DEFINITIONS 



Acceptable plantation. A plantation that has 

 at least the following number of planted trees per 

 plantation aero at the end of the fifth 3'ear after 

 planting: 



Trees 



All eastern species 400 



Engelmann spruce and lodgepole pine 300 



Other western species 200 



All timber products consumed (roundwood 

 basis). Total volume of timber consumed in a 

 specified period, in terms of log and bolt volume. 

 Includes roundwood equivalent of net imports of 

 semifinished and finished timber products — such 

 as lumber, woodpulp, and paper. 



Allowable cut. The volume of live sawtimber 

 and growing stock that can be cut during a given 

 period while building up or maintaining sufficient 

 growing stock to meet specified growth levels. 



All-timber volume. Net volume in cubic feet 

 of live and salvable dead sawtimber trees and pole- 

 timber trees of commercial species, and cull trees 

 of all species, from stump to a minimum 4.0-inch 

 top inside bark. Includes bole only of softwoods 

 but both bole and limbs of hardwoods to a mini- 

 mum 4.0-inch diameter inside bark. Also given 

 in standard cords. 



Bureau of Land Management ownership. See 

 Ownership. 



Catastrophic timber mortality. The net volume 

 removed from live sawtimber or growing stock on 

 commercial forest land during a specified period 

 through death from natural causes of extreme 

 severity. The loss in volume is of sufficient 

 quantity' to cause a major dislocation of forest 

 management and timber utilization plans for a 

 State or region. E.xamples of catastrophes: An 

 unusually severe insect attack, an extraordinary 

 windstorm such as the New England hurricane or 

 a holocaust such as the Tillamook burn. A 

 catastrophe is characterized by its unpredictable 

 nature, suddenness and concentration of occur- 

 rence, and extreme quantity of destruction. 

 Although the loss usually is suffered in less than a 

 year, it may extend over more than a year, as in 

 insect attacks. Past losses are considered catas- 

 tropliic if the individual occiuTence resulted in an 

 annual mortality greater than the net annual 

 growth of the affected State or region in 1952. 



' Assembled by John R. McGuire. 



- Special terms used in describing the world timber 

 situation are defined under that heading, p. '.iA-i. 



Chaparral land area. Lands supporting heavily 

 branched dwarf trees or shrubs, tisually evergreen, 

 the crown canopy of which covers more than 50 per- 

 cent of the ground and whose primary value is 

 watershed protection. The more common chap- 

 arral constitiunits are species of Quercus, Cerco- 

 carpus, Garnja, Ceanothus, Arctostaphylos, and 

 Adettostoma. Types dominated by such shrubs 

 as Artemisia, Opuntia, Purshia, Gutierrezia, or 

 semidesert species are not commonly considered 

 chaparral. 



Commercial forest land area. See Forest land 

 area. 



Commercial species. Tree species considered in 

 determining stocking and growing stock. In- 

 cludes species presently or prospectively usable for 

 commercial timber products; excludes so-called 

 weed species sucli as sassafras, hawthorn, and 

 ironwood. 



County and municipal ownership. See Owner- 

 ship. 



Cropland. See Land area. 



Cull trees. Live trees of sawtimber or pole- 

 timber size that are uTimerchantable for saw logs 

 now or prospectively because of defect, rot, oi' 

 species. 



Sound cull trees. Live trees of sawtimber or 

 poletimber size which meet regional specifica- 

 tions of freedom from rot, but will not make at 

 least one merchantable saw log now or prospec- 

 tively (according to regional specifications) 

 because of roughness, poor form, or species. 



Rotten cull trees. Live trees of sawtimber or 

 poletimber size which fail to meet regional 

 specifications of proportion of sound volume to 

 total volume. 



Diameter classes. A classification of trees 

 based on diameter of the bole, outside bark, meas- 

 ured at breast height (4/2 feet above the ground). 

 D. b. h. is the common abbreviation for "diameter 

 at breast height." Two-inch diameter classes, 

 of which the even inch is the approximate mid- 

 point, are used. For example, the 6-inch class 

 includes trees 5.0 to 6.9 inches in d. b. h., the 12- 

 inch class includes trees 11.0 to 12.9 inches in 

 d. b. h. 



Disposable personal income. All monetary in- 

 come received diu'ing a specified period by indi- 

 vidual persons after payment of direct personal 

 taxes. 



Farm ownership. See Ownership). 

 Federal ownership. See Ownership. 



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