FOREST INFLUElSrCES. 



1— INTRODUCTION AND SUMMARY OF CONCLUSIONS. 



By B. E. Fkrnow. 



INTRODUCTION. 



One of the arguments upon wliicli a change of policy in regard to 

 our forests, and especially on the i>art of the National Government, is 

 demanded, refers to the influence wliich it is claimed forest areas exert 

 upon climate and waterflow. It is argued that the wholesale removal 

 and devastation of forests affects climate and waterflow unfavorably. 



Popular writers on forestry, friends of forestry reform, and the public 

 mind have readily taken hold of this proposition, enlarged upon it, and 

 generalized without sufficient and relevant premises, and before it was 

 possi1)le for science and systematic observations to furnish grounds or 

 sound deductions; hence we have had only presumptions supported by 

 superficial reasoning and occasional experiences. Even scientific writers 

 have discussed the question without proper basis, and have sought to 

 reason out the existence or absence of such an influence uj^on general 

 premises and such evidence as the history of the world seemed to fur- 

 nish, or else upon observations which were either of too short duration 

 to allow elimination of other disturbing factors or else were otherwise 

 unreliable. 



From the complication of causes which produce climatic conditions 

 it has always been difficult to prove, when changes of these conditions 

 in a given region were observed, that they are i)ermanent and not due 

 merely to the general periodic variations which have been noted in all 

 climates of the earth, or that they are due to a change of forest condi- 

 tions and to no other causes; hence some climatologists have thought 

 ])roper to deny such influences entirely. On the other hand, there are 

 as trustworthy and careful observers who maintain the existence of such 

 influences; but only of late has the question been removed from the 

 battle-field of opinions, scientific and unscientific, to the field of experi- 

 ment and scientific research, and from the field of mere speculation to 

 that of exact deduction. But the crop of incontrovertible facts is still 



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