XXI. THE ICE-COAT ON THE TREES 



"First there came down u, thawing rain 

 And its dull drops froze on the boughs again; 

 Then there steamed up a freezing dew 

 Which to the drops of the thaw-rain grew; 



And a northern whirlwind, wandering about 

 Like a wolf that had smelt a dead child out, 

 Shook the boughs thus laden and heavy and stiff, 

 And snapped them off with his rigid griff." 



— Shelley (The Sensitive Plant). 



Winter imposes some hard conditions upon tree life. In 

 the "frozen north" there are no trees; and in our temperate 

 clime there are only those that are able to withstand a long 

 period of inactivity, a succession of freezings and thawings, 

 and the heavy mechanical stresses imposed by high winds 

 and snow and ice. The majority of our woody plants have 

 met the difficulties of the situation by dropping their leaves 

 on the approach of winter. Most of the tall conifers have 

 adjusted themselves to bear winter's white burden. While 

 retaining their leaves, they spread their branches horizontally 

 in whorls around a single axis, and when the snow bends 

 them, the higher branches rest upon the lower from top to 

 bottom in mutual support. As John Burroughs poetically 

 puts it, "The white pine and all its tribe look winter cheerily 

 in the face, tossing the snow, masquerading in arctic livery, in 

 fact, holding high carnival from fall to spring." 



The severest test of the strength of a tree comes not from 

 snow, but from ice; it comes not when the weather is coldest, 

 but when there has been a thaw, and the thermometer is 

 hovering around the freezing point. When the air is full of 

 moisture, and the trees have been suddenly cooled by radia- 

 tion, the water freezes to them, completely encasing them in 

 ice. This usually happens toward nightfall ; and if it con- 



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