Forests - Our Lifeline Summary Class 7 NCERT Summary Chapter 12

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.