphere, soil, hydrosphere, or a change in the structure of ecosystems.

3.1. Solar radiation

Solar radiation is the main source of energy for the ecosystem. It is a great blessing for all living things and at the same time a factor that establishes a rigid framework for its existence.

Direct or scattered solar radiation is not required only for a small group of living things - some species of mushrooms, deep-water fish, soil microorganisms, etc.

The most important physiological and biochemical processes carried out in a living organism, due to the presence of light, include the following (according to N. Green et al., 1990):

1. Photosynthesis (1-2% of the solar energy incident on the Earth is used for photosynthesis);

2. Transpiration (about 75% - for transpiration, which provides cooling of plants and the movement of aqueous solutions of mineral substances along them);

3. Photoperiodism (provides synchronization of vital processes in living organisms to periodically changing environmental conditions);

4. Movement (phototropism in plants and phototaxis in animals and microorganisms);

5. Vision (one of the main analyzing functions of animals);

6. Other processes (synthesis of vitamin D in humans in the light, pigmentation, etc.).

The basis of biocenoses of central Russia, as well as most terrestrial ecosystems, are producers. Their use of sunlight is limited by a number of natural factors and, first of all, by temperature conditions. In this connection, special adaptive reactions were developed in the form of a layer, leaf mosaic, phenological differences, etc. According to the requirements of lighting conditions, plants are divided into light or light-loving (sunflower, plantain, tomato, acacia, melon), shadow or non-loving (forest herbs, mosses) and shade-tolerant (sorrel, heather, rhubarb, raspberry, blackberry).

Plants form the living conditions of other species of living creatures. That is why their reaction to broadcast conditions is so important. Environmental pollution leads to a change in exposure: a decrease in the level of solar insolation, a decrease in the amount of photosynthetically active radiation (the PAR component of solar radiation with a wavelength of 380 to 710 nm), and a change in the spectral composition of light. As a result, it destroys cenoses based on the arrival of solar radiation in certain parameters.

3.2. Temperature.

For the natural ecosystems of our zone, the temperature factor, along with light supply, is decisive for all life processes. The activity of populations depends on the time of year and time of day, because each of these periods has its own temperature conditions.

Individuals of many species are not able to maintain a constant body temperature and in the cold season or day, they reduce the level of vital processes up to suspended animation. This primarily concerns plants, microorganisms, fungi and poikilothermic (cold-blooded) animals. Activity is maintained only by homo-thermal (warm-blooded) species. Heterothermic organisms, being in an inactive state, have a body temperature not much higher than the temperature of the environment; in the active state - fairly high (bears, hedgehogs, bats, gophers).

Thermoregulation of homoyothermal animals is ensured by a special type of metabolism, which occurs with the release of animal heat in the body, the presence of heat-insulating integument, size, physiology, etc.

As for the plants, they developed a number of properties in the process of evolution:

1. Cold resistance - the ability to tolerate low positive temperatures (from ° C to + 5 ° C) for a long time;

2. Winter hardiness - the ability of perennial species to tolerate a set of winter adverse conditions;

3. Frost resistance - the ability to tolerate negative temperatures for a long time;

4. Anabiosis - the ability to tolerate a period of prolonged lack of environmental factors in a state of sharp decline in metabolism;

5. Heat resistance - the ability to tolerate high (St. + 38 ° ... + 40 ° C) temperatures without significant metabolic disorders;

6. Ephemerality - a reduction in ontogenesis (up to 2-6 months) in species growing under conditions of a short period of favorable temperature conditions.

7. Resistance to changes in temperature conditions.

Thermal pollution of the environment leads to a shift in the phenological phases of the development of living organisms or to abnormal changes at certain stages of ontogenesis. As a result, a number of populations do not have time or cannot give full-fledged offspring, some do not have time to prepare for a period of adverse conditions and die. Global warming at + 0.5..1.5 ° C, according to most experts, will lead to disastrous consequences for the biosphere.

3.3 Humidity

Moisture conditions in our zone are favorable enough for the existence of organisms. Most living creatures are 70-95% water. Water is needed for all biochemical and physiological processes. Therefore, it is so important for biocenoses of all ecosystems.

The availability of moisture in different periods of the year and day is different. In the process of evolution, living organisms have adapted to regulate the level of water consumption and maintain the optimal composition of the internal environment.

In relation to the water regime, the following ecological groups of living creatures are distinguished:

1. Hydrobionts - inhabitants of ecosystems, whose entire life cycle takes place in water;

2. Hygrophytes - plants of wet habitats (Kaluga marsh, European swimsuit, broadleaf cattail);

3. Hygrophils - animals that live in very moist parts of ecosystems (mollusks, amphibians, mosquitoes, wood lice);

4. Mesophytes - plants of moderately moistened habitats;

5. Xerophytes - plants of dry habitats (feather grass, wormwood, astrogale);

6. Xerophiles - inhabitants of arid territories that cannot tolerate increased moisture (some species of reptiles, insects, desert rodents and mammals).

7. Succulents - plants of the most arid habitats that can accumulate significant moisture reserves inside the stem or leaves (cacti, aloe, agave);

8. Sclerophytes - plants of very arid territories that can withstand severe dehydration (camel spine, Saksaul, Saksagyz);

9. Ephemeras and ephemeroids - annual and perennial herbaceous species having a shortened cycle coinciding with a period of sufficient moisture.

Moisture consumption of plants can be characterized by the following indicators:

1. Drought tolerance - the ability to tolerate reduced atmospheric and (or) soil drought;

2. Moisture resistance - the ability to tolerate waterlogging;

3. The transpiration coefficient is the amount of water spent on the formation of a unit of dry mass (for white cabbage 500-550, for pumpkin-800);

4. The coefficient of total water consumption - the amount of water consumed by the plant and soil to create a unit of biomass (for meadow grasses - 350-400 m3 of water per ton of biomass);

Violation of the water regime, pollution of surface water is dangerous, and in some cases fatal to cenoses. A change in the water cycle in the biosphere can lead to unpredictable consequences for all living organisms.

3.4. Air-gas mode

The atmosphere of the Earth has a fairly stable composition. 21% of oxygen in the surface air layer provides full breathing to all organisms in natural ecosystems. 0.03% carbon dioxide is enough for photosynthetic plant reactions. The horizontal and vertical movement of air masses creates the necessary air exchange for all the inhabitants of the ecosystem - from soil microorganisms to insects and birds.

The air-gas regime can be violated in natural conditions very rarely (for example, during an eruption of a volcano), in anthropic ones - quite often. The main air pollutants in our environment are carbon monoxide, sulfur dioxide, nitrogen dioxide, formaldehyde, dust. Difficult photosynthesis, respiration, many other physiological processes, and in some cases modifying them, atmospheric pollution stops or stops the growth and development of living organisms, leading in some cases to their death.

Abiotic environmental factors will only fully play their ecological role when the consequences of human life are within the ability of the biosphere to self-purify and self-repair.

General laws of the combined action of factors on organisms

4.1. The concept of optimum

Each organism, each ecosystem develops with a certain combination of factors: moisture, light, heat, availability and composition of nutrient resources. All factors act on the body at the same time. For each organism, population, ecosystem, there is a range of environmental conditions - a range of stability (Fig. 1), in the framework of which the vital activity of objects occurs.

In the process of evolution, organisms formed certain requirements for environmental conditions. Doses of factors at which the organism, population or biocenosis achieve the best development and maximum productivity corresponds to the optimum conditions. With a change in this dose in the direction of decrease or increase, the body is suppressed and the stronger the deviation of the factor value from the optimum, the greater the decrease in viability, up to the death of the body or destruction of the biocenosis. The conditions under which vital activity is maximally depressed, but the body and biocenosis still exist, are called pessimal.

EXAMPLE. In the north, the limiting factor is heat; in the south, moisture availability. In the Far North, the most productive forests of Kayander larch forbs grow in floodplains - there is a favorable hydrothermal regime and soils during floods are regularly replenished with nutrients. The lowest productivity forests are from the same larch, but with a cover of sphagnum mosses, formed on the northern slopes of the mountains under conditions of constant overmoistening and cold soil. The permafrost level under the moss cover does not fall below 30 cm. In Southern Primorye, optimal forest growing conditions are characteristic of the northern slopes in their middle part, and pessimal to dry southern slopes with a convex surface.

Many examples can be given of optimums and pessimums in plants, animals, and their communities with respect to light, moisture, heat supply, soil salinity, and other factors.

4.2. The concept of tolerance

For different types of plants and animals, the limits of the conditions in which they feel good vary. For example, some plants prefer very high humidity, while others prefer arid habitats. Some species of birds fly to warmer climes, others - crossbills, pine trees and chicks hatched in winter. The wider the quantitative limits of environmental conditions under which an organism, species and ecosystem can exist, the higher the degree of their endurance, or tolerance. The property of species to adapt to environmental conditions is called environmental plasticity(Fig. 2), and the environmental valency of the species is judged by the amplitude of the natural fluctuations of the factor transferred by the populations.

Species with narrow ecological plasticity, i.e. able to exist in conditions of a small deviation from its optimum, highly specialized, are called stenobiontic  (stenos - narrow), species widely adapted, able to exist with significant fluctuations of factors - eurybiontic  (eurys - wide) The boundaries beyond which existence is impossible are called the lower and upper limits of endurance, or ecological valency.

EXAMPLE. Fish of salt and fresh water bodies - stenobionts. Three-spined stickleback and salmon are eurybionts. Stenobionts-plants: Chosenia, Korean poplar - floodplain plants, hygrophytic plants (marsh marigold, cattail,), Primorye xerophytes - densely flowered pine, Manchurian apricot, woodpecker, etc. Almost all mammals, including humans, can be referred to stenobionts. A small deviation of air temperature (22-26 ° C) and water (28-38 ° C) from the “normal” value, a low oxygen content and a high content of harmful substances (chlorine, mercury vapor, ammonia, etc.) in the air is enough to cause a sharp deterioration in his condition.

In relation to one factor, the type of m. stenobiont, in relation to another - eurybiont. Depending on this, directly opposite pairs of species are distinguished: stenothermal - eurythermic (with respect to heat), stenohydric - euryhydric (with respect to moisture), stenohalic - eurythalic (with respect to salinity), wall-eurythric (with respect to light), etc.

There are other terms that characterize the relationship of species to environmental factors. Adding the ending “phyl” (phyleo (Greek) - I love) means that the species has adapted to high doses of the factor (thermophile, hygrophil, oxyphil, gallophil, chionophile), and adding “phob”, on the contrary, to low (gallophob, chionophobe) . Instead of a “thermophobe”, a “cryophile” is usually used; instead of a “hyphrophobe”, a “xerophile” is used.

Typical euribionts are simple organisms, fungi. Among higher plants, species of temperate latitudes can be attributed to eurybionts: common pine, Daurian larch, Mongolian oak, Schwerin willow, lingonberry, and most species of heather.

Stenobiontism is produced in species that develop for a long time in relatively stable conditions. The more pronounced it is, the smaller the range of the species, or its community. The most common species have a wide range of tolerance to all factors. They are called cosmopolitans. But there are few such species.

In nature, there is no place where one factor acts on the body. All factors act simultaneously and the totality of these actions is called constellation. The values \u200b\u200bof the factors are not always equivalent. They may all be insufficient, and then there is general inhibition of biota (poor development of vegetation cover, decreased productivity, changes in the fractional structure of biomass, changes in other ecosystem indicators), but more often some of them are in abundance, even in the optimum, and others are in deficit. Moreover, the constellation is not a simple sum of the influence of factors, because the degree of influence of some factors on organisms and populations depends on the degree of influence of other factors.

EXAMPLE. With optimal heat supply, the tolerance of plants and animals to a lack of moisture and nutrition increases, and a lack of heat is accompanied by a decrease in moisture demand and an increased need for nutrients. Moreover, this is observed in plants and animals. In plants with a lack of heat and waterlogging of the soil, nutrient elements become physiologically inaccessible, and increased soil fertility is required to ensure tolerance. Also in animals - to enhance the protective functions of the body in the cold, you need to eat well. So, always before laying down in a den, a bear accumulates subcutaneous fat. Gas exchange reactions in fish are not the same in water of different salinity. In beetles of the genus Blastophagus, the reaction to light depends on temperature. At a temperature of 25 ° C they creep into the light (positive phototropism), when it decreases to 20 ° C or increases to 30 ° C - the reaction is neutral, and at values \u200b\u200bbelow and above these limits - they hide.

However, the compensatory possibilities of the factors are limited. No factor can be completely replaced by another, and if the value of at least one of the factors goes beyond the upper or lower endurance limits of the biota component, the existence of the latter becomes impossible, no matter how favorable the other factors are.

EXAMPLE. The normal survival of the sika deer in Primorye takes place only in oak trees on the southern slopes, as here, the snow power is insignificant and provides the deer with sufficient food supply for the winter period. The limiting factor for deer is deep snow. The lack of heat limits the spread to the north of most species and formations of the Manchu flora: pine from densely flowered pine, whole-leaf fir and its formations are common only in Southern Primorye. And in the permafrost distribution zone, larch prevails everywhere. For cedar dwarf elder and Kamchatka alder, the decisive propagation factors are high air humidity and overwintering conditions. They tolerate frosty winters only if there is a thick snow cover that protects the shoots from drying out and frostbite with the winter monsoons of the Far East. These species form thickets only in the coastal regions of the Sea of \u200b\u200bOkhotsk and the Bering Sea, and in the continental districts - in the subalpine zone at an altitude of not less than 1000 m / n. In the early stages of development, the limiting factor in conifers may be excess light. All of them, even the grave pine, require shading in the first years of life.

In the middle of the 19th century (1846), the German agricultural chemist Liebig deduced the "law of the minimum." In an experiment with mineral fertilizers, he found that those factors that are at a minimum in a given habitat have the greatest impact on plant endurance. He wrote in 1955: "Elements that are completely absent or not in the right amount prevent other nutrient compounds from producing an effect or reduce their nutritional effect." This is true not only for batteries, but also for other vital factors. Liebig's law is applicable only in the stationary state of the ecosystem, i.e. when the influx of matter and energy into the system is balanced by their outflow.

A factor whose level is close to the endurance limits of a particular organism, species, and other components of a biota is called limiting. And it is to this factor that the body adapts (produces adaptations) in the first place. The law of limiting, or limiting, factors applies not only to the situation when these factors are at the “minimum”, but also at the “maximum”, that is, goes beyond the upper endurance limit of the organism (ecosystem).

Under pessimal conditions, there are several limiting factors, and their general inhibitory effect may be higher than the total inhibitory effect of individual factors.

EXAMPLE with southern slopes - insolation increases the dryness of the environment, prevents the increase in soil fertility.

Often the limiting factor is at one of the stages of development of the species. As you know, juvenile individuals are the most vulnerable and for them limiting factors may some. In different geographical zones, the limiting factors are different: in the Far North - more often it is warm, in the southern regions - moisture. Different species respond differently to the same factor. By the reaction of their adult individuals to a particular factor, it is possible to construct an ecological series (in descending order or increase in the action of the factor).

An EXAMPLE of the ecological range of tree species in terms of shade tolerance: larch - white birch - aspen - willow - linden - oak - daur birch - ash - maples - alder - elm - hornbeam - spruce - cedar - fir. The ecological series of forest types (by heat supply): larch (L.) grassy - L. green moss - L. lingonberry - L. sphagnum (Fig. 3). The ecological series of forest types (by moisture): elmovnik (or ashberry), large grass and fern - oak wood (D.) with motley birch - D. sedge - D. rhododendron sedge - D. mariannik-sedge - D. sedge rare-cover (Fig. 4 )

Within the population, it is also possible to distinguish individuals who are the most and least sensitive to the same factor. This is due to a combination of hereditary (genetic) and acquired (phenotypic) traits of organisms. Due to the environmental identity in populations, there are individuals with different viability. The most resilient survive periods of adverse conditions, contributing to the conservation of the species in extreme conditions.

4.5.   Rule of advance V.V. Alekhine

Set nerd you. You. Alekhine (1951). The same communities are zonal in one zone and extrazonal in others. In the second case, outside the northern borders of the range, they occupy the most favorable habitats for themselves, outside the southern borders - the least favorable. This is especially evident on the northern and southern slopes of the forest zone. On the cold northern slopes in the Magadan Region, larch thickets with sphagnum cover grow, and on the warm southern slopes, larch moss-lichen woodlands (Chukotka) and stony-birch forbs (Northern Okhotsk Sea). In the southwestern regions of Primorye, the northern slopes are occupied by moist coniferous-deciduous forests, and the southern slopes are occupied by dry oak forests with rare interspersed pine forests with densely flowered (grave) and apricot trees, which on the outskirts turn into forest-steppe communities.

The revealed pattern is of great importance, because allows you to accurately describe the vegetation of unexplored territories and reconstruct its former appearance in the places where it was destroyed.

Station - the habitat of a population of a species that is inherent in environmental conditions that meet the requirements of the species. Each species has its own set of stations. Within the same zone and time period, the species occupies one station. With the transition to another zone or with the transition to a different age stage, the species may change stations. The rule of zonal habitat change was established by entomologist Grieg. Yakovl. Bey-Bienko (1966). In the northern regions, many species of insects usually behave like hygrophobes, occupying drier, thinner areas, while in the southern regions they are hyphrophytes, settle in moist, shady places, with dense vegetation cover (migratory locust). Another example is lasia ants (Lasius niger, L. flavus) in humid meadows populate hummocks, and in dry meadows in the steppes, they prefer wetter habitats. A zonal change of habitat is also characteristic of plants.

So, the cedar dwarf tree in Southern Primorye grows only in the subalpine zone at an altitude of 1000-1100 m to 1400-1600 m above sea level, with a move to the north it goes down and forms a dense undergrowth in valley larch forests. North 60 ° N - on South Chukotka and the Okhotsk coast, the eastern and southeastern slopes and foothills of mountains and hills are occupied by continuous thickets of cedar dwarf elf.

4.7. The rule of zonal tiers M.S. Gilyarova

In different zones, the same species occupy different tiers. When moving north, they naturally move from the upper tiers to the lower, warmer, and some to the soil. This set the soil. Zoologist Mercur. Serg. Gilyarov.

EXAMPLE. Larvae of the stag beetle (Lucanus cervus) in the forest zone develop in decaying dead wood and stumps, and in the steppe they live in rotten roots to a depth of 1 m.

In addition to the zonal (spatial) change of habitats, temporary shifts occur: seasonal (during the month and even one day during microclimate fluctuations - during periods of drought or typhoons, insects and rodents either hide under the protection of crowns of shrubs and trees, or are selected in open places) and annual (in case of deviation of weather conditions from the average annual norms). Due to the change of habitats, species retain their ecological status in constantly changing conditions. At the same time, upon successful resettlement, they occupy new habitats, and even change them. As a result, the ecology and physiology of individuals and populations begins to change. In such cases, the change of stations becomes one of the leading factors in evolution.

The principle of static fidelity and the principle of zonal and vertical change of habitats, opposite to it, indicate the complex connection of organisms with the environment. Studying them is very important for understanding the ecology of species, as the basis for the protection of rare and useful species and the fight against harmful species.

5. The environmental significance of abiotic factors

Under different environmental conditions, biological processes occur at different speeds. For example, the growth of many plants depends on the concentration of various substances (water, carbon dioxide, nitrogen, hydrogen ions).

The temperature example shows that this factor is carried by the body only within certain limits. The body dies if the temperature of the environment is too low or too high. In an environment where the temperature is close to these extremes, living inhabitants are rare. However, their number increases as the temperature approaches the average value, which is the best (optimal) for a given species.

Tolerance (from Greek tolerance - patience) is the ability of organisms to withstand changes in living conditions (fluctuations in temperature, humidity, light). For example: some die at a temperature of 50 °, while others withstand boiling.

Under different environmental conditions, biological processes in organisms occur at different speeds. For example, the growth of many plants depends on the concentration of various substances (water, carbon dioxide, nitrogen, hydrogen ions).

It is possible that it is tolerance that will save nature from too unreasonable human exposure. In addition, there are still places on Earth relatively little affected by human influence. Therefore, by the time a person creates unbearable conditions for himself, some life will remain and continue to evolve, if only a person does not tear the planet to shreds as a result of an atomic catastrophe. There are also plants that produce substances that lead to their own death.

Organisms with a wide range of tolerance are denoted by the prefix "heuris". Eurybiont is an organism that can live under various environmental conditions. For example: eurythermic is an organism that suffers wide temperature fluctuations. Organisms with a narrow tolerance range are denoted by the prefix "wall-". Stenobiont - an organism that requires strictly defined environmental conditions. For example: trout is a stenothermal species, and perch is eurythermic. Trout does not tolerate large temperature fluctuations, if all the trees disappear along the banks of the mountain stream, this will lead to a temperature increase of several degrees, as a result of which the trout will die, and the perch will survive.

When placing the body in new conditions, after a while it gets used to, adapts. This leads to a shift in the tolerance curve and is called adaptation or acclimatization. For the normal development of organisms, the presence of various factors of a strictly defined quality is necessary, each of them must be in a certain amount. In accordance with the law of tolerance, an excess of a substance can be as harmful as a deficiency, that is, everything is good in moderation. For example: a crop may die in both arid and too rainy summers.

The law of the minimum.

The intensity of certain biological processes is often sensitive to two or more environmental factors. In this case, the decisive factor will belong to such a factor, which is available in a minimum quantity, in terms of the needs of the organism. This rule was formulated by the founder of the science of mineral fertilizers Justus Liebig (1803-1873) and was called the law of the minimum. Yu. Liebig discovered that plant yields can be limited by any of the main nutrients, if only this element is in short supply.

Moreover, according to the law of minimum, the deficiency of any one substance is not compensated by the excess of all others. If there is a lot of nitrogen, potassium and other nutrients in the soil, but there is not enough phosphorus (or vice versa), the plants will develop normally only until they absorb all the phosphorus.

Factors that restrain the development of organisms due to a shortage or excess compared to needs are called limiting.

The provision on limiting factors greatly facilitates the study of complex situations. Despite the complexity of the relationship between organisms and their environment, not all factors have the same environmental significance. For example, oxygen is a physiological factor for all animals, but from an environmental point of view, it becomes limited only in certain habitats. If a fish dies in a river, then the oxygen concentration in the water should be measured first, since it is highly variable, oxygen reserves are easily depleted, and often it is not enough. If the death of birds is observed in nature, it is necessary to look for another reason, since the oxygen content in the air is relatively constant and sufficient from the point of view of the requirements of terrestrial organisms.

6. Adaptation of living organisms to environmental conditions.

According to the theory of C. Darwin, organisms are volatile. It is impossible to find two absolutely identical individuals of the same species. These differences are partly inherited. All this is easily explained from the point of view of genetics. Each species and each population is saturated with various mutations, that is, changes in the structure of organisms caused by corresponding changes in the chromosomes that occur under the influence of environmental or internal factors. These changes in the signs of the body are spasmodic and inherited. The vast majority of these mutations are usually unfavorable, so almost all of them are recessive, that is, their manifestations disappear after a certain number of generations. However, all this set of changes is a reserve of heredity, the gene pool of a species or population, which can be mobilized through natural selection when changing the conditions of existence of populations.

If the population lives in relatively constant conditions, then almost all mutations are cut off by natural selection, which in this case is called stabilizing. Only mutations are fixed that lead to less variability of traits, as well as mutations that contribute to energy saving due to getting rid of functions that have become “superfluous” under constant conditions. This contributes to the formation of stenobionts. Often, stabilizing selection leads to degeneration, that is, evolutionary changes associated with a simplification of the form of organization, usually accompanied by the disappearance of some organs that have lost their significance. So the whales lost their hind limbs, the lancelet does not have its own digestive organs, etc. In exchange for the lost, new organs may be acquired.

When environmental conditions change, environmental pressure on the population forms, and the carriers of mutations that “guessed” those changes that are more favorable for new environmental conditions than the initial forms are most likely to survive. They give the greatest offspring, in which there is an even greater refinement of forms that satisfy the new state of the environment. As a result, with each new generation, forms gradually change. This natural selection is called driving.

Minor evolutionary changes that contribute to better adaptation to certain environmental conditions are called ideal adaptation. These are various private devices: protective coloration, the flat shape of bottom fish, the adaptation of seeds to dispersal, the degeneration of leaves in thorns to reduce transpiration, etc. Ideoadaptation usually results in small systematic groups: species, genera, and families.

More substantial evolutionary changes that are not adaptations to individual environmental factors, leading to significant changes in life forms, giving rise to new orders, classes, types, etc., are called aromorphosis. An example of aromorphosis is the emergence of ancient fish on land and the formation of a class of amphibians. The consequences of aromorphosis are also the emergence of such qualities of living beings as the psyche and consciousness. Aromorphosis marks a major revolutionary change in the structure of the biosphere, apparently caused by global changes in the environment.

Arguing on the principle of analogy, we can assume that just as the environment affects us, forcing us to look for ways to adapt to it, we can also act on the cells of our organisms as a supersystem, forcing them to adapt to external conditions for them in those ways which we expect from them and which for some reason we need. For example, we begin to regularly load our muscles, and our muscle tissues, adapting to new conditions, begin to grow and become stronger in response to these loads. Exposure can occur along a more complex chain, for example, in case of fright, adrenaline is released into our bloodstream, forcing all cells to go into a stressful, that is, more active, state, using their reserves for this, which gives the whole body additional strength to overcome external danger . Thus, the mechanism of influence on internal subsystems by changing environmental factors for these subsystems is, apparently, a fairly universal mechanism of influence of any supersystem on its internal organization.

Most likely, the intracellular level is no exception. If the cell of our body falls into altered conditions, and these changes are either fixed or periodically repeated, then the cell tries to adapt to new conditions, changing its structure accordingly, that is, changing the intracellular environment, thereby affecting the organelles inhabiting it, including and on chromosomes, which are also probably forced to adapt to external conditions for them. It is possible that, with some effects on the body, almost the entire genetic apparatus in all cells undergoes a certain effect, which leads to completely unambiguous changes in the structure of chromosomes. It means that the external environment can directly affect our genetic apparatus.

That is, the mutations that we talked about may not be random at all, but quite directed. Then the theory of natural selection acquires a slight adjustment:   Among the mutations present in the population at a specific change in environmental conditions, those that are directly initiated by this change predominate. That is, the mutations themselves are, apparently, directed and designed to find new forms that meet the requirements of a changing environment. And since the response of life to external changes, as we have already said, obeying the principle of optimality, turns out to be quite unambiguous, it is possible that a particular mutation of any trait is of a chain nature. That is, having arisen once in the offspring of one pair, a successful mutation is “contagious” for other pairs of parents giving their offspring, but with the same successful mutations. As a result, for one generation within the framework of the species, different parents can have children with the same characteristics that differ from the characteristics of the parents, thereby forming a completely new subspecies. And then it is already useless to look for some intermediate links. A new subspecies (and subsequently a new species) appears immediately, almost at the same time, and immediately turns out to be represented by a large enough number of individuals for stable reproduction. True, so far this is only a hypothesis.

Such processes appear, apparently, in those very periods of serious environmental changes that threaten the extinction of this species. It was then that the “whorl” was formed, that is, a huge number of mutations appeared, the purpose of which was: to find the right solution, a new form. And this solution will certainly be found, because, as we have already said, for this, life involves the “technique of trial grope”, which is “a specific and irresistible weapon of any expanding multitude” (Teilhard de Chardin's terminology). Mutations fill the entire possible space of variants of new forms, and then the environment itself determines which of these forms will become fixed in life and which will disappear without passing the test of natural selection. Sometimes such a whorl generates a whole bunch of new phyla, that is, evolutionary branches, which are different answers to the same change in the environment.

Adaptation of organisms to environmental factors is caused not only by evolutionary rearrangements occurring in the biosphere. Often organisms use the natural orientation and frequency of these factors to distribute their functions over time and program their life cycles in order to make the best use of favorable conditions. Due to the interaction between organisms and natural selection, the entire community becomes programmed for various kinds of natural rhythms. In these cases, environmental factors act as a kind of synchronizer of processes in the biosphere.

According to the degree of direction of action, environmental factors can be classified as follows:

1) periodic factors (daily, annual, etc.);

2) repeated without strict periodicity (floods, hurricanes, earthquakes, etc.);

3) unidirectional factors (climate change, waterlogging, etc.);

4) random and uncertain factors, the most dangerous for the body, as they are often found for the first time.

In the best way, living organisms manage to adapt to periodic and unidirectional factors, characterized by certainty of actions, therefore amenable to unambiguous interpretation. That is, the requirement of a supersystem in this case is quite understandable.

A special case of such adaptations to repetitive factors is, for example, photoperiodism - this is the body's response to daylight hours in the temperate and polar zones, which is perceived as a signal for changing developmental phases or behavior of organisms. Examples of photoperiodism are phenomena such as leaf fall, molting of animals, bird flights, etc. In relation to plants, usually short-day plants are distinguished that exist in the southern latitudes, where during the long growing season the day is relatively short, and long-day plants characteristic of the northern latitudes, where during the short growing season the day is longer.

Another example of adaptation to the periodicity of natural phenomena is daily rhythm. For example, in animals, when day and night change, respiratory rate, heart rate, etc., change. For example, gray rats are more labile in their daily rhythm than black ones, therefore they are easier to master new territories, having already populated almost the entire globe.

Another example is seasonal activity. This is not necessarily a change of seasons, but also a change, for example, of the doge season and drought, etc.

Adaptations to tidal rhythm, which is associated with both solar and lunar days (24 hours 50 minutes), are also interesting. Daily ebbs and flows are shifted by 50 minutes. The strength of the tides changes during the lunar month (29.5 days). With the new moon and full moon, the tides reach a maximum. All these features leave an imprint on the behavior of the littoral organisms (tidal zone). For example, individual fish lay eggs at the boundary of the maximum tide. The release of fry from eggs is confined to the same period.

Many rhythmic adaptations are inherited even when animals move from one zone to another. In such cases, the entire life cycle of the body may be disrupted. For example, ostriches in Ukraine can lay eggs directly in the snow.

Mechanisms of adaptation to the periodicity of processes may be the most unexpected. For example, in some insects, a kind of birth control is based on photoperiodism. Long days in late spring and early summer cause the formation of a neurohormone in the ganglion of the nerve chain, under the influence of which dormant eggs appear, giving larvae only next spring, no matter how favorable food and other conditions are. Thus, population growth is constrained even before food stocks become a limiting factor.

Adaptation to factors recurring without strict periodicity is much more complex. Nevertheless, the more characteristic this factor is for nature (for example, fires, severe storms, earthquakes), the more specific adaptation mechanisms life finds for them. For example, in contrast to the length of the day, the amount of precipitation in the desert is completely unpredictable, however, some annual desert plants usually use this fact as a regulator. Their seeds contain a germination inhibitor (an inhibitor is a substance that inhibits processes), which is washed out only by a certain amount of precipitation, which will be enough for the full life cycle of this plant from seed germination to the maturation of new seeds.

In relation to forest fires, plants also developed special adaptations. Many plant species invest more energy in underground storage organs and less in reproductive organs. These are the so-called “recovering” species. Species “dying in maturity," on the contrary, produce numerous seeds, ready to germinate immediately after a fire. Some of these seeds have been lying in forest litter for decades without sprouting or losing germination.

The most dangerous for living organisms are factors of indeterminate action. Natural systems have the ability to recover well from acute stresses such as fires and storms. Moreover, many plants even need random stresses to maintain a “vitality” that enhances the sustainability of existence. But subtle chronic disturbances, especially characteristic of anthropogenic impact on nature, give weak reactions, therefore they are difficult to track, and most importantly it is difficult to assess their consequences. Therefore, adaptations to them are formed extremely slowly, sometimes much slower than the accumulation time of the effects of chronic stress beyond the limits after which the ecosystem is destroyed. Industrial waste containing new chemicals that nature has not yet encountered is especially dangerous. One of the most dangerous stressors is thermal pollution of the environment. A moderate increase in temperature can have a positive effect on life, but after a certain limit, stress effects begin to appear. This is especially noticeable in water bodies directly related to thermal power plants.

Ecological valency, the degree of adaptability of a living organism to changes in environmental conditions. Ecological valency is a species property. Quantitatively, it is expressed by the range of environmental changes within which this species maintains normal life. Ecological valency can be considered both in relation to the reaction of a species to individual environmental factors, and in relation to a complex of factors. In the first case, species that undergo wide changes in the strength of the influencing factor are indicated by the term consisting of the name of this factor with the prefix “evry” (heurythermic in relation to the influence of temperature, euryhaline in relation to salinity, eurybate in relation to depth, etc.); species adapted only to small changes in this factor are denoted by a similar term with the prefix “wall” (stenothermal, stenohaline, etc.). Species with a wide ecological valency with respect to a complex of factors are called eurybionts, as opposed to stenobionts, which have little adaptability. Since eurybiontism makes it possible to populate a variety of habitats, and stenobiontism sharply narrows the range of suitable stations for the species, these two groups are often called respectively euryly or stenotopic.

Human pressure on the environment already exceeds all conceivable limits. But it also grows every year.

7. Biotic factors and their description.

The most important biotic factors include food availability, food competitors and predators.

1. The general pattern of action of biotic factors

An important role in the life of each community is played by the living conditions of organisms. Any element of the environment that has a direct effect on a living organism is called an environmental factor (for example, climatic factors).

Distinguish between abiotic and biotic environmental factors. Abiotic factors include solar radiation, temperature, humidity, light, soil properties, water composition.

Food is considered an important environmental factor for animal populations. The quantity and quality of food affect the fertility of organisms (their growth and development), life expectancy. It has been established that small organisms need more food per unit mass than large ones; warm-blooded - more than organisms with a variable body temperature. For example, titmouse blue tit, with a body weight of 11 g, needs to consume food at a rate of 30% of its weight annually, singing thrush with a mass of 90 g - 10%, and buzzard with a mass of 900 g - only 4.5%.

Biotic factors include various relationships between organisms in the natural community. Distinguish the relationship of individuals of one species and individuals of different species. The relationships of individuals of one species are of great importance for its survival. Many species can breed normally only when they live in a fairly large group. So, cormorant normally lives and breeds, if in its colony there are at least 10 thousand individuals. The principle of minimum population size explains why rare species are difficult to save from extinction. For the survival of African elephants in the herd must be at least 25 individuals, and reindeer - 300-400 goals. Living together facilitates the search for food and the fight against enemies. So, only a pack of wolves can catch large-sized prey, and a herd of horses and bison can successfully defend themselves from predators.

At the same time, an excessive increase in the number of individuals of one species leads to overpopulation of the community, increased competition for territory, food, and leadership in the group.

The study of the relationship of individuals of one species in the community is engaged in population ecology. The main task of population ecology is to study the number of populations, its dynamics, causes and consequences of changes in numbers.

Populations of different species, living together for a long time in a certain territory, form communities, or biocenoses. The community of different populations interacts with environmental environmental factors, together with which it forms a biogeocenosis.

A limiting or limiting environmental factor, i.e., a lack of one or another resource, has a great impact on the existence of individuals of one and different species in a biogeocenosis. For individuals of all species, the limiting factor may be low or high temperature, for the inhabitants of aquatic biogeocenoses - water salinity, oxygen content. For example, the spread of organisms in the desert is limited by high air temperatures. The study of the limiting factors involved in applied ecology.

For human economic activity, it is important to know the limiting factors that lead to a decrease in the productivity of agricultural plants and animals, to the destruction of insect pests. So, scientists have established that the limiting factor for the larvae of the nutcracker is very low or very high soil moisture. Therefore, to combat this pest of agricultural plants, drainage or strong moistening of the soil is carried out, which leads to the death of larvae.

Ecology studies the interaction of organisms, populations, communities among themselves, the impact on them of environmental factors. Autecology studies the relationships of individuals with the environment, and synecology studies the relationships of populations, communities, and habitats. Distinguish between abiotic and biotic environmental factors. For the existence of individuals, populations, limiting factors are important. Greatly developed population and applied ecology. Ecological advances are used to develop conservation measures for species and communities in agricultural practice.

Classification of biotic interactions:

1. Neutralism - no population affects another.

2. Competition is the use of resources (food, water, light, space) by one organism, which thereby reduces the availability of this resource for another organism.

Competition is intraspecific and interspecific.

If the population is small, then intraspecific competition is weak and resources are abundant.

With a high population density, intense intraspecific competition reduces the availability of resources to a level that restrains further growth, thereby regulating the population size. Interspecific competition is the interaction between populations that adversely affects their growth and survival. When the Caroline squirrel was imported from North America to Britain, the number of ordinary squirrel decreased, because

caroline protein was more competitive. Competition is direct and indirect. Direct - this is intraspecific competition associated with the struggle for habitat, in particular the protection of individual sites in birds or animals, expressed in direct collisions.

With a lack of resources, it is possible to eat animals of their own species (wolves, lynxes, predatory bugs, spiders, rats, pike, perch, etc.) Indirect - between shrubs and grass plants in California.

  1. Biosphere: the functions of living matter.

Composition of living matter is the totality of living organisms living in the biosphere. Living matter has biomass, has productivity and has properties that are special compared to inert matter. These properties provide the most important functions of living matter.

1. Energy function. It is determined by the properties of the photosensitive substance chlorophyll of green plants, with the help of which plants capture, accumulate solar energy, and convert it into the energy of chemical bonds of molecules of organic substances. Organic substances created by green plants serve as a source of energy for representatives of other kingdoms of living beings.

2. Transport function. The nutritional interactions of living matter lead to the displacement of huge masses of chemical elements and substances against gravity and in the horizontal direction. This movement is the transport function of living matter.

3. Destructive function.  The mineralization of organic substances, the decomposition of dead organics into simple inorganic compounds, determines the destructive function of living matter. This function is mainly performed by fungi, bacteria.

4. Concentration function  there is an accumulation of certain substances in living things. Shells of mollusks, shells of diatoms, animal skeletons are all examples of the manifestation of the concentration function of living matter.

5. Living matter transforms the physicochemical parameters of the medium. This is another major function of living matter - environmentdeveloping. For example, forests regulate surface runoff, increase air humidity, and enrich the atmosphere with oxygen.

8.2. Biosphere: global biogeochemical circulation of substances, energy flows.

Life has existed for billions of years. Inorganic matter is constantly consumed from the environment. During this time, it could be used up, because the amount of matter on Earth is finite. The final amount of matter in the biosphere acquired the property of infinity through the cycle of matter. The nutrition, respiration and reproduction of organisms and the processes of creation and accumulation of decay of organic matter associated with them provide a constant circulation of matter and energy.

The biogeochemical circulation of substances is a repeating interconnected physical, chemical and biological processes of transformation and movement of matter in nature.

The driving forces of the biogeochemical cycle are the energy flows of the sun and the activity of living matter. As a result of the biogeochemical cycle, huge masses of chemical elements are moved, and the energy accumulated during photosynthesis is concentrated and redistributed.

The biogeochemical cycle in the biosphere is not completely closed, an insignificant part of the substance is “buried”. This led to the accumulation of biogenic oxygen in the atmosphere, and various chemical elements and compounds in the earth's crust.

The whole living world receives the necessary energy from organic substances created by photosynthetic plants or chemosynthetic microorganisms. The main channel of energy transfer is the food chain from the food source of plants, or producers, to consumers and reducers. In this case, the corresponding trophic levels are formed.

With each subsequent transfer from one trophic level to another, most of the energy (up to 90%) is lost in the form of heat. This limits the number of links — the shorter the chain, the greater the amount of energy available.

Thus, life on our planet is carried out as a constant cycle of matter, supported by the flow of solar energy.

The biosphere is closely related to the space environment. Every second, more than 1000 charged particles fly into the area of \u200b\u200b1 m² across the boundary of the Earth’s atmosphere from space in the direction of the Earth’s surface. Cosmic radiation could in a short time decompose all the air in the atmosphere into ions and electrons. Life on Earth would be impossible. However, this does not happen, since the Earth is protected from cosmic rays by a magnetic field. The lines of the earth's magnetic field reflect cosmic rays with low energy, and they, as a rule, cannot penetrate into the lower layers of the atmosphere. Only cosmic rays with very high energy are capable of breaking through the Earth’s magnetic field and reaching the surface of the Earth, regardless of geographic latitude.

In the magnetosphere, charged particles are mainly held by magnetic field lines. When the next portion of particles arrives, some of them “shake” into the atmosphere. This creates electric currents and is the cause of geomagnetic storms.

Another protective shield of the Earth is ozone screen. The ozonosphere (ozone screen) consists of ozone - a blue gas with a pungent odor. Its height is from 10 to 15 km, the maximum is 20-25 km. Ozone is formed in the stratosphere when, under the influence of ultraviolet rays, oxygen molecules decay into free atoms, which can attach to its other molecules. Another reaction is also possible - free oxygen atoms can attach to ozone molecules with the formation of two oxygen molecules. In the stratosphere, ozone absorbs ultraviolet rays of solar radiation, thereby protecting all life. In recent years, the ozone layer has been depleted. The main reason for the depletion is the use of chlorofluorocarbons - freons, which are widely used in production and everyday life as refrigerants, blowing agents, solvents, aerosols. Freons catalyze the decomposition of ozone, upsetting the balance between it and oxygen towards a decrease in ozone concentration.

8.4. Biosphere: biological diversity.

Life as a stable planetary phenomenon is possible only when it is of different quality.

The biological diversity of the biosphere includes the diversity of all types of living creatures that inhabit the biosphere, the diversity of genes that form the gene pool of any population of each species, as well as the diversity of ecosystems of the biosphere in various natural zones.

The amazing diversity of life on Earth is not just the result of the adaptation of each species to specific environmental conditions, but also the most important mechanism for ensuring the stability of the biosphere.

Only a few species in the ecosystem have significant numbers, large biomass and productivity. Such species are called dominant. Rare or small species have low abundance and biomass. As a rule, dominant species are responsible for the main energy flow and are the main environment-forming agents that strongly influence the living conditions of other species. Small species make up a reserve and, if various external conditions change, they can fall into the dominant species or take their place. Rare species mainly create species diversity.

In characterizing diversity, indicators such as species richness andevenness of distribution of individuals.

Species richness is expressed by the ratio of the total number of species to the total number of individuals or to unit area. For example, in two communities, under equal conditions, 100 individuals live. But in the first, these 100 individuals are distributed between ten species, and in the second - between three species. In the given example, the first community has a richer species diversity than the second.

Suppose that in the first and second communities there are 100 individuals and 10 species. But in the first community, individuals between species are distributed by 10 in each, and in the second - one species has 82 individuals, and the rest 2.

As in the first example, the first community will have a more even distribution of individuals than the second.

The conservation of biological diversity is an indispensable condition for the conservation and development of natural ecosystems, the existence of life as a whole.

8.5. Biosphere: mechanisms of sustainability.

The biosphere is an open system that exchanges matter and energy with the environment. This is possible because in the ecosystem there are not only autotrophs - producers of organic matter, but also heterotrophs - consumers and destroyers of organic matter. A relative equilibrium is established between the processes of creating organic matter and its transformation and destruction, and the ecosystem remains stable. Sustainability -this is a property of the ecosystem, which is manifested in the maintenance of its composition, structure and functions, as well as in the ability to recover if they are violated. The stability of the biosphere is determined by:

- the exceptional diversity of living matter;

- the interchangeability of its constituent ecosystems;

- duplication of links of biogeochemical cycles;

- the vital activity of living matter.

Biological diversity provides a wealth of informational, material and energy connections between living and inert matter, as well as the relationship of the biosphere with space, geospheres, and the processes of the global biogeochemical cycle.

The existence of each species depends on many other species, the destruction of one of the species may lead to the disappearance of other species associated with it. Individuals of one species and their metabolic products, as well as their dead bodies, are food for other species, which ensures self-cleaning of ecosystems.

The socio-economic development of society has come and a clear contradiction with the limited resource-reproducing and life-supporting capabilities of the biosphere. The depletion of the natural resources of land and the ocean, the irretrievable loss of plant and animal species, environmental pollution, the simplification and degradation of ecosystems. Therefore, humanity is looking for ways of sustainable development of society and nature.

8.6. Biosphere: the danger of depleting the biological diversity of species and ecosystems

Biological diversity - genetic, species, ecosystem - is the root cause of the sustainability of both the biosphere as a whole and each individual ecosystem. Life as a stable planetary phenomenon is possible only when it is represented by diverse species and ecosystems.

But in modern conditions, the scale of human economic activity has grown so much that there is a danger of loss of biological diversity. Different types of human activity lead to the direct or indirect destruction of various species and ecosystems of the biosphere.

There are several main types of environmental degradation that are currently the most dangerous for biological diversity. For example, flooding or siltation of productive lands, their concreting, asphalting or building deprive wild animals of their habitats. Irrigated land cultivation reduces yields due to erosion and depletion of soil fertility. Abundant field irrigation can lead to salinization, i.e., to an increase in the concentration of salts in the soil to a level not tolerated by plants. As a result, typical plants of these places disappear. Deforestation in large areas in the absence of reforestation leads to the destruction of habitats of wild animals, change of vegetation, and reduction of its diversity. Many species disappear due to their extermination, as well as due to environmental pollution. Most species disappear due to the destruction of natural habitats, the destruction of natural ecosystems. This is one of the main reasons for the depletion of biological diversity.

Under the biological diversity of the biosphere, we understand the diversity of all types of living organisms that make up the biosphere, as well as the whole variety of genes that form the gene pool of any population of each species, as well as the diversity of ecosystems of the biosphere in various natural zones. Unfortunately, at present, all kinds of human activities lead to a decrease in biological diversity. The biosphere is losing biodiversity. This is one of the environmental dangers.

Humanity still does not know much about biological diversity, for example, there is still no exact data on the number of species in the biosphere. Specialists still cannot always determine which territories require special protection measures and the organization of nature reserves on them. A huge number of poorly studied species, for example in tropical forests.

To preserve biodiversity, it is necessary to invest in its study; improve environmental management, trying to make it rational; solve global environmental problems at the international level.

UNESCO adopted the World Heritage Convention, which combines natural and cultural monuments. The Convention calls for the care of objects that are of value to all of humanity. The conservation of biodiversity depends on the leaders of countries, and on the behavior of each inhabitant of the planet.

9 Sustainability of the environment (ecosystems) in Russia.

Sustainability is one of the most important parameters of any systems, including environmental ones. It determines the ability of the system to maintain itself when environmental changes. In the context of this definition, sustainability can be considered synonymous with the term vitality. The theoretical foundations of a qualitative and semi-quantitative assessment of the stability of complex systems are described in the Web atlas “Russia as a system”. In the most general form, this work shows that the viability of systems is determined by three groups of its parameters - volume (mass of the substance of the system), productivity (speed of self-reproduction of the substance of the system) and structural harmony. As applied to ecological systems, the quantitative measurement of the first two groups of parameters is well established by classical biogeography. Methods for calculating the structural harmony of ecosystems (the third component) were developed by us and are presented in the “Atlas of biological diversity of European Russia and adjacent territories” (M., PAIMS, 1996).

The level of potential sustainability of indigenous ecosystems of Russia, that is, the level of sustainability of ecosystems before they are transformed by humans, is shown on the following map

The maximum stability falls on the forest-steppe of European Russia, the Cis-Urals and the middle taiga of Siberia, and the stability of systems decreases to the north and south. The minimum in Russia is observed in the Arctic deserts. Since only the very edge of the Turanian deserts enters Russia, their level of stability is still quite high.

The European forest-steppe - a combination of oak forests and meadow steppes - is undoubtedly the optimal zone of life within Russia. As for Siberia, the retreat here of maximum stability to the north, of course, is associated with the general ecological youth of the local forest-steppe. Recall that while in the European forest-steppe the main forest-forming species is oak - the climacteric species - the final stage of ecological succession, then in Siberia it is replaced by birch - the pioneer species, the first settling in non-forest areas.

The high stability potential of indigenous ecosystems in the most general form determines the ability of the natural environment to return to its original state in cases of both natural (e.g., climatic) and anthropogenic impacts. In this capacity, it is the sustainability of ecosystems that sets the width of the “corridor of opportunities” for the economic development of human civilization, all forms of which are capable of changing nature. Even having lost a significant part of its area, indigenous ecosystems of stable types continue to ensure the invariability of the regime of natural cycles, biomass production, and utilization of substances harmful to living organisms. This feature is associated with the original role of soils — reservoirs of the “memory” of an ecosystem — preserving many of the initial qualities of ecosystems even after anthropogenic transformation of the territory. Such capabilities of sustainable ecosystems are well illustrated by the map of disturbance of natural ecosystems.

The map shows that the potential sustainability of Russia's ecosystems is almost everywhere reduced to some extent due to the replacement of indigenous ecosystem types, less stable anthropogenic derivatives (agrocenoses or secondary forests) or complete destruction during development and urbanization. Moreover, the maximum impact area is characteristic precisely for areas with the most stable natural complexes. In Russia they say: - “Those who are lucky will be brought down on him.” Stable ecosystems of the southern taiga and forest-steppe of Russia retained the possibility of a fairly autonomous, without external support, development of industrial civilization of the past century and a half despite the maximum loss of natural complexes.

The steppes of the European part of Russia were secondarily (after casting during a period of serious threat from the steppe nomads in the 13th – 17th centuries) mastered in the 18th – 19th centuries, that is, against the backdrop of a fairly highly developed agriculture. On the other hand, having the highest and most stable productivity, these steppes during the socialist period experienced the most severe consequences of the pursuit of the growth of arable wedges, “the struggle against the grass field system”, etc. At the same time, the ecosystem’s sustainability reserve provided economic development opportunities with radical modernization and an increase in the human energy capacity. It is characteristic that regions with a high stability of natural conditions correlate to a large extent with areas of high stability (viability) of society. On the contrary, in the more southern steppes and semi-deserts (Caspian littoral) and in the north - in the tundra, natural conditions, due to biota's own instability, significantly limit human arbitrariness in choosing options and the intensity of economic activity. Accordingly, the socium of these regions is much less stable. It is with this that the preferential preservation of traditional forms of environmental management in dry steppes, semi-deserts, tundra and northern taiga is associated. Industrial civilization is usually present here in the form of enclaves, the existence of which is possible only with constant support (resources, people, energy) from more stable areas. These enclaves look like a foreign body within a region and most destructively affect its nature.

Despite the high level of sustainability of the ecosystems of the southern taiga and forest-steppe of European Russia, the threat of loss of natural balance and unpredictable destruction of all forms of management (especially agriculture) of these areas were recognized back in the Stalin period. At the end of the 40s. The plan for the massive creation of forest belts and artificial reservoirs was adopted. The implementation of the plan was to significantly increase the stability of ecosystems in the steppes of southern Russia. Unfortunately, the plan was not fully implemented. But even in its realized part, it did not completely achieve the desired results, since part of the forest belts was planted by the “nesting method” of TD Lysenko and died almost immediately, sufficient funds were not allocated from the very beginning for the creation of ponds, and for the most part were broken by the first high flood. As the plan was forgotten, and the shortage of bread in the country increased, massive reduction of forest belts began - large tractors are more convenient to handle large tracts of forest and forest belts.

The last map shows an indicator reflecting the current level of ecosystem sustainability, taking into account both the loss of area of \u200b\u200bindigenous natural complexes and the decrease in the viability of anthropogenic ecosystems (agrocenoses, secondary forests, etc.). The map shows that in the regions with the most favorable (comfortable) living conditions of a person and economic development, the possibilities of development due to the resources of the natural environment are practically exhausted. This cannot but cause serious concerns - the main region is the donor population of the country and one of the three main centers of stability of its society is in the zone of maximum decrease in the sustainability of ecosystems. A decrease in stability increases its vulnerability to anthropogenic transformation, which is extremely dangerous for maintaining the health of not only the population of the Black Earth Region, but also Russia as a whole.

In this regard, of the three main centers of increased vitality of society, the North Caucasus is in the most favorable position. Since in Russia it is the most archaic (with an ethnic level of social memory) center, its ties with the environment are most close. Perhaps it is precisely the higher preservation of the sustainability of its ecosystems that contributes to the success of its struggle with the actual Russian centers.

Conclusion

For an ecosystem consisting of many species of different evolutionary levels, the influence of the whole complex of biotic factors always represents a complex system of interactions, in which, for example, the microclimate on the soil surface largely depends on the species composition and degree of development of the upper layers of vegetation, burrowing animals change conditions of aeration and drainage of the soil and affect the conditions of existence of vegetation.

A complete account of all the interactions of abiotic and biotic factors in natural ecosystems is almost impossible, therefore, in real conditions, one has to confine oneself to analysis of only the most important factors that determine not specific features, but only the type of ecosystem.

This allows us to determine more or less reliably only the direction of changes in the ecosystem as its possible reaction to certain changes in abiotic conditions, in particular, caused by human activity. The specific course of such changes should always be monitored in real time by a monitoring system of the natural environment - regular monitoring of ecosystem parameters.

The main task of creating this work was to familiarize ourselves with the concept of ecosystems in ecology, the factors influencing them and the problems of their relationship with humans. Having done this work, I tried to convey the importance and relevance of the problems associated with ecosystems, gave examples and solutions to these problems. The basic laws of ecology have also been described, examining in detail the factors affecting the human environment. The relevance of my work is clear! Each person needs to know the basic laws, processes, features, occurring and characteristic of ecosystems, and ecology as a whole. All this is necessary to know in order to try to minimize the negative impact of human activity on the surrounding nature, since there will be no nature, there will be no life on earth ....

List of references

1. Environmental Chemistry / Ed. J.O.M. Bokris-M: Chemistry 1982;
2. Shustov S. B., Shustova L.V. Chemical fundamentals of ecology. M: Education, 1995;
3. Ecology. Tutorial. M: Knowledge 1997
4. Gorelov A.A. Ecology: a training manual. - M .: Center. 1999.
5. Gulyaev S.A., Zhukovsky V.M., Komov S.V. Fundamentals of natural science. / Tutorial. - Yekaterinburg .: UralEcoCenter, 2001 .-- 560 p.
6. Moiseev N.N. Man and the biosphere. - M .: Young Guard, 1995 .-- 302 p.
7. Nikolaykin N.N., Nokolaykina N.E., Melekhova O.P. Ecology. - M.: Bustard, 2004.
8. Petrov V.V. Environmental Law of Russia. - M .: Publishing house BEK. 1995.

9. www.postupim.ru/9/himiya/853.shtml

10. www.krugosvet.ru

11. www.naveki.ru

Annex 1

Appendix 2

The effect of the temperature factor on living organisms

Transparency 1

I. The Sun is the most important source of energy and life on Earth, the condition of the photosynthesis process and the main factor in the cycle of substances in nature, therefore the image of the Sun is placed on the circuits of the cycles or mentally suggest its participation in various processes.

II. Carbon dioxide in the atmosphere and hydrosphere of the Earth. Directional arrows in the opposite direction represent a dynamic equilibrium that determines the carbon dioxide content in the atmosphere and the World Ocean. The state of this equilibrium is influenced not only by biochemical processes, but also by the production activity of people, volcanic eruptions.

III. Oxygen in the atmosphere and hydrosphere of the Earth.

The picture is similar to the previous one.

When considering individual cycles, one should restrict oneself to only one component of the atmosphere, for example, nitrogen, or consider the atmosphere as nothing more (transparencies 14, 15, 16).

(In contrast to the above study guide, where only the atmosphere and hydrosphere are presented, the lithosphere (“inanimate nature”), covering the coast and bottom of the ocean, is also marked in separate cycles represented on transparencies.)

Transparency 2.

IV. Eruption.

V. Lightning against the sky.

VI. Factory with smoking chimneys.

Transparency 3.

VII. Rocks, lithosphere.

Viii. Carbonate deposits.

IX. Plant and animal remains.

X. Fossil fuel deposits.

Transparency 4.

Xi. The soil.

XII. Microorganisms (putrefactive, nitrifying, denitrifying bacteria, azotobacter, sulfur bacteria, etc.); When discussing transparencies, invite students to decipher which image relates to a given microorganism.

Xiii. Mineral fertilizers

Xiv. Deposits of phosphate fertilizers (phosphorites, apatites).

Transparency 5.

Xv. Land plants.

XVI Algae.

Xvii. Land animals.

Xviii. Aquatic animals are fish.

Images placed on transparencies 1–5 are used to draw up diagrams of various cycles. Slides 1, 2 reflect global natural phenomena occurring on Earth, human production activities commensurate in scale with biogeochemical processes occurring in all shells of the earth's crust: litho, hydro and atmosphere. Slides 3, 4, 5 are somehow connected with biogeochemical processes taking place on the Earth’s surface. The content of each of the transparencies can be used as a topic for lively conversation or student speech. At the same time, students use knowledge from the courses of natural history, biology, geography, and physics; in this way intersubject communications are strengthened.

The series emphasizes the complexity and inconsistency of biogeochemical processes. They include the processes of creation (photosynthesis and chemosynthesis) and destruction (decay and decay of organic substances). The role of various microorganisms, without which life on our planet is unthinkable, is especially noted.

Already with such a general consideration of the issue, grandiose contours of the processes of creation and destruction, proceeding in the form of cycles of substances and the accompanying energy processes, emerge. Then the cycles are concretized by the example of individual chemical elements (first, the examples should be simple, include a small number of components). Gradually, the cycles become more complicated, a larger number of components participate in them, and the number of connections between them increases.

The circuits of circuits are given as examples in slides 6–20 (the recommendations available in the training manual “The Cycle of Some Substances in Nature” should be used in this case as well: an approximate procedure for constructing circuits, identifying the main one by selecting components and establishing relationships between them using different arrows - in direction, color, thickness, etc.).

In the above diagrams, the possibilities of using the previously mentioned 18 components are far from exhausted. Here, the creativity of students, their curiosity, the spirit of competition in achieving the best results can fully manifest themselves. Other chemical elements of biological importance, such as manganese, iron, zinc, may be involved in the field of view of students. All this will stimulate the cognitive activity of students, contribute to an expanded and in-depth study of chemistry, the creative application of knowledge to solve feasible cognitive tasks. The slide shows cycling schemes of varying degrees of complexity, which will allow you to use an individual approach to students, to a certain extent, to differentiate learning. For each of the following transparency, you can organize a conversation, a story that will contribute to the development of thinking, oral speech of students.

Transparency 6.

Only the most general connections between inanimate nature (VII - rocks) and wildlife (XV - plants, XVII - animals) are shown. The main and secondary connections are indicated by different arrows.

Transparency 7.

The previous scheme is supplemented by a new component - soil (XI).

Transparency 8.

Another complication is introduced into the circulation scheme - microorganisms (XII), which play a significant role in soil formation.

Transparency 9.

Microorganisms primarily convert organic residues into inorganic substances digestible by plants. They also carry out the synthesis of organic substances.

Transparencies 10, 11

They show the relationship between plants and land animals and the relationship between aquatic animals and plants.

Transparency 12.

New components (IX, XI, XII, VII, IV, IV) are included in the cycle scheme with the participation of terrestrial plants and animals. A similar scheme for aquatic plants and animals can be offered to students to build on their own.

Transparency 13.

Fuel combustion and limestone burning increase the carbon dioxide content in the atmosphere (hydrosphere); at the same time, the oxygen content in the air decreases.

Transparency 14.

The diagram, in particular, shows that the movement of carbon dioxide and oxygen in plants and animal organisms occurs in opposite directions.

Transparency 15.

The diagram shows two opposing processes: the binding of atmospheric nitrogen and the conversion of bound nitrogen to atmospheric nitrogen. Under natural conditions, these processes are balanced.

Transparency 16.

The natural nitrogen cycle is greatly influenced by the fact that more nitrogen is bound to the crop from the soil than its supply is replenished.

Question for students: What conclusion follows from this?

Transparency 17.

Unlike nitrogen, phosphorus compounds in the soil are not replenished, and they must be applied in the form of fertilizers.

Transparency 18.

The arrows indicate the migration routes of sulfur, with the beginning being the assimilation of the sulfate ion by plants and the inclusion of sulfur in the composition of organic substances. Students can follow the migration of sulfur on their own. Point out to students how sulfur compounds get into the atmosphere and the resulting environmental pollution.

Transparency 19.

Students will be able to independently understand the presented scheme, taking into account that potassium ions enter the plants with the soil solution.

Transparency 20.

Calcium ions, like potassium ions, come from soil solution to plants, and from them to animals. Further migration of these elements goes in different ways, which is due to the unequal solubility of their salts in water. Calcium accumulates in bones, shells, chalk, gypsum, phosphorite, apatite, etc. While calcium carbonate is practically insoluble in water, calcium bicarbonate dissolves well in water. This mutual conversion of carbonate to bicarbonate (and vice versa) is the reason for the high mobility of calcium in nature. A significant role in this process is assigned to carbon dioxide. But this is only one of the options for the calcium cycle. The calcium cycle in the hydrosphere is different. Invite students to follow this process on their own.

When covering the issue of the cycle of chemical elements, it is important to note that various chemical reactions constantly occur in nature. Some of these reactions take place without the participation of living beings, and some with their direct participation, that is, in living nature. As a result of chemical processes, atoms move, move. As a result of this, there is an exchange of substances and energy between all the shells of the Earth: lithosphere, atmosphere, hydrosphere, biosphere. The cycle of chemical elements is the reason for the constant flow of chemical reactions. We can say that due to the cycle of chemical elements life on Earth is possible.

The cycle of substances is the repeating processes of transformation and movement of substances in nature, having a more or less cyclical nature. The cycles of carbon and oxygen play a particularly important role for life on Earth.

Further, you can consider, for example, the oxygen cycle. A simple substance, oxygen is contained in the atmosphere, and as a chemical element, it is part of many natural compounds. The bulk of oxygen is contained in the earth's crust, where it is associated with silicon, aluminum, iron, forming rocks and minerals: oxides (SiO2, A12O3,

Fe2O3); carbonates (CaCO3, MgCO3, FeCO3); sulfates (CaSO4, alum), etc.

Minerals and rocks in the course of centuries-old weathering can appear on the surface, where they will receive a supply of energy coming from the Sun. Energy is spent on the reconstruction of rock crystals containing oxygen, and will remain there as the internal energy of the resulting crystalline compounds. These rocks will change their structure over time, collapse, dissolve, recrystallize, enter into chemical reactions, etc., absorbing and releasing energy. Thus, oxygen in the earth's crust plays a large role in the exchange of energy between the layers of the lithosphere.

In nature, there are many reactions during which oxygen is consumed (respiration, combustion, slow oxidation, etc.), and only one reaction, as a result of which oxygen is released. This photosynthesis is a process that occurs in the light in the leaves of plants:

Most of the oxygen (3/4) is secreted by land plants, and 1/4 is formed during the life of plants of the oceans.

Molecular oxygen is also present in the hydrosphere. A very large volume of oxygen is always dissolved in natural waters.

The equation for the photosynthesis reaction is not required to be written.

The oxygen cycle connects the atmosphere with the hydrosphere and lithosphere.

Briefly, the main links of the oxygen cycle can be described as follows: photosynthesis (O2 evolution) - oxidation of elements on the Earth's surface - the influx of compounds into the deep zones of the earth's crust - partial restoration of compounds in the Earth's interior with the formation of CO2 and H2O - the removal of CO2 and H2O into the atmosphere and hydrosphere - photosynthesis.

It is easy to see that carbon-containing compounds are involved in many processes. Of these, the most famous are oil, coal, peat, natural gas, and carbonates. Chemical processes also occur with them in nature:

From the above equations it is seen that the conversions of carbon and oxygen are closely related, which indicates the unity of the cycles of various chemical elements in nature.

The role of living beings, in particular humans, in the cycle of chemical elements is increasing. For example, due to human activities, the release of many substances into the atmosphere, hydrosphere and soil increases. The emission of carbon monoxide (IV) into automobiles, thermal power plants, factories and factories and active deforestation creates the danger of an increase in the content of this oxide in the atmosphere, which can lead to a greenhouse effect and climate change on the planet.

When answering this question, it is important to use the circuit diagrams of various elements available in the chemical room.

When covering the issue of the cycle of chemical elements, it is important to note that various chemical reactions constantly occur in nature. Some of these reactions take place without the participation of living beings, and some with their direct participation, that is, in living nature. As a result of chemical processes, atoms move, move. As a result of this, there is an exchange of substances and energy between all the shells of the Earth: lithosphere, atmosphere, hydrosphere, biosphere. The cycle of chemical elements is the reason for the constant flow of chemical reactions. We can say that due to the cycle of chemical elements life on Earth is possible.

The cycle of substances is the repeating processes of transformation and movement of substances in nature, having a more or less cyclical nature. The cycles of carbon and oxygen play a particularly important role for life on Earth.

Further, you can consider, for example, the oxygen cycle. A simple substance, oxygen is contained in the atmosphere, and as a chemical element, it is part of many natural compounds. The bulk of oxygen is contained in the earth's crust, where it is associated with silicon, aluminum, iron, forming rocks and minerals: oxides (SiO2, A12O3,

Fe2O3); carbonates (CaCO3, MgCO3, FeCO3); sulfates (CaSO4, alum), etc.

Minerals and rocks in the course of centuries-old weathering can appear on the surface, where they will receive a supply of energy coming from the Sun. Energy is spent on the reconstruction of rock crystals containing oxygen, and will remain there as the internal energy of the resulting crystalline compounds. These rocks will change their structure over time, collapse, dissolve, recrystallize, enter into chemical reactions, etc., absorbing and releasing energy. Thus, oxygen in the earth's crust plays a large role in the exchange of energy between the layers of the lithosphere.

In nature, there are many reactions during which oxygen is consumed (respiration, combustion, slow oxidation, etc.), and only one reaction, as a result of which oxygen is released. This photosynthesis is a process that occurs in the light in the leaves of plants:

Most of the oxygen (3/4) is secreted by land plants, and 1/4 is formed during the life of plants of the oceans.

Molecular oxygen is also present in the hydrosphere. A very large volume of oxygen is always dissolved in natural waters.

The equation for the photosynthesis reaction is not required to be written.

The oxygen cycle connects the atmosphere with the hydrosphere and lithosphere.

Briefly, the main links of the oxygen cycle can be described as follows: photosynthesis (O2 evolution) - oxidation of elements on the Earth's surface - the influx of compounds into the deep zones of the earth's crust - partial restoration of compounds in the Earth's interior with the formation of CO2 and H2O - the removal of CO2 and H2O into the atmosphere and hydrosphere - photosynthesis.

It is easy to see that carbon-containing compounds are involved in many processes. Of these, the most famous are oil, coal, peat, natural gas, and carbonates. Chemical processes also occur with them in nature:

From the above equations it is seen that the conversions of carbon and oxygen are closely related, which indicates the unity of the cycles of various chemical elements in nature.

The role of living beings, in particular humans, in the cycle of chemical elements is increasing. For example, due to human activities, the release of many substances into the atmosphere, hydrosphere and soil increases. The emission of carbon monoxide (IV) into automobiles, thermal power plants, factories and factories and active deforestation creates the danger of an increase in the content of this oxide in the atmosphere, which can lead to a greenhouse effect and climate change on the planet.

When answering this question, it is important to use the circuit diagrams of various elements available in the chemical room.

Between the lithosphere, hydrosphere, atmosphere and living organisms of the Earth, an exchange of chemical elements constantly occurs. This process has a cyclical nature: moving from one sphere to another, the elements again return to their original state. The cycle of elements took place throughout the entire history of the Earth, numbering 4.5 billion years.

Giant masses of chemicals are carried by the waters of the oceans. This primarily relates to dissolved gases - carbon dioxide, oxygen, nitrogen. Cold water at high latitudes dissolves atmospheric gases. When entering the tropical zone with ocean currents, it releases them, since the solubility of gases decreases upon heating. The absorption and evolution of gases also occurs when warm and cold seasons change.

The appearance of life on the planet had a huge impact on the natural cycles of some elements. This primarily refers to the cycle of the main elements of organic matter - carbon, hydrogen and oxygen, as well as such vital elements as nitrogen, sulfur and phosphorus. Living organisms also affect the cycle of many metal elements. Despite the fact that the total mass of living organisms of the Earth is millions of times less than the mass of the earth's crust, plants and animals play a crucial role in the movement of chemical elements.

Human activity also affects the cycle of elements. It has become especially noticeable in the last century. When considering the chemical aspects of global changes in the cycles of chemical elements, one should take into account not only changes in natural cycles due to the addition or removal of chemicals present in them as a result of normal cyclic or human-induced effects, but also the release of chemicals into the environment that did not previously exist in nature. Consider one of the most important examples of cyclic movement and migration of chemical elements.

Carbon - the main element of life - is contained in the atmosphere in the form of carbon dioxide. In the ocean and fresh waters of the Earth, carbon is in two main forms: in the composition of organic matter and in the composition of interconnected inorganic particles: bicarbonate ion -, carbonate ion and dissolved carbon dioxide. A large amount of carbon is concentrated in the form of organic compounds in animals and plants. A lot of "non-living" organic matter is present in the soil. The lithosphere carbon is also found in carbonate minerals (limestone, dolomite, chalk, marble). Part of the carbon is part of oil, coal and natural gas.

A connecting link in the natural carbon cycle is carbon dioxide (Fig. 1).

A simplified diagram of the global carbon cycle. The numbers in the framework reflect the size of the tanks in billions of tons - gigatons (Gt). The arrows show the flows, and the numbers associated with them are expressed in GT / year.

The largest carbon reservoirs are marine deposits and sediment on land. However, most of this substance does not interact with the atmosphere, but undergoes a cycle through the solid part of the Earth at geological time scales. Therefore, these reservoirs play only a minor role in the relatively fast carbon cycle that takes place with the participation of the atmosphere. The next largest reservoir is seawater. But here, the deepest part of the oceans, where the bulk of carbon is contained, does not interact with the atmosphere as quickly as their surface. The smallest reservoirs are the land biosphere and atmosphere. It is the small size of the last tank that makes it sensitive to even minor changes in the percentage of carbon in other (large) tanks, for example, when burning fossil fuels.

The modern global carbon cycle consists of two smaller cycles. The first of these consists in the binding of carbon dioxide during photosynthesis and its new formation during the life of plants and animals, as well as in the decomposition of organic residues. The second cycle is due to the interaction of atmospheric carbon dioxide and natural waters:

In the last century, human activity has made significant changes to the carbon cycle. The burning of fossil fuels — coal, oil, and gas — has led to an increase in carbon dioxide emissions. This does not greatly affect the distribution of carbon masses between the Earth’s shells, but can have serious consequences due to an increase in the greenhouse effect.