FOREST TREES AND FOREST REGIONS OF THE U. S. 37 



own about one-twelfth of the saw timber and one-third of the cord- 

 wood timber. About 88,000,000 acres of commercial forest land are 

 in public ownership mostly in the national forests, 10,600,000 in 

 State, county, or town ownership, while 150,000,000 acres are owned 

 by farmers and 247,000,000 acres by other private individuals or 

 lumber concerns. 



CORDWOOD 



A vast amount of timber less than saw-timber size is now growing 

 in our forests. A portion is found in saw- timber trees, while the 

 greater amount is on forest lands where the trees have not yet reached 

 saw-timber sizes. The total amount is estimated at nearly 2,400,- 

 000,000 cords. The annual cut of cordwood material for all purposes, 

 including fuel wood and pulp wood, is probably about 80,000,000 

 cords. The total supply of. wood suitable for paper pulpwood is 

 estimated at 1,800 million cords, or about one-third of the total 

 quantity of wood of all lands and sizes in continental United States. 

 Nearly one-half is in the southeastern part of the country, one-fifth 

 in the Pacific-coast region, one-tenth in New England, and the rest 

 in the central and Rocky Mountain regions. 



FOREST DRAIN AND GROWTH 



The total amount of timber being cut or destroyed is estimated at 

 16 billion cubic feet yearly. Of the drain on forests as a whole, about 

 5 percent is due to fire, 6 percent to insects, disease, drought, or wind, 

 and 86 percent to cutting for use. The yearly drain of standing saw 

 timber by cutting for lumber and by other losses amounts to a total 

 of 59 billion board feet, or six times the amount of growth of that 

 class of timber. 15 



The yearly growth of timber of all kinds or species in the United 

 States (continental area) has been estimated at a little over 7 billion 

 cubic feet. Of this a little over one-half is softwoods (pines, spruces, 

 firs, etc.). The yearly growth of saw timber is estimated at a total of 

 9.7 billion board feet. Of this two-thirds is softwoods and one- third 

 hardwoods. More than one-half of the total growth of all timber, 

 including saw timber, is taking place on somewhat more than 100 

 million acres of forest land in the southeastern portion of the United 

 States (southern and a portion of the central hardwood forest regions) . 

 The western forest region is making a small growth because of the 

 larger percentage of old growth timber and young timber. 



Thus the forest timber supplies of the United States are being 

 seriously depleted. The total yearly drain on saw timber amounts to 

 about six times the estimated yearly growth, and about twice for all 

 kinds of wood in trees including saw timber and all smaller material. 



FOREST TYPES OR TREE ASSOCIATIONS 



Within each of the forest regions are found various natural groups 

 or associations of different species of trees. They occur over areas 

 varying widely in extent from a few acres to millions of acres. Such 

 groups or tree associations are known as " forest types." 



" The relation between cubic feet of wood in trees and board feet of saw timber varies greatly with the 

 size and shape of the trees. In round figures, the present estimates are based upon 1,000 cubic feet of 

 wood in trees yielding about 4,000 board feet of saw timber and 3,000 cords of wood. Saw-timber trees 

 often yield 5,000 board feet of saw timber for each 1,000 cubic feet of wood in the tree. 



