APPENDIX 301 



Blank. An opening in the forest where, from any cause, very few or no 

 trees are growing. 

 G., Blosse. F., yide. 



Blaze, V. The process of marking a tree by means of a sharp instrument, 

 removing part of the bark. 



Blaze, n. A spot made on a tree by chipping off a piece of bark. 



Block. See Under subdivision. 



Blow-down. See Windfall. 



Board foot. A unit of measurement represented by a board one foot 

 long, one foot wide and one inch in thickness, or its equivalent in 

 volume. In finished or surfaced lumber the board foot measure is 

 based on the measurement before surfacing or other finishing, or on 

 the superficial measure only. 



Board measure. A term expressing the board foot content of roimd or 

 manufactured timber; and for expressing the volume of logs, trees or 

 stands in terms of the estimated amount of lumber which may be cut 

 therefrom according to various log rules (g. v.). Usually abbreviated 

 B.M.; units of larger quantities stated in thousands, are abbreviated 

 M. B. M. 



Board rule. 1. A tabular statement showing the board foot contents 

 for various widths and lengths of squared timber, or of sawed 

 timber. 



2. A graduated stick for determining the contents of squared timber. 

 The number of board feet in squared timber of given widths and lengths, 

 or of sawed timber, is shown upon the rule. See Scale stick. 

 Syn.: lumber rule, lumber scale. 



Board scale. See Board measure. 



Bole. See Stem. 



Border cutting. See Reproduction, Strip-selection method. 



Breast-height. A height of 4^ feet above the average ground surface or 

 above the root collar, the diameters of standing trees being ordinarily 

 measured at this height (abbreviation d. b. h.). 

 G., Brusthohe. F., hauteur d'homme. 



Breast-height form factor. See Form factor. 



Broadcast seeding method. See Direct seeding. 



Broken. See Crown density. 



Brushwood stage. See Development class. 



Budget regulation. See Regulation of cut. 



