Environment (NCERT Class 7 Geography Chapter 1 Notes)

Components of Environment
Components of Environment
What is Environment?
The environment can be defined as the surrounding or conditions in which a living organism operates. It is the amalgam of natural and human-made phenomena. The natural environment refers to both biotic and abiotic conditions on earth. The man-made environment refers to human activities such as religion and education, human-made objects such as buildings, roads and bridges, and interaction between humans.

Natural Environment

Land, water, air, plants, animal and other living organism forms the natural environment. The lithosphere, atmosphere, hydrosphere and biosphere are part of the natural environment. The first three are components of the abiotic environment and the last biosphere is the component of the biotic environment.

Lithosphere
  1. It is the hard top layer of earth's crust. It is made up of minerals and rocks and covered by a thin layer of soil.
  2. It is irregular in shape and consists of a variety of landforms such as mountains, plateaus, plains and valleys.
  3. It provides us with space for forests, grasslands, agricultural lands and human settlement.
  4. It is the source of minerals.

Hydrosphere
  1. The water in oceans, lakes, glacier and water vapour forms the hydrosphere.
  2. Water is essential for all living organisms to survive.

Atmosphere
  1. It is the thin layer of air that surrounds the earth.
  2. The earth gravitational force holds the atmosphere around it.
  3. The earth atmosphere consists of 78 per cent of nitrogen, 21 per cent of oxygen and 1 per cent of other gases such as carbon dioxide and argon.
  4. The changes in atmospheric conditions cause a change in weather and climate.

Biosphere

  1. The biosphere is the narrow zone where land, water and air interact with each other to support life. The plants and animals together make the biosphere.

What is Ecosystem?
  1. An ecosystem can be defined as the relation between a living organism with other living organisms and its surroundings.
  2. Examples of the natural ecosystem are rain forest ecosystem, grassland ecosystem, desert ecosystem, marine ecosystem and so on.
  3. Examples of man-made ecosystems are aquarium, garden, orchards, canals, parks and zoos.
Source: NCERT Class 7 Geography