200 OUTLINES OF FORESTRY. 



or to prevent the loss of its own heat by radia- 

 tion. 



Therefore, an area of ground covered with for- 

 ests is subjected to smaller changes of temperature 

 than a bare, uncovered area. 



The climate of the forest is more equable than 

 that of the open fields, because the forest takes 

 in and parts with its heat more slowly than the 

 fields. 



A layer of snow tends to preserve the tempera- 

 ture of the ground on which it falls. If snow 

 falls on unfrozen ground, the ground will probably 

 remain unfrozen throughout the year until the 

 snow melts ; and, when the melting occurs, the 

 water will drain slowly into the earth. If, how- 

 ever, the snow falls after the ground is frozen, the 

 ground will probably remain frozen until the snow 

 melts, when the water will drain rapidly off the 

 surface. 



The presence of the forest tends to keep the 

 ground unfrozen until protected by a layer of 

 snow, and in this way, when the snow melts, the 

 water sinks quietly into the ground, and disastrous 

 floods are thus avoided. . 



The forest, by keeping the air over it moister than 

 that over the fields, increases the ability of the air 



