20 Forests — their Influence upon Climate and Rainfall. [January, 



argument and opinion is decidedly on the side of the baneful 

 effects of the destruction of forest growth, the testimony of some 

 of the best scientific minds of different ages being very strong on 

 this point 



It is but fair to say, however, that not a few observers of note 

 deny any effects of woods on the moisture and other conditions 

 of the atmosphere; and even stranger still, it has been declared 

 that the climate of the Western States has, if anything, been im- 

 proved by the denudation of forests ; but this assertion rests, 

 we think, on too slender evidence to be entitled to credence. It 

 may be safely assumed that forests favorably affect the meteoro- 

 logical conditions. Our subject presents many difficulties owing 

 chiefly to the fact that numerous causative elements enter 

 into the question, some of which are of a conflicting tendency, 

 and though a question so confessedly intricate may perhaps never 

 be susceptible of solution, nevertheless any new light on the sub- 

 ject, however faint the ray, must be considered welcome. 



One of the ways in which forests are usually considered to 

 exert an influence over the climate, is by obstructing the free 

 passage of wind currents. This is an element of the question 

 which is, perhaps, better established than, any other, but is of too 

 great importance to be disposed of in a summary manner. It is 

 evident that trees are well adapted to break the force of the wind ; 

 the branches, and particularly the leaves, on account of their im- 

 mense numbers and close proximity, serve as efficient barriers, 

 and the trunk holds up the bushy top and defies the tempest, 

 while roots in turn are continually extending their grip on mother 

 earth in order to support the trunk. And it can be readily under- 

 stood that the particles not checked by the first row of trees to 

 the windward, would have their force diminished and be promptly 

 checked by the trees to the rear. In this wise belts or clumps of 

 trees afford shelter to the leeward of them from the chilly, or 

 even frigid blasts, which are known in many localities to be very 

 unfavorable to the maturation of fruit-crops and harvests. Of little 

 less importance, perhaps, is their effect in protecting from the 

 drying winds -of summer, which are frequently the cause of 

 blighted crops and other mischief, due to their power to enhance 

 evaporation from vegetation and from the soil during the dry sea- 

 son. For this reason woods are also needed even on our coast. 

 The sea breezes as they strike the land become warmed, their 



