TEEES AND THEIE VALUE FOE PLANTING 75 



seriously by insects or disease, Norway pine sliould hold an 

 important place in forestry in the future. It is propagated 

 as for white pine. 



Jack Pine (Pinus divaricata). — Jack pine is a northern 

 tree extending south to northern New England, New York, 

 and the Lake States. It is most abundant on the sand plains 

 of Michigan, Wisconsin and Minnesota. It is a comparatively 

 small tree. Mature stands will not average more than 70 feet 

 high and 10 inches in diameter. Individual trees are found 

 100 feet high and 18 inches in diameter. Its importance lies 

 in the fact that it will grow well on poor, dry sands. It forms 

 a tap root that grows deep into the ground, making it possible 

 for the tree to stand very dry conditions. It is a very intol- 

 erant tree. It makes very rapid growth in youth. At 10 years 

 of age trees on poor soil are often 18 feet high. It will some- 

 times grow 3 feet a year at that age. Its growth slows down 

 later, so that at 60 years of age the trees are only 60 feet 

 high and from 5 to 8 inches in diameter. It has short life, 

 the average age of stands seldom exceeding 80 to 90 years. 

 It bears large quantities of seed every year. Cones are often 

 produced on trees at 5 years of age. The seeds are light 

 and are blown long distances by the wind. It quickly seeds 

 up burned over areas. The cones, which naturally open with 

 difficulty, are dried out by fire and open readily after it has 

 passed to scatter the seed. It can easily be propagated arti- 

 ficially by sowing the seed. The wood is soft, light and brittle, 

 but has many uses, including bed slats, boxes, ceiling, crates, 

 flooring, furniture and siding. It will be an important tree 

 locally in its natural range on soil too dry and sandy for other 

 species of trees to grow. 



Scotch Pine {Pinus sylvestris) . — Scotch pine is a native of 

 Europe and has been planted extensively in this country chiefly 

 for ornamental purposes. Many plantations of this tree have 

 been started. It grows to be a tree 70 feet high and ij^ 

 to 3 feet in diameter, and may reach 120 feet in height and 



