22 THE SCHOOL BOOK OP FORESTRY 



In some parts of the United States forestry 

 experts can tell where they are by the local tree 

 growth. For example, in the extreme northern 

 districts the spruce and the balsam fir are native. 

 As one travels farther south these give way to 

 little Jack pine and aspen trees. Next come the 

 stately forests of white and Norway pine. Some- 

 times a few slow-growing hemlock trees appear 

 in the colder sections. If one continues his jour- 

 ney toward the equator he will next pass through 

 forests of broad-leaved trees. They will in- 

 clude oak, maple, beech, chestnut, hickory, and 

 sycamore. 



In Kentucky, which is a centre of the broad- 

 leaved belt, there are several hundred different 

 varieties of trees. Farther south, the cone- 

 bearing species prevail. They are followed in 

 the march toward the Gulf of Mexico by the 

 tropical trees of southern Florida. If one jour- 

 neys west from the Mississippi River across the 

 Great Plains he finally will come to the Rocky 

 Mountains, where evergreen trees predominate. 

 If oak, maple, poplar, or other broad-leaved trees 

 grow in that region, they occur in scattered 

 stands. In the eastern forests the trees are close 

 together. They form a leafy canopy overhead. 



