Forest Types of the Coeur d'Alene Mountains 113 



moisture content of the soil. The wind factor also largely deter- 

 mines the destructiveness of forest fires, which in baring the soil 

 of plant life and humus has a decided effect on soil moisture. 

 The effect of aspect in determining the factors which produce a 

 certain type may be shown as follows : 



elting 

 empera- 



Evapo 

 Snow 

 Soil t 



de 



r > 



W c/i - 



^ c\i 



4-1 G 



w 2 "So 



^ o^o 



T3 g ^3 ^ 



.s < > S 



03 



CJ 



^>3 



O> V3 

 II 1 



These are probably the main factors chiefly influencing the 

 formation of the two great types, though others might be men- 

 tioned. Light of course is of great importance in influencing 



