It is our moral duty to protect, restore and conserve/preserve forest as they are highly beneficial for mankind In India, around $30 \%$ of land was covered by forest in early 20th century, which has been reduced to $18-19 \%$ by the year 2000. National Forest Commission of India (1988) recommended a relatively large forest cover (67\%) for the hills and $33 \%$ for the plains.

Recommendation a large forest area for hills is due to its properties like checking soil erosion, percolation and recharging ground water, checking landslide and other natural calamities and to maintain the original flora and fauna of hills.

Slash and burn agriculture can be environment friendly if

(i) small widely scattered plots are used for cultivation as the forest ecosystem will not suffer damage.

(ii) crop rotation is used so that soil does not loose fertility entirely.

(iii) keeping cropping period small and fallow (unplanted) period longer.

The main idea behind joint forest management concept introduced by the Government of India was involving the local communities in the forest conservation.

This concept was adopted considering the extraordinary courage and dedication the local people showed in protecting the wildlife through the movements like Bishnoi's is movement in Jodhpur and Chipko Movement in Garhwal Himalayas.

The inflammation of cornea caused due to the excessive absorption of ultravioet-B radiations is called snow-blindness cataract.

High concentrations of DDT disturb calcium metabolism in birds, which causes thinning of egg shell and their premature breaking, eventually causing decline in bird populations.