APPENDIX — DEFINITIONS 



631 



which case the stand would be classified as 

 white pine or redwood. 

 Major eastern forest type groups. 



White-red-jack pine. Forests in which 50 

 percent or more of the stand is eastern white 

 pme, led pine, or jack pine, singly or in com- 

 bination. Common associates include hem- 

 lock, aspen, birch, and maple. 



Spruce-fir. Forests in which 50 percent or 

 more of the stand is spruce or true firs, singly 

 or in combination. Common associates in- 

 clude white-cedar, tamarack, maple, birch, 

 and hemlock. 



Longleaf-slash pine. Forests in which 50 

 percent or more of the stand is longleaf or 

 slash pine, singl}"" or in combination. Com- 

 mon associates include other southern pines, 

 oak, and gum. 



Loblolly-shortleaf pine. Forests in which 

 50 percent or more of the stand is loblolly 

 pine, shortleaf pine, or other southern yellow 

 pines (exceptmg longleaf oi' slash pine), 

 singly or in combination. Common associates 

 include oak, hickory, and gum. 



Oak-pine. Forests in which 50 percent oj- 

 more of the stand is hardwoods, usually 

 upland oaks, but in which southern pines 

 make up 25-49 percent of the stand. Com- 

 mon associates include gum, hickory, and 

 yellow-poplar. 



Oak-hickory. Forests in which 50 percent 

 or more of the stand is upland oaks or hickory, 

 singly or in combination, except where pines 

 comprise 25-49 percent, in which case the 

 stand would be classified oak-pine. Com- 

 mon associates include yellow-poplai-, elm, 

 maple, and black walnut. 



Oak-gum-cypress. Bottom-land forests in 

 which 50 percent or more of the stand is 

 tupelo, blackgum, sweetgum, oaks, or south- 

 ern cypress, singly or in combination, except 

 where pines comprise 25-49 percent, in which 

 case the stand would be classified as oak-pine. 

 Common associates include cottonwood, wil- 

 low', sycamore, beech, and maple. 



Elm-ash-cottonwood. Forests in which 50 

 percent or more of the stand is elm, ash, or 

 cottonwood, singly or in combination. Com- 

 mon associates include willow, sycamore, 

 beech, and maple. 



Maple-beech-birch. Forests in which 50 

 percent or more of the stand is maple, beech 

 or yellow birch, singly or in combination. 

 Common associates include hemlock, elm, 

 basswood, and white pine. 



Aspen-birch. Forests in which 50 percent 

 or more of the stand is aspen, balsam poplar, 

 paper birch, or gray birch, singly or in com- 

 bination. Common associates include maple 

 and balsam fir. 



Fuelwood (round wood basis). All fuelwood 

 cut directly from trees or parts of trees, including 

 that cut from dead and cull timber as well as from 

 growing stock. 



Gross national product (GNP). The estimated 

 total output of all goods and services during a 

 specified period (usually one year) expressed in 

 dollars; may be in terms of the year-to-year buying 

 power of the dollar, or in constant dollars at their 

 buying power as of some specified year. Gross 

 national product in constant dollars is an index of 

 the cpiantity output of all goods and services, 

 valued at prices of the specified year. 



Growing stock. Net volume in cubic feet of 

 live sawtimber trees and live poletimber trees 

 from stump to a minimiun 4-inch top (of central 

 stem) inside bark. The volume of this material is 

 also measured in standard cords, outside bark. 

 Growth. 



Net annual growth of sawtimber. Tlie 

 change, during a specified 3^ear, in net board-foot 

 volume of live sawtimber resulting from natural 

 causes exclusive of catastrophic losses. 



Net annual growth of growing stock. The 

 change during a specified year in net cubic - 

 foot volume of growing stock resulting from 

 natural causes exclusive of catastrophic losses. 

 Also given in standard cords. 



Ingrowth of sawtimber. The net volume of 

 trees that reach minimum sawtimber size 

 (eastern softwoods, 9.0 inches d. b. h.; western 

 softwoods and all hardwoods, 11.0 inches 

 d, b. li.) during a specified year. 



Ingrowth of growing stock. Tlie net volume 

 of trees tliat reach minimum poletimber size 

 (5.0 inches d. b. h.) during a specified year. 

 Gross growth. Net aniuial growtli plus annual 

 mortality. 



Needed growth. Tiie net aiuuial growth, on 

 commercial forest land, of timber that would 

 meet a specified future level of timber demand 

 plus a margin for catastropliic losses, new forms 

 of wood use and losses of commercial forest 

 land to other uses. Needed growth and timbej- 

 removal are the same quantity on a national 

 basis, but for an individual species group needed 

 growth is the proportion of total national needed 

 growth which can be contributed by a species 

 group on the basis of its realizable growth. 



Realizable growth.^ The net annual growth 

 of timber that would be attained if the better 

 present-day forestry practice in the various 



' In the plaii.s and review draft, realizable growth was 

 defined as growth that it would be practical to attain if 

 all forest land was managed as extensively as justified 

 under .specified assumptions as to future prices and other 

 economic conditions. However, in making estimates of 

 realizable growth, the most practical guide available was 

 the growth that would be attained if the better present- 

 day forestry practices in the various regions were extended 

 to all commercial forest land. The definition has therefore 

 been revised to reflect procedures actually used. 



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