Chapter Notes: Chapter 1 - Environment, SST, Class 7 | EduRev Notes

ENVIRONMENT
The word ‘Environment’ is derived from French word “Environer/ Environner” meaning “neighbourhood”.
The natural factors, places, people, things, etc. that surround a living organism is called environment. It is a combination of both natural as well as man-made phenomena.

Fig: Components of Environment

Natural Environment
The natural environment comprises of biotic and abiotic conditions, whereas the man-made phenomena comprise the activities and interactions among human beings.

Fig: Natural Environment

Everything around us that is natural and not made by humans is a part of the natural environment.
(i) Land, water, air, plants, and animals comprise the natural environment.
(ii) Lithosphere, atmosphere, hydrosphere and biosphere are the four domains of the natural environment.

Fig: Bio Sphere

DOMAINS

• Lithosphere is the domain that provides us forests, grasslands, land for human agriculture and settlements. Lithosphere is the solid crust or the hard-top layer of the earth. It is made up of rocks and minerals and covered by a thin layer of soil.
• The hydrosphere comprises various sources of water and different types of water bodies like rivers, lakes, seas, oceans, etc. It is essential for all living organisms.
• The atmosphere is the thin layer of air that surrounds the earth. It protects us from the harmful rays and scorching heat of the sun. It consists of a number of gases, dust and water vapour. The changes in the atmosphere produce changes in the weather and climate.
• Biosphere is a narrow zone of the earth where land, water, and air interact with each other to support life. 

ECOSYSTEM 

Fig: Ecosystem

(i) It is a system formed by the interaction of all living organisms with each other and with the physical and chemical factors of the environment in which they live, all linked by transfer of energy and material.

An Ecosystems are the foundation of ‘Biosphere’ and maintain the natural balance of the earth. All plants, animals and human beings depend on their immediate surroundings. Often, they are also interdependent on each other. This relation between the living organisms, as well as the relation between the organisms and their surroundings form an ecosystem.

HUMAN ENVIRONMENT

• Human beings interact with the environment and modify it according to their needs.
• The wheel was invented, surplus food was produced, barter system emerged, trade started and commerce developed.
• Industrial revolution enabled large scale production. Transportation became faster. Information revolution made communication easier and speedy across the world.
• A perfect balance is necessary between the natural and human environment.
• Environment is changing because of our increasing needs due to which we are modifying and sometimes even destroying our natural surroundings.
• Humans must learn to thrive and use their environment in a harmonious way.