Nutrition plays an important role in any ecosystem. Food is an energy source for continuing the life processes of organisms. Accordingly, food chains are formed in each ecological system . If we give them a definition, we get the following: the trophic or food chain is the relationship between animals, plants, microorganisms on the principle of "food - consumer".
The structure is very simple. Representatives of the next link eat organisms of the previous link. As a rule, the number of links reaches 3-4 and only very rarely - 5. The food chains in the reservoir, especially in the freshwater, completely fall under trophic and can be of two types.
Types of Food Chains
There are two types of food chains in a community of a reservoir. The first is pasture, the second is detrital. Both types of food chains are divided into several levels. The first is occupied by producers - plants that consume solar energy. At the second level are the primary consumers - animals that consume plant foods. The third step is occupied by secondary consumers - animals that are consumed exclusively by plant-eaters, and parasites of primary consumers. On the fourth are reducers and consumers of the third order - predators, parasites and bacteria.
Pasture food chains in the reservoir are characteristic for the upper layers, and detrital ones for the bottom layers. But it is impossible to clearly separate them - they, like everything in nature, are interconnected. But no matter what chains are present in the ecosystem, there is a general rule for them. Each trophic level (link) most of the energy that is absorbed by food, is spent on maintaining normal life.
The power circuit in the pond. Examples
In any body of water, it is easy to give an example of the simplest food chain. Consider the ecosystem of Lake Baikal. In connection with the diversity of flora and fauna, the food chain in a reservoir is represented by several species. Since they are interconnected, some components of one can be replaced by elements from another. The trophic chains of Lake Baikal are divided into two - the epipelegial and bathipeligial. The first prevails at the coastal level and in areas of mixing water layers, the second is inherent in the bottom zone.
The producers (primary link) are various types of algae. The consumables of the first order are the epishura. This species of planktonic crustaceans is the main consumer of phytoplankton and algae and is zooplankton. Epishura serves as food for the next link - second-order consumers. This group includes macrohectopus (zooplankton) and omul at all stages of development. But if fish consume only primary consumers, then macrogetopus also consumes producers. In turn, these crustaceans serve as food for omul, gobies, golomyanki and other fish. The final link is the seal, which consumes representatives of the previous level.
Detrital Power Circuits
Any lake, pond or sea has a different depth in different parts of the occupied area. Detrital food chains in a pond prevail in the water column into which sunlight does not penetrate. The producer is organic residues of plant and animal origin. Crustaceans and deep-sea fish, as well as bacteria , become consumables of the first order. These detritophages often become food for consumers of the first and second order trophic food chain.
Ecosystem variability
It is almost impossible to find a body of water, saline or freshwater, in which each link in the food chain would be represented by only one species of animal or plant. Such an ecosystem is doomed to extinction, since the absence of one element leads to an interruption of the food chain in the reservoir. If each link is filled with several species of animals or plants, then such a system is stable, since the absence of one or another component is replaced or supplemented by another. Annual populations each year have a different number of individuals. And only due to the diversity of species there is no interruption of the food chain and the destruction of the ecosystem.