636 



TIMBER RESOURCES FOR AMERICA'S FUTURE 



wardt's Comparative Strength Properties of Woods 

 Grown in the United States, fully identified 

 above. Included are: 



Soft maple Cottonwood and aspen 



Sweetgum Basswood 



Tupelo and blackgum Yellow-poplar 



Other soft hardwoods 



Western softwoods. 



Douglas-fir 



Ponderosa and Jeffrey 



pines 

 True firs 



Western hemlock 

 Sugar pine 

 Western white pine 

 Redwood 



Western hardwoods 



Aspen 



Sitka spruce 

 Engelmann and other 



spruces 

 Western larch 

 Western redcedar 

 California incense-cedar 

 Lodgepole pine 

 Other western softwoods 



Red alder 

 Other western hardwoods 



Stand improvement measures. Measures, such 

 as pruning, release cutting, girdling, weeding, or 

 poisoning of cull trees, applied with purposeful 

 intent to improve growing conditions in either 

 natural or planted stands, and not with the intent 

 of producing commercial timber products. 

 Stand size class. 



Sawtimber stands. Stands of sawtimber 

 trees having a minimum net volume per acre 

 of 1,500 board-feet. International ,Vinch rule, 

 except in softwood types in the Douglas-fir 

 subregion of the Pacific Northwest and in Cali- 

 fornia west of the Sierras, where the minimum 

 net volume per acre is 4,000 board-feet, Interna- 

 tional /4-inch rule. 



Poletimber stands. Stands failing to meet 

 the sawtimber stand specifications, but at least 

 10-percent stocked with poletimber and larger 

 trees and with at least half this minimum 

 stocking in poletimber trees. 



Seedling and sapling stands. Stands not 

 qualifying as sawtimber or poletimber stands, 

 but at least 10-percent stocked with trees and 

 with at least half this minimum stocking in 

 seedlings or saplings. 



Nonstocked and other areas. Areas not 

 qualifying as sawtimber, poletimber, or seedling 

 and sapling stands. 



Standard error. The range about a sample- 

 estimated average or total, within which the odds 

 are 2 to 1 that the average or total based on com- 

 plete coverage (100-percent sample) would fall. 

 State ownership. See Ownership. 

 Stocking. Stocking is the extent to which 

 growing space is effectively utilized by present or 

 potential growing-stock trees of commercial 

 species. Degree of stocking is synonymous with 

 "percent of growing space occupied" and means 

 the ratio of actual stocking to full stocking for 

 comparable sites and stands. Stocking may be 

 measured in terms of number of trees, volume, 



basal area, cover canopy, or other criterion, or 

 combination of criteria. 



Nonstocked areas. Areas that are 0- to 10- 

 percent stocked with present or potential grow- 

 ing-stock trees. 



Poorly stocked stands. Stands that are 10- 

 to 39-percent stocked with present or potential 

 growung-stock trees. 



Well- and medium-stocked stands. Stands 

 that are 40-percent or more stocked with present 

 or potential growing-stock trees. 

 Timber-connected economic activity. The es- 

 timated man-years of employment, wages and 

 salaries paid, and national income, directlj" 

 associated Avith the growing and protection of the 

 timber resource ; and with the harvesting, process- 

 ing, fabrication, transportation, and distribution 

 of timber products. 

 Timber cut. 



Timber cut from live sawtimber. The net 

 board-foot volume of live sawtimber trees cut 

 or killed by logging during a specified year. 



Timber cut from growing stock. The net 

 cubic-foot volume of live sawtimber and pole- 

 timber trees cut or killed by logging during a 

 specified year. Also given in standard cords. 

 Timber products output. The volume of timber 

 products cut from growing stock on commercial 

 forest land and from other sources such as cull 

 trees, salvable dead trees, limbs, saplings, material 

 less than 4 inches in diameter, timber on non- 

 commercial and nonforest lands, and plant resi- 

 dues. Timber products include saw logs, veneer 

 logs and bolts, cooperage logs and bolts, pulp- 

 wood, fuelwood, piling, poles, posts, hewn ties, 

 mine timbers, and various other round, split, or 

 hewn products. 



Timber removal. The volume of growing stock 

 and live sawtimber which would be cut to supply 

 projected demands for timber products plus an 

 allowance for removals of inventory due to unan- 

 ticipated new uses for wood, catastrophic events, 

 and conversion of commercial forest land to other 

 uses. Timber removal on a national basis is the 

 same as needed growth, but for an individual 

 species group is the proportion of total national 

 removal of timber which can be contributed 

 annually with least impairment of prospects for 

 future growth. 



Tract. A single parcel of land that is not con- 

 tiguous to any other parcel in the same owner- 

 ship, and that includes one or more areas of 

 commercial forest land. 



Tree size class. Any one of the following tree 

 classes in whicli the trees are grouped chieflv 

 according to diameter at breast height, outside 

 bark: 



Sawtimber trees. Trees of commercial spe- 

 cies that contain at least one merchantable 

 saw log as defined by regional practice and 



^ 



