Our Environment: Types, Components and Functions

The word environment originated from the French word “environ” which means surrounding. Thus, the environment can be defined as all the living and nonliving things that surround us and are responsible for nourishing the life that exists on earth. All the organisms, plants, human beings and natural resources such as water, soil, and physical interactions form an important aspect of our environment. Due to rising concerns such as global warming, pollution, deforestation and climate change, there is a need to conserve and protect our environment from further destruction. 

Ecosystems

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• The term ecosystem was first coined by A.G. Tansley 1935. ‘Eco’ means environment and ‘system’ implies a complex of co-ordinated units. 
• An ecosystem is a community of different species which interact with one another and with their nonliving environment exchanging energy and matter at different levels in the environment.
• Ecosystem includes all the natural units of earth such as living things (plants, animals and microorganisms) which function together with the nonliving environment (air,water and soil) in a particular area.
• Examples of ecosystems are: Forest,pond,mountain,sea,river etc.
• Ecosystems are of two types-natural and man-made.

Types of Ecosystem

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1. Natural ecosystem:

It is a type of ecosystem which is found naturally on earth.It can be further classified into different types of “biomes”- 

• Aquatic biomes such as sea,pond, river, lake
• Terrestrial biomes such as forest, desert, mountains etc.

2. Man-made ecosystem:

​It is an artificial type of ecosystem which is created by human beings. Eg.crop fields, aquariums, gardens,parks,zoos etc.

Natural and Man-made ecosystem

Components of the ecosystem

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The environment consists of both biotic (living things) and abiotic components (nonliving things)

Biotic components:

• Producers:

​ Organisms which are capable of synthesizing their own food are known as the producers (Eg.plants). They are also called autotrophs.

• Consumers: 

All organisms which get their food by feeding upon other organisms (tiger, man) are called carnivores. They are also known as heterotrophs.

Herbivores – These are the ones who feed directly on producers and are known as primary consumers (e.g. rabbit, human) 

Carnivores – Meat eaters: They feed on other consumers.

» If they feed on herbivores they are known as Secondary consumers (Eg.frog) 

» If they feed on other carnivores directly, they are known as Tertiary consumers (Eg.snake, fish) 

Omnivores – Organisms which feed on both plants and animals. (Eg. humans, rat) 

Detritivores - Organisms which feed on the parts of dead organisms (Eg. ants, earthworms).

• Decomposers:

Decomposers are known to be the organisms which derive their nutrition through the process of breaking down complex organic compounds into simpler organic constituents (bacteria, fungi).

Abiotic components:

Abiotic components

• Physical Factors: The sunlight, average temperature, annual rainfall, wind, soil type, water availability etc. are some of the important physical factors constituting the abiotic component.
• Chemical Factors: Essential nutrients like carbon, nitrogen, phosphorus, potassium, hydrogen, oxygen and sulphur are some of the chemical factors influencing the ecosystem.

Functions of an ecosystem:

The major functional attributes of an ecosystems are:

• Cycling of nutrients: In the ecosystem, biotic components and other materials like N, C, H2O are circulated within and outside of the system. This is known as the biogeochemical cycle.
• Energy can be transferred from one trophic level to the other in the form of a chain called the food chain.
• Assists in primary and secondary production.
• Helps in ecosystem development and regulation.

Food Chain

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• Definition: 

The transfer of food energy from the source in plants through a series of organisms that consume and are consumed is known as the ‘food chain’.

Food chain

• Examples: 

 Grass(Producer) → Deer(Herbivore) → Tiger(Carnivore),  Grass(Producers) → Insect(Herbivores) → Frog(Carnivores) → Snake(Secondary Carnivore).

• Significance of food chains:

1. Helps in understanding of interaction among various organisms at different trophic levels.
2. Helps in transferring of energy at different trophic levels of the ecosystem.
3. It gives dynamicity to the biological activities and the ecosystem.

Also Read: Food Chains and Webs

Food Web

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• Definition: The interlocking pattern of various food chains in an ecosystem is known as the food web. In a food web, many food chains are interconnected and thus there are increased possibilities of eating and getting eaten by different organisms of various species. Example: Insects, rats, deers, etc. may eat grass; these inturn may be eaten by carnivores (snake, tiger). Thus, there is an interlocking of various food chains and this is termed as a food web.

The major environmental threats posed due to human activities are:

• Problem of waste disposal.
• Shortage of food and impoverishment of biological diversity.
• Destruction of ozone layer.
• Climatic changes and global warming
• Pollution
• Depletion of freshwater resources.

The two of the major problems from the above list are ozone layer depletion and waste disposal:

1. Depletion of ozone layer:

A single molecule of ozone (O3) is formed from the combination of three atoms of oxygen. The major significant function of ozone is to shield the surface of the earth from ultraviolet (UV) radiation from the Sun. This radiation is highly damaging to organisms, and can cause skin cancer in human beings.

Formation of ozone: Ozone is formed when the higher energy UV radiations split apart some molecular oxygen (O2) into free oxygen (O) atoms. These atoms then combine with the molecular oxygen to form ozone which is depicted below in the equations:

Depletion of ozone layer

Depletion of ozone layer: Ozone layer gets depleted – due to the use of chemicals like CFC’s(chlorofluorocarbons), aerosol sprays etc. Depletion of ‘ ozone layer would cause skin cancer in humans and animals and severe damage to the plants and its species.

2. The problem of waste disposal:

Industrialization, change in lifestyle and attitude of humans, rise in demand of consumer goods have created a major problem in the form of wastes/garbage accumulation and its disposal. These problems are more concentrated in urban areas. The method of disposal of waste should be done properly and in a scientific way. Different methods for waste disposal are: Incineration, Composting, Land fillings, Reusing, Recycling etc.

Also Read: Ozone Layer and How it is getting depleted