Our Liviiif; Rcxdiirci's — Tcncstrial F.iosxsleiiis 



?/5 



wilderness, parks, and other land classifications. 



Forest land is widely but unevenly distrib- 

 uted. North Dakota has the smallest percentage 

 of forest cover ( 1 % ) and Maine has the greatest 

 (89%). Forest areas vary greatly from sparse 

 scrub forests of the arid interior West to the 

 highly productive forests of the Pacific coast 

 and the South, and from pure hardwood forests 

 to multispecies mixtures and coniferous forests. 

 In total. 52</f of the forest land is east of the 

 Great Plams states. In the East, the oak-hickory 

 forest type group is most common, while in the 

 West, the category referred to as "other soft- 

 woods" is most common. 



U.S. forests provide wildlife habitat and 

 thereby support biodiversity; take carbon out of 

 the air and thus serve as carbon sinks; and pro- 

 vide the outdoor environments desired by many 

 people for recreation. 



Timbeiiand forests are logged for lumber, 

 plywood, and paper products. This timbeiiand 

 is generally the most productive and capable of 

 producing at least 1 .4 m'* of industrial wood per 

 hectare a year (20 tV'^/acre) and is not reserved 

 from timber harvest (Powell et al. 1993). 

 Two-thirds of the nation's forested ecosystems 

 ( 198 million ha or 490 million acres) are classed 

 as timberland. Because of historical interest in 

 timber production, more information is avail- 

 able for the characteristics of timber inventories 

 on timberland than for other forest land. 



Timberland ownership patterns vary through- 

 out the United States. For the country as a whole, 

 73% of all timberland is owned by private indi- 

 viduals and firms. The remaining 27% is in fed- 

 eral, state, and other public ownerships. Much of 

 the privately owned land is in the East and much 

 of the national forest land is in the West (Fig. 2). 

 Most of the publicly owned land is managed 

 according to plans that account for the various 

 uses and values provided by forest cover Forest 

 industry lands are generally managed with tim- 

 ber production being the main interest. Other pri- 

 vate forest lands are managed for a variety of 

 interests, reflecting the divergent views of the 

 some 6 million owners in this category. 



The nation's timberland contains an estimat- 

 ed 24.3 biUion m-^ (858 billion ft'' ) of timber, of 

 which 92% is in growing stock — live, sound 

 trees suited for roundwood (timber) products. 

 Softwoods such as pine are generally used to 

 make lumber and plywood for use in construc- 

 tion. Hardwoods, such as oak, are used in mak- 

 ing furniture and pallets. Both softwoods and 

 hardwoods are used in manufacturing paper 

 products. The nation's softwood growing stock 

 volume amounts to 57% of the total, with about 

 66% of this volume in the West. Total softwood 

 growing .stock volume has been slightly declin- 

 ing recently (Fig. 3). By contrast, hardwood 



growing sti)ck volume increased 7%- between 

 1987 and 1992. More than 9()%> of all hardwood 

 timber volume is in the eastern United States. 



Mortality, Growth, Harvest 



Mortality is the result of natural causes such 

 as insects, disease, fire, and windthrow. 

 Between 1962 and 1986. mortality averaged 

 122 million m^ (4.3 billion ft'') per year 

 Mortality increased to 155 million m"* (5.5 bil- 

 lion ft'') in 1991. but was still less than 1%- of 

 the U.S. growing stock volume. 



Net annual growth, which already has mor- 

 tality subtracted out, totaled 612 million m-^ 

 (21.6 billion ft-') in 1991— about 2.7% of the 

 growing stock inventory. Total growing stock 

 growth declined about 2% between 1986 and 

 1991 (Fig. 4), the first decline in net annual 

 growth since 1952. The decline between 1986 

 and 1991 occurred with softwoods, which 

 declined 4.4% to 339 million m'* (12 billion 

 ft''). Net annual growth for hardwoods 

 increased 0.9%. 



Removals from timber inventories are losses 

 by other than natural causes (mortality) and 

 include harvest of roundwood products. Timber 

 removals from growing stock inventory in 1991 

 totaled 461.5 million m'' (16.3 billion ft'') or 

 2.1% of the inventory. Average timber removals 

 have risen each decade since the I950's. Almost 

 55% of all timber removals came from the 

 forests of the South, up from 45% in 1970. 

 Twenty-three percent of all removals came from 

 Pacific coast forests, 17% from the North, and 

 5% from forests in the Rocky Mountains. 

 Softwoods accounted for two-thirds of all grow- 

 ing stock removals in 1991. Timber removals 

 continued to be concentrated on private land in 

 1991. 



The growth-removals ratio for the United 

 States is greater than one for all species (1.3). 

 for softwoods (l.I), and for hardwoods (1.8), 

 which indicates that the timber inventory is 

 increasing. In the 1920's, timber growth was 

 about one-half the rate of harvest. By the 

 I940's, improved forest growth rates (partly 

 because of forest protection from fire), as well 

 as declines in harvest rates, resulted in timber 

 growth and harvest coming into approximate 

 balance. 



References 



Powell. D.S.. J.L. Faulkner. D.R. Darr. Z. Zliu. and D.W. 

 MacCleery. 199.1. Forest resources of the United States, 

 1992. Gen. Tech. Rep. RM-2-14. U.S. Forest Service, 

 Rocky Mountain Forest and Range E.xperiment Station. 

 Fort Collins, CO. 132 pp. 



USFS. 1992. Forest Service resource inventories: an 

 overview. Forest inventory, economics, and recreation 

 research. U.S. Forest Service, Washington. DC. 39 pp. 



120- 



East 



Region 



Fig. 2. Timberland ownership pat- 

 terns by regions. 1992 (Powell el 

 al. 1993). 



Hardwoods 



B Softwoods 



m 



Hn 

 I 



■"i-|"l 



77 87 92 

 Years 



Fig. 3. Softwood and hardwood 

 growing stock volume, selected 

 years (Powell etal. 1993). 



700- 



I 500 

 I 400- 



m 

 E 

 -g 300- 



Z3 



o 



200 j 



100- 



0- 





52 62 70 76 86 91 



Years 



Fig. 4. Net annual growth, select- 

 ed vears (Powell et al. 1993). 



For furtlier information: 



David R. Darr 



U.S. Forest Service 



PO Bo.x 96090 



Washington. DC 20090 



