Rhynchites are the inhabitants of fruits. The poplar pipe-roller, apoder and attelab showed us that similar work can be done with different tools. And it is possible to do different works with the same tools: a similar structure does not determine the similarity of instincts. Rinkhits -

THE ANCIENT INHABITANTS OF THE EARTH...Lower organisms are the most widespread both in space and in time...A. P.

Animals - inhabitants of the underwater garden In natural reservoirs, plants coexist with various aquatic animals. Plants need animals, they cause water movement, provide plants with necessary chemical elements, releasing excrement, metabolites,

Soils and biogeocenosis We observe the closest interaction and complete community of the organic world and the inorganic world.V. V. Dokuchaev Complete community of the organic and inorganic world Dokuchaev’s definition of soil as a natural body formed

Chernozem, humus and soil fertility The rye is ripening under the hot cornfield, And from cornfield to cornfield the whimsical wind drives away the golden shimmers of A. A. Fet Rye is ripening under a hot cornfield Junior editor of the statistical department of the Ministry of State Property V. I. Chaslavsky in 1875 accepted

The dust of centuries on the surface of the soil And earth fell from the sky onto the blinded fields. Yu. Kuznetsov Earth fell from the sky onto the blinded fields. The air contains a lot of dust - solid particles, fragments of minerals, salts - several hundredths of a millimeter in size. It is estimated that

Soil is a living organism consisting of countless microscopic living beings. The number and diversity of living microorganisms in soil is immeasurable. 1 g of soil contains billions of bacteria, fungi, algae and other organisms, and in addition, a great many earthworms, woodlice, centipedes, snails and other soil organisms, which, as a result of the metabolic process, process dead protein organisms and other organic residues into nutrients, available for absorption by plants. Thanks to their activity in the soil, humus is formed from the original plant and protein material, from which, as a result of combining with water and oxygen, nutrients for plants are released. The loose structure of the soil is also achieved largely due to the activities

soil organisms that naturally mix mineral and organic substances, producing a new enriched substance. This significantly increases soil fertility. The study of soil-dwelling animals is the subject of a special branch of science - soil zoology, which was formed only in our century. After specialists developed methods for recording and recording animals, which was associated with significant technical difficulties, a whole kingdom of creatures appeared before the eyes of zoologists, diverse in structure, lifestyle and their significance in the natural processes occurring in the soil. By biological diversity animal world soils can only be compared with coral reefs - a classic example of the richest and most diverse natural communities on our planet.

Among them are large invertebrates such as earthworms, and microorganisms that cannot be seen with the naked eye. In addition to their small sizes (up to 1 mm), most soil-dwelling invertebrate animals also have an inconspicuous coloring of the body covers, whitish or gray, so they can only be seen after special treatment with fixatives, under a magnifying glass or microscope. Microorganisms form the basis of the animal population of the soil, the biomass of which reaches hundreds of centners per hectare. If we talk about the number of earthworms and other large invertebrates, then it is measured in tens and hundreds per square meter, and the number of small and microscopic organisms reaches millions and billions of individuals.

For example, protozoa and roundworms (nematodes) with a body size of up to 0.01 mm, in their physiology, are typically aquatic creatures capable of breathing oxygen dissolved in water. Their small size allows them to content themselves with microscopic droplets of moisture that fill narrow soil cavities. There the worms move, find food, and reproduce. When the soil dries out, they can long time be in an inactive state, covered on the outside with a dense protective shell of solidified secretions.

Larger soil organisms include soil mites, springtails, and small worms - the closest relatives of earthworms. These are already real land animals. They breathe atmospheric oxygen, inhabit air cavities within the soil, root passages, and burrows of larger invertebrates. Small sizes, flexible

Soil organisms are a vital link in a closed metabolic cycle. Thanks to their vital activity, all products of organic origin are decomposed, processed and acquire a mineral form accessible to plants. Minerals dissolved in water move from the soil to the roots of plants, and the cycle begins again

body allow them to use even the narrowest gaps between soil particles and penetrate deep horizons of dense loamy soils. For example, oribatid mites go 1.5-2 m deep. For these small soil inhabitants, the soil is also not a dense mass, but a system of passages and cavities connected to each other. Animals live on their walls, like in caves. Overmoistening of the soil turns out to be just as unfavorable for its inhabitants as drying out. Soil invertebrates with body sizes larger than 2 mm are clearly visible. Here you can find various groups of worms, terrestrial mollusks, crustaceans (woodlice, amphipods), spiders, harvestmen, false scorpions, centipedes, ants, termites, larvae (beetles, dipterous and hymenopteran insects), butterfly caterpillars. Earthworms and some insect larvae have highly developed muscles. By contracting their muscles, they increase the diameter of their body and push soil particles apart. Worms swallow soil, pass it through their intestines and move forward, as if “eating” through the soil. Behind them they leave their excrement with metabolic products and mucus, abundantly secreted in the intestinal cavity. The worms cover the surface of the burrow with these mucous lumps, strengthening its walls, so such burrows remain in the soil for a long time.

And insect larvae have special formations on the limbs, head, and sometimes on the back, with which they act like a shovel. For example, in mole crickets, the front legs are turned into strong digging tools - they are expanded, with jagged edges. These scrapers are capable of loosening even very dry soil. In larvae

Khrushchev, digging passages to a considerable depth, serve as a loosening tool upper jaws, which look like triangular pyramids with a jagged top and powerful ridges on the sides. The larva hits the soil lump with these jaws, breaks it into small particles and scoops them up under itself. Other large soil inhabitants live in existing cavities. They are distinguished, as a rule, by a very flexible thin body and can penetrate very narrow and winding passages. Digging activity animals has great importance for soil. The system of passages improves its aeration, which favors the growth of roots and the development of aerobic microbial processes associated with humification and mineralization of organic material. It is not for nothing that Charles Darwin wrote that long before man invented the plow, earthworms learned to cultivate the soil correctly and well. He dedicated a special book to them, “The Formation of the Soil Layer by Earthworms and Observations on the Lifestyle of the latter.”

Main role soil organisms is the ability to quickly process plant residues, manure, household waste, turning them into high quality natural organic fertilizer vermicompost. In many countries, including ours, they have learned to breed worms on special farms to produce organic fertilizers. The following examples will help to evaluate the contribution of the invisible workers of the soil in shaping its structure. Thus, ants building soil nests throw more than a ton of soil per 1 hectare to the surface from deep layers of soil. In 8-10 years they process almost the entire horizon populated by them. And desert woodlice lift from a depth of 50-80 cm to the surface soil enriched with elements of mineral nutrition for plants. Where the colonies of these woodlice are located, the vegetation is taller and denser. Earthworms are capable of processing up to 110 tons of earth per 1 hectare per year.

Moving in the ground and feeding on dead plant debris, animals mix organic and mineral soil particles. By dragging ground litter into deep layers, they thereby improve the aeration of these layers and promote the activation of microbial processes, which leads to the enrichment of the soil with humus and nutrients. It is animals who, through their activities, create the humus horizon and soil structure.

The role of earthworms in the biological life of the soil

Earthworms loosen the soil, penetrating, unlike other soil organisms that can live only in one soil layer, into different layers of soil. Air and water penetrate through the holes made by the worms to the roots of the plants.

Earthworms help enrich the soil with oxygen, which prevents the processes of decay of organic material

: Earthworms absorb organic residues, along with which mineral particles, grains of clay, soil algae, bacteria, and microorganisms enter the digestive tract. There, this heterogeneous material is mixed and processed, thanks to metabolic processes, supplemented by secretions of the intestinal microflora of the worm, acquiring a new state, and then enters the soil in the form of droppings. This qualitatively improves the composition of the soil and gives it a sticky, lumpy structure.

Man learned to cultivate the soil, fertilize it and obtain high yields. Does this replace the activities of soil organisms? To some extent, yes. But with intensive land use modern methods, when the soil is overloaded with chemicals (mineral fertilizers, pesticides, growth stimulants), with frequent disturbances of its surface layer and its compaction by agricultural machines, deep disturbances occur natural processes, which lead to gradual soil degradation and a decrease in its fertility. Excessive amounts of mineral fertilizers poison the earth and kill its biological life. Chemical treatments destroy not only pests in the soil, but also beneficial animals. This damage takes years to repair. Today, during the period of greening our thinking, it is worth thinking about what criteria to evaluate the damage caused to the crop. Until now, it was customary to count only losses from pests. But let's also count the losses caused to the soil itself from the death of soil formers.

To preserve the soil, this unique natural resource The earth, capable of self-restoring its fertility, must first of all preserve its animal world. Soil organisms and soil formers do what humans with their powerful technology cannot yet do. They need a stable environment. They need oxygen in the system of passages made and a supply of organic residues, shelters and passages that are not disturbed by humans. Reasonable farming, gentle methods of soil cultivation and maximum avoidance of chemical plant protection products mean the creation of conditions for preserving the living bioworld of the soil - the key to its fertility.

Nutrients in the soil

Plants can obtain all the components necessary for life from the soil only in mineral form. Nutrients that are rich in organic matter, humus and organic fertilizers can be absorbed by plants only after the decomposition process is completed organic compounds or their mineralization.

The presence of sufficient nutrients in the soil is one of the main factors for the successful development of plants. Its above-ground part, root system, flowers, fruits and seeds, plants are built from organic substances: fats, proteins, carbohydrates, acids and other substances produced by the green leafy mass of plants. To synthesize organic substances, plants need ten main elements, which are called biogenic. Biogenic chemical elements They are constantly part of organisms and perform certain biological functions that ensure the viability of organisms. Biogenic macroelements include carbon (C), calcium (Ca), iron (Fe), hydrogen (H), potassium (K), magnesium (Mg), nitrogen (N), oxygen (O), phosphorus (P), sulfur (S). The plant receives some of these elements from the air, for example oxygen and carbon; it receives hydrogen from the decomposition of water during the process of photosynthesis.

Nutrient metabolism process

Nutrients play a vital role in the cyclical process of metabolism, ensuring the life of plants. Water dissolves nutrients and trace elements, creating a soil solution that is absorbed by plant roots. Solar energy helps transform nutrients through the process of photosynthesis, which, in turn, depends on the presence in plant tissue of a number of trace elements involved in the formation of the colored substance chlorophyll

Instead, the remaining elements come to the plant exclusively from the soil in the form of compounds dissolved in water, the so-called soil solution. If there is a serious deficiency of any of the elements in the soil, the plant weakens and develops only to a certain stage until it exhausts its internal biological reserve of this element existing in the plant tissues. After this stage, the plant may die. In addition to biogenic macroelements, plant development requires microelements, which are usually contained in very small quantities, but nevertheless play an important role in metabolic processes. Microelements include: aluminum (A1), boron (B), cobalt(Co), copper (Cu), manganese (Mn), molybdenum Mo), sodium (Na), silicon (Si), zinc (Zn). Hei - residue or excess of microelements leads to To metabolic disorders, which leads to

entails a lag in the growth and development of the plant, a decrease in yield and other consequences. Some of the listed microelements are not vital and are often classified by researchers into the group of so-called “useful elements.” Nevertheless, their presence is required for the full development of the plant. All components must be present in the plant’s nutrition in a balanced form, since the absence of at least one of the main elements, such as nitrogen, phosphorus, potassium or calcium, inevitably entails insufficiency or inability for the plant to absorb the other three elements, as well as other nutrients . That is why the presence of all elements is so important for the plant to fully absorb the entire nutritional complex.

The ability of plants to absorb nutrients from environment determined by the quality and volume of the root system. Plants absorb nutrients throughout the growing season, but unevenly. The need of plants for nutrients changes during different periods of development. During the period of intensive growth, plants especially need nitrogen; during flowering and fruiting, the need for phosphorus and potassium increases. Assimilated nutrients are selectively fixed in various plant organs.

All around us: on the ground, in the grass, in the trees, in the air - life is in full swing everywhere. Even a resident who has never gone deep into the forest big city often sees birds, dragonflies, butterflies, flies, spiders and many other animals around him. The inhabitants of reservoirs are also well known to everyone. Everyone, at least occasionally, has seen schools of fish near the shore, water beetles or snails.

But there is a world hidden from us, inaccessible to direct observation—the peculiar world of the animals of the soil.

There is eternal darkness there; you cannot penetrate there without destroying the natural structure of the soil. And only isolated, accidentally noticed signs show that beneath 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 holes, holes in gopher holes in the steppe or holes of shore swallows in a cliff above the river, piles of earth on paths thrown out by earthworms, and they themselves crawling out after the rain, masses of winged ants suddenly appearing literally from underground or fatty larvae of cockchafers that come across when digging up the ground.

Soil animals find their food either in the soil itself or on its surface. The life activity of many of them is very useful. The activity of earthworms is especially useful, as they drag a huge amount of plant debris into their burrows: this promotes the formation of humus and returns substances extracted from it by plant roots to the soil.

Invertebrates in forest soils, especially earthworms, process more than half of all fallen leaves. Over the course of a year, on each hectare, they throw out to the surface up to 25-30 tons of soil they have processed, turning it into good, structural soil. If you distribute this soil evenly over the entire surface of a hectare, you will get a layer of 0.5-0.8 cm. Therefore, it is not for nothing that earthworms are considered the most important soil builders.

Not only earthworms “work” in the soil, but also their closest relatives - smaller whitish annelids (enchytraeids, or pot worms), as well as some types of microscopic roundworms (nematodes), small mites, various insects, especially their larvae, and finally woodlice, millipedes and even snails.

The purely mechanical work of many animals living in it also affects the soil. They make passages in the soil, mix and loosen it, and dig holes. All this increases the number of voids in the soil and facilitates the penetration of air and water into its depths.

This “work” involves not only relatively small invertebrate animals, but also many mammals - moles, shrews, marmots, ground squirrels, jerboas, field and forest mice, hamsters, voles, mole rats. The relatively large passages of some of these animals penetrate the soil to a depth of up to 4 m.

The passages of large earthworms go even deeper: in most worms they reach 5-2 m, and in one southern worm even up to 8 m. These passages, especially in denser soils, are constantly used by plant roots, penetrating deeper into them.

In some places, for example in the steppe zone, a large number of passages and holes are dug in the soil by dung beetles, mole crickets, crickets, tarantula spiders, ants, and in the tropics - termites.

Many soil animals feed on roots, tubers, and plant bulbs. Those that attack cultivated plants or forest plantations are considered pests, for example the cockchafer. Its larva lives in the soil for about four years and pupates there. In the first year of life, it feeds mainly on roots. herbaceous plants. But, as it grows, the larva begins to feed on the roots of trees, especially young pines, and causes great harm to the forest or forest plantations.

The larvae of click beetles, darkling beetles, weevils, pollen eaters, caterpillars of some butterflies, such as cutworms, the larvae of many flies, cicadas and, finally, root aphids, such as phylloxera, also feed on the roots of various plants, greatly harming them.

A large number of insects damaging the above-ground parts of plants- stems, leaves, flowers, fruits, lays eggs in the soil; Here, the larvae that emerge from the eggs hide during the drought, overwinter, and pupate. Soil pests include some species of mites and centipedes, naked mucilage worms and extremely numerous microscopic roundworms - nematodes. Nematodes penetrate from the soil into the roots of plants and disrupt their normal functioning. Many predators live in the soil. “Peaceful” moles and shrews eat huge amounts of earthworms, snails and insect larvae; they even attack frogs, lizards and mice. They eat almost continuously. For example, a shrew eats an amount of living creatures per day equal to its own weight.

There are predators among almost all groups of invertebrates living in the soil. Large ciliates feed not only on bacteria, but not on protozoa, such as flagellates. The ciliates themselves serve as prey for some roundworms. Predatory mites attack other mites and small insects. Thin, long, pale-colored centipedes, geophiles, living in cracks in the soil, as well as larger dark-colored drupes and scolopendras, holding on to stones, stumps, and forest floors are also predators. They feed on insects and their larvae, worms and other small animals. Predators include spiders and related haymakers (“mow-mow-leg”). Many of them live on the soil surface, in litter, or under objects lying on the ground.

Many predatory insects live in the soil: ground beetles and their larvae, which play a significant role

role in the extermination of insect pests, many ants, especially the larger species, which exterminate large numbers of harmful caterpillars, and finally the famous antlions, so named because their larvae hunt ants. The antlion larva has strong sharp jaws, its length is about cm. The larva digs a funnel-shaped hole in dry sandy soil, usually at the edge of a pine forest, and buries itself in the sand at the bottom, with only its wide-open jaws exposed. Falling on the edge of the funnel small insects, most often ants, roll down. The antlion larva grabs them and sucks them out.

In some places, a predatory fungus is found in the soil. The mycelium of this fungus, which has the tricky name - didymozoophage, forms special trapping rings. Small soil worms—nematodes—get into them. With the help of special enzymes, the fungus dissolves the rather durable shell of the worm, grows inside its body and eats it out completely.

In the process of adaptation to living conditions in the soil, its inhabitants developed a number of features in the shape and structure of the body, in physiological processes, reproduction and development, in the ability to tolerate unfavourable conditions and in behavior. Although each animal species has characteristics unique to it, in the organization of various soil animals there are also common features characteristic of entire groups, since living conditions in the soil are basically the same for all its inhabitants.

Earthworms, nematodes, most millipedes, and the larvae of many beetles and flies have a highly elongated flexible body, allowing them to easily move through winding narrow passages and cracks in the soil. Bristles in rain and other annelids, hairs and claws in arthropods allow them to significantly accelerate their movements in the soil and stay firmly in burrows, clinging to the walls of the passages. Look how slowly a worm crawls along the surface of the earth and with what speed, essentially instantly, it hides in its hole. When making new passages, many soil animals alternately lengthen and shorten their bodies. In this case, cavity fluid is periodically pumped into the front end of the animal. It swells strongly and pushes away soil particles. Other animals make their way by digging the ground with their front legs, which have turned into special digging organs.

The color of animals that constantly live in the soil is usually pale - grayish, yellowish, whitish. Their eyes, as a rule, are poorly developed or not at all, but their organs of smell and touch are very finely developed,

Scientists believe life originated in a primordial ocean and only much later spread from here to land (see article “The Origin of Life on Earth”). It is very possible that for some terrestrial animals the soil was a transitional environment from life in water to life on land, since soil is a habitat intermediate in its properties between water and air.

There was a time when only aquatic animals existed on our planet. Many millions of years later, when land had already appeared, some of them were caught more often than others. Here, to escape drying out, they buried themselves in the ground and gradually adapted to permanent life in the primary soil. Millions more years passed. The descendants of some soil animals, having developed adaptations to protect themselves from drying out, finally had the opportunity to reach the surface of the earth. But they probably couldn’t stay here for long at first. Yes, willows - they must have walked only at night. Yes, to this day the soil provides shelter not only for “its own” soil animals that live in it constantly, but also for many that come to it only temporarily from a body of water or from the surface of the earth in order to lay eggs, pupate, go through a certain stage of development, escape from heat or cold.

The animal world of the soil is very rich. It includes about three hundred species of protozoa, more than a thousand species of roundworms and annelids, tens of thousands of species of arthropods, hundreds of mollusks and a number of vertebrate species.

Among them there are both useful and harmful. But the majority of soil animals are still listed under the “indifferent” heading. Perhaps honoring this is the result of our ignorance. Studying them is the next task of science.

There is a world hidden from us, inaccessible to direct observation - a unique world of soil animals. There is eternal darkness there; you cannot penetrate there without disturbing the natural structure of the soil. And only isolated, accidentally noticed signs show that beneath 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 holes, holes in gopher holes in the steppe or sand swallow holes in a cliff above the river, piles of earth on the path thrown out by earthworms, and the earthworms themselves crawling out after the rain, as well as masses unexpectedly appearing literally from underground winged ants or fatty larvae of chafers that are found in the ground.

As a habitat for animals, soil is very different from water and air. Try waving your hand in the air - you will notice almost no resistance. Do the same in water - you will feel significant resistance from the environment. And if you put your hand into a hole and cover it with earth, not only will it be difficult to move it, but 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 in the way, then the animal can advance only by breaking through a passage and raking the earth back or swallowing the earth and passing it through the intestines. The speed of movement will, of course, be insignificant.

Every animal needs to breathe to live. The conditions for breathing in soil are different than in water or air. Soil consists of solid particles, water and air. Solid particles in the form of small lumps occupy slightly more than half the volume of the soil; the rest of the volume accounts for the gaps - pores, which 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.

Earthworm.

Thanks to this structure of the soil, numerous animals live in it and breathe through their skin. If they are taken out of the ground, they quickly die from drying out of the skin. Moreover, hundreds of species of real freshwater animals live in the soil, inhabiting rivers, ponds and swamps. True, these are all microscopic creatures - lower worms and single-celled protozoa. They move and float in a film of water covering soil particles.

If the soil dries out, these animals secrete a protective shell and, as it were, fall asleep, falling into a state suspended animation. Oxygen enters the soil air 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 through respiration. They all emit carbon dioxide. There is 10-15 times more of it in soil air than in the atmosphere. Free gas exchange between 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, which you have probably often observed.

Among soil animals there are also predators and those that feed on parts of living plants, mainly roots. There are also consumers of decomposing plant and animal residues 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 life activity of many of them is very useful. Earthworms are especially useful. They drag a huge amount of plant debris into their burrows, which contributes to the formation of humus and returns substances extracted from it by plant roots to the soil.

In forest soils, invertebrates, especially earthworms, process more than half of all leaf litter. Over the course of a year, on each hectare they throw up to 25-30 tons of processed soil onto the surface, thereby creating good, structural soil. If you distribute this soil evenly over the entire surface of a hectare, you will get a layer of 0.5-0.8 cm. Therefore, earthworms are rightly considered the most important soil builders.

Medvedka.

Not only earthworms “work” in the soil, but also their closest relatives - smaller whitish annelids (enchytraeids, or pot worms), as well as some types of microscopic roundworms (nematodes), small mites, various insects, especially their larvae, and finally woodlice, millipedes and even snails.

The purely mechanical work of many animals living in it also affects the soil. They make passages, mix and loosen the soil, and dig holes. All this increases the number of voids in the soil and facilitates the penetration of air and water into its depths. This “work” involves not only relatively small invertebrate animals, but also many mammals - moles, marmots, ground squirrels, jerboas, field and forest mice, hamsters, voles, and mole rats. The relatively large passages of some of these animals go 1-4 m deep. The passages of large earthworms also go deep: in most of them they reach 1.5-2 m, and in one southern worm even 8 m. Along these passages, especially in denser soils, plant roots penetrate deeper. In some places, such as steppe zone, a large number of passages and holes are dug in the soil by dung beetles, mole crickets, crickets, tarantula spiders, ants, and in the tropics - termites.

Mole. Its front paws are well adapted for digging.

Many soil animals feed on roots, tubers, and plant bulbs. Those that attack crops or forest plantations are considered pests, e.g. Chafer. Its larva lives in the soil for about four years and pupates there. In the first year of life, it feeds mainly on the roots of herbaceous plants. But, as it grows, the larva begins to feed on the roots of trees, especially young pines, and causes great harm to the forest or forest plantations. The larvae of click beetles, darkling beetles, weevils, pollen eaters, caterpillars of some butterflies, such as cutworms, the larvae of many flies, cicadas and, finally, root aphids, such as phylloxera, also feed on the roots of various plants, greatly harming them.

Many insects that damage the above-ground parts of plants - stems, leaves, flowers, fruits - lay eggs in the soil; Here, the larvae that emerge from the eggs hide during drought, overwinter, and pupate. Soil pests include some species 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 functioning.

An antlion larva at the bottom of a sand funnel she created.

There are many predators living in the soil. “Peaceful” moles eat huge amounts of earthworms, snails and insect larvae; they even attack frogs, lizards and mice. These animals eat almost continuously. For example, a mole eats almost as much living matter in a day as it weighs itself.

There are predators among almost all groups of invertebrates living in the soil. Large ciliates feed not only on bacteria, but also on protozoa, such as flagellates. The ciliates themselves serve as food for some roundworms. Predatory mites attack other mites and small insects. Thin, long, pale-colored centipedes are geophiles that live in cracks in the soil, as well as larger dark-colored drupes and centipedes that stay under stones and in stumps, also predators. They feed on insects and their larvae, worms and other small animals. Predators include spiders and related haymakers. Many of them live on the soil surface, in litter or under objects lying on the ground.

Many predatory insects live in the soil. These are ground beetles and their larvae, which play a significant role in exterminating pest insects, many ants, especially larger species, which destroy large numbers of harmful caterpillars, and, finally, the famous antlions, so named because their larvae hunt ants. The antlion larva has strong sharp jaws, its length is about 1 cm. The larva digs a funnel-shaped hole in dry sandy soil, usually at the edge of a pine forest, and buries itself in the sand at the bottom, with only its jaws wide open. Small insects, most often ants, that fall on the edge of the funnel roll down. Then the antlion larva grabs the victim and sucks it out. Adult antlions resemble dragonflies in appearance, their body length reaches 5 cm, and their wingspan reaches 12 cm.

In some places, a predatory... mushroom is found in the soil! The mycelium of this fungus, which has the tricky name “didimozoophage,” forms special trapping rings. Small soil worms - nematodes - get into them. With the help of special enzymes, the fungus dissolves the rather durable shell of the worm, grows inside its body and eats it out completely.

In the process of evolution, the inhabitants of the soil have developed adaptations to the corresponding living conditions: features of the shape and structure of the body, physiological processes, reproduction and development, the ability to tolerate unfavorable conditions, and behavior. Earthworms, nematodes, most millipedes, and the larvae of many beetles and flies have a highly elongated flexible body that allows them to easily move through winding narrow passages and cracks in the soil. Bristles in earthworms and other annelids, hairs and claws in arthropods allow them to significantly accelerate their movements in the soil and stay firmly in burrows, clinging to the walls of passages. Look how slow

a worm crawls along the surface of the earth and at what speed, essentially instantly, it hides in its hole. When making new passages, some soil animals, such as worms, alternately extend and contract their bodies. In this case, cavity fluid is periodically pumped into the front end of the animal. It swells strongly and pushes away soil particles. Other animals, such as moles, clear their way by digging the ground with their front paws, which have turned into special digging organs.

The color of animals that constantly live in the soil is usually pale - grayish, yellowish, whitish. Their eyes, as a rule, are poorly developed or completely absent. But the organs of smell and touch have developed very subtly.

The animal world of the soil is very rich. It includes about three hundred species of protozoa, more than a thousand species of roundworms and annelids, tens of thousands of arthropods, hundreds of mollusks and a number of vertebrate species. Among soil animals there are both beneficial and harmful. But most of them are still listed under the “indifferent” heading. It is possible that this is the result of our ignorance. Studying them is the next task of science.

I immediately remembered how I help my grandmother hunt a mole. :) How he tortured us then, and only by shoving the hose into his hole, we managed to get rid of the uninvited guest. In general, despite the benefits of this animal for the soil, it turned out to be not so useful for our harvest.

Soil inhabitants

This world is practically hidden from us, but this does not mean that life is impossible there. On the contrary, there is a peculiar world inhabited by a mass of animals. The significant difference lies in the soil itself as a habitat, which is significantly different from air or water. Some are easy enough to see, but some you can barely see through a microscope! So, the soil is inhabited by the following living creatures:

• invertebrate animals;
• microorganisms;
• mushrooms;
• insects;
• vertebrates.

The role of animals in soil fertility

With regard to the contribution to soil formation, and consequently to increased fertility, the following types of living organisms can be roughly distinguished based on their function:

• processing - take part in decomposition, while synthesizing new compounds;
• mixing - this group distributes the processed substance throughout the entire layer;
• loosening - moving through the thickness, facilitating the access of air and water.

When organic residues enter the soil, chlorophyll-free organisms are the first to begin “working,” modifying the substances, making them available for absorption by plants. By the way, the soil contains the largest concentration of microorganisms in the world: just 1 gram of forest soil contains over 15 million single-celled organisms. Insects make a lot of moves, thereby significantly increasing ventilation, a number of physical properties and water supply. In addition, they recycle a significant portion of plant waste.

As for invertebrates, we should especially highlight earthworms, which contribute to the speedy biological cycle. Vertebrates are mainly represented by rodents. Thus, not only animals cannot exist outside the soil, but its formation is actually impossible without them, because by destroying and transforming organic matter they not only increase the thickness of the layer, but also increase its fertility.