Who eats birds food chain. Types of food relationships. Forest food connections

In living nature there are practically no living organisms that do not eat other creatures or are not food for someone. Thus, many insects feed on plants. The insects themselves are prey for larger creatures. Certain organisms are the links from which the food chain is formed. Examples of such “dependence” can be found everywhere. Moreover, in any such structure there is a first initial level. As a rule, these are green plants. What are some examples of food? What organisms can be links? How does the interaction between them occur? More on this later in the article.

general information

The food chain, examples of which will be given below, is a certain set of microorganisms, fungi, plants, animals. Each link is at its own level. This “dependence” is built on the principle “food - consumer”. At the top of many food chains is man. The higher the population density in a particular country, the fewer links will be contained in the natural sequence, since people are forced in such conditions to eat plants more often.

Number of levels

How does interaction occur within ecological pyramids?

How does the food chain work? The examples given above show that each subsequent link should be more high level development than the previous one. As already mentioned, relationships in any ecological pyramid are built on the “food-consumer” principle. Due to the consumption of some organisms by others, energy is transferred from lower levels to the highest. The result occurs in nature.

Food chain. Examples

Conventionally, several types of ecological pyramids can be distinguished. There is, in particular, a grazing food chain. Examples that can be seen in nature are sequences where the transfer of energy occurs from lower (protozoan) organisms to higher (predator) organisms. Such pyramids, in particular, include the following sequences: “caterpillars-mice-vipers-hedgehogs-foxes”, “rodents-predators”. The other, detrital food chain, examples of which will be given below, is a sequence in which the biomass is not consumed by predators, but a process of decay with the participation of microorganisms takes place. It is believed that this ecological pyramid begins with plants. This is, in particular, what the forest food chain looks like. Examples include the following: “fallen leaves—rotting with the participation of microorganisms,” “dead (carnivorous)—predators—centipedes—bacteria.”

Producers and consumers

In a large body of water (ocean, sea), planktonic organisms are food for Cladocera (animal filter feeders). They, in turn, are prey for predatory mosquito larvae. A certain type of fish feeds on these organisms. They are eaten by larger predatory individuals. This ecological pyramid is an example of a sea food chain. All organisms acting as links are at different trophic levels. At the first stage there are producers, at the next - consumers of the first order (consumers). The third trophic level includes 2nd order consumers (primary carnivores). They, in turn, serve as food for secondary predators - third-order consumers, and so on. As a rule, ecological pyramids of land include three to five links.

open water

Beyond the shelf sea, in the place where the slope of the continent breaks off more or less abruptly towards the deep-sea plain, the open sea begins. This area has predominantly blue and clear water. This is due to the absence of inorganic suspended compounds and a smaller volume of microscopic planktonic plants and animals (phyto- and zooplankton). In some areas, the surface of the water has a particularly bright blue color. For example, in such cases they talk about so-called ocean deserts. In these zones, even at a depth of thousands of meters, sensitive equipment can detect traces of light (in the blue-green spectrum). The open sea is characterized by the complete absence of various larvae of benthic organisms (echinoderms, mollusks, crustaceans) in the composition of zooplankton, the number of which sharply decreases with distance from the coast. Both in shallow water and in wide open spaces, the only source of energy is sunlight. As a result of photosynthesis, phytoplankton, with the help of chlorophyll, forms organic compounds from carbon dioxide and water. This is how the so-called primary products are formed.

Links in the sea food chain

Organic compounds synthesized by algae are transferred indirectly or directly to all organisms. The second link in the food chain in the sea is animal filter feeders. The organisms that make up phytoplankton have microscopically small sizes (0.002-1mm). They often form colonies, but their size does not exceed five millimeters. The third link is carnivores. They are filter feeders. There are quite a lot of such organisms in the shelf, as well as in the open seas. These, in particular, include siphonophores, ctenophores, jellyfish, copepods, chaetognaths, and carinarids. Among fish, herring should be classified as filter feeders. Their main food is formed in northern waters large clusters. The fourth link is considered to be predatory large fish. Some species are of commercial importance. The final link should also include cephalopods, toothed whales and seabirds.

Nutrient transfer

Broadcast organic compounds within food chains is accompanied by significant energy losses. This is mainly due to the fact that most of it is spent on metabolic processes. About 10% of the energy is converted into body matter by the organism. Therefore, for example, the anchovy, which feeds on planktonic algae and is part of an exceptionally short food chain, can develop in such huge quantities as it does in the Peruvian Current. The transfer of food into the twilight and deep zones from the light zone is due to active vertical migrations of zooplankton and individual species fish Animals moving up and down different time days they end up at different depths.

Conclusion

It should be said that linear food chains are quite rare. Most often, ecological pyramids include populations belonging to several levels at once. The same species can eat both plants and animals; carnivores can feed on both first- and second-order consumers; Many animals consume living and dead organisms. Due to the complexity of linkages, the loss of a species often has virtually no effect on the state of the ecosystem. Those organisms that took the missing link for food may well find another source of food, and other organisms begin to consume the food of the missing link. This way the community as a whole maintains balance. The ecological system that contains more complex food chains, consisting of large quantity links, including many different types.

A food chain is a complex structure of links in which each of them is interconnected with the neighboring or some other link. These components of the chain are various groups of flora and fauna organisms.

In nature, a food chain is a way of moving matter and energy in an environment. All this is necessary for the development and “construction” of ecosystems. Trophic levels are a community of organisms located at a certain level.

Biotic cycle

The food chain is a biotic cycle that connects living organisms and inanimate components. This phenomenon is also called biogeocenosis and includes three groups: 1. Producers. The group consists of organisms that produce food substances for other creatures through photosynthesis and chemosynthesis. The product of these processes are primary organic substances. Traditionally, producers are the first in the food chain. 2. Consumers. The food chain places this group above the producers because they consume the nutrients that the producers produced. This group includes various heterotrophic organisms, for example, animals that eat plants. There are several subspecies of consumers: primary and secondary. The category of primary consumers includes herbivores, and the secondary consumers include carnivores that eat the previously described herbivores. 3. Decomposers. This includes organisms that destroy all previous levels. A clear example This may be the case when invertebrates and bacteria decompose plant debris or dead organisms. Thus, the food chain ends, but the cycle of substances in nature continues, since as a result of these transformations mineral and other minerals are formed. useful material. Subsequently, the formed components are used by producers to form primary organic matter. The food chain has a complex structure, so secondary consumers can easily become food for other predators, which are classified as tertiary consumers.

Classification

Thus, it takes a direct part in the cycle of substances in nature. There are two types of chains: detritus and pasture. As the names indicate, the first group is most often found in forests, and the second - in open spaces: field, meadow, pasture.

Such a chain has a more complex structure of connections; it is even possible for fourth-order predators to appear there.

Pyramids

one or more existing in a specific habitat form the paths and directions of movement of substances and energy. All this, that is, organisms and their habitats, form functional system, which is called an ecosystem (ecological system). Trophic connections are rarely straightforward; they usually take the form of a complex and intricate network, in which each component is interconnected with the others. The interweaving of food chains forms food webs, which mainly serve to construct and calculate ecological pyramids. At the base of each pyramid is the level of producers, on top of which all subsequent levels are adjusted. There is a pyramid of numbers, energy and biomass.

Complex nutritional interactions exist between autotrophs and heterotrophs in ecosystems. Some organisms eat others, and thus carry out the transfer of substances and energy - the basis for the functioning of the ecosystem.

Within an ecosystem, organic matter is created by autotrophic organisms such as plants. Plants are eaten by animals, which in turn are eaten by other animals. This sequence is called a food chain (Fig. 1), and each link in the food chain is called a trophic level.

Distinguish

Grassland food chains(grazing chains) - food chains that begin with autotrophic photosynthetic or chemosynthetic organisms (Fig. 2.). Pasture food chains are found predominantly in terrestrial and marine ecosystems.

An example is the grassland food chain. Such a chain begins with capture solar energy plant. The butterfly, feeding on the nectar of a flower, represents the second link in this chain. A dragonfly, a predatory flying insect, attacks a butterfly. A frog hiding among the green grass catches a dragonfly, but itself serves as prey for such a predator as the grass snake. He could have spent a whole day digesting the frog, but before the sun had even set, he himself became the prey of another predator.

The food chain, going from a plant through a butterfly, dragonfly, frog, snake to a hawk, indicates the direction of movement of organic substances, as well as the energy contained in them.

In the oceans and seas autotrophic organisms(unicellular algae) exist only up to the depth of light penetration (maximum up to 150-200 m). Heterotrophic organisms living in deeper layers of water rise to the surface at night to feed on algae, and in the morning they go deeper again, making daily vertical migrations up to 500-1000 m long. In turn, with the onset of morning, heterotrophic organisms from even deeper layers rise upward to be nourished by those descending from surface layers other organisms.

Thus, in the deep seas and oceans there is a kind of “food ladder”, thanks to which organic matter created by autotrophic organisms in the surface layers of water is transported along the chain of living organisms to the very bottom. In this regard, some marine ecologists consider the entire water column to be a single biogeocenosis. Others believe that the environmental conditions in the surface and bottom layers of water are so different that they cannot be considered as a single biogeocenosis.

Detrital food chains(decomposition chains) - food chains that begin with detritus - dead remains of plants, corpses and animal excrement (Fig. 2).

Detrital chains are most typical for communities of continental reservoirs, the bottom of deep lakes, oceans, where many organisms feed on detritus formed by dead organisms of the upper illuminated layers of the reservoir or that entered the reservoir from terrestrial ecosystems, for example, in the form of leaf litter.

The ecosystems of the bottom of the seas and oceans, where sunlight does not penetrate, exist only due to the constant settling there of dead organisms living in the surface layers of water. The total mass of this substance in the World Ocean per year reaches at least several hundred million tons.

Detrital chains are also common in forests, where most of the annual increase in the live weight of plants is not consumed directly by herbivorous animals, but dies, forming litter, and is then decomposed by saprotrophic organisms, followed by mineralization by decomposers. Fungi are of great importance in the decomposition of dead plant matter, especially wood.

Heterotrophic organisms that feed directly on detritus are called detritivores. In terrestrial ecosystems they are many species of insects, worms, etc. Large detritivores, which include some species of birds (vultures, crows, etc.) and mammals (hyenas, etc.) are called scavengers.

In aquatic ecosystems, the most common detritivores are arthropods - aquatic insects and their larvae, and crustaceans. Detritivores can feed on other, larger heterotrophic organisms, which themselves can serve as food for predators.

Trophic levels

Typically, different trophic levels in ecosystems are not separated in space. However, in some cases they are quite clearly differentiated. For example, in geothermal springs autotrophic organisms - blue-green algae and autotrophic bacteria that form specific algal-bacterial communities (“mats”) are common at temperatures above 40-45 ° C. At more low temperatures they don't survive.

On the other hand, heterotrophic organisms (mollusks, larvae of aquatic insects, etc.) are not found in geothermal springs at temperatures above 33-36 ° C, so they feed on fragments of mats carried by the current to areas with lower temperatures.

Thus, in such geothermal sources, an autotrophic zone is clearly distinguished, where only autotrophic organisms are common, and a heterotrophic zone, where autotrophic organisms are absent and only heterotrophic organisms are found.

Trophic networks

In ecological systems, although there are a number of parallel food chains, e.g.

herbaceous vegetation -> rodents -> small predators
herbaceous vegetation -> ungulates -> large predators,

which unite the inhabitants of the soil, herbaceous cover, tree layer, there are other relationships. In most cases, the same organism can serve as a source of food for many organisms and thus be integral part different food chains and prey to different predators. For example, daphnia can be eaten not only by small fish, but also by the predatory crustacean Cyclops, and roach can be eaten not only by pike, but also by otter.

The trophic structure of a community reflects the relationship between producers, consumers (separately of the first, second, etc. orders) and decomposers, expressed either by the number of individuals of living organisms, or their biomass, or the energy contained in them, calculated per unit area per unit time.

For me, nature is a kind of well-oiled machine, in which every detail is provided. It’s amazing how well everything is thought out, and it’s unlikely that a person will ever be able to create something like this.

What does the term "power chain" mean?

According to the scientific definition, this concept includes the transfer of energy through a number of organisms, where the producers are the first link. This group includes plants that absorb inorganic substances, from which nutritious organic compounds are synthesized. They feed on consumers - organisms that are not capable of independent synthesis, and therefore are forced to eat ready-made organic matter. These are herbivores and insects that act as “lunch” for other consumers - predators. As a rule, the chain contains about 4-6 levels, where the closing link is represented by decomposers - organisms that decompose organic matter. In principle, there can be much more links, but there is a natural “limiter”: on average, each link receives little energy from the previous one - up to 10%.

Examples of food chains in a forest community

Forests have their own characteristics, depending on their type. Coniferous forests are not distinguished by rich herbaceous vegetation, which means that the food chain will have a certain set of animals. For example, a deer enjoys eating elderberry, but it itself becomes prey for a bear or lynx. The broad-leaved forest will have its own set. For example:

• bark - bark beetles - tit - falcon;
• fly - reptile - ferret - fox;
• seeds and fruits - squirrel - owl;
• plant - beetle - frog - snake - hawk.

It is worth mentioning scavengers who “recycle” organic remains. There are a great variety of them in forests: from the simplest single-celled ones to vertebrates. Their contribution to nature is enormous, since otherwise the planet would be covered with animal remains. They also transform dead bodies into inorganic compounds, which plants need, and everything starts anew. In general, nature is perfection itself!

Nature is designed in such a way that some organisms are a source of energy, or rather food, for others. Herbivores eat plants, carnivores hunt herbivores or other predators, and scavengers feed on the remains of living things. All these relationships are closed in chains, in the first place of which are producers, and then come consumers - consumers of different orders. Most chains are limited to 3-5 links. Example of a food chain: – hare – tiger.

In fact, many food chains are much more complex; they branch, close, and form complex networks called trophic networks.

Most food chains begin with plants - these are called pastures. But there are other chains: they are from the decomposed remains of animals and plants, excrement and other waste, and then follow microorganisms and other creatures that eat such food.

Plants at the beginning of the food chain

Through the food chain, all organisms transfer energy, which is contained in food. There are two types of nutrition: autotrophic and heterotrophic. The first is to receive nutrients from inorganic raw materials, and heterotrophs use organic matter for life.

There is no clear boundary between the two types of nutrition: some organisms can obtain energy in both ways.

It is logical to assume that at the beginning of the food chain there should be autotrophs, which convert inorganic substances into organic matter and can be food for other organisms. Heterotrophs cannot start food chains, since they need to obtain energy from organic compounds - that is, they must be preceded by at least one link. The most common autotrophs are plants, but there are other organisms that feed in the same way, for example, some bacteria or. Therefore, not all food chains begin with plants, but most of them are still based on plant organisms: on land these are any representatives higher plants, in the seas - algae.

In the food chain, there cannot be other links before autotrophic plants: they receive energy from soil, water, air, and light. But there are also heterotrophic plants, they do not have chlorophyll, they live off or hunt animals (mainly insects). Such organisms can combine two types of nutrition and stand both at the beginning and in the middle of the food chain.

Food chains are numerous branches intersecting with each other that form trophic levels. In nature, there are grazing and detrital food chains. The former are otherwise called “chains of consumption”, and the latter “chains of decomposition”.

Trophic chains in nature

One of the key concepts necessary for understanding natural life is the concept of “food (trophic) chain.” It can be considered in a simplified, generalized form: plants - herbivores - predators, but food chains are much more branched and complex.

Energy and matter are transferred along the links of the food chain, up to 90% of which is lost during the transition from one level to another. For this reason, the chain usually has 3 to 5 links.

Trophic chains are included in the general cycle of substances in nature. Since real connections are quite branched, for example, many, including humans, feed on plants, herbivores, and predators, food chains always intersect with each other, forming food networks.

Types of food chains

Conventionally, trophic chains are divided into pasture and detritus. Both of them function equally simultaneously in nature.

Pasture trophic chains are relationships between groups of organisms that differ in their feeding methods, the individual links of which are united by relationships of the “eaten - eater” type.

The simplest example food chain: cereal plant - mouse - fox; or grass - deer - wolf.

Detrital food chains are the interaction of dead herbivores, carnivores, and dead plant organic matter with detritus. Detritus is for various groups microorganisms and products of their activity that take part in the decomposition of the remains of plants and animals. These are bacteria (decomposers).

There is also a food chain connecting decomposers and predators: detritus - detritivore (earthworm) - () - predator ().

Ecological pyramid

In nature, food chains are not stationary; they branch and intersect widely, forming so-called trophic levels. For example, in a grass-herbivore system, the trophic level includes many species of plants consumed by that animal, and the herbivore level contains numerous species of herbivores.

Living organisms do not live on Earth separately, but constantly interact with each other, including hunter-food relationships. These relationships, successively concluded between series of animals, are called food chains or food chains. These may include unlimited amount creatures of various species, genera, classes, types, and so on.

Power circuit

Most organisms on the planet feed on organic food, including the bodies of other creatures or their waste products. Nutrients move sequentially from one animal to another, forming food chains. The organism that begins this chain is called a producer. As logic dictates, producers cannot eat organic substances– they take energy from inorganic materials, that is, they are autotrophic. These are mostly green plants and different kinds bacteria. They produce their bodies and nutrients for their functioning from mineral salts, gases, and radiation. For example, plants obtain food through photosynthesis in light.

Next in the food chain are consumers, which are already heterotrophic organisms. First-order consumers are those who feed on producers - or bacteria. Most of them are . The second order consists of predators - organisms that feed on other animals. This is followed by consumers of the third, fourth, fifth order and so on - until the food chain is closed.

Food chains are not as simple as they might seem at first glance. An important part of the chains are detritivores, which feed on the decaying organisms of dead animals. On the one hand, they can eat the bodies of predators who died in the hunt or from old age, and on the other hand, they themselves often become their prey. As a result, closed power circuits arise. In addition, the chains branch; at their levels there is not one, but many species that form complex structures.

Ecological pyramid

Closely related to the concept of a food chain is the term ecological pyramid: this is a structure showing the relationships between producers and consumers in nature. In 1927 scientist Charles Elton effect, called the rule of the ecological pyramid. It lies in the fact that when transferring nutrients from one organism to another, to the next level of the pyramid, part of the energy is lost. As a result, the pyramid gradually moves from the foot to the top: for example, per thousand kilograms of plants there are only one hundred kilograms, which, in turn, become food for ten kilograms of predators. Larger predators will extract only one from them to build their biomass. These are arbitrary figures, but they provide a good example of how food chains operate in nature. They also show that the longer the chain, the less energy reaches its end.

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