THE FOREST. 19 



has a very marked effect on the growth of vegetation. 

 This is especially the case where high ranges of hills and 

 other local conditions modify the climate. 



A Northern Slope receives no full sunlight; the sim's rays 

 fall obliquely in the morning or toward evening, according 

 to the angle of elevation. The winds it receives in winter 

 are colder than those received by the southern slope, but 

 the few winds which strike it during the growing season are 

 not strong, hot, or very dry. As the vegetation is a little 

 delayed on a northern slope, there is less danger from late 

 spring frosts than on a sunnier aspect, and as the snow 

 melts slowly, there is a better chance for its waters to soak 

 into the ground. In consequence of these facts trees are less 

 liable to suffer from drought on the same kind of land with 

 a northern than with a southern exposure. The trees keep a 

 more regular form and growth is more uniform and certain. 

 It will generally be found that where timber is cut off from 

 a northern slope growth renews itself very quickly, for tree 

 seeds are most likely to grow under the conditions found 

 there. 



An Eastern Slope receives the sun in the cool morning 

 hours when the temperature and light are moderate. It is 

 not exposed to hot, dry winds nor to the intense heat of 

 the sun. The soil retains its moisture fairly well and trees 

 make a good growth. For trees it ranks next in value to 

 a northern slope. 



A Southern Slope receives the most direct rays of the 

 sun and the full force of hot, dry winds and beating rains 

 during the growing season. Consequently vegetation is 

 more liable to injury by late spring frosts, because of 

 starting earlier in the spring, than in any other location. 

 The soil is most liable to erosion from beating summer rains 

 and dries up most quickly after the spring rains. The trees 

 grow irregular in form, the seeds seldom start well on 

 southern or western slopes, and when once cleared, tree- 



