The food chain is a relationship between different groups of organisms (animals, mushrooms, plants and others), during which one individual is eating in order to obtain nutrients, as well as energy. This phenomenon is called a chain, since there is an exact series of those who eat, and those who will eat.
All organisms are divided into links in a chain, and each belonging to one of the links can be eaten by a representative of the subsequent link. The number of links basically does not exceed 4-5, but in some situations they may be much larger. The main reason due to which the links cannot be more is the limitation, which will be described below.
- The value of the food chain
- Autotrophs (producers)
- Heterotrophs (consumers)
- Destructors (gearboats)
- Levels (links) of the food (trophic) chain
- The first trophic level
- The second trophic level
- The third trophic level
- The fourth trophic level
- The fifth trophic level
- Types of food chains
- Pasture food chain
- Detrite food chain
- Energy in the food chain
- Food chains examples
- The food chain in insects
- Food chain in biogeocenosis
- The food chain of gearboxes
- Aquatic food chain
- Food network
The value of the food chain
The main value of the food chain is to preserve the stable state of living organisms, because if there were no such hierarchy, then some certain predators would have the opportunity to destroy everyone, depriving the weaker opportunity to eat and develop. The food chain is a certain regulator of all the energy in the biosphere, because even plants that are considered food for herbivores are only part of the chain. In the absence of such relationships between living organisms, the biosphere would become lifeless millions of years ago. That is why the food chain must exist and in no case should interfere, because when the one link is destroyed, others begin to die after it, creating a chain reaction.
Autotrophs are those living organisms that do not eat others, because they have the ability to produce their own food. Basically, they create food with simple molecules, for example, carbon dioxide or carbon. They are also divided into two main types:
- Chemoavtotrophs that feed due to chemical reactions. The process of their nutrition is called chemosynthesis and consists in involving inorganic compounds.
- Photo automops (they are also called photosynthetic organisms), these include plants that process sunlight through photosynthesis in order to produce nutrients and not destroy other living organisms. From other examples, cyanobacteria and algae can be given.
If you delve into ecology and biology, then we can draw a very simple conclusion: it is autotrophs that are the main one for all ecosystems on Earth. Most of the food chains begin with them, since they are able to survive without eating other organisms, which means that more primary links cannot be simply unable to be. They are called manufacturers or producers.
Heterotrophs, which are called consumers in the ecological community, are not able to produce nutrients from solar or chemical energy. Because of this, they have to eat other creatures or products produced by them. People belong to this category, like animals, mushrooms, as well as most other bacteria. The role of heterotrophs is the consumption of other organisms. There are many species, therefore it is simply impossible to highlight some basic ones, because they vary depending on different ecological roles.
Heterotrophs can be herbivorous (insects, some animals, such as cows or horses), carnivorous (most predators), and omnivorous (bears, monkeys and most birds). A person belongs to omnivorous, because in his diet he uses both animal and vegetable protein.
This group is also considered consumers, but it has significant differences from heterotrophs, so they are not fullfledged consumers, it will be better to say that they are an intermediate stage between autotrophs and heterotrophs. They process dead creatures, decomposing them into inorganic compounds, and then they use everything that can be useful to the body from them. This group mainly includes mushrooms and some types of bacteria, and their role is no less than that of consumers and producers. Many researchers even think that their value in the food chain is much higher than that of the latter, since they do not destroy populations, do not interfere with the development of other organisms, but remove the remnants that interfere with the germination of healthy plants, for example.
It is thanks to the reducers that the food chain remains healthy, since the nutrients from unfinished plants or the remnants of heterotroph food return to the soil, allowing the biosphere to function normally.
Levels (links) of the food (trophic) chain
In the food chain, as mentioned above, mainly four or five levels, each of which differs in importance and their representatives. Some living organisms at the same moment can relate to several levels at once, but this is more exception to the rules, so talking about them does not make sense. Five main levels of the trophic chain will be listed below, thanks to which the biosphere still operates without special interruptions:
The first trophic level
Any process should begin with something, so at the beginning of the food chain the first trophic level lies. It consists of autotrophic organisms (producers), which generate food from solar energy or chemical reactions for their survival. Almost all plants can be called the main representatives, since photosynthesis is what animals or bacteria can simply be in.
The second trophic level
After the first level, the second begins, which is quite logical. It includes all herbivorous consumers who eat plants in their food. These are mainly caterpillars, insects, small animals, such as hares or sheep, as well as many other living organisms. This level can be called intermediate, because its representatives are not so strong as to eat other heterotrophs or destructors, but at the same time they have the opportunity to eat autotrophs.
The third trophic level
The third level is the majority of not the largest, but not weak animals that feed on herbivorous. They are called secondary consumers or predators. Something about this level cannot be said more, since too many living organisms belong to it.
The fourth trophic level
The fourth level is the refuge of strong predators, which without any problems eat representatives of the second and third. They have natural enemies, but their number is very small, since it is these living organisms that receive the ability to resist and protect against others. For example, these include owls that eat snakes, and they, in turn, feed on hares or other rodents. Thus, you can notice a pattern and sequence, because hares feed on plants. That’s all, four steps, four levels, four living organisms.
The fifth trophic level
These are the last of the main links. Representatives of this group are called the highest predators or even superkthe. Animals belonging to the fifth level have no natural enemies. They are kings of their ecosystem and can do whatever they want.
In addition, it is noteworthy that we can name the fact that after the death of any organism, his corpse is eaten by detritophages, and the remnants decompose with the help of reducers. The food chain is completely consistent, because the remains laid out by the destructors are sent back to the soil, and plants are already feeding on them, t.e. representatives of the first level, and the whole chain begins in a new. That is why it is safe to say that the food chain is a closed system, which has its own cycle of nutrients.
Some living organisms can roam from one level to another, depending on the ecosystem in which they live. From the most understandable example, one can lead to a bear, which belongs to the fifth level and is considered the highest predator. This animal often eats berries, which means that acts as a representative of herbivores and belongs to the second level, but this does not mean that secondary consumers will be able to eat it. By the way, in only one day a person can change his location in the chain several times.
Types of food chains
Scientists identify, as correctly, two divisions of food chains:
Pasture food chain
The beginning of this type of food chain is living green plants that are designed for subsequent eating their herbivorous animals. They, in turn, will be eaten by predators of the third, fourth or fifth trophic level. Such ecosystems depend on solar energy that autotrophs feed on.
If we summarize, then the pasture type of food chains entirely and completely depends on the movement of energy generated by autotrophs along other links. This is the main type to which most of all ecosystems that exist in nature. At the bottom, several examples of pasture food chains will be listed:
Plant > rodent > thirdlevel predator (fox/wolf) > Fourth level predator (lion, leopard)
Grass > insect > bird > bird
Detrite food chain
Detrite food chain originates from decaying organic materials, which in turn eat detritophages for food. After that, these organisms become food for predators. The main difference between a detritus type and pasture can be called the fact that Detritis does not need a large amount of solar energy and does not particularly depend on it. The more living creatures are in the chain, the more organic substances detritophages will be able to get after their death. Of the main examples, the litter of moderate forests can be called.
Energy in the food chain
All the energy that is produced in any of the ecosystem is transferred between trophic levels during nutrition. But this process is very wasteful and ineffective, because the same insect eats only part of the plant, taking a small amount of energy. Food chains, despite the most importance and, it would seem, a full sequence, are extremely limited:
During the transition from one trophic level to another, part of the energy is preserved as a biomass of organisms. But after using this organism, a different, higher link in the chain, only ten percent of the energy remains. Then another transition occurs, one creature ate another and again received only 10%. Thus, the loss of initial energy becomes very large and all the efficiency of the system is actually completely absent. It is for this reason that all food chains are limited to 3-6 levels, because then there simply will not be energy for power.
All this loss of energy occurs in the form of heat or waste that appears after consumption. Of the main reasons for the lack of efficiency in a seemingly worked out scheme, the scheme can be distinguished by millions of years:
- Each trophic level, like each organism, has a large amount of energy in the form of heat. Due to the fact that living organisms breathe, move and simply exist, this is heat consumed, but restored during nutrition or food. When one animal eats another, it already loses a lot of energy, because the body with all its might tries to maintain life and spends a huge amount of energy on this, in particular thermal.
- Each body has a certain number of molecules that cannot be digested. It is because of this that they come out in the form of feces that every living organism has, in particular a person.
- In fact, not all representatives of a certain link will be eaten, since they may simply not find or not notice. Because of this, they simply die after some time, for example, from illness or from old age. After that, a creature that was supposed to eat already dead also dies, creating a chain reaction.
- Feces and dead organisms are food for the destructors that process them and lay them on nutrients, and in exchange they take energy for their own life, without giving it to anyone.
Since there is a law of conservation of energy in nature, even from physics lessons, everyone knows that no energy can disappear without a trace. All energy goes in the form of heat, which is released as a result of any action of living organisms.
Food chains examples
Examples of ecosystems, which have their own food chains, in nature there are many. Therefore, it is easier to divide them into some categories and already from this to build up when compiling some kind of visual dietary links:
The food chain in insects
If you take a general view, then the baking chain has the same insects like this: vegetation> Phytophages> Entomophages> Large predators. Fitophages, by the way, are called small and familiar insects, such as aphids, butterflies and others. They eat vegetation, after which they become prey for larger insects, which are entomophages. After that, they become food for birds or other large predatory animals, whether it be amphibians or mammals. This chain will look more visible: nectar bee dragonfly snake eagle.
Food chain in biogeocenosis
Biogeocenosis is a certain group of organisms that interact with each other and are closely related. If any animal of biogeocenosis dies, then it disappears the entire food chain of the ecosystem, since representatives of other links simply cannot find another food for themselves. From visual examples, one can distinguish: dandelion caterpillar mole raven. Thus, if the caterpillar dies before the mole eats it, then the latter will not have food and he will die after it, but the crow is much easier in this regard, because it has wings and can just fly to another food, but without energy which is extracted from food, he will not be able to do this and also die.
The food chain of gearboxes
Reducers (destroyers or destructors) are those organisms that, using their glands, are able to decompose the remnants of organic substances to the simplest inorganic. The best example is most mushrooms. They are the key link of the detritis chain, since they are able to restore the balance of the missing substances in the ecosystem.
Aquatic food chain
In nature, there are not only ground food links and levels that were described above, but also water, which has quite significant differences. But even so, in addition to differences, these chains often intersect, because water beings can attack terrestrial, and vice versa. Thus, the same birds, for example, wintering, are part of a ground chain, but feed on water, fish. In the same way happens in the opposite direction: there are fish that track and hunt insects. In addition, decaying organisms, representatives of a detritus food chain, can in the same way belong to the aquatic environment.
Contrary to the opinion of many people and even some scientists, the food chain and the network are different, although adjacent concepts. If the food chain is called the relationship between living organisms in the ecosystem, then the food network is the ecosystem, which includes all food chains in a certain system. Thus, the food network does not show some kind of chain of relationships, does not build a certain sequence, but summarizes a certain result, including all living organisms. The food network exists to describe all relations between organisms in the ecosystem.
An example of a food network