What is ecosystem? – An introduction

What is ecosystem?

The term ecosystem is made up of two words, ‘eco’ means the environment, and ‘system’ refers to the interrelating unit. An ecosystem is the Ecological unit, consisting of all living beings and their surrounding environment, where they often exchange materials and energy.

Definition of EcosystemThe  term “ecosystem” was first introduced by A.G. Tansley (1935). He defined Ecosystem as, ” the system resulting from the integrations of all the living and nonliving actors of the environment”.


An Ecosystem is a naturally occurring segment of nature, having all living organisms, along with components of an abiotic environment. 

According to the concept of ecosystem, a single rock, lake, forest or entire planet may be studied as an ecosystem.

Let’s understand the ecosystem by an example. Imagine a Lake where fish, frogs, algae, aquatic flowers and many other organisms are found. All these are not only interdependent, but are also mutually interlinked with abiotic components like water, air, sun. This complete system of community, in which the interrelation of biotic components and abiotic components forms the ecosystem.

The boundaries of an Ecosystem is decided by geographical barriers, like deserts, mountains, rivers, or oceans. Some ecosystems are isolated like lakes or rivers.

Structure of an Ecosystem

An ecosystem structure means what an ecosystem looks like. Ecosystem structure refers to the composition of various parts of the ecosystem and how those parts are organized. The physical and biological organization of the ecosystem determine the structure of Ecosystem. Ecosystems may vary in time and size.

The concepts like trophic level and Ecological pyramid fall under the ecosystem structure. From the structural aspect, any ecosystem has two components: biotic and abiotic, commonly referred to as components of the ecosystem.

Components of Ecosystem

Biotic components

Biotic components, usually known as biological components, include all living organisms and their products.  This includes plants, animals, fungi, bacteria, and their waste products such as excreta and fallen leaves.

Based on their activity, Biotic components are further classified into the three categories: Producer, consumer, and decomposer.

  1. Producers: They are capable of making their own food through photosynthesis. Such producers are green plants.
  2. Consumers: they depend on producers for their food. Basically they are herbivorous, carnivorous, and omnivorous animals.
  3. Decomposer: they decompose the dead organic matter. such decomposers are bacteria and fungi.

Abiotic components

Abiotic components refer to non-living things, mainly categorised as climatic factors, physical factors, and chemical substances. Some of the major abiotic constituents are water, soil, sunlight, air, and temperature.

Function of an ecosystem

Ecosystem functions are sometimes also referred to as ecosystem processes or ecological processes.

For a fuller understanding of ecosystems, apart from their structure, it is also necessary to understand functions of the ecosystem. The ecosystem functions describe what ecosystems actually do. 

It can be defined as a process that takes place in an ecosystem as a result of the interactions of living organisms with each other or their environment (abiotic components). The concept of food chain, energy flow, and biogeochemical cycles are studied under the processes of the ecosystem.

The function/process of an ecosystem include 

  • biogeochemical cycles
  • transformation of solar energy into food through photosynthesis
  • Circulation of elements and nutrients through Energy Flow
  • decomposition
  • growth and development of plants
  • Nutrient uptakes and transformation rates
  • reproductive and population survival rate.

Ecosystem services

Ecosystem services are the output of ecosystems that have social values ​​and depend on the structure and function of the ecosystem. The Millennium Ecosystem Assessment (MA) has classified ecosystem services into four categories: provisioning, regulating, cultural and supporting services.

  1. Provisioning Services: This include fruits, vegetables, fish, trees, wood, water, and any benefits that people can directly extract from nature.
  2. Regulating Services: This service regulates natural phenomenon such as decomposition, erosion, and water purification.
  3. Cultural Services: This is non-material benefits from nature that is associated with cultural advancement and development of people.
  4. Supporting Services: The most fundamental services that nature provides, such as photosynthesis, water cycle, and soil formation. This process allows life to sustain on earth.

Types of Ecosystems

There are many types of Ecosystems, they are generally classified into natural and artificial ecosystems. Depending on the dimension of the Ecosystem, they can be classified into Macro and Micro Ecosystems. There are two types of natural Ecosystem: terrestrial and aquatic ecosystems.

Terrestrial ecosystems

This is typically a land-based Ecosystem. They provide goods such as water, grass, soil, timber, and wood. The different examples of terrestrial ecosystems are 

  • Forest
  • desert
  • grassland
  • tundra
  • mountain

Aquatic ecosystems

Here the species are adapted to live in different aquatic habitats. based on the salinity levels, Aquatic ecosystems are classified into freshwater and marine ecosystems. The examples of aquatic ecosystems are

  • Freshwater Ecosystems: ponds , lakes, wetland, river.
  • Marine Ecosystems: coral reefs and deep ocean.


  • An ecosystem is composed of biotic components and environment.
  • Ecosystem structure is related to composition of various parts of the Ecosystem, including concepts such as Ecological pyramids and trophic levels.
  • The functions of the ecosystem describe the energy flow and material cycling.
  • Ecosystem services describe the human benefits obtained from ecosystems.
  • The various types of ecosystems include pond, forest, lake, tundra, mountain, marine, and wetland ecosystems.




Ecosystem Function