How many National Parks are there in India?

Which of the following is not a fast-growing tree?

To reduce the use of $LPG$ by making use of solar energy is an example of $......$

What are 'biodiversity hotspots'? What is the measure of the biodiversity?

The three $R's$ that will help us to conserve natural resources for long-term use are

Due to the active and willing participation of the local community,the Sal forests of Arabari underwent a remarkable recovery by $1983$. $A$ previously worthless forest was valued ₹ $12.5$ crores.
$(a)$ Explain how it became possible to bring such a change.
$(b)$ Mention any two values shown in this approach of forest management.