206 EFFECTS OF F0EE3T TEGETATIOX 0^ CLIMATE. 



to tlic cutting down of forests on coffee estates ; and, there- 

 fore, he proceeds to "inquire what effects the destruction of 

 forests actually may have had on the climate and streams of the 

 countr}^" 



He is led to admit that it is only twelve years since the felling 

 of the forests in Coorg has taken place extensively, and that the 

 effects are only gradually perceived, but do go on till they acquire 

 a disastrous power. In Coorg there are 20,000 acres denuded 

 of forest to make way for coffee, and the clearings are partly in 

 the bamboo, chiefly in the dense jungle tracts. These clearings 

 are along the banks and crests of low hills and the slopes and 

 passes, which are densely wooded, and well supplied with 

 springs, forming numerous streams. He then shows how these 

 streams percolate the soil and are preserved by the forest and the 

 matted soil. At the same time the shade of the forest prevents 

 evaporation, the trees exhale much, and a portion is returned in 

 dew or fog to be wafted away. 



His information, during his tour in Coorg and Mysore, con- 

 vinced him that " the facts elicited on the whole go to prove 

 that the tropical forest is the alma mater of springs and streams. 

 " Various instances," (he says) " have been brought to my notice 

 of springs and small streams having become quite dry since the 

 forest was cleared away in their neighbourhood, while in numer- 

 ous cases those that used to be perennial only contain water now 

 during and for a short period after the monsoon. Similar results 

 have been found to follow the destruction of forests growing near 

 the source of streams in all parts of the world." He next shows 

 from Major Sankey's report on public works in Coorg for the 

 official year 1865-6, that " great damage has been done to roads 

 and bridges residting from forest clearance, by the removal of the 

 binding influence of tree roots to keep the banks" of the nullahs 

 in position. 



The remainder of Dr. Bidie's paper is occupied by reasoning 

 to show the injury to the atmosphere, producing malaria and 

 increase of heat, the forest always breathing " soft land airs" 

 from the jungle, and to " these land winds is due the coolness of 

 the nights, which will generally admit of sound slumber"; and in 

 these words he quotes from Cameron, on the Tropical Possessions 

 in Malayan India, — " That the cutting down of forests in Coorg 

 has rendered both earth and air drier is shown by perennial 

 streams having become periodical, by many plants perishing that 

 used to flourish during the dry season, and by other remarkable 

 changes in natural phenomena. He finally points out the 

 effects of clearings on animal life, and the introduction of new 

 and troublesome plants from other regions." 



