What is an Ecosystem?
An ecosystem is defined as the complex system of living organisms, their interrelationship and their physical environment. These all comprise a particular unit of space. An ecosystem is categorized into the following factors. These are the factors of an ecosystem on which the whole ecosystem relies on.
Biotic factors - All living members
Abiotic factors - Minerals, climate, soil, water, sunlight and all other non-living things.
The fundamental source of energy is from the sun. The energy is used by the ecosystem’s autotrophs, self-sustaining organisms. It consists mainly of green vegetation, which is capable of photosynthesis. It uses the sun’s energy to convert carbon dioxide and water into energy-rich carbohydrates. The autotrophs use this energy stored as carbohydrates to form complex compounds such as proteins, lipids, starch, etc. These all maintain an organisms’ life process. The autotrophic level of the ecosystem is termed as producer level, as these are the driving force of the cycle.
The organic matter generated from autotrophs sustains the other level, i.e. the heterotrophs. These are also termed as consumers as they cannot make their food and have to rely on producers for their food. They decompose the complex organic material built up by autotrophs. Animals, bacteria, fungi and other microorganisms come under the category of heterotrophs.
The autotrophs and heterotrophs together make up a various feeding level in an ecosystem. The components of the ecosystem are explained in brief in the following pointers:
The producer level: It composes those organisms that make their food.
The primary consumer level: It composes those organisms that feed on the producer level.
The secondary consumer level: It composes those organisms that feed on primary consumers.
The movement of organic matter and energy consumption from the producer level to the final consumer level makes up a food chain. However, in the process of forming a food chain, it becomes a food web as the ecosystem overlaps and interconnects. The final link in the food chain is always made up of the decomposers (heterotrophs that break down dead organisms and wastes).
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Components of Ecosystem
We will consider an ecosystem from a structural perspective. An ecosystem consists of biotic and abiotic components. We observe that organisms living in any ecosystem are nowhere identical, but can be categorized into species. These species present provide their contribution towards an ecosystem. The example would include the number of species, number of individuals of each species and their distribution across an ecosystem.
Then comes the functional component of an ecosystem. It comprises of:
To survive, an ecosystem needs five basic components. All other components follow after. The various components further include energy, mineral, nutrient, water, oxygen and living organisms. Most of the energy in an ecosystem comes from the Sun. It consists of interdependent and interacting elements of the natural environment in a geographical area. The elements of an ecosystem consist of both living as well as non-living things. The material elements cycle through an ecosystem via the food chain and other pathways.
It is by far considered as one of the major processes in an ecosystem. It is obtained initially from the Sun and then moves through the food chain. At each stage, the consumer only retains a fraction of the energy it takes in. The remaining energy is dissipated as heat and cannot be recycled further. It is considered as an open system concerning energy as it depends on continued energy flow and loses energy in the process.
After energy, the other major process in an ecosystem is the cycling of material in the form of nutrients. Unlike energy, the material is not entered into an ecosystem from any external source. Rather, it is chemically transformed. No material is lost in the cycle. It is also considered as a closed system concerning material flow. The movement of elements of an ecosystem such as carbon, phosphorus and nitrogen through the ecosystem is known as biogeochemical energy.
Energy and nutrient availability constraint an ecosystem’s productivity. In the ocean, light is plentiful at the surface but becomes scarce deep down. Nutrients also become scarce, so productivity is limited. These are certain considerations included while discussing an ecosystem in brief. At all levels, no resource will be equally distributed.