CHAPTER II. 



TREES IN THE FOREST. 



The nature of a tree, as shown by its behavior iu the 

 forest, is called its silvicultural character. It is made 

 up of all those qualities upon which the species as a 

 whole, and every individual tree, depends in its strug- 

 gle for existence. The regions in which a tree will live, 

 and the places where it will flourish best; the trees it 

 will grow with, and those which it kills or is killed by; 

 its abundance or scarcity; its size and rate of growth — 

 all these things are decided by the inborn qualities, or 

 silvicultural character, of each particular kind of tree. 



THE VARIOUS REQUIREMENTS OF TREES. 



Different species of trees, like different races of men, 

 have special requirements for the things upon which 

 their life depends. Some races, like the Eskimos, live 

 only in cold regions. (See PI. XI.) Others, like the 

 South Sea Islanders, must have a very warm climate 

 to be comfortable, and are short-lived in any other. (See 

 fig. 23.) So it is with trees, except that their diflerent 

 needs are even more varied and distinct. Some of 

 them, like the Willows, Birches, and Si)ruces of north- 

 ern Canada, stand on the boundary of tree growth 

 within the Arctic Circle. Other si^ecies grow only in 

 tropical lands, and can not jesist even the lightest 

 Irost. (See PL XII.) It is always the highest and low- 

 est temperature, rather than the average, which decides 

 where a tree will or will not grow. Thus the average 

 temperature of an island where it never freezes may be 

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