104 OH THE DISTRIBUTION OF FORESTS IN INDIA. 



daced from South America, and promises to be one of the greatest 

 blessings to the people of India. 



So much will be clear from these remarks, that in the climate of 

 India the luxuriance of arborescent vegetation is a sure index of 

 moisture. A glance at the map might tempt us to go further, and 

 to say that the limits of distribution of the different species in India 

 seem to depend in a greater degree on moisture than on other climatic 

 conditions. The northern limit of Teak, it is true, seems to be more 

 influenced by the temperature of the cold season than by moisture. 

 Natural Teak forests are not found where the mean temperature of 

 the three cool months is considerably less than G0°, though the tree 

 will stand occasional night frosts, which are not uncommon in some 

 of the valleys of the Satpoora range. But no teak is found on the 

 Aravulli hills about Ajmere, though that place has a mean tempera- 

 ture of 65° during the cold season. In this direction it apparently 

 is the want of sufficient moisture which has limited the further ex- 

 tension of the species by natural means. By cultivation, this, as 

 most other trees, has been extended far beyond its natural limits ; 

 numerous fairly-growing teak trees are found in gardens in Bengal, 

 the north-west, and even in the Punjab ; a teak plantation has been 

 commenced in Sikkim ; and it has been proposed to cultivate this 

 valuable tree on a large scale in Assam. Within certain limits the teak 

 tree does adapt itself to different conditions of soil and climate; but 

 limits there are, and, as far as our present knowledge goes, it thrives 

 best with a rainfall above 30 inches, a mean temperature during the 

 three cool months of between 60° and 80°, and during the rest of 

 the year between 70° and 90°. Teak is spread over a great part of 

 the dry belt of Southern India, but only as poor coppice, yielding 

 a scanty crop of poles and rafters, and never attaining any large 

 size. 



The Sal tree is found in two large belts, one extending along the 

 foot of the Himalaya range from Assam to the Sutlej river, with a 

 few outlying patches beyond, and the other occupying the eastern 

 part of Central India. The Sal depends, to a much greater extent 

 than the teak, on certain peculiarities of soil; it is mainly found on 

 sandstone, conglomerate, and gravel, but does not thrive on the 

 heavy clay-soil which overlies the extensive trap-rocks of the 

 Deccan and part of Central India, and this peculiarity may have a 

 considerable influence in limiting the area of its distribution. It 

 stands more cold than teak, but it does not seem to thrive with less 

 than 40 inches of rain. 



