80 TIMBER TRENDS IN THE UNITED STATES 



Table 54. — Commercial forest land in the United States, by productivity class and by section, January 1, 196S 



Productivity class 



Total U.S.i 



North 



South 



Rocky Mountains 



Pacific 



; coast 



120 cu. ft. or more 



85-120 cu. ft 



50-85 cu. ft _ 



Million 



acres 



43 



117 



232 



117 



Percent 



8.5 



22.9 



45.6 



23.0 



Million 



acres 



2 



30 



95 



45 



Percent 



1.2 



17.4 



55.2 



26.2 



Million 

 acres 

 16 

 63 

 93 

 29 



Percent 



8.0 



31.3 



46.3 



14.4 



Million 



acres 



1 



9 



20 



36 



Percent 



1.5 



13.6 



30.3 



54.6 



Million 



acres 



24 



15 



24 



7 



Percent 

 34.3 

 21.4 

 34.3 



25-50 cu. ft 



10 







All classes 



509 



100.0 



172 



100.0 



201 



100.0 



66 



100.0 



70 



100.0 







Extrapolated from partial data for each section. 



(table 54). An additional 23 percent of the total 

 area is capable of growing from 85 to 120 cubic 

 feet per acre. These lands, composing 31 percent 

 of the Nation's total commercial forest, are capable 

 of producing roughly half of the potential growth. 

 Commercial forest lands of medium quality, 

 capable of producing from 50 to 85 cubic feet per 

 acre annually, make up about 46 percent of the 

 total area. Somewhat less than a fourth of the 

 total area is capable of producing between 25 and 

 50 cubic feet per acre annually. The relatively 

 low productive capacity of these poorer sites tends 

 to reduce possibilities for investments in timber 

 growing, although this acreage can still be expected 

 to grow considerable timber for industrial use. 



Pacific Coast States Have 

 the Highest Productivity 



The highest concentration of commercial forest 

 lands capable of producing more than 120 cubic 

 feet of growth per acre annually is in the Pacific 

 Coast States, notably in the forests of western 

 Washington, western Oregon, and northern Cali- 

 fornia (figure 36). In this section there are about 

 24 million acres of this highly productive land, and 

 a total of 39 million acres with a capacity in excess 

 of 85 cubic feet per acre. This area has a rela- 

 tively small amount of forest that will not produce 

 more than 50 cubic feet per acre annually. 



Southern States Have a Large 

 Area of Productive Lands 



Almost 80 million acres in the South have the 

 capacity to produce 85 cubic feet or more of timber 

 per acre and about 16 million acres could produce 

 in excess of 120 cubic feet annually. The better 



timber growing lands in the South are found 

 mainly in the Coastal Plain from North Carolina 

 to Texas, including the slash pine forests of 

 southern Georgia, for example, and loblolly pine 

 areas in Louisiana and southern Arkansas. The 

 Mississippi Delta and other stream bottoms slicing 

 through the Coastal Plain also contain many 

 valuable hardwood forests capable of high yields. 



One-Fifth of North's Area 

 Has High Productivity 



The North ranks behind the Pacific coast and 

 South in average timber growing capacity, but 

 nevertheless has about 32 million acres or one-fifth 

 of its area capable of growing more than 85 cubic 

 feet per acre annually. About three-fourths of 

 the forest land in the North has the capability of 

 producing in excess of 50 cubic feet per acre per 

 year. 



Rocky Mountains Have 

 Varied Capability 



The Rocky Mountain forests include a wide 

 range of timber growing capabilities but on the 

 average are somewhat less productive than forests 

 in other sections. An estimated 10 million acres 

 of commercial forests in the Rockies are capable 

 of growing more than 85 cubic feet per acre 

 annually. These more productive lands are 

 located mainly in Idaho and western Montana. 

 More than half of the commercial forest land in 

 this section is of relatively low site capability, 

 and much of it under current conditions is eco- 

 nomically inoperable for timber harvesting and 

 management. 



