Forests Our Lifeline - Revision Notes
CBSE Class 7 Science
Revision Notes
Chapter – 17
Forests: our lifeline
- Forest: Large area of land thickly covered with trees, bushes, etc.
- We get various products from the forests around us.
- Forest is a system comprising various plants, animals and micro-organisms.
- In a forest, trees from the uppermost layer, followed by shrubs, the herbs to the lowest layer of vegetation.
- Different layers of vegetation provide food and shelter for animals, birds and insects.
- The various components of the forest are interdependent on one another.
- The forest keeps on growing and changing, and can regenerate.
- In the forest, there is interaction between soil, water, air and living organisms.
- Forests protect the soil from erosion.
- Soil helps forests to grow and regenerate.
- Forests are the lifeline for the forest-dwelling communities.
- Forests influence climate, water cycle and air quality.
- Deforestation: Cutting down of trees is known as deforestation.
- Importance of Forests:
- Provide timber.
- Purify air.
- Provide shelter.
- Prevent soil erosion.
- Control floods.
- Noise absorbers.
- Independence of Plants and Animals in Forest:
- Plants and animals depends on each other to remain alive.
- All organisms interact with each other and their physical environment to derive energy and survive.
- Effects of deforestation:
- Amount of carbon dioxide in air will increase, resulting in the increase of earth’s temperature. (Global Warming)
- Animals will not get food and shelter.
- Soil will not hold water, which will cause floods.
- Endanger lives and environment.
- Conservation of Forests:
- Do not allow overgrazing.
- Promote afforestation.
- Protect wildlife.
- Control forest fires.
- Food Chain: Interdependence between producers and consumers studied in form of various linkage that appears as a chain. or Interdependence of organisms which shows who eats whom.
- Food Web: A system of interdependent food chains used to represent various relationships in organisms.
