Ecosystem
The environment includes our physical surroundings like air, water, soil and all the organisms such as plants, animals, human beings and micro-organisms like bacteria and fungi (called decomposers).
An ecosystem is a self-contained unit of living things and their non-living environment. All the interacting organisms in an area together with the non-living constituents of the environment form an ecosystem. It therefore consists of biotic components and abiotic components.
There are two types of ecosystem:
- Terrestrial ecosystem: These are land-based ecosystems such as forest, grassland, desert, mountains etc.
- Aquatic ecosystem: These are water based eco-systems such as ponds, lakes, river, sea, aquarium etc.
Ecosystems can also be classified as natural ecosystems and artificial ecosystem. Examples of natural ecosystems are forests, ponds etc whereas examples of the artificial ecosystems are gardens, aquarium and crop- fields.
Components of an Ecosystem
Abiotic Components
The abiotic components of an ecosystem include the physical environment like air, water, soil along with the inorganic substances like carbon dioxide, nitrogen, oxygen, water, phosphorus, sulphur, sodium and other elements present in them. The physical factors which affect our climate such as light, temperature, pressure, humidity are also considered as abiotic components.
Biotic Components
The biotic component of an ecosystem is a community of organisms which is made up of many inter dependent populations.
It includes three types of organisms:
- Producers: These are the autotrophs that synthesize their own food such as green plants and certain blue green algae.
- Consumers: These are the heterotrophs that depend on other organisms for food. These organ¬isms consume the food produced either directly from producers or indirectly by feeding on other consumers. They can be further classified as herbivores, carnivores, omnivores and parasites.
- Decomposers: These are the organisms that consume the dead remains of other organisms. The microorganisms comprising bacteria and fungi break down the dead remains and waste products of organisms which comprises of complex inorganic substances into simpler inorganic substances that go into the soil and are used up once more by the plants.
The Functioning of an Ecosystem
An ecosystem is a self-sufficient unit. It involves input of energy and matter which are exchanged between the living and non-living components in a cyclic process.
Importance of Decomposers
The decomposers help in decomposing the dead bodies of plants and animals and in this way act as cleansing agents of the environment. The various nutrients which are initially taken by plants from the soil, air and water are returned to the soil, air, and water (nutrient pool) after the death of plants and animals. They help in recycling the materials in the ecosystem.
Example 1.
What is the role of decomposers in the ecosystem?
Answer:
Decomposers feed on dead and decaying organisms and breakdown the complex organic compounds into simpler substances. In this way, they help in recycling nutrients to the soil and also help in cleaning the environment.