The trophic chain is the relationship at the nutritional level between various macro- and micro-organisms through which energy and matter are transformed in ecosystems. All plant, animal and microscopic organisms are closely related to each other on the principle of "food - consumer".
Basic definitions
The food chain is one of the most significant properties of any ecosystem. This is the food chain. It shows a certain horizontal sequence of views. This reflects the movement in the ecosystem in the process of feeding biochemical energy and organic substances. For example: grass - hare - wolf - bacteria. As a rule, at the top of the trophic pyramid is a large predator. This term itself is a derivative of the Greek word "trophy", which means "food". Before understanding what a food chain is, you need to consider such concepts as producers, consumers and decomposers.
Producers
Producers are called a grouporganisms that are able to synthesize complex organic substances from mineral compounds. These include, first of all, autotrophs. These are plants and microscopic algae that are capable of converting external solar energy into biochemical energy through photosynthesis. It accumulates in cells and is involved in metabolism. In ecosystems, examples of producers are ferns, mosses, gymnosperms and flowering plants. In the ocean, it's plankton. The smallest green algae is an example of the producers of all aquatic ecosystems.
Consumers
Consumers are various types of organisms that feed exclusively on organic matter, which is synthesized by producers. In an ecosystem, heterotrophs are called consumers. It can be carnivores and herbivores, insects. Distinguish consumers of a different order. This division is based on the position of organisms in the food chain.
Consumers of the 1st order include herbivorous animals, insects and birds. For example, the forest food chain may include a hare, a mouse, a roe deer, an elk. All these animals are consumers of the 1st order. Their distinguishing feature is that they eat producers, that is, plants. These are mainly rodents, ungulates, snakes, lizards and various amphibians, as well as insects, fish, small birds.
Consumers of the 2nd and subsequent orders are exclusively predatory species. They build their proteins from organic material of animal and plant origin. This group includes bears, the canine family,felines, large birds of prey, reptiles and snakes. In the ocean ecosystem, this niche is occupied by whales and dolphins.
Decomposers
Decomposers are microorganisms that utilize organic residues. These are bacteria and fungi. They live in the soil and activate the processes of decay. A synonym for the word decomposers is the term "destructors". Currently, bacteriophages are also added to this group.
Main types of food chains
There are only two main types of food chains: detrital and pasture. They have significant differences. The pasture food chain (or grazing chain) is built on the complex relationships of various groups of plants, animals and saprophytes. It is based on autotrophic organisms. First of all, these are plants. Then there are herbivores. For example, ungulates or rodents. In the oceans and seas, it can be zooplankton. And finally, at the top of the food chain are predators of the 2nd order. These are species that are not hunted naturally. For example, bears, representatives of the cat family, birds of prey. Especially long pasture food chains in the oceans. Here, consumers of the 6th and 7th order are found.
Detrital food chains are based on decomposition processes. They always involve fungi or saprophytic microorganisms.
Detrital food chains
Such chains of decay are most common in forests and where most of the plant mass is not directly consumed by herbivoresanimals. But at the same time, she disappears. It is processed by microscopic fungi and bacteria, which are called saprophytes. All detrital food chains always start with detritus. They are continued by microorganisms that destroy and utilize them. Then come detritivores and their consumers - predatory species. In the ecosystems of the seas and oceans, especially at great depths, detrital chains also predominate. Here conditions are created under which a large number of predators do not survive, so microorganisms take their place.
Trophic levels
The trophic chain consists of several levels. These links can be easily found in any ecosystem on the planet. The first level is always represented by producers. The second - consumers of a different order. In short chains, as a rule, there are three links, in long chains their number is not limited. But the last will always be microorganisms and fungi. Any trophic food chain ends with decomposers. Their main function in various ecosystems is the utilization of organic matter to mineral compounds. The longest food chains form in the oceans and seas. The shortest of them are in the forest and meadows. Such an interconnected series of successive trophic levels forms the food chain.
It is very important to clarify that the food chain is not always complete. It may be missing some links. Sometimes they "fall out" for one reason or another. First, not always in the chain there are plants - producers. They are absent in those communities that were formed on the basis of decay of plant and (or)animal remains. A vivid example of this is the litter of foliage in the forests. Secondly, heterotrophs, that is, animals, may be absent in trophic chains. Or they may be few. For example, in the same forests, falling fruits and branches, bypassing consumers, immediately begin to decompose. In this case, the producers are immediately followed by the decomposers. In each ecosystem, trophic chains are formed based on environmental conditions. Under certain influences, especially on the part of a person, these chains can increase or, as it happens more often, be reduced due to the disappearance of certain links.
Examples of food chains
The trophic chain, depending on how many links it consists of, can be simple and multilevel. An example of a simple complete chain, in which there are producers, consumers and decomposers, may look like this: aspen - beaver - bacteria.
Complex food chains contain more links. But usually their number does not exceed 6-7 in existing natural ecosystems. Such long chains can be found in the seas and oceans. In the rest of the real ecosystems, there are usually 5 links. There are several examples of how to compose a food chain for different areas:
1. Algae - roach - perch - burbot - bacteria.
2. Plankton - coral - pomegranate fish - white shark - bacteria.
3. Grass - grasshopper - frog - already - falcon.
These are all examples of grazing chains of predators. But there are other types of relationships as well. For example, chainsparasites. They look like this: grass - cow - tapeworm - bacteria. Sometimes consumers can fall out of the chain: currant - powdery mildew fungus - phage. The grazing food chain differs from the parasitic one in that the size of predators in them increases as the level of the link sequence increases. But saprophytes still remain in the role of decomposers in both cases. Detrital chains look a little different: leaf litter - microscopic mold fungi - bacteria.
