Ecosystem

Ecosystem is a unit consisting of living organisms which form biocenosis with all elements of inanimate environment, namely biotope. Every natural ecosystem is an open system and functions due to the flow of energy and matter circulation. Energy flow is one-way whereas matter circles in ecosystem in closed circuit. Solar power is the most important power in ecosystems. Not all energy is accumulated in organisms. Some of it is used for basic metabolic processes and building structures of organisms; however, some of it is lost in the form of heat.

To make matter circulation possible, the presence of producers, consumers and reducers, or at least producers and reducers, is essential. Owing to producers organic matter is synthesized. Consumers eat organisms or dead organic matter. Decomposers (reducers) decompose dead organic matter and release inorganic nutrients for producers. Due to reducers and decay processes:

• matter circulation in the environment is closed influencing growth and development of plants,
• nutrients are included in the circulation,
• food for heterotrophic organisms is produced.

Ecosystem is divided into:

• autotrophic ecosystem which functions on the basis of the presence of light and organic matter called autochthonous matter which is produced in the process of photosynthesis mainly by green plants. The examples of such ecosystems are a forest, a peat bog, a meadow, a pond, a lake.
• heterotrophic ecosystem which is incomplete, which is not self-sufficient, devoid of producers, where matter comes from outside and is called allochthonous matter. The example of such an ecosystem is a cave. The lack of light makes it impossible for plants to exist.