Organisms that live in the soil environment are called. What animals live in the soil. The invisible world of soil

Soil is the habitat for many organisms. Creatures that live in the soil are called pedobionts. The smallest of them are bacteria, algae, fungi and single-celled organisms that live in soil waters. In one m? can live up to 10?? organisms. Invertebrate animals such as mites, spiders, beetles, springtails and earthworms live in the soil air. They feed on plant remains, mycelium and other organisms. Invertebrate animals live in the soil, one of them is the mole. It is very well adapted to living in completely dark soil, so it 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 collectively called nanofauna (protozoa, rotifers, tardigrades, nematodes, etc.), the soil is a system of micro-reservoirs.

To slightly larger air-breathing animals, the soil appears as a system of small caves. Such animals are collectively called microfauna. The sizes of representatives of soil microfauna range from tenths to 2-3 mm. This group includes mainly arthropods: numerous groups of mites, primary wingless insects (collembolas, proturus, two-tailed insects), small species of winged insects, symphila centipedes, etc. They do not have special adaptations for digging. They crawl along the walls of soil cavities using their limbs or wriggling like a worm. Soil air saturated with water vapor allows breathing through the covers. Many species do not have a tracheal system. Such animals are very sensitive to drying out.

Larger soil animals, with body sizes from 2 to 20 mm, are called representatives of mesofauna. These are insect larvae, millipedes, enchytraeids, 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 tunnels.

Megafauna or soil macrofauna are large diggers, mainly mammals. A number of species spend their entire lives in the soil (mole rats, mole moles, moles, moles of Eurasia, golden moles of Africa, marsupial moles of Australia, etc.). They create entire systems of passages and burrows in the soil. The appearance and 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 ecological group of burrow inhabitants (gophers, marmots, jerboas, rabbits, badgers, etc.). They feed on the surface, but reproduce, 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. Burrowers have structural features characteristic of terrestrial animals, but have a number of adaptations associated with the burrowing lifestyle.

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, at meeting a hare. One gets the impression that it is these clearly visible animals that form the basis of our fauna. In fact, the animals that are easy to see in the forest are only a tiny part of it.

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

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

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

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

In all terrestrial ecosystems, the vast majority of invertebrates (both in number of species and number of individuals) are soil dwellers or are closely associated with the soil at some point in their life cycle. According to calculations by Boucle (1923), the number of insect species associated with soil is 95–98%.

In terms of ability to adapt to living conditions, there are no animals equal to nematodes. In this respect, they can only be compared with bacteria and protozoan single-celled organisms. This universal adaptability is largely explained by the development of a dense outer cuticle in nematodes, which increases their vitality. In addition, the body shape and movement patterns of nematodes have been shown to be suitable for life in various environments.

Nematodes take part in the mechanical destruction of plant tissue: they “drill” into dead tissue and, with the help of secreted enzymes, destroy cell walls, opening paths for bacteria and fungi to enter.

In our country, harvest losses of vegetables, grains 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 causes the greatest harm to vegetable growing in the southern regions, where it is found in open ground. In the north, it is found only in greenhouses, damaging mainly cucumbers and tomatoes. The main damage is caused by females, while males, having completed development, go out into the soil and do not feed.

Soil nematodes have a bad reputation: they are seen primarily as pests of cultivated plants. Nematodes destroy the roots of potatoes, onions, rice, cotton, sugar cane, sugar beets, ornamental and other plants. Zoologists are developing measures to combat them in fields and 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 diverse, but also amazingly resistant to physical and chemical factors. Wherever they begin to study these worms, new species unknown to science are discovered everywhere. In this regard, nematodes seriously claim second place in the animal world, after insects: experts believe that there are at least 500 thousand species, but there is reason to believe that the true number of nematode species is much higher.

How does soil renew itself? Where does she get the strength to “feed” such a huge number of different plants? Who helps create the organic matter on which its fertility depends? It turns out that a huge number of different animals live under our feet, in the soil. If you collect all living organisms from 1 hectare of steppe, they will weigh 2.2 tons.

Representatives of many classes, units, and families live here in close proximity. Some process the remains of living organisms that fall into the soil - they crush, crush, oxidize, decompose into their constituent substances and create new compounds. Others mix the incoming substances with the soil. Still others lay collector passages that provide access to the soil for water and air.

Various non-chlorophyll organisms begin work first. It is they who decompose organic and inorganic residues that fall into the soil and make their substances available for plant nutrition, which in turn support the life of soil microorganisms. There are so many microorganisms in the soil that you will not find anywhere else. In total, in 1 g of forest litter there were 12 million 127 thousand of them, and in 1 g of soil taken from a field or garden there were only 2 billion bacteria, many millions of different microscopic fungi and hundreds of thousands of other microorganisms.

The soil layer is no less rich in insects. Entomologists believe that 90% of insects are associated with soil at one stage or another of their development. In the forest floor alone (Leningrad region), scientists discovered 12 thousand species of insects and other invertebrates. In the most favorable soil conditions, up to 1.5 billion protozoa, 20 million nematodes, hundreds of thousands of rotifers, earthworms, mites, small insects - springtails, thousands of other insects, hundreds of earthworms and gastropods were found per 1 m2 of litter and soil.

Among all this diversity of soil animals, there are active assistants to humans in the fight against invertebrate pests of forests, crops, gardens and garden plants. First of all, these are ants. The inhabitants of one anthill can protect 0.2 hectares of forest from pests, destroying 18 thousand harmful insects in 1 day. Ants also play a big role in the life of the soil itself. When building anthills, they, like earthworms, remove soil from the lower layers of the soil, constantly mixing humus with mineral particles. Within 8-10 years, ants completely replace the top layer of soil in the area of ​​their activity. Their burrows in saline steppes help destroy salt licks. Like earthworm tunnels, they make it easier for plant roots to penetrate deep into the soil.

Not only invertebrate animals, but also many vertebrates live in the soil permanently or temporarily. Amphibians and reptiles make their shelters in it and breed their offspring. And the caecilian amphibian spends its entire life in the ground.

The most common shrew is the mole, a mammal from the order of insectivores. He spends almost his entire life underground. The head, which immediately turns into the body, resembles a wedge with which the mole expands and pushes to the sides in its passages the earth, loosened by its paws. The mole's paws turned into peculiar shoulder blades.

Its short, soft coat allows it to move forward and backward without difficulty. The mole galleries, laid by moles, stretch for hundreds of meters. For the winter, moles go deeper, where the ground does not freeze, following their prey - earthworms, larvae and other invertebrate inhabitants of the soil.

Shore swallows, bee-eaters, kingfishers, rollers, puffins, or puffins, tubebills and some other birds make their nests in the ground, digging special holes for this. This improves air access to the soil. In places of mass nesting of birds, as a result of the accumulation of nutrients - fertilizers coming from droppings, a kind of herbaceous vegetation is formed. In the north, their burrows have more vegetation than in other places. The burrows of earth-moving rodents - marmots, mole mole rats, mole rats, gophers, jerboas, voles - also contribute to changes in the composition of the soil.

Observations of soil animals, carried out in a school biology club or a club at a young naturalists station on the instructions of scientists, will help expand your knowledge.

Many birds, mammals, reptiles, insects, etc. live on the surface of the earth. However, there are also animals that live underground. This article will tell you about creatures that live underground almost their entire lives. Underground animals - who lives underground photo TOP 10 - look!

Underground animals - who lives underground photo TOP 10

Naked mole rat

Underground animals - who lives underground photo - naked mole rat

This small rodent belongs to the mole rat family. Its distinctive features are cold-bloodedness, lack of sensitivity to pain and various acids. Of all the rodents, the naked mole rat lives the longest - 28 years. Perhaps this baby may outwardly scare someone, but in reality this animal is not aggressive and kind.

Giant mole rat

Underground animals - who lives underground photo - giant mole rat

Of all the representatives of mole rats, the giant mole rat is the largest. This giant reaches 35 centimeters in length and weighs about one kilogram. The upper body is colored light gray or ocher-brown. This underground creature lives only underground, never emerging from its structures. Mole rats love to build multi-tiered systems of entrances and exits. Most often, they dig their feeding passages at a depth of 30-50 centimeters, usually in layers of sand. The entire length of these feeds reaches 500 meters, but there are passages even shorter. Storerooms and nesting chambers of mole rats are located at a depth of up to 3 meters. These creatures have huge teeth that can easily bite through the bayonet of a shovel, so it is better not to pick them up.

Underground animals - who lives underground photo - mole

Even small children know that the mole is an underground animal. Moles belong to mammals, to the order of insectivores. Moles live in Eurasia and North America. Moles come in both very small and large sizes. For example, some of them barely reach 5 centimeters, while others grow up to 20 centimeters. The weight of moles ranges from 9 grams to 170 grams. Moles are perfectly adapted to life underground. The body of these creatures is elongated, round, on which there is smooth and velvety fur. The main feature of the mole, which helps it move in any direction underground, is its fur coat, the fibers of which grow upward.

Tuco-tuco

Underground animals - who lives underground photo - tuco-tuco

Tiny rodents whose weight does not exceed 700 grams. The babies reach 20-25 centimeters in length, and the length of their tail can reach 8 centimeters. The morphological characteristics of these animals fully indicate that they are adapted to life underground. Tuco-tuco leads an exclusively underground lifestyle, they build many intricate passages in which their storerooms, latrines and nesting chambers are stored. Animals use sandy or loose soils to build their homes.

Underground animals - who lives underground photo - gopher

The next creature reaches 10-35 centimeters in length, and its tail is 5-15 centimeters. The weight of gophers barely reaches one kilogram. The animals spend most of their lives in their intricate passages, which they make on various soil horizons. The length of the tunnels can reach 100 meters.

spotted snake

Underground animals - who lives underground photo - spotted snake

This species belongs to the cylindrical genus. The snake is quite small in size, but very dense. The color of the snake is black with brown spots arranged in two rows. It lives only underground and feeds on earthworms.

Underground animals - who lives underground photo - simple crucian carp

This fish almost always lives in the bottom mule, but when the reservoir dries up, it burrows underground. Crucian carp can dig from 1 to 10 meters, and can live underground for several years.

Medvedka

Underground animals - who lives underground photo - mole cricket

This insect is one of the largest. The mole cricket can grow up to 5 centimeters in length. The belly of this creature is three times larger than the cephalothorax, soft to the touch, and reaches 1 centimeter in diameter. At the end of the abdomen there are thread-like paired appendages, the length of which is 1 centimeter. Like other creatures on this list, the mole cricket leads an underground lifestyle, but there are times when the insect comes to the surface, usually at night.

Chafer

Underground animals - who lives underground photo - cockchafer

Adults of the eastern type reach a length of 28 millimeters, and of the western type - 32 millimeters. Their body is black and their wings are dark brown. May beetles live underground, but in May they come to the surface and live there for about two months. After two weeks, the mating process occurs, as a result of which the female lays eggs underground at a depth of 20 centimeters. The process of laying eggs can be carried out in several stages at once, as a result of which the female lays about 70 eggs. As soon as the clutch comes to an end, the female immediately dies.

Earthworm

Underground animals - who lives underground photo - earthworm

The worms grow up to 2 meters in length, and their body consists of a huge number of ring-shaped segments. When moving, the worms rely on special bristles, which are located on each ring, with the exception of the front one. The approximate number of bristles on each segment ranges from 8 to several dozen. Earthworms can be found everywhere except Antarctica, as they do not live there. Despite the fact that they lead an underground lifestyle, worms crawl to the surface of the earth after rain, which is why they got their name.

We have known these animals since childhood. They live in the soil, under our feet: lazy earthworms, clumsy larvae, nimble centipedes are born from earthen lumps crumbling under a shovel. Often we disdainfully throw them aside or immediately destroy them as pests of garden plants. How many of these creatures inhabit the soil and who are they? friends or enemies?

The study of soil-dwelling animals is the subject of a special branch of science - soil zoology, which was formed only in the last century. After specialists developed methods for recording and recording these 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. In terms of biological diversity, the fauna of the soil can only be compared with coral reefs - a classic example of the richest and most diverse natural communities on our planet.

Gullivers are here too, it seems earthworms, and Lilliputians, who 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. Lilliputians 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 1 m2, and small forms - in hundreds of thousands and even millions of individuals. Here, for example, are the simplest and roundworms (nematodes), with body sizes up to one hundredth of a millimeter. In terms of their physiology, these are typically aquatic creatures capable of breathing oxygen dissolved in water. The smallest sizes allow such animals to be content with microscopic droplets of moisture filling narrow soil cavities. There they move, find food, and reproduce. When the soil dries out, these creatures are able to remain in an inactive state for a long time, becoming covered on the outside with a dense protective shell of solidified secretions.

The larger Lilliputians include soil mites, springtails, and small worms - the closest relatives of earthworms. These are already real land animals. They breathe atmospheric oxygen, inhabit airborne subsoil cavities, root passages, and burrows of larger invertebrates. Their small size and flexible body allow them to use even the narrowest gaps between soil particles and penetrate into the 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 we encounter various groups of worms, terrestrial mollusks, crustaceans (woodlice, amphipods), spiders, harvestmen, pseudoscorpions, centipedes, ants, termites, larvae (beetles, dipterous and hymenopteran insects), and butterfly caterpillars. The inhabitants of the underground kingdom also include some species of vertebrates that live in burrows and feed on soil invertebrates or plant roots. These are the well-known moles, gophers, etc. The soil passages are too small for them, so the giants had to acquire special devices for moving in dense substrate.

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, scraper or pick. For example, the front legs are transformed into highly specialized digging tools - they are expanded, with jagged edges. These scrapers are capable of loosening even very dry soil. In beetle larvae, which dig to a considerable depth, the upper jaws, which have the form of triangular pyramids with a jagged top and powerful ridges on the sides, serve as loosening tools. 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.

The digging activity of animals is of great importance for the soil. The passage system improves its aeration, which favors root growth 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.”

In recent years, many publications have appeared about these animals, which are capable of quickly processing plant residues, manure, and household waste, turning them into high-quality “ vermicompost" In many countries, including ours, they have learned to breed worms on special farms to produce organic fertilizers and as a source of feed protein for fish and poultry.

The following examples will help to evaluate the contribution of invisible soil organisms in the formation of 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 wood lice, living in Central Asia, lift soil enriched with elements of mineral nutrition for plants from a depth of 50-80 cm to the surface. 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. This is on our soddy-podzolic soils near Moscow.

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.

Man has learned to fertilize it and get high yields. Does this replace animal activities? To some extent, yes. But with intensive land use using 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 of natural processes occur, which lead to gradual soil degradation and a decrease in its fertility. Excessive amounts of mineral fertilizers poison the soil and deteriorate the quality of agricultural products.

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 of our economy and our thinking, it is worth thinking about what criteria to assess 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 of the Earth, capable of self-restoring its fertility, it is necessary, first of all, to preserve its animal world. Little visible and invisible workers are doing what a person with his powerful technology cannot yet do. They need to be protected not only in nature reserves and national parks, but also on lands used by humans. Animals need a stable environment. They need oxygen in the system of passages made and a supply of organic residues, shelters that are not disturbed by humans, where animals breed and find shelter from cold and drought. And we carefully remove the remains of roots and stems from the beds, trample the soil around the beds, and apply mineral fertilizers that dramatically change the composition of the soil solution. Reasonable farming, including homestead farming, also means creating suitable conditions for preserving the animal life of the soil - the key to it. Seven years ago, on my garden plot, which was prone to water erosion, I switched to a sod-humus soil maintenance system. The site is located on the Volga slope with a slope of 30-50°...