24 Effects of Frost : Injuries from Knows. 



forth new buds from the older wood, and thus were able to show 

 hopeful signs of recovery. 



99. The injury from frosts depends more on the season than on 

 its intensity. A late spring frost will kill down the young shoots 

 of conifers that would endure a severe winter. 



100. Many trees, and especially oaks, pines, and firs, arc found 

 cracked into deep fissures from the unequal action of the frost upon 

 their woody tissues. Such cracks do not heal up or grow over, but 

 remain as a furrow always visible upon the outside, and greatly im- 

 pairing its value for lumber. 



101. A freezing rain may load down the branches of trees so as 

 to break them. The roots of young seedling trees may be thrown 

 out of the ground by frost, and the fruit-season may be checked by 

 a frost that kills the buds or blossoms but that is not severe enough 

 to injure the foliage ; or its maturity may be prevented by an early 

 autumnal frost. 



102. Trees accustomed to alternately wet and dry seasons, such 

 as conifers from the Pacific coast, become exceediugly liable to win- 

 ter-kill, especially after a mild and damp autumn. A long-continued 

 period of very cold weather in winter has been noticed as more 

 likely to injure the growth of trees than more intense frost for a shorter 

 period. 



103. The effects of frost are always to be feared in high moun- 

 tainous regions and in deep humid valleys, for the atmosphere is there 

 always loaded with vapors that condense in fogs as soon as the 

 sun is hid. Young trees bear these exposures with much peril until 

 they get to a height of fifteen or twenty feet ; that is to say, above 

 the ground fogs, or at least above the level at which these injuries 

 are most likely to happen. 



Of t1i3 Injuries from Snows. 



104. When damp snow falls upon the branches of forest trees, 

 and especially the evergreens, it may break them down by its 

 weight, especially when this is increased by rain, or, when frozen 

 on, it is exposed to a strong wind. An instance occurred in Scot- 

 land, in the early part of 1879, when great damage was done to 

 evergreen forests, and to less extent to the oak, birch, and larch 

 trees, from the weight of snows. 



105. In the Rocky Mountain region snow-slides often do great 



