NCERT Class VII Science Solutions: Chapter 17-Forests: Our Lifeline Part 1

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Question 1:

Explain how animals dwelling in the forest help it grow and regenerate.

Answer:

Various types of animals (herbivores, carnivores, omnivores) live in forests and contribute to food chain. Following activities show how animals help forest grow and regenerate.

  • Animals help in dispersal of seeds from one part of the forest to other part.

  • Animal’s excreta and their dead bodies when decomposed into soil act as manure for the plants.

  • Microorganisms convert dead plants and leaves into humus which is rich in nutrients. Humus in soil provide necessary minerals for plant growth.

Question 2:

Explain how forests prevent floods.

Answer:

Forest acts as a natural absorber of rainwater and allows it to seep. When rainwater falls on leaves of trees and plants, it does not fall directly on the ground. It drips slowly on the forest ground (does not stagnate) and hence prevent floods.

Forest roots hold the soil firmly together. This:

1) Keeps the soil porous as a store for rainwater flowing over the ground?

2) Prevents soil from being eroded and deposited in riverbeds, reducing their capacity to contain water.

Picture shows how to forests prevent floods

Forests Prevent Floods

Picture shows how to forests prevent floods