Food chain examples. Food chains

Portal for the student. Self-training

Autotrophs (producers)

Heterotrophs (consumers)

Destructors (reducers)

Food (trophic) chain levels

Types of food chains

Energy in the food chain

Importance of the food chain

First trophic level

Second trophic level

Third trophic level

Fourth trophic level

Fifth trophic level

pasture food chain

detritus food chain

TROPHIC CHAINS

Purpose of work: obtaining skills in compiling and analyzing food (trophic) chains.

General information

There are various connections between living organisms in ecosystems. One of the central links, which, as it were, cements a variety of organisms into one ecosystem, is food, or trophic. Food links unite organisms on the basis of the food-consumer principle. This leads to the emergence of food, or trophic chains. Within an ecosystem, energy-containing substances are created by autotrophic organisms and serve as food for heterotrophs. Food bonds are mechanisms for transferring energy from one organism to another. A typical example is an animal eating plants. This animal, in turn, can be eaten by another animal. In this way, energy can be transferred through a number of organisms.

Each subsequent feeds on the previous one, supplying it with raw materials and energy.

Such a sequence of transfer of food energy in the process of nutrition from its source through a successive series of living organisms is called food (trophic) chain, or power circuit. Trophic chains- this is the path of a unidirectional flow of solar energy absorbed in the process of photosynthesis through the living organisms of the ecosystem into the environment, where its unused part is dissipated in the form of low-temperature thermal energy.

mice, sparrows, pigeons. Sometimes in the ecological literature any food connection is called the “predator-prey” connection, meaning the predator is the eater. The stability of the predator-prey system is ensured by the following factors:

- the inefficiency of the predator, the flight of the prey;

- ecological restrictions imposed by the external environment on the population size;

- availability of alternative food resources for predators;

- reducing the delay in the reaction of a predator.

The place of each link in the food chain is trophic level. The first trophic level is occupied by autotrophs, or the so-called primary producers. Organisms of the second trophic level are called per-

primary consumers, the third - secondary consumers, etc.

Food chains are divided into two main types: pasture (grazing chains, consumption chains) and istritic (decomposition chains).

Plant → hare → wolf Producer → herbivore → carnivore

The following food chains are also widespread:

Plant material (e.g. nectar) → fly → spider → shrew → owl.

Rose bush sap → aphid → ladybug → spider → insectivorous bird → bird of prey.

In aquatic, in particular, marine ecosystems, the food chains of predators are longer than in terrestrial ones.

The detrital chain begins with dead organic matter - detritus, which is destroyed by detritivores eaten by small predators, and ends with the work of decomposers that mineralize organic residues. Deciduous forests play an important role in the detrital food chains of terrestrial ecosystems, most of the foliage of which is not eaten by herbivorous animals and is part of the forest litter. The leaves are crushed by numerous detritophages (fungi, bacteria, insects), then swallowed by earthworms, which evenly distribute humus in the surface layer of the soil, forming a mulle. Decaying

the micro-organisms that complete the chain produce the final mineralization of dead organic residues (Fig. 1).

In general, typical detrital chains of our forests can be represented as follows:

leaf litter → earthworm → blackbird → sparrow hawk;

dead animal → carrion fly larvae → common frog → snake.

Rice. 1. Detritus food chain (according to Nebel, 1993)

As an initial organic material that undergoes biological processing in the soil by organisms inhabiting the soil, wood can be considered as an example. Wood that falls on the soil surface is primarily processed by insect larvae of longhorn beetles, borers, borers, which use it as food. They are replaced by mushrooms, the mycelium of which primarily settles in the passages made in the wood by insects. Mushrooms loosen and destroy wood even more. Such loose wood and the mycelium itself turn out to be food for fireflower larvae. At the next stage, ants settle in the already heavily damaged wood, which destroy almost all larvae and create conditions for a new generation of fungi to settle in the wood. Snails begin to feed on such mushrooms. The destruction and humification of wood is completed by decomposer microbes.

The humification and mineralization of manure from wild and domestic animals entering the soil proceeds similarly.

As a rule, the food of each living being is more or less varied. Only all green plants "eat" the same way: carbon dioxide and mineral salt ions. In animals, cases of a narrow specialization of nutrition are quite rare. As a result of a possible change in animal nutrition, all organisms in ecosystems are involved in a complex network of food relationships. Food chains are closely intertwined with each other, form food or food webs. In a food web, each species is directly or indirectly related to many. An example of a food web with the distribution of organisms by trophic levels is shown in Fig. 2.

Food webs in ecosystems are very complex, and it can be concluded that the energy entering them migrates from one organism to another for a long time.

Rice. 2. Food web

Food connections play a dual role in biocenoses. First, they

provide the transfer of matter and energy from one organism to another.

Together, thus, species coexist that support each other's life. Second, food ties serve as a mechanism for regulating the numerical

Representation of food webs can be traditional (Fig. 2) or using directed graphs (digraphs).

A geometrically oriented graph can be represented as a set of vertices, denoted by circles with vertex numbers, and arcs connecting these vertices. An arc defines a direction from one vertex to another. A path in a graph is a finite sequence of arcs in which the beginning of each subsequent arc coincides with the end of the previous one. An arc can be denoted by a pair of vertices that it connects. A path is written as a sequence of vertices through which it passes. A path is a path whose start vertex coincides with the end vertex.

FOR EXAMPLE:

IN 3;

1, 2 or 1, 3, 2 - paths from the top

		to the top

In the power network, the top of the graph displays the simulation objects; arcs, indicated by arrows, lead from the victim to the predator.

Any living organism occupies a certain ecological niche. An ecological niche is a set of territorial and functional characteristics of the habitat that meet the requirements of a given species. No two species have identical niches in the ecological phase space. According to Gause's principle of competitive exclusion, two species with similar ecological requirements cannot occupy the same ecological niche for a long time. These species compete, and one of them displaces the other. Based on power networks, you can build competition graph. Living organisms in the competition graph are displayed as graph vertices, an edge is drawn between the vertices (connection without direction) if there is a living organism that serves as food for the organisms displayed by the above vertices.

The development of a competition graph allows you to identify competing species of organisms and analyze the functioning of the ecosystem and its vulnerability.

The principle of matching the growth of the complexity of the ecosystem and the increase in its stability is widespread. If an ecosystem is represented by a food web, different ways of measuring complexity can be used:

- determine the number of arcs;

- find the ratio of the number of arcs to the number of vertices;

To measure the complexity and diversity of the food web, the trophic level is also used, i.e. place of an organism in the food chain. The trophic level can be determined both by the shortest, as well as by the longest food chain from the considered peak, which has a trophic level equal to "1".

WORK PROCEDURE

Exercise 1

Make a network for 5 participants: grass, birds, insects, hares, foxes.

Task 2

Set the food chains and the trophic level according to the shortest and longest path of the food network from task "1".

		Trophic level and food chain
power supply	the shortest way		along the longest path

4 . Insects

Note: The pasture food chain starts with producers. The organism listed in column 1 is the upper trophic level. For consumers of the first order, the long and short paths of the trophic chain coincide.

Task 3

Propose a trophic web according to the task option (Table 1P) and make a table of trophic levels for the longest and shortest paths. Food preferences of consumers are given in table. 2P.

Task 4

Make a food web according to Fig. 3 and place its participants in trophic levels

REPORT OUTLINE

1. The purpose of the work.

2. Food web graph and competition graph based on the training example (tasks 1, 2).

3. Table of trophic levels according to the training example (task 3).

4. Food network graph, competition graph, table of trophic levels according to the task option.

5. Scheme of the trophic web with the placement of organisms by trophic levels (according to Fig. 3).

Rice. 3. Tundra biocenosis.

First row: small passerines, various two-winged insects, rough-legged buzzard. Second row: arctic fox, lemmings, snowy owl. Third row: white partridge, white hares. Fourth row: goose, wolf, reindeer.

Literature

1. Reimers N.F. Nature management: Dictionary reference. - M.: Thought, 1990. 637 p.

2. Animal life in 7 volumes. Moscow: Education, 1983-1989.

3. Zlobin Yu.A. General ecology. Kyiv: Naukova Dumka, 1998. - 430 p.

4. Stepanovskikh A.S. Ecology: Textbook for universities. – M.: UNITIDANA,

5. Nebel B. Environmental Science: How the World Works. – M.: Mir, 1993.

– v.1 – 424 p.

6. Ecology: Textbook for technical universities / L.I. Tsvetkova, M.I. Alekseev, and others; Ed. L.I. Tsvetkova.–M.: ASV; St. Petersburg: Himizdat, 2001.-552p.

7. Girusov E.V. and others. Ecology and economics of environmental management: Textbook for universities / Ed. Prof. E.V. Girusova. - M .: Law and Law, UNITI,

		Table 1P
		Species structure of biocenosis
	The name of the bio	Species composition of the biocenosis

	Cedar forest	Korean cedar, yellow birch, various-leaved hazel,
		sedge, white hare, flying squirrel, common squirrel,
		wolf, brown bear, Himalayan bear, sable,
		mouse, nutcracker, woodpecker, fern.
	waterlogged	Sedges, iris, common reed. A wolf, a fox come in,
		brown bear, roe deer, mouse. Amphibians - Siberian salamander
	reed grass	sky, tree frog of the Far East, Siberian frog. Snail-
		ka, earthworm. Birds - far eastern white
		stork, piebald harrier, pheasant, Japanese crane, Dahurian beetle
		ravl. Swallowtail butterflies.
	white birch	Aspen, flat-leaved birch (white) aspen, alder, dio-
		rather nipponskaya (herbaceous liana), cereals, sedges,
		forbs (clover, rank). Shrubs - lespedeza, row-
		binnik, meadowsweet. Mushrooms - boletus, boletus.
		Animals - raccoon dog, wolf, fox, bear boo
		red deer, Siberian red deer, roe deer, Siberian salamander, frog
		ka siberian, mouse. Birds - spotted eagle, titmouse,

	Spruce grass-	Plants - fir, larch, Korean cedar, maple, row-
		rowan binnik, honeysuckle, spruce, sedges, cereals.
	shrubby	Animals - white hare, common squirrel, flying squirrel
		ha, wolf, brown bear, Himalayan bear, sable,
		harza, lynx, red deer, elk, hazel grouse, owl, mouse, butterfly

		Plants - Mongolian oak, aspen, flat-leaved birch,
		linden, elm, maakia (the only one in the Far East
		tree belonging to the legume family), shrubs -
		lespedeza, viburnum, mountain ash, wild rose,
		herbs - lily of the valley, sedges, hellebore, wild garlic, bells,
		bells. Animals - chipmunk, raccoon dog
		ka, wolf, fox, brown bear, badger, weasel, lynx, ka-
		ban, red deer, roe deer, hare, Siberian salamander, tree frog
		Far Eastern, Siberian frog, mouse, lizard
		generative, jay, woodpecker, nuthatch, lumberjack beetle, blacksmith

		Plants - aspen, flat-leaved birch, hawthorn, shi-
		povnik, spirea, peony, cereals. Animals - raccoon
		dog, wolf, fox, brown bear, Siberian weasel, red deer, co
		sulya, Siberian salamander, Siberian frog, mouse, lizard
		viviparous, jay, woodpecker, nuthatch, spotted eagle,
		lumberjack beetle, grasshopper,

		Table 2P
	The food spectrum of some species

Living organisms		Food habits - "menu"
	Grass (cereals, sedges); bark of aspen, linden, hazel; berries (zemlyani-

	Cereal seeds, insects, worms.
Flying squirrel

	and their larvae.
Plants	They consume solar energy and minerals, water,
	oxygen, carbon dioxide.
	Rodents, hares, frogs, lizards, small birds.

Common squirrel	Pine nuts, hazel nuts, acorns, cereal seeds.
	Shrub seeds (eleutherococcus), berries (lingonberries), insects
	and their larvae.
Insect larvae	Mosquito larvae - algae, bacteria.
mosquitoes,	Dragonfly larvae are insects, fish fry.
	Herb juice.
	Rodents, hares, frogs, lizards.

Steller's sea eagle	Fish, small birds.

brown bear	Euryphage, gives preference to animal food: wild boars (swine-
	ki), fish (salmon). Berries (raspberry, bird cherry, honeysuckle, pigeons)
	ka), roots.
Himalayan bear-	Angelica (bear pipe), forest berries (lingonberries, raspberries,
	fly, blueberry), honey (wasps, bees), lilies (bulbs), mushrooms,
	nuts, acorns, ant larvae.
Insects	Herbaceous plants, tree leaves.

	Mouse, squirrel, hare, hazel grouse.
	Predator. Hares, squirrels, pigs.
		grass (wintering horsetail), legumes (vetch, rank),
		hazel bark, willows, birch undergrowth, shrub roots (le-
	china, raspberry).
	Buds of birch, alder, linden; cereals; rowan berries, viburnum; needles fir-
	you, spruce, larches.
	Mouse, chipmunk, hares, foxes, snakes (already, snake), lizard, white
	ka, bat.
	Mice, hares, roe deer, a flock can kill a deer, elk, wild boar.
Earwig	Predator. Fleas, beetles (small), slugs, earthworms.
Woodcutter beetle	Bark of birch, cedar, linden, maple, larch.
	Plant pollen.
peacock-eye
	Mouse, hare, chipmunk, Siberian salamander, crane chicks,
	stork, duck; Far Eastern tree frog, pheasants, worms,
	large insects.
	Bark of hazel, birch, willow, oak, sedge, reed grass, reed; leaves be-
	cuts, willows, oaks, hazels.
	Predator. Crustaceans, mosquito larvae.

Tree frog far-		Aquatic invertebrates.

		Herbs (reed grass), sedge, mushrooms, plant residues and soil.
		Plants, fish and its eggs during spawning, insects and their larvae

earthworm		Dead plant remains.
Far Eastern		Snail, tree frog, Siberian frog, fish (loach, rotan), snakes,
White stork		mice, locusts, chicks of passerines.
Japanese crane		Rhizomes of sedges, fish, frogs, small rodents, chicks.
harrier piebald		Mouse, small birds (buntings, warblers, sparrows), frogs,
		lizards, large insects.
		Buds of birch, alder, reed grass.
butterflies swallowtail		Plant pollen (violets, corydalis).
		Carnivorous gives preference to animal food - hares, young
		elk, roe deer, deer, wild boar.
Raccoon co-		Rotten fish, birds (larks, fescue, warblers).

		Branch forage (birch, aspen, willow, hazel; oak, linden leaves),
		acorns, oak bark, algae in shallow waters, three-leaf watch.
		Mosquito, spiders, ants, grasshoppers.

lizard		Insects and their larvae, earthworms.

spotted eagle		Predator. Small mammals, pheasant, mice, hares, foxes,
		birds, fish, rodents.
		Squirrels, chipmunks, birds.
Chipmunk		Seeds of apple-tree, wild rose, viburnum, fieldfare, mountain ash; mushrooms;
		nuts; acorns.
		Roots, earthworms, mice, insects (ants and their larvae).
		Predator. Mice.
		Cereal seeds, nuts.
		Pine nuts, acorns, berries (rowan), apple tree.
		Lumberjack beetles, woodworm insects.
		Wild boar, hare, roe deer, moose, deer, elk, deer (wounded animals).
Nuthatch		Insects; tree seeds, berries, nuts.
Lemmings		Granivorous. Sedges, shiksha, cereals.
		Granivorous.
		Predator. Lemmings, partridge chicks, gulls.
snowy owl		Lemmings, mice, voles, hares, ducks, pheasants, black grouse.

ptarmigan		Herbivorous. Cereal seeds; buds of birches, willows, alders.
		Herbivores, leaves and bark of trees, moss - reindeer moss.
white hare		In winter - bark; in summer - berries, mushrooms.
		Herbivores. Sedges, grasses, algae, shoots of aquatic plants.
Reindeer		Yagel, cereals, berries (cloudberries, cranberries), mice.
		Roe deer, red deer, spotted deer, wild boar.
Daphnia, cyclops		Unicellular algae.

The energy of the sun plays a huge role in the reproduction of life. The amount of this energy is very high (about 55 kcal per 1 cm2 per year). Of this amount, producers - green plants - as a result of photosynthesis fix no more than 1-2% of energy, and deserts and the ocean - hundredths of a percent.

The number of links in the food chain may be different, but usually there are 3-4 (rarely 5). The fact is that so little energy is supplied to the final link of the food chain that it will not be enough if the number of organisms increases.

Rice. 1. Food chains in the terrestrial ecosystem

The set of organisms united by one type of food and occupying a certain position in the food chain is called trophic level. Organisms that receive their energy from the Sun through the same number of steps belong to the same trophic level.

The simplest food chain (or food chain) may consist of phytoplankton, followed by larger herbivorous planktonic crustaceans (zooplankton), and the chain ends with a whale (or small predators) that filter these crustaceans from the water.

Nature is complex. All its elements, living and non-living, are one whole, a complex of interacting and interconnected phenomena and beings adapted to each other. These are links in the same chain. And if at least one such link is removed from the general chain, the results may be unexpected.

Breaking food chains can have a particularly negative impact on forests, whether they are forest biocenoses of the temperate zone or biocenoses of the tropical forest that are rich in species diversity. Many species of trees, shrubs or herbaceous plants use the services of a particular pollinator - bees, wasps, butterflies or hummingbirds that live within the range of this plant species. As soon as the last flowering tree or herbaceous plant dies, the pollinator will be forced to leave this habitat. As a result, phytophages (herbivores) that feed on these plants or fruits of the tree will die. Predators that hunt phytophages will be left without food, and then changes will sequentially affect the rest of the food chain. As a result, they will also affect a person, since he has his own specific place in the food chain.

Food chains can be divided into two main types: grazing and detrital. Food prices that begin with autotrophic photosynthetic organisms are called pasture, or eating chains. At the top of the pasture chain are green plants. Phytophages are usually found at the second level of the pasture chain; animals that eat plants. An example of a pasture food chain is the relationship between organisms in a floodplain meadow. Such a chain begins with a meadow flowering plant. The next link is a butterfly that feeds on the nectar of a flower. Then comes the inhabitant of wet habitats - the frog. Its protective coloration allows it to lie in wait for the victim, but does not save it from another predator - the common grass snake. The heron, having caught the snake, closes the food chain in the floodplain meadow.

If the food chain begins with dead plant remains, corpses and animal excrement - detritus, it is called detritus, or decomposition chain. The term "detritus" means a decay product. It is borrowed from geology, where the products of the destruction of rocks are called detritus. In ecology, detritus is the organic matter involved in the decomposition process. Such chains are characteristic of the communities of the bottom of deep lakes and oceans, where many organisms feed on detritus formed by dead organisms from the upper illuminated layers of the reservoir.

In forest biocenoses, the detrital chain begins with the decomposition of dead organic matter by saprophage animals. Soil invertebrates (arthropods, worms) and microorganisms take the most active part in the decomposition of organic matter. There are also large saprophages - insects that prepare the substrate for organisms that carry out mineralization processes (for bacteria and fungi).

In contrast to the pasture chain, the size of organisms does not increase when moving along the detrital chain, but, on the contrary, decreases. So, gravedigger insects can stand on the second level. But the most typical representatives of the detrital chain are fungi and microorganisms that feed on dead matter and complete the process of bioorganic decomposition to the state of the simplest mineral and organic substances, which are then consumed in dissolved form by the roots of green plants at the top of the pasture chain, thereby starting a new circle of movement of matter.

In some ecosystems, pasture chains predominate, in others, detrital chains. For example, a forest is considered an ecosystem dominated by detrital chains. In the rotting stump ecosystem, there is no grazing chain at all. At the same time, for example, in the ecosystems of the sea surface, almost all producers represented by phytoplankton are consumed by animals, and their corpses sink to the bottom, i.e. leave the published ecosystem. These ecosystems are dominated by grazing or grazing food chains.

General rule concerning any the food chain, states: at each trophic level of the community, most of the energy absorbed with food is spent on maintaining life, dissipated and can no longer be used by other organisms. Thus, the food consumed at each trophic level is not fully assimilated. A significant part of it is spent on metabolism. With each subsequent link in the food chain, the total amount of usable energy transferred to the next higher trophic level decreases.

Hope Lichman
GCD "Food chains in the forest" (preparatory group)

Target. To give children an idea of the relationships that exist in nature, about food chains.

Tasks.

To expand children's knowledge about the relationship of plants and animals, their food dependence on each other;

To form the ability to make food chains, to justify them;

To develop the speech of children, answering the questions of the teacher; enrich the dictionary with new words: relationship in nature, link, chain, food chain.

Develop children's attention, logical thinking.

Contribute to the education of interest in nature, curiosity.

Methods and techniques:

Visual;

Verbal;

Practical;

Problem-search.

Forms of work: conversation, task, explanation, didactic game.

Educational Development Areas: cognitive development, speech development, social and communicative development.

Material: bibabo grandmother toy, owl toy, illustrations of plants and animals (clover, mouse, owl, grass, hare, wolf, cards of plants and animals (leaf, caterpillar, bird, spikelets, mouse, fox, clock, balloon, meadow layout, emblems green and red according to the number of children.

Reflection.

Children sit on chairs in a semicircle. Knock on the door. Grandma (bibabo doll) comes to visit.

Hello guys! I came to visit you. I want to tell you a story that happened in our village. We live near the forest. The inhabitants of our village tend cows in the meadow, which is located between the village and the forest. Our cows ate clover and gave a lot of milk. At the edge of the forest, in the hollow of an old large tree, lived an owl that slept during the day, and at night flew to hunt and hooted loudly. The cry of the owl prevented the villagers from sleeping, and they drove her away. The owl got offended and flew away. And suddenly, after a while, the cows began to lose weight and give very little milk, since there was little clover, but there were many mice. We cannot understand why this happened. Help us get everything back!

Goal setting.

Guys, do you think we can help the grandmother and the villagers? (children's answers)

How can we help the villagers? (children's answers)

Joint activities of children and teacher.

Why did it happen that the cows began to give little milk?

(There was not enough clover.) The teacher lays out a picture of clover on the table.

Why is there not enough clover?

(Mice gnawed.) The teacher lays out a picture of a mouse.

Why are there so many mice? (The owl flew away.)

Who hunted mice?

(There is no one to hunt, the owl has flown away.) A picture of an owl is laid out.

Guys, we have a chain: clover - mouse - owl.

Do you know what other chains are?

The teacher shows a chain decoration, a door chain, a picture of a dog on a chain.

What is a chain? What does it consist of? (children's answers)

From links.

If one link in the chain breaks, what will happen to the chain?

(The chain will break, break.)

Correctly. Let's look at our chain: clover - mouse - owl. Such a chain is called a food chain. Why do you think? Clover is food for mice, mice are food for owls. Therefore, the chain is called the food chain. Clover, mouse, owl are the links of this chain. Think about it, is it possible to remove a link from our food chain?

No, the chain will break.

Let's remove the clover from our chain. What will happen to the mice?

They will have nothing to eat.

If the mice disappear?

If an owl flies away?

What mistake did the villagers make?

They destroyed the food chain.

Correctly. What conclusion do we draw?

It turns out that in nature all plants and animals are interconnected. They cannot do without each other. What needs to be done so that the cows again give a lot of milk?

Bring back the owl, restore the food chain. The children call the owl, the owl returns to the hollow of the old big tree.

So we helped the grandmother and all the villagers, returned everything back.

And now you and your grandmother and I will play the didactic game “Who eats whom?”, We will practice and train our grandmother in compiling food chains.

But first, let's remember who lives in the forest?

Animals, insects, birds.

What are the names of animals and birds that eat plants?

Herbivores.

What are the names of animals and birds that eat other animals?

What are the names of animals and birds that eat both plants and other animals?

Omnivorous.

Here are pictures of animals, birds. On the pictures depicting animals and birds, circles of different colors are pasted. Predatory animals and birds are marked with a red circle.

Herbivores and birds are marked with a green circle.

Omnivorous - blue circle.

Children have sets of pictures of birds, animals, insects and cards with a yellow circle on their tables.

Listen to the rules of the game. Each player has his own field, the presenter shows a picture and names the animal, you must make the correct food chain, who eats whom:

1 cell - these are plants, a card with a yellow circle;

2 cells are animals that eat plants (herbivores - with a green circle, omnivores - with a blue circle);

3 cells are animals that feed on animals (predators - with a red circle; omnivores - in blue). Dash cards complete your chain.

The winner is the one who correctly assembles the chain, it can be long or short.

Independent activity of children.

Plants - mouse - owl.

Birch - hare - fox.

Pine seeds - squirrel - marten - hawk.

Grass - elk - bear.

Grass - hare - marten - eagle owl.

Nuts - chipmunk - lynx.

Acorns - boar - bear.

Cereal grain - mouse vole - ferret - owl.

Grass - grasshopper - frog - snake - falcon.

Nuts - squirrel - marten.

Reflection.

Did you like our communication with you?

What did you like?

What new did you learn?

Who remembers what a food chain is?

Is it important to keep it?

In nature, everything is interconnected, and it is very important that this relationship be preserved. All inhabitants of the forest are important and valuable members of the forest brotherhood. It is very important that a person does not interfere with nature, does not litter the environment and takes care of animals and flora.

Literature:

The main educational program of preschool education From birth to school, edited by N. E. Veraksa, T. S. Komarova, M. A. Vasilyeva. Mosaic - Synthesis. Moscow, 2015.

Kolomina N.V. Education of the fundamentals of ecological culture in kindergarten. M: TC Sphere, 2003.

Nikolaeva S. N. Methods of ecological education of preschoolers. M, 1999.

Nikolaeva S.N. We learn nature - we prepare for school. M. : Education, 2009.

Salimova M. I. Classes in ecology. Minsk: Amalfeya, 2004.

There are many holidays in the country,

But Women's Day is given to Spring,

After all, only women are subject to

Create a spring holiday - caress.

I wholeheartedly congratulate everyone

Happy International Women's Day !

Related publications:

"Children about safety." Basic rules of safe behavior for preschool children in verse"For children about safety" Basic rules of safe behavior for preschool children in verse. Purpose of the activity: To educate.

Formation of understanding of the synonymous meanings of words in children of senior preschool age in various activities The system is carried out in several stages. First, synonyms are entered into the children's passive vocabulary. Familiarization of children with words that are close in meaning.

Consultation for parents "What toys do older preschool children need" Nowadays, the choice of toys for children is so diverse and interesting that for every parent interested in the development of their child,.

Consultation for parents "Cartoon is not a toy for children" for children of senior preschool age CONSULTATION FOR PARENTS "Cartoon is not a toy for children!" Many parents are concerned about the relationship between the child and the TV. What to watch?

Short-term creative project "Children about the war" for children of senior preschool age. Type of the project: According to the activity dominating in the project: informational. According to the number of project participants: group (children of preparatory school.

Abstract of the lesson-conversation "About the war for children" for senior preschool age Type of activity: The teacher's story "About the war for children." View photo presentation. Educational area: Cognitive development. Target:.

Pedagogical project "Children of preschool age about the holiday of Christmas" Pedagogical project "Children of preschool age about the holiday of Christmas".

Teaching children of preschool age the basics of a healthy lifestyle in various activities Educator is an amazing profession. Another plus is that it provides an opportunity to look into the country of childhood, into the world of a child. And at least.

The development of value-semantic perception and understanding of works of art in preschool children In our time, the main goal of education is to prepare a comprehensively harmoniously developed personality of the child. Creativity is the way.

Fairy tale and games to make it easier for children to understand the seasons TALE AND GAMES TO MAKE CHILDREN UNDERSTAND THE SEASONS “Four Daughters of the Year”. A long time ago it was like this: today the sun is hot, flowers.

Image Library:

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- 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, process energy 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 it comes to their role in food chains, autotrophs can be called producers or manufacturers.

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.

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.

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.

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.

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.

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).

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

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.

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

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.

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 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.

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.

B - contour passing through vertices 2, 4,