What are the inhabitants of the soil called? Who lives in the soil

T.V. Lukarevskaya

When we enter the forest on a summer day, we immediately notice fluttering butterflies, singing birds, jumping frogs, we rejoice at a running hedgehog, a meeting with a hare. One gets the impression that it is these well-marked animals that form the basis of our fauna. In fact, the animals that are easy to see in the forest are only an insignificant part of it.

Soil animals form the basis of the population of our forests, meadows, and fields. The soil, at first glance so lifeless and unsightly, turns out to be literally crammed with life upon closer examination. If you look closely, unusual pictures will open.

Some of the inhabitants of the soil are easy to see. It - earthworms, centipedes, insect larvae, small mites, wingless insects. Others can be seen with a microscope. In the thinnest films of water that envelop soil particles, rotifers, flagellates scurry about, amoebas crawl, roundworms writhe. How many real workers are here, indistinguishable to the naked eye, but doing, nevertheless, a titanic work! All these inconspicuous creatures keep clean our common home - the Earth. Moreover, they also warn of the danger that threatens this house when people behave unwisely in relation to nature.

In the soil of central Russia, per 1 m2, you can find up to 1 thousand species that differ greatly in number soil inhabitants: up to 1 million ticks and springtails, hundreds of centipedes, insect larvae, earthworms, about 50 million roundworms, the number of protozoa is even difficult to estimate.

This whole world, living by its own laws, ensures the processing of the dead plant residues, cleaning soils from them, maintaining a water-resistant structure. Soil animals constantly plow the soil, moving up particles from the lower layers.

In all terrestrial ecosystems, the vast majority of invertebrates (both in terms of the number of species and the number of individuals) are soil dwellers or are closely associated with the soil during a certain period of their life. life cycle. Boucle (1923) calculated that the number of insect species associated with the soil is 95–98%.

Centipede

earthworm

In terms of the ability to adapt to living conditions, there are no equal nematodes among animals. In this respect, they can only be compared with bacteria and the simplest unicellular organisms. Such universal adaptability is largely due to the development of a dense outer cuticle in nematodes, which increases their vitality. In addition, the shape of the body and the nature of the movements of nematodes turned out to be suitable for life in various environments.

Nematodes take part in the mechanical destruction of plant tissues: they “burrow” into dead tissues and, with the help of secreted enzymes, destroy cell walls, opening up pathways for bacteria and fungi to penetrate.

In our country, yield losses of vegetables, cereals and industrial crops due to damage by roundworms sometimes reach 70%.

Nematode

The formation of tumors - galls - on the roots of the host plant is caused by another pest - the southern root-knot nematode (Meloidogyne incognita). It brings the greatest harm to vegetable growing in southern regions where it occurs in open field. In the north, it occurs only in greenhouses, mainly damaging cucumbers and tomatoes. The main harm is caused by females, while males, having completed development, go into the soil and do not feed.

Soil nematodes are notorious: they are seen primarily as pests of cultivated plants. Nematodes destroy the roots of potatoes, onions, rice, cotton, sugar cane, sugar beet, ornamental and other plants. Zoologists are developing measures to combat them in the fields and in greenhouses. A great contribution to the study of this group of animals was made by the famous evolutionary biologist A.A. Paramonov.

Nematodes have long attracted the attention of evolutionists. They are not only extremely versatile, but also amazingly resistant to physical and chemical influences. Wherever they begin to study these worms, new species unknown to science are found everywhere. In this regard, nematodes seriously claim the second - after insects - place in the animal world: experts believe that there are at least 500 thousand species of them, but there is reason to believe that the true number of nematode species is much higher.

All around us: on the ground, in the grass, on the trees, in the air - life is in full swing everywhere. Even a resident of a big city who has never delved into the forest often sees around him birds, dragonflies, butterflies, flies, spiders and many other animals. Well known to all and the inhabitants of the reservoirs. Everyone, at least occasionally, had to see schools of fish near the shore, water beetles or snails.
But there is a world hidden from us, inaccessible to direct observation, a peculiar world of soil animals.
There is eternal darkness, you cannot penetrate there without destroying the natural structure of the soil. And only a few, accidentally noticed signs show that under the surface of the soil among the roots of plants there is a rich and diverse world of animals. This is sometimes evidenced by mounds above mole burrows, holes in gopher burrows in the steppe or burrows of sand martins in a cliff above a river, heaps of earth on a path thrown out by earthworms, and they themselves, crawling out after rain, as well as masses suddenly appearing literally from under the ground. winged ants or fat larvae of May beetles that come across when digging up the earth.
Soil is usually called the surface layer earth's crust on land, formed during the weathering of the parent rock under the influence of water, wind, temperature fluctuations and the activities of plants, animals and humans. The most important property of the soil, which distinguishes it from the barren parent rock, is fertility, that is, the ability to produce a crop of plants.

As a habitat for animals, soil is very different from water and air. Try to wave your hand in the air - you will not notice almost any resistance. Do the same in water - you will feel a significant resistance of the environment. And if you lower your hand into the hole and cover it with earth, then it will be difficult to pull it back out. It is clear that animals can move relatively quickly in the soil only in natural voids, cracks, or previously dug passages. If there is nothing of this on the way, then the animal can advance only by breaking through the passage and raking the earth back or by swallowing the earth and passing it through the intestines. The speed of movement in this case, of course, will be insignificant.
Every animal needs to breathe in order to live. Conditions for respiration in soil are different than in water or air. Soil is composed of solid particles, water and air. Solid particles in the form of small lumps occupy a little more than half of its volume; the rest is accounted for by gaps - pores that can be filled with air (in dry soil) or water (in soil saturated with moisture). As a rule, water covers all soil particles with a thin film; the rest of the space between them is occupied by air saturated with water vapor.
Due to this structure of the soil, numerous animals live in it and breathe through the skin. If they are taken out of the ground, they quickly die from drying out. Moreover, hundreds of species of real freshwater animals inhabiting rivers, ponds and swamps live in the soil. True, these are all microscopic creatures - lower worms and unicellular protozoa. They move, float in a film of water covering soil particles. If the soil dries out, these animals secrete protective shell and how they fall asleep.

Soil air receives oxygen from the atmosphere: its amount in the soil is 1-2% less than in atmospheric air. Oxygen is consumed in the soil by animals, microorganisms, and plant roots. They all emit carbon dioxide. In the soil air it is 10-15 times more than in the atmosphere. Free gas exchange of soil and atmospheric air occurs only if the pores between the solid particles are not completely filled with water. After heavy rains or in the spring, after the snow melts, the soil is saturated with water. There is not enough air in the soil, and under the threat of death, many animals leave it. This explains the appearance earthworms on the surface after heavy rains.
Among soil animals there are both predators and those that feed on parts of living plants, mainly roots. There are also consumers of decaying plant and animal remains in the soil - perhaps bacteria also play a significant role in their nutrition.
Soil animals find their food either in the soil itself or on its surface.
The vital activity of many of them is very useful. The activity of earthworms is especially useful. They drag a huge amount of plant debris into their burrows, which contributes to the formation of humus and returns to the soil substances extracted from it by plant roots.
In forest soils, invertebrates, especially earthworms, recycle more than half of all leaf litter. For a year, on each hectare, they throw up to 25-30 tons of earth processed by them, turned into a good, structural soil, to the surface. If you distribute this land evenly over the entire surface of a hectare, you get a layer of 0.5-0.8 cm. Therefore, earthworms are not in vain considered the most important soil formers. Not only earthworms “work” in the soil, but also their closest relatives - smaller whitish annelids (enchytreids, or potworms), as well as some types of microscopic roundworms (nematodes), small mites, various insects, especially their larvae, and finally woodlice, centipedes and even snails.

Medvedka

The purely mechanical work of many animals living in it also affects the soil. They make passages, mix and loosen the soil, dig holes. All this increases the number of voids in the soil and facilitates the penetration of air and water into its depth.
Such “work” involves not only relatively small invertebrates, but also many mammals - moles, shrews, marmots, ground squirrels, jerboas, field and forest mice, hamsters, voles, mole rats. Relatively large passages of some of these animals go deep from 1 to 4 m.
The passages of large earthworms go even deeper: in most of them they reach 1.5-2 m, and in one southern worm even 8 m. These passages, especially in denser soils, are constantly used by plant roots penetrating into the depths. In some places, for example in steppe zone, a large number of moves and holes are dug in the soil by dung beetles, bears, crickets, tarantula spiders, ants, and termites in the tropics.
Many soil animals feed on roots, tubers, and bulbs of plants. Those that attack cultivated plants or forest plantations, are considered pests, such as the cockchafer. Its larva lives in the soil for about four years and pupates there. In the first year of life, she feeds mainly on roots. herbaceous plants. But, growing up, the larva begins to feed on the roots of trees, especially young pines, and brings great harm to the forest or forest plantations.

The paws of the mole are well adapted to life in the soil.

Larvae of click beetles, dark beetles, weevils, pollen eaters, caterpillars of some butterflies, such as nibbling scoops, larvae of many flies, cicadas, and, finally, root aphids, such as phylloxera, also feed on the roots of various plants, severely damaging them.
A large number of insects that damage the aerial parts of plants - stems, leaves, flowers, fruits, lay eggs in the soil; here, the larvae hatched from the eggs hide during the drought, hibernate, and pupate. Soil pests include some types of mites and centipedes, naked slugs and extremely numerous microscopic roundworms - nematodes. Nematodes penetrate from the soil into the roots of plants and disrupt their normal life. Many predators live in the soil. "Peaceful" moles and shrews eat a huge amount of earthworms, snails and insect larvae, they even attack frogs, lizards and mice. These animals eat almost continuously. For example, a shrew eats an amount of living creatures equal to its own weight per day!
There are predators among almost all groups of invertebrates living in the soil. Large ciliates feed not only on bacteria, but also on simple animals, such as flagellates. The ciliates themselves serve as prey for some roundworms. Predatory mites attack other mites and tiny insects. Thin, long, pale-colored geophile centipedes, living in cracks in the soil, as well as larger dark-colored drupes and centipedes, keeping under stones, in stumps, are also predators. They feed on insects and their larvae, worms and other small animals. The predators include spiders and haymakers close to them (“mow-mow-leg”). Many of them live on the surface of the soil, in bedding or under objects lying on the ground.

Antlion larva.

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Soil dwellers

Any garden, even the smallest, is not only trees, shrubs, creepers, flowers and herbs that we have planted or sown. Whether we like it or not, other tenants will certainly appear in it, settling, as they say, without permission, and guests, very numerous, dropping in for just a few minutes or staying for a long time. In addition, even before the bookmark, it already had its own world, which had developed a long time ago. Crawling, jumping, flying, in a word, living his intense, difficult life, he is extremely rich and diverse. Let's get to know him a little better. And let's start our acquaintance with the inhabitants of the soil.

Soil: breathable and silent.

The soil is not just earth, a mechanical mass, a mixture of small and large particles, mineral and organic, as it is sometimes imagined, no, it is all inhabited, mastered by various organisms that live and develop. Roots of trees, bushes, flowers, herbs penetrate it in all directions and to a considerable depth. Their secretions and residues after decay have a very significant impact not only on the physical and Chemical properties soil aggregates, but also on the biological activity of the soil. They affect it comprehensively: they contribute to the penetration of air into the deeper layers, cause shifts in balance. aqueous solution, contribute to the decomposition of mineral substances, provide the microcosm with organic nutrition.

Much depends on the amount and composition of plant root secretions, since it is they that determine the development of microorganisms in the root zone, as well as the activity of biochemical processes here. The roots themselves serve as food for many inhabitants of the soil - mites and nematodes, fungi that form mycorrhiza grow on them, and bacteria that form nodules develop here.

There are millions of them per gram.

Often on the surface of the soil, especially in shady places, under trees and bushes, it is easy to notice green or even blue-green, like velvet, surfaces or pads. To the touch from below, they are often hard, like crusts, sometimes thin and delicate, like films, otherwise they lie like a felt coating on a wet surface. This phenomenon is called soil bloom. It's called algae. It is clearly visible in the spring, when there is a lot of moisture, the soil is not yet covered with plants, but it is already warm and sunny. Then hundreds of millions of cells of green algae can develop on one square meter, and their biomass in this area reaches 100 grams or more. In summer, they actively grow along the edges of the ridges, between rows, under trees and bushes. They also inhabit tree trunks, cracks and depressions of the bark on them, live on fallen leaves and under them. Their number varies from 5 thousand to 1.5 million in each gram of soil. In soddy-podzolic, for example, their biomass in a layer of 10 centimeters usually ranges from 40 to 300 kilograms per hectare.

Along with other plants, algae form a lot of organic matter, thereby contributing to the accumulation of humus in the soil and increasing its fertility.

carry out photosynthesis and produce oxygen environment and cyanobacteria. Some of them form on the surface of the soil rather large, several centimeters long, dark olive-green mucoid-cartilaginous colonies, consisting of numerous filaments located inside the mucus. Sometimes such colonies almost completely cover the ground. Others form blurry films of a purple hue on it. Most often they can be found in contaminated areas. They have pure green color, do not form any crusts or films, but populate the upper layer of the soil very densely, sometimes giving it a greenish tint.

Countless in the garden and representatives of mushrooms. It is they who are sometimes the cause of many diseases of horticultural crops and often cause considerable damage to the harvest of fruits and berries. The bulk of fungi lives in the soil, where their mycelium (mycelium) often reaches a total length of 1000 meters in one gram. Mushrooms decompose organic matter and synthesize hydrolytic enzymes, which allows them to absorb complex substances such as pectin, cellulose, and even lignin. During the day, they are able to decompose organic substances three to seven times more than they themselves can absorb. And in the soil, their biomass often exceeds the bacterial one.

Marsupials cause such dangerous diseases like powdery mildew and apple or pear scab. On old, dying parts of trees, stumps and roots, tinder fungi and hat mushrooms. Among them, in the garden, champignons are most often found, developing on a manure or humus substrate, as well as honey agarics, grebes and a number of inedible agaric mushrooms.

It is impossible not to name unicellular fungi - different types yeast. They develop well in the soil environment at a low temperature close to zero, and almost stop development at 20 degrees Celsius. Many yeast fungi occur on leaves, inside them, in the nectar of flowers, in the apiary of trees, on fruits and berries.

Has its representatives in the garden and such a special group lower plants like lichens. Their body is made up of two different organisms- fungus and algae. Lichen fungi are not found in a free-living state. They grow slowly, especially cortical ones - they grow from 1 to 8 millimeters per year. Most often they can be seen on the bark of trees, especially old ones, or directly on the soil, where they form crusts, bushes. Resistant against direct and bright sunlight and drying out, are able to absorb water directly from the atmosphere, even at low humidity. Lichens secrete complex organic acids, the so-called lichen acids, which have antibiotic properties. Studies have shown that lichens provide a habitat for a variety of yeasts and other fungi, spores and bacteria.

Bacteria are involved in almost all biochemical processes occurring in the soil. They make up the bulk of the microbiological population of the soil - their number reaches hundreds of millions and even billions in one gram - and largely determine its biological activity.

Inhabitants of the dark halls.

Numerous soil animals have a very significant influence on the composition of the soil, its structure and fertility in general. Their number in middle lane it is greatest in the uppermost part of the soil horizon, and at a depth of half a meter or more it decreases sharply. In the steppe and forest-steppe zones, on chernozems, they penetrate twice and three times deeper. If there is a sufficient amount of water in the soil pores, unicellular animals actively develop here - flagellates, ciliates, sarcodes. Their number is large - up to several hundred thousand in one gram of soil, and the biological mass reaches 40 grams per square meter.

Life in the soil, which has the thinnest capillaries, has led to the fact that the simplest animals here are 5-10 times smaller in size than similar creatures living in rivers, lakes, ponds. In some of them, the cells have become flat, the usual outgrowths and spines are absent. Among the rhizopods there are naked and testate amoebae, they do not have a constant body shape, but seem to shimmer - from place to place, flowing around their victims - the plant cells that they feed on - and thus include them in their protoplasm. Infusoria - typical inhabitants of water bodies - are much smaller in the soil than flagellates and amoebas, but scientists still found representatives of 43 genera!

But worms play a particularly important role in the life of the soil, in enriching it with organic matter necessary for plants. They are divided into two groups - lower and higher. The former include rotifers and nematodes - the simplest of multicellular living beings.

Rotifers have circular rows of cilia on the front of their body, thanks to which they rotate and move. Usually they live in ponds, lakes, rivers, but they are also found in the soil - they swim in water capillaries and films. They feed on bacteria and unicellular algae.

From higher worms a significant role in the life of the soil is played by enchitreids, which measure from 3 to 45 millimeters in length, and a thickness of 0.2-0.8 millimeters. The smallest move in the soil along its natural pores and channels, others make their way, eating through it. Biomass enchitreid on good garden plots often reaches 5 grams per square meter. Most of them are in the upper soil layer, since their main food is dying roots. Sometimes they gnaw out their parts damaged by nematodes. They are also abundant where there is moist humus. In this they differ from earthworms, of which there are also about 200 species.

Snails. Lives in the garden and another group of animals - snails. Although they, like other mollusks, for the most part are typical inhabitants of water bodies, the so-called lung snails have also adapted to a terrestrial lifestyle. Due to the presence of a shell, they relatively easily tolerate adverse conditions - cold, drought, heat, and slugs that do not have a shell hide under mulch, leaf litter or climb deeper into the soil in heat and cold. Among lung snails there are herbivores and predators, some cause significant damage to plants, such as grape snails.

Slugs feed on freshly fallen leaves, grass, dying tissues, but can also damage living plants. The so-called field slug damages the seedlings of vegetable, horticultural, field and forest crops. Some feed on algae, lichens, mushrooms, that is, they act as orderlies and are harmless to the garden.

There are still many tiny creatures in the soil that influence the life of fruit and berry crops. Some of them are visible to the naked eye and are called tardigrades, or bear cubs. Their body is short, in a kind of shell (cuticle). four couples short legs like muscular tubercles with claws. In the mouth, a stylet is a kind of knife with which they pierce plant tissues and suck out the contents of living cells. In the soil with leaf litter, there are many springtails and shell mites, wood lice, centipedes, and insect larvae. Woodlice, like earthworms, make small passages in the soil, improve its porosity, aeration, and process primary plant material into humus. Millipedes are terrestrial animals but lead a secretive life, hiding in soil burrows, under mulch or leaves. Among them there are very small ones, 1.5-2 millimeters, and quite large ones - 10-15 centimeters, for example, geophiles. The body of centipedes consists of many segments, each of which has two limbs. These include very frequent kivsyaki in the garden.

Insect larvae. The soil of the garden is also densely populated by various representatives of a countless family of insects. Many always, and others only at a certain stage, live in the soil, for example, the larvae of the ground beetle, the click beetle, the beetle, the May beetle, and the dung beetle. Some larvae behave like earthworms, others damage healthy plant roots and cause significant damage to them, especially when mass reproduction. So, for pupation in the soil, more than a hundred caterpillars of the meadow moth leave on each square meter. Wireworms have a noticeable effect on the state of some garden and garden crops - long, yellowish, hard-to-touch larvae of click beetles, legless weevil larvae. The larvae of some butterflies and sawfly beetles also live in the soil. photosynthesis cyanobacteria soil

Medvedka. Well adapted to permanent life in the soil, especially in the structural, highly humus, chernozem, and such an insect as the bear. It is able to quickly make fairly wide, long passages at the very surface of the soil and cause considerable damage to crops, especially in areas with loose, humus and fairly moist soil. She and her larvae feed on the roots and stems of plants: they eat out tubers, corms, root crops and seeds. Strawberries, strawberries, vegetable crops suffer the most from them.

Adult insects and their larvae overwinter in the soil. They wake up in the spring as soon as it warms up. Places inhabited by a bear are easy to detect by winding rolls of loose earth and holes that go to the surface of the soil, as well as damaged plants. Usually in May, bears make in the ground at a depth of up to 15 centimeters a cave-nest the size of egg and lay 300-350 eggs in them, from which larvae (nymphs) soon appear, living in the soil for more than a year. And the entire period of development of the bear from an egg to an adult insect lasts about two years. They destroy the bear with the help of poisoned baits or mechanically. The activity of such widespread insects as ants is great, but since their role in the garden is very diverse, we will talk about them separately, as well as about earthworms, frogs, birds, bees, and here we will briefly touch only on the main ones after earthworms - rodents and moles.

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Soil is a habitat for many organisms. Creatures that live in the soil are called pedobionts. The smallest of them are bacteria, algae, fungi and unicellular organisms that live in soil waters. In one m can live up to 10?? organisms. The soil air is inhabited by invertebrates such as mites, spiders, beetles, springtails and earthworms. They feed on plant remains, mycelium and other organisms. Vertebrate animals live in the soil, one of them is the mole. He is very well adapted to living in completely dark soil, so he is deaf and almost blind.

The heterogeneity of the soil leads to the fact that for organisms of different sizes it acts as a different environment.

For small soil animals, which are united under the name of nanofauna (protozoa, rotifers, tardigrades, nematodes, etc.), the soil is a system of micro-reservoirs.

For air-breathers of slightly larger animals, the soil appears as a system of shallow caves. Such animals are united under the name microfauna. The sizes of representatives of soil microfauna are from tenths to 2-3 mm. This group includes mainly arthropods: numerous groups ticks, primary wingless insects (springtails, proturs, two-tailed insects), small species of winged insects, centipedes symphyla, etc. They do not have special adaptations for digging. They crawl along the walls of soil cavities with the help of limbs or wriggling like a worm. Soil air saturated with water vapor allows you to breathe through the covers. Many species do not have a tracheal system. Such animals are very sensitive to desiccation.

Larger soil animals, with body sizes from 2 to 20 mm, are called representatives of the mesofauna. These are insect larvae, centipedes, enchytreids, earthworms, etc. For them, the soil is a dense medium that provides significant mechanical resistance when moving. These relatively large forms move in the soil either by expanding natural wells by pushing apart soil particles, or by digging new passages.

Soil megafauna or soil macrofauna are large excavations, mostly mammals. A number of species spend their entire lives in the soil (mole rats, mole voles, zokors, Eurasian moles, African golden moles, Australian marsupial moles, etc.). They make whole systems of passages and holes in the soil. Appearance and the anatomical features of these animals reflect their adaptability to a burrowing underground lifestyle.

In addition to the permanent inhabitants of the soil, among large animals, one can distinguish a large environmental group inhabitants of holes (ground squirrels, marmots, jerboas, rabbits, badgers, etc.). They feed on the surface, but breed, hibernate, rest, and escape danger in the soil. A number of other animals use their burrows, finding in them a favorable microclimate and shelter from enemies. Norniks have structural features characteristic of terrestrial animals, but have a number of adaptations associated with a burrowing lifestyle.

Soil dwellers. We had to consider the land in the yard, in the garden, in the field, on the banks of the river. Have you seen small bugs swarming in the ground? The soil is literally saturated with life - rodents, insects, worms, centipedes and other living organisms live in it at different depths. If these inhabitants of the soil are destroyed, then the soil will not be fertile. If the soil becomes infertile, then in winter we will have nothing to eat.

Soil dwellers. Everyone is familiar with these animals - both adults and children. They live right under our feet, although we do not always notice them. Lazy earthworms, clumsy larvae, nimble centipedes are born from earthen lumps crumbling under a shovel. Often we squeamishly throw them aside or immediately destroy them as pests of garden plants. How many of these creatures inhabit the soil and who are they our friends or enemies? Let's try to figure it out...

About the most inconspicuous ... The roots of plants, myceliums of various fungi penetrate the soil. They absorb water and mineral salts dissolved in it. Especially a lot of microorganisms in the soil. So, in 1 sq. cm soil contains tens and even hundreds of millions of bacteria, protozoa, unicellular fungi and even algae! Microorganisms decompose the dead remains of plants and animals into simple minerals, which, dissolving in soil water, become available to plant roots.

Multicellular inhabitants of the soil Live in the soil and larger animals. These are, first of all, various ticks, slugs, and some insects. They do not have special devices for digging passages in the soil, so they live shallow. But earthworms, centipedes, insect larvae can make their own way. The earthworm pushes the soil particles apart with the head section of the body or “bites in”, passing it through itself.

And now - about the largest ... The largest of the permanent inhabitants of the soil are moles, shrews and mole rats. They spend their whole lives in the soil, in complete darkness, so they have undeveloped eyes. Everything they have is adapted for life underground: an elongated body, thick and short fur, strong digging front legs in a mole and powerful incisors in a mole rat. With their help, they create complex systems of moves, traps, pantries.

The soil is home to a huge number of living organisms! So, many organisms live in the soil. What difficulties do they face? First, the soil is quite dense, and its inhabitants must live in microscopically small cavities or be able to dig, make their way. Secondly, light does not penetrate here, and the life of many organisms passes in complete darkness. Thirdly, there is not enough oxygen in the soil. But it is fully provided with water, it contains a lot of mineral and organic substances, the stock of which is constantly replenished due to dying plants and animals. In the soil there are no such sharp temperature fluctuations as on the surface. All this creates favorable conditions for the life of numerous organisms. The soil is literally saturated with life, although it is not as noticeable as life on land or in a reservoir.