If an agricultural field is liberally irrigated for a prolonged period of time,it is likely to face the problem of:

The Wildlife Protection Act was introduced in:

Read the following statements carefully and select the correct ones.
$I.$ $UV$ rays are essential for the production as well as degradation of ozone gas.
$II.$ Ozone present in the ionosphere acts as a shield absorbing $UV$ radiation coming from the sun.
$III.$ One-fourth of the incoming solar radiation is reflected by the atmospheric gases and clouds,and only half of the incoming solar radiation falls on the earth's surface,heating it. Of this,only a small portion is reflected back.

The average concentration of $CO_2$ in the atmosphere is

Which of the following does not affect the forest ecosystem?

Eutrophication is caused by