The trophic chain is a food-level relationship between various macro- and microorganisms through which the transformation of energy and matter proceeds in ecosystems. All plant, animal and microscopic organisms are closely interconnected according to the principle "food - consumer".
Key Definitions
The trophic chain is one of the most significant properties of any ecosystem. This is the food chain. It shows a specific horizontal sequence of species. 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 you figure out what the food chain is, you need to consider concepts such as producers, consumers, and reducers.
Producers
Producers are a group of organisms that are capable of synthesizing complex organic substances from mineral compounds. These include, first of all, autotrophs. These are plants and microscopic algae, which are capable of converting external solar energy into biochemical energy through photosynthesis. It accumulates in the cells and is involved in metabolism. In ecosystems, examples of producers are fern, moss, gymnosperms and flowering plants. In the ocean it is plankton. The tiniest green algae are an example of producers of all aquatic ecosystems.
Consumers
Consumers are various types of organisms that feed exclusively on organic matter that is synthesized by producers. In the ecosystem, heterotrophs are called consumers. It can be carnivores and herbivores, insects. Distinguish between consumers of different orders. 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, a forest food chain may include hare, mouse, roe deer, and moose. All these animals are 1st order consumers. Their distinguishing feature is that they are eaten by producers, that is, plants. These are mainly rodents, ungulates, snakes, lizards and various amphibians, as well as insects, fish, small birds.
Consumables of the 2nd and subsequent orders are exclusively predatory species. They build their proteins from organic material of animal and vegetable origin. This group includes bears, a family of canine, feline, large birds of prey, reptiles and snakes. In the ecosystem of the ocean, this niche is occupied by whales and dolphins.
Reducers
Reducers are called microorganisms utilizing organic residues. These are bacteria and fungi. They live in the soil and activate the processes of decay. A synonym for the word reducers is the term "destructors". Currently, bacteriophages are added to this group.
The main types of trophic chains
There are only two main types of food chains: detrital and pasture. They have significant differences. The pasture food chain (or the eating chain) is built on the complex relationships of various groups of plants, animals and saprophytes. Its basis is autotrophic organisms. This is primarily a plant. Then come the herbivores. For example, ungulates or rodents. In 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 in natural conditions. For example, bears, representatives of the cat family, birds of prey. Especially long pasture food chains in the oceans. Consumers of the 6th and 7th order are found here.
Detritic trophic chains are based on decomposition processes. They always involve fungi or microorganisms-saprophytes.
Detritic trophic chains
Such decomposition chains are most common in forests, as well as where most of the plant mass is not directly consumed by herbivores. But at the same time she disappears. It is processed by microscopic fungi and bacteria called saprophytes. All detrital food trophic chains always begin with detritus. They are continued by microorganisms that destroy and dispose of them. Then come the detritophages and their consumers - predatory species. In ecosystems of the seas and oceans, especially at great depths, detrital chains also prevail. Here conditions are created under which a large number of predators do not survive, therefore microorganisms take their place.
Trophic levels
The trophic chain consists of several levels. These links can be easily found in any ecosystem of the planet. The first level is always represented by producers. The second - by consumers of different orders. In short chains, as a rule, there are three links; in long chains, their number is unlimited. But the last will always be microorganisms and fungi. Any trophic food chain ends with reducers. Their main function in various ecosystems is the utilization of organic matter to mineral compounds. The longest trophic food chains form in the oceans and seas. The shortest of them are in the forest and meadows. Such an interconnected series of consecutive trophic levels forms a food chain.
It is very important to clarify that the trophic food chain is not always complete. It may be missing some links. Sometimes they “fall out” for one reason or another. First of all, producer plants are not always present in the chain. They are absent in those communities that were formed on the basis of decay of plant and (or) animal remains. A striking example is the litter of leaves in the forests. Secondly, in the trophic chains heterotrophs, i.e. animals, may be absent. Or there may be few of them. For example, in the same forests, falling fruits and branches, bypassing consumers, immediately begin to decompose. In this case, producers are immediately followed by reducers. Trophic chains are formed in each ecosystem based on environmental conditions. Under certain influences, especially on the part of man, these chains can increase or, as often happens, decrease due to the disappearance of certain links.
Examples of trophic chains
The trophic chain, depending on how many links it consists of, can be simple and multi-level. An example of a simple complete chain in which producers, consumers and reducers are present may look as follows: aspen - beaver - bacteria.
Complex trophic 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 remaining real ecosystems, the links are usually 5. One can give several examples of how to make up the food chain for different areas:
1. Algae - roach - perch - burbot - bacteria.
2. Plankton - coral - pomacenter fish - white shark - bacteria.
3. Grass - grasshopper - frog - already - falcon.
These are all examples of pasture predator chains. But there are other types of relationships. For example, parasite chains. They look as follows: grass - cow - tapeworm - bacteria. Sometimes, consumers may drop out of the chain: currant - powdery mildew - phage. The pasture food chain differs from the parasitic one in that the size of the predators in them increases as the level of the link sequence increases. But saprophytes still remain in the role of reducers in both cases. Detritic chains look a little different: leaf litter - microscopic mold fungi - bacteria.