Question

why the forest have decline in last 200 years

Answer 1

Forest have declined in last 200 yrs due to following reasons -
1 British rule - during the time of British rule many trees were cut down for industrial purposes and to supply timber to navy for making ships.
2 Railway Lines - Many trees were cut down to lay down the railway lines . from 1848 to 1850 approximately 30,000 hectares of forest land was cleared.
3 Shifting Agriculture - Many tribal people practice shifting agriculture which also makes a large plot of land unfit for agriculture for more than 3 years.

Answer 2

the reason for the decline of forest in last 200 years.                                                         more number cutting trees . deforestation.                                                              in the colonial period  7.5 million trees have been cut for railways and for ship building.                                                                                                                so many trees have been cut for plantations.                                                        so these are main reasons