NCERT 8th Class (CBSE) Science: Conservation of Plants and Animals

Question: List four ways in which forests are useful to us.

Answer: Forests are useful to us in the following ways:

1. They yield valuable products, such as timber, wood, wood pulp, latex, etc.
2. They protect wildlife, since wildlife depends on forests for food and shelter.
3. They help in maintaining the balance between carbon dioxide and oxygen in the atmosphere.
4. They regulate the temperature of the earth.
5. They maintain the water cycle in nature.
6. They prevent soil erosion.

Question: List three main causes of deforestation.

Answer: Three main causes of deforestation are:

1. To build homes, factories, roads and dams.
2. For farming, as more food is needed to feed the growing population.

Question: ‘Deforestation can lead to desertification’. How?

Answer: Deforestation .causes an increase in soil erosion. As the top soil gets eroded, the lower hard and rocky soil with less humus gets exposed. This soil is less fertile. Over time, continued soil erosion can convert the land into a desert. This is called desertification.

Question: What effect can deforestation have on groundwater? Give reasons.

Answer: Deforestation causes reduction in groundwater’ due to decreased water absorption capacity of the soil. The reduction in absorption of water into the soil can result in floods.

Question: What do you mean by planned harvesting of forests? How does it help in their conservation?

Answer: Planned harvesting of forest is the cutting of only some of the trees in a forest. The uncut trees prevent erosion and produce seeds so that new trees can grow. In this way, it helps in forest conservation.

Question: In what ways are wildlife conservation and forest conservation related?

Answer: Wildlife conservation is closely related to forest conservation. When a forest is destroyed, a large number of animals become extinct or endangered. So, to conserve the habitat of endangered animals, it is necessary to protect the forests.