CHAPTER II. 



TREES IN THE FOREST. 



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

 forest, is called its silviciiltural character. It is made 

 lip 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 Hourish best 5 the trees it 

 will grow wdth, 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 PL 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 different 

 needs are even more varied and distinct. Some of 

 them, like the Willows, Birches, and Spruces of north- 

 ern Canada, stand on the boundary of tree growth 

 within the Arctic Circle. Other species grow only in 

 tropical lauds, and can not resist even the lightest 

 frost. (See PI. 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 

 temx^erature of an island where it never I'reezes may be 

 25 



