The food web is known as the structure formed by the existing food interrelationships between the members of an ecosystem. Through this network, the different species transfer nutrients and energy: each species feeds on another and in turn is food for a third.
Food network also called food chain, food chain or food chain. Species are the nodes of the network or links in the chain: to survive, they obtain energy from those that are located at a lower level. In other words: one species, feeding on another, receives what it needs to continue living.
It is important to establish that in every trophic chain three types of protagonists can be established, such as the following, based on what the passage of energy is:
-The producers, which would be plants and which are characterized by the ability to being able to generate energy by themselves, specifically through the process known as photosynthesis.
-The consumers, who come to be animals and what they do is obtain energy by feeding on other species. This would be the case, for example, of carnivorous animals.
-The decomposers. These are the beings that what they do is degrade the organic matter that has been derived from the other "scales" of the food chain.
Starting from all this, we find the fact that the food web, triangular in shape, is made up of the following levels, from the bottom to the top: decomposers, plants and consumers, where herbivores, primary predators and secondary predators are found..
Because it is a network or chain, the species that eats another is, simultaneously, food for a different species. For example: a snake can feed on a rodent, but in turn it is prey for a hawk. The rodent, for its part, is ingested by the snake and feeds on insects. Thus, from the links between the members of the biological community, the food web is formed.
This functioning of the food web means that, if one species disappears, the entire system becomes unbalanced and can even collapse. Let us suppose that, by action of man, a species X becomes extinct. All the animals that used to eat this species run out of food and can no longer survive. In turn, those species that were preyed upon by the disappeared species begin to multiply their number of specimens, something that ends up exerting pressure for the disappearance of new species.
In addition to this circumstance, the food web can be affected for numerous other reasons. Thus, in particular, one of the most serious damages that can suffer is acid rain. And it is that this can cause the elimination, for example, of phytoplankton, which is what insects feed on. Outcome? That when that disappears, they can survive as they should, so they could die and that would trigger that, in turn, the animal species that eat those can end up going through the same trance and so on with the rest of this food chain.