Set formed by a biotic community and abiotic factors interact, resulting in an exchange of matter between living and non-living parts.
In functional terms, it is the basic unit of ecology, including biotic communities and abiotic environment mutually influencing each other in order to strike a balance.
The size of an ecosystem is very variable. Both an ecosystem is a coniferous forest and a rotting tree trunk in which several populations of tiny beings survive. Just as it is possible to associate all existing ecosystems in a much larger one, which is the ecosphere, it is also possible to delimit smaller ones in each, sometimes occupying such small areas that they are called microecosystems.
Depending on their geographical situation, the main ecosystems can be classified into: terrestrial or aquatic. In either case, there are four basic constituents:
Abiotic Factors - non-living compounds of the environment;
Biotic Factors - formed by living organisms. These can be classified into:
- Producers - autotrophic beings, in most cases green plants, capable of making their own food from simple inorganic substances;
- Consumed - heterotrophic organisms, almost always animals, which feed on other beings or particles of organic matter;
- Decomposers - heterotrophic beings, mostly bacteria and fungi that break down the complex substances of organisms, releasing simple substances that can be assimilated into the environment by producers.