Notes For All Chapters Science Class 7
Revision Notes of Ch 12 Forests: Our Lifeline Class 7th Science
Topics in the chapter
Forest
Deforestation
Effect of deforestation
Independence of plants and animals in forest
Canopy
Food chain
Food web
Importance of forests
Conservation of forests
Forest
→ It is a large area of land thickly covered with trees, bushes etc.
→ It is a system comprising various plants, animals and micro-organisms.
→ It is also protect the soil from erosion.
→ It influences climate, water cycle and air quality.
→ The uppermost layer of forest is trees followed by shrubs, the herbs to the lowest layer of vegetation.
→ Different layers of vegetation provide shelter and food for birds, animals and insects.
→ The components of forest are interdependent on one another.
→ Forest keeps on growing and changing. Also forest can regenerate.
Deforestation
→ It is a process of cutting down of trees is known as deforestation.
Effect of deforestation
→ Due to deforestation the amount of carbon dioxide in air will increase, which increase the temperature of earth.
→ Deforestation cause floods because soil lost the capacity to hold water.
→ Insects, animals, birds will not get food and shelter.
→ It cause endanger lives and environment.
Independence of plants and animals in forest
→ Animals and plants depend on each other to remain alive.
→ Organisms interact with each other and their physical environment to derive energy and survive.
Canopy
→ It is the aboveground portion of a plant community or crop, formed by plant crowns.
→ In terms of forest canopy refers to the upper layer formed by mature tree crowns and including other biological organisms.
Food chain
→ It is an interdependence of organisms which shows that who eats whom is known as food chain.
→ Interdependence of producer to consumer and form of various linkages that appears as a chain is known as food chain.
Food web
→ It is a system of interdependent food chain used to represent various relationships in organisms is called food web.
Importance of forests
→ It purify air
→ It prevent soil erosion
→ Forest is noise absorbers
→ It provide timber
→ It provide shelter to the animals
→ It helps in to control floods
Conservation of forests
→ Control forest fires
→ Promote afforestation
→ Do not allow overgrazing
→ Protect wildlife
→ Social forestry
→ Establishment of national parks and bio-reserves.
NCERT Solutions of Forests: Our Lifeline Class 7
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