NCERT 7th Class (CBSE) Science: Forests: Our Lifeline

Question: Explain how forests prevent floods.

Answer: Forest absorbs rainwater and allows it to seep naturally; its leaves and branches prevent rain to hit the ground directly.

Question: What are decomposers? Explain with example.

Answer: The micro-organisms which convert the dead plants and animals to humus are known as decomposers like Fungi and bacteria. They convert dead leaves and dead animals into humus.

Question: What role does decomposer play in forest?

Answer: Decomposers convert dead leaves and dead animals into humus.

Question: Explain the role of forest in maintaining the balance between oxygen and carbon dioxide in the atmosphere.

Answer: Plants release oxygen in the atmosphere during the process of photosynthesis. This oxygen is inhaled by the animals for respiration, they release carbon dioxide which is absorbed by plants. In this way the oxygen and carbon dioxide cycle goes on. Since forest contain a large number of plants, they help much in this cycle and maintain balance in nature.

Question: Explain the importance of forest.

Answer: Forests provide us with oxygen. They protect soil and provide habitat to a large number of animals. Forests help in bringing good rainfall in neighbouring areas. They are a source of medicinal plants, timber and many other useful products. By the process of transpiration and photosynthesis, forests maintain the temperature. Forests provide shelter for the animals and act as a protective camouflage. Forests provide shelter and food to the tribes living in the jungle. Forest trees such as the bamboo are used in making furniture, baskets, ladders, etc. The teak tree is used to make furniture. The Neem tree is used for medicinal purposes. Forests also provide wood to make paper and other products such as gum, wax, rubber, and honey. Forest influence climate, water cycle and air quality. Forests play a very important role in the food chain. When forests are affected, they affect living beings such as animals and plants.

Question: What would happen if forests disappear?

Answer: The conditions and issues we have to face when forests disappears are:

1. Soil erosion: Trees in a forest hold soil with their roots. If trees are gone, soil will be washed away.
2. Landslides: Without trees, land will be very unstable and easily down the slope.
3. Water pollution: Without tree roots holding the soil in a forest, soil will run into the river.
4. Temperature increase
5. Loss of biodiversity: Plants and animals will lose their food and shelter.
6. Floods: Bald hills and mountains can no longer hold back sudden flows of water, which cause floods.
7. Increase in carbon dioxide: Depletion of forests results in increase in carbon dioxide, which will cause global warming.