A food chain is the transfer of energy from its source through a series of organisms. All living beings are connected, as they serve as food objects for other organisms. All food chains consist of three to five links. The first are usually producers - organisms that are capable of producing organic substances from inorganic ones themselves. These are plants that obtain nutrients through photosynthesis. Next come the consumers - these are heterotrophic organisms that receive ready-made organic substances. These will be animals: both herbivores and carnivores. The closing link of the food chain is usually decomposers - microorganisms that decompose organic matter.

The food chain cannot consist of six or more links, since each new link receives only 10% of the energy of the previous link, another 90% is lost in the form of heat.

What are food chains?

There are two types: pasture and detritus. The former are more common in nature. In such chains, the first link is always the producers (plants). They are followed by consumers of the first order - herbivorous animals. Further - consumers of the second order - small predators. Behind them - consumers of the third order - large predators. Further, there may also be fourth-order consumers, such long food chains are usually found in the oceans. The last link is the decomposers.

The second type of power circuits - detritus- more common in forests and savannahs. They arise due to the fact that most of the plant energy is not consumed by herbivorous organisms, but dies off, then being decomposed by decomposers and mineralized.

Food chains of this type start from detritus - organic residues of plant and animal origin. First-order consumers in such food chains are insects, such as dung beetles, or scavengers, such as hyenas, wolves, vultures. In addition, bacteria that feed on plant residues can be first-order consumers in such chains.

In biogeocenoses, everything is connected in such a way that most types of living organisms can become participants in both types of food chains.

Food chains in deciduous and mixed forests

Deciduous forests are mostly distributed in the Northern Hemisphere of the planet. They are found in Western and Central Europe, in Southern Scandinavia, in the Urals, in Western Siberia, East Asia, North Florida.

Deciduous forests are divided into broad-leaved and small-leaved. The former are characterized by such trees as oak, linden, ash, maple, elm. For the second - birch, alder, aspen.

Mixed forests are those in which both coniferous and deciduous trees grow. Mixed forests are characteristic of the temperate climate zone. They are found in the south of Scandinavia, in the Caucasus, in the Carpathians, in the Far East, in Siberia, in California, in the Appalachians, near the Great Lakes.

Mixed forests consist of trees such as spruce, pine, oak, linden, maple, elm, apple, fir, beech, hornbeam.

Very common in deciduous and mixed forests pasture food chains. The first link in the food chain in the forests are usually numerous types of herbs, berries such as raspberries, blueberries, strawberries. elderberry, tree bark, nuts, cones.

First-order consumers will most often be such herbivores as roe deer, elk, deer, rodents, for example, squirrels, mice, shrews, and also hares.

Second order consumers are predators. Usually it is a fox, wolf, weasel, ermine, lynx, owl and others. A vivid example of the fact that the same species participates in both pasture and detrital food chains will be the wolf: it can both hunt small mammals and eat carrion.

Second-order consumers can themselves become prey to larger predators, especially birds: for example, small owls can be eaten by hawks.

The closing link will be decomposers(decay bacteria).

Examples of food chains in a deciduous-coniferous forest:

• birch bark - hare - wolf - decomposers;
• wood - Maybug larva - woodpecker - hawk - decomposers;
• leaf litter (detritus) - worms - shrews - owl - decomposers.

Features of food chains in coniferous forests

Such forests are located in the north of Eurasia and North America. They consist of trees such as pine, spruce, fir, cedar, larch and others.

Here everything is very different from mixed and deciduous forests.

The first link in this case will not be grass, but moss, shrubs or lichens. This is due to the fact that in coniferous forests there is not enough light for a dense grass cover to exist.

Accordingly, the animals that will become consumers of the first order will be different - they should not eat grass, but moss, lichens or shrubs. It can be some types of deer.

Despite the fact that shrubs and mosses are more common, herbaceous plants and bushes are still found in coniferous forests. These are nettle, celandine, strawberry, elderberry. Hares, moose, squirrels usually eat such food, which can also become first-order consumers.

The consumers of the second order will be, like mixed forests, predators. These are mink, bear, wolverine, lynx and others.

Small predators such as mink can become prey for third order consumers.

The closing link will be the microorganisms of decay.

In addition, in coniferous forests are very common detrital food chains. Here, the first link will most often be plant humus, which is fed by soil bacteria, becoming, in turn, food for unicellular animals that are eaten by fungi. Such chains are usually long and may consist of more than five links.

Examples of food chains in a coniferous forest:

• pine nuts - squirrel - mink - decomposers;
• plant humus (detritus) - bacteria - protozoa - fungi - bear - decomposers.

Most living organisms eat organic food, this is the specificity of their life on our planet. Among this food are plants, and the meat of other animals, their products of activity and dead matter, ready for decomposition. The very process of nutrition in different species of plants and animals occurs in different ways, but the so-called They are always formed, they transform matter and energy, and nutrients can thus pass from one creature to another, carrying out the circulation of substances in nature.

in the forest

Forests of various kinds cover quite a lot of land surface. It is the lungs and the instrument of cleansing our planet. It is not for nothing that many progressive modern scientists and activists oppose mass deforestation today. The food chain in the forest can be quite diverse, but, as a rule, includes no more than 3-5 links. In order to understand the essence of the issue, let us turn to the possible components of this chain.

Producers and consumers

1. The first are autotrophic organisms that feed on inorganic food. They take energy and matter to create their own bodies, using gases and salts from their environment. An example is green plants that get their nutrition from sunlight through photosynthesis. Or numerous types of microorganisms that live everywhere: in the air, in the soil, in the water. It is the producers that for the most part make up the first link in almost any food chain in the forest (examples will be given below).
2. The second are heterotrophic organisms that feed on organic matter. Among them are those of the first order that directly carry out nutrition at the expense of plants and bacteria, producers. The second order - those who eat animal food (predators or carnivores).

Plants

As a rule, the food chain in the forest begins with them. They are the first link in this cycle. Trees and shrubs, grasses and mosses get their food from the organic matter using sunlight, gases and minerals. A food chain in a forest, for example, may begin with a birch tree, the bark of which is eaten by a hare, who, in turn, is killed and eaten by a wolf.

herbivorous animals

In a variety of forests, animals that feed on plant foods are found in abundance. Of course, for example, it is very different in its content from the land middle lane. They live in the jungle different kinds animals, many of which are herbivores, which means they make up the second link in the food chain, eating plant foods. From elephants and rhinos to barely visible insects, from amphibians and birds to mammals. So, in Brazil, for example, there are more than 700 species of butterflies, almost all of them are herbivores.

Poorer, of course, is the fauna in the forest belt of central Russia. Accordingly, there are much fewer options for the supply chain. Squirrels and hares, other rodents, deer and elk, hares - this is the basis for such chains.

Predators or carnivores

They are called so because they eat flesh, eating the meat of other animals. They occupy a dominant position in the food chain, often being the final link. In our forests, these are foxes and wolves, owls and eagles, sometimes bears (but in general they belong to which they can eat both plant and animal food). In the food chain, both one and several predators can take part, eating each other. The final link, as a rule, is the largest and most powerful carnivore. In the forest of the middle lane, this role can be played, for example, by a wolf. There are not too many such predators, and their population is limited by the food base and energy reserves. Since, according to the law of conservation of energy, when nutrients pass from one link to the next, up to 90% of the resource can be lost. This is probably why the number of links in most food chains cannot exceed five.

Scavengers

They feed on the remains of other organisms. Oddly enough, there are also quite a lot of them in the nature of the forest: from microorganisms and insects to birds and mammals. Many beetles, for example, use the corpses of other insects and even vertebrates as food. And bacteria are able to decompose the dead bodies of mammals in a fairly short time. Scavenging organisms play a huge role in nature. They destroy matter, transforming it into inorganic substances, release energy, using it for their life activity. If it were not for scavengers, then, probably, the entire earthly space would be covered with the bodies of animals and plants that have died for all time.

in the forest

To make a food chain in the forest, you need to know about those inhabitants who live there. And also about what these animals can eat.

1. Birch bark - insect larvae - small birds - birds of prey.
2. Fallen leaves - bacteria.
3. Butterfly caterpillar - mouse - snake - hedgehog - fox.
4. Acorn - mouse - fox.
5. Cereals - mouse - eagle owl.

There are also more authentic ones: fallen leaves - bacteria - earthworms - mice - mole - hedgehog - fox - wolf. But, as a rule, the number of links is not more than five. The food chain in a spruce forest is slightly different from that in a deciduous forest.

1. Cereal seeds - sparrow - wild cat.
2. Flowers (nectar) - butterfly - frog - already.
3. Fir cone - woodpecker - eagle.

Food chains can sometimes intertwine with each other, forming more complex, multi-level structures that combine into a single forest ecosystem. For example, the fox does not disdain to eat both insects and their larvae and mammals, so several food chains intersect.

Every organism must receive energy for life. For example, plants consume energy from the sun, animals feed on plants, and some animals feed on other animals.

A food (trophic) chain is a sequence of who eats whom in a biological community () to obtain nutrients and energy that support life.

Autotrophs (producers)

Autotrophs- living organisms that produce their food, that is, their own organic compounds, from simple molecules such as carbon dioxide. There are two main types of autotrophs:

• Photoautotrophs (photosynthetic organisms), such as plants, convert energy from sunlight to produce organic compounds- sugars - from carbon dioxide in the process. Other examples of photoautotrophs are algae and cyanobacteria.
• Chemoautotrophs obtain organic matter through chemical reactions involving inorganic compounds (hydrogen, hydrogen sulfide, ammonia, etc.). This process is called chemosynthesis.

Autotrophs are the backbone of every ecosystem on the planet. They make up the majority of food chains and webs, and the energy derived from photosynthesis or chemosynthesis sustains all other organisms in ecological systems. When we are talking about their role in food chains, autotrophs can be called producers or producers.

Heterotrophs (consumers)

Heterotrophs, also known as consumers, cannot use solar or chemical energy to produce their own food from carbon dioxide. Instead, heterotrophs obtain energy by consuming other organisms or their by-products. Humans, animals, fungi and many bacteria are heterotrophs. Their role in food chains is to consume other living organisms. There are many types of heterotrophs with different ecological roles, from insects and plants to predators and fungi.

Destructors (reducers)

Another group of consumers should be mentioned, although it does not always appear in food chain diagrams. This group consists of decomposers, organisms that process dead organic matter and waste, turning them into inorganic compounds.

Decomposers are sometimes considered a separate trophic level. As a group, they feed on dead organisms supplied at various trophic levels. (For example, they are able to process decaying plant matter, the body of a squirrel undereaten by predators, or the remains of a dead eagle.) In a sense, the trophic level of decomposers runs parallel to the standard hierarchy of primary, secondary, and tertiary consumers. Fungi and bacteria are key decomposers in many ecosystems.

Decomposers, as part of the food chain, play an important role in maintaining a healthy ecosystem, because thanks to them, nutrients and moisture return to the soil, which are further used by producers.

Food (trophic) chain levels

Scheme of food (trophic) chain levels

A food chain is a linear sequence of organisms that transfer nutrients and energy from producers to top predators.

The trophic level of an organism is the position it occupies in the food chain.

First trophic level

The food chain starts with autotrophic organism or producer that produces its own food from a primary source of energy, usually solar or hydrothermal energy from mid-ocean ridges. For example, photosynthetic plants, chemosynthetic and.

Second trophic level

This is followed by organisms that feed on autotrophs. These organisms are called herbivores or primary consumers and consume green plants. Examples include insects, hares, sheep, caterpillars, and even cows.

Third trophic level

The next link in the food chain are animals that eat herbivores - they are called secondary consumers or carnivorous (predatory) animals(for example, a snake that feeds on hares or rodents).

Fourth trophic level

In turn, these animals are eaten by larger predators - tertiary consumers(for example, an owl eats snakes).

Fifth trophic level

Tertiary consumers eat quaternary consumers(for example, a hawk eats owls).

Each food chain ends with a top predator or superpredator - an animal without natural enemies (for example, a crocodile, a polar bear, a shark, etc.). They are the "masters" of their ecosystems.

When an organism dies, it is eventually eaten by detritivores (such as hyenas, vultures, worms, crabs, etc.) and the rest is decomposed with the help of decomposers (mainly bacteria and fungi), and energy exchange continues.

Arrows in the food chain show the flow of energy, from the sun or hydrothermal vents to top predators. As energy flows from body to body, it is lost at every link in the chain. The collection of many food chains is called food web.

The position of some organisms in the food chain can vary because their diet differs. For example, when a bear eats berries, it acts as a herbivore. When it eats a plant-eating rodent, it becomes a primary predator. When a bear eats salmon, it acts as a super predator (this is due to the fact that salmon is a primary predator, since it feeds on herring, and she eats zooplankton, which feeds on phytoplankton that produce their own energy from sunlight). Think about how people's place in the food chain changes, even often within a single meal.

Types of food chains

In nature, as a rule, two types of food chains are distinguished: pasture and detrital.

pasture food chain

Diagram of a pasture food chain

This type of food chain begins with living green plants that are meant to feed on herbivorous animals that feed on predators. Ecosystems with this type of circuit are directly dependent on solar energy.

Thus, the grazing type of the food chain depends on the autotrophic capture of energy and its movement along the links of the chain. Most ecosystems in nature follow this type of food chain.

Pasture food chain examples:

• Grass → Grasshopper → Bird → Hawk;
• Plants → Hare → Fox → Lion.

detrital food chain

Diagram of the detritus food chain

This type of food chain starts with decaying organic material - detritus - which is consumed by detritus feeders. Then, predators feed on detritophages. Thus, such food chains are less dependent on direct solar energy than grazing ones. The main thing for them is the influx of organic substances produced in another system.

For example, this type of food chain is found in decaying bedding.

Energy in the food chain

Energy is transferred between trophic levels when one organism feeds on another and receives nutrients from it. However, this movement of energy is inefficient, and this inefficiency limits the length of food chains.

When energy enters the trophic level, some of it is stored as biomass, as part of the body of organisms. This energy is available for the next trophic level. Typically, only about 10% of the energy that is stored as biomass at one trophic level is stored as biomass at the next level.

This principle of partial energy transfer limits the length of food chains, which typically have 3-6 levels.

At each level, energy is lost in the form of heat, as well as in the form of waste and dead matter, which are used by decomposers.

Why does so much energy exit the food web between one trophic level and another? Here are some of the main reasons for inefficient power transfer:

• At each trophic level, a significant amount of energy is dissipated as heat as organisms perform cellular respiration and move about in daily life.
• Some organic molecules that organisms feed on cannot be digested and pass out in the form of feces.
• Not all individual organisms in a trophic level will be eaten by organisms from the next level. Instead, they die without being eaten.
• Feces and uneaten dead organisms become food for decomposers, which metabolize them and convert them into their own energy.

So, none of the energy actually disappears - all this eventually leads to the release of heat.

Importance of the food chain

1. Food chain studies help understand food relationships and interactions between organisms in any ecosystem.

2. Thanks to them, it is possible to evaluate the mechanism of energy flow and the circulation of substances in the ecosystem, as well as to understand the movement of toxic substances in the ecosystem.

3. Studying the food chain allows you to understand the problems of biomagnification.

In any food chain, energy is lost each time one organism is consumed by another. In this regard, there must be many more plants than herbivorous animals. There are more autotrophs than heterotrophs, and therefore most of them are herbivores rather than predators. Although there is intense competition between animals, they are all interconnected. When one species goes extinct, it can affect many other species and have unpredictable consequences.

In order to answer this question and correctly draw up food chains, you first need to find out what food chains are.

What is a "supply chain"

The food chain is the main relationship of animals, plants, insects to supply themselves with food (or being food). A food chain, or in other words, a food chain, is a series of organisms that feed on each other. That is, each creature feeds on another creature and is itself food for other organisms. Hence the name "chain", that is, sequentially, one after the other, it is a closed system. The chain may include microorganisms, fungi, insects, plants, animals. There is a clear distribution between them - one is food, the other is a consumer. Food chains, both animal and human, usually begin with plants.

Food chains can be made not only on and in soil, but also in water, in the sky, in the forest-steppe, and so on. It may also be that there is an association of different tiers, animals living on these tiers and plants growing on them. For example, an insect that lives on the soil is food for a bird that lives in the air, in the upper tier. That is, it is not necessary that the food chain consists of animals and plants from only one tier.

An example of food chains in soil

Above, we found out what a food chain is. In order to make examples of food chains in the soil, you need to find out who is the inhabitant of the soil, who can participate in these chains.

• Firstly, these are worms, larvae, insects.
• Secondly, these are various microorganisms, decayed plants, tree roots and other growing organisms.
• Thirdly, these are animals, such as a mole, a shrew, a bear and the like.

Knowing the inhabitants of the soil, we can already compose food chains. For example:

• decayed plant remains -> earthworms -> moles -> hedgehogs;
• plant root -> ant larva -> shrews;
• plant root -> beetle -> mole.

Thus, we have compiled three examples of a food chain in soil. Many more similar examples could be made.

January 28, 2016

A meadow is a piece of land on which perennial herbaceous vegetation grows, forming a corresponding cover. Meadows usually occur on highly fertile soils, and in order for herbs to form, a favorable water and temperature regime of the environment is needed. Meadow food chains have their own characteristics. The first link is usually made up of various - annual and perennial - plants that grow in abundance there. Among them are cereals, legumes, rosette and creeping, well-known flowers: bluebells, poppies, chamomile, cornflowers, clover and many others.

Meadow food chains

In the meadow, as in other areas where animals and plants grow in abundance, these food sequences are formed according to standard rules. The participants in the process are traditionally divided into producers and consumers. The former consume energy and nutrition for their functioning directly from materials that are not organic. So, most green plants get their nutrition through the process of photosynthesis in the sun. And microorganisms living in the soil in the meadow (in one gram of fertile land up to a million or more) use gases and salts for energy. Such producers are, as a rule, the first link in the meadow food chain. They are consumed by first plan consumers who eat plant foods, getting the necessary energy from it. Next come the consumers of the second (third, fourth) level, which are carnivorous, that is, they feed on animal food. Closes the food chain of the meadow, as a rule, the strongest, fastest and largest predator that is found in this area. There are usually not many such animals, and their populations are limited.

Food chains in the meadow. Examples

Now let's move on to compiling these sequences. Usually they can consist of several links (sometimes 5-6). To compose a food chain for a meadow, knowledge is required: who lives in a given area, what kind of food base this or that animal has. We propose the following chain:

clover - butterfly - dragonfly - frog - already - hawk.

The first link in this composed sequence of 6 links is the plant, which receives inorganic substances from the soil and air and, with the help of sunlight and the process of photosynthesis, converts them into life energy. Butterfly, consumer of the first type, feeds on plant and nectar. The dragonfly eats the butterfly, the frog eats the dragonfly. Already eating frogs. And the snake itself can be eaten by a bird of prey, but a fox, for example, can also act as the last link.

to the pasture

There may also be a shorter supply chain, of 4 links, for example:

wheat - field mouse - snake (viper) - bird of prey (kite or hawk).

Another food chain characteristic of the meadow zones of the Russian Federation in the middle zone:

annual plant buttercup - orthoptera insect grasshopper - mammal shrew - bird of prey buzzard.

And in a pasture, a meadow where cows and other animals graze, a food chain can be built even with the participation of people as one of the final links:

the vegetation that a cow eats is a cow that gives milk and meat - a person.

Source: fb.ru

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