THE GROWING STOCK. 258 



The undergrowth, shruhs, herbs, etc., should also be 

 described. 



c. Density of the Growing Stoclc. 



To every method of treatment, as determmed l)y the objects 

 of management, corresponds a normal density of the growing 

 stock. The degree of density may be defined as over-crowded, 

 crowded, open, very open, interrupted, irregular, etc. Such 

 terms are indefinite and subject to different interpretations. 

 It is better to place the normal density as equal to 1, and 

 express the actual stocking in decimals of it. The degree of 

 density can be determined by ocular estimate, or, more 

 accurately, by comparing the basal area of the stems with 

 that of a normally stocked wood, or, still more accurately, 

 by comparing the volume of the wood with that of a fully 

 stocked wood of the same age. When the density of stocking 

 is insufficient, it should be stated, whether the wood is 

 generally open, or whether the deficiency is due to greater 

 or smaller blanks. 



By a blank is understood an area, which, though it belongs 

 to the wood producing area, has no trees on it, or so few, that 

 its complete re-stocking is necessary. Areas, which are not 

 destined for the production of trees, are not included here, as 

 they form part of the areas set aside for other purposes, such 

 as fields, meadows, etc., or are altogether unfit for the produc- 

 tion of trees, such as bare rocks, boulder drifts, swampy ground 

 which cannot be drained, etc. As regards the latter, it is not 

 always easy to draw the line between actual blanks and wood- 

 land, as they frequently have a thin stocking, which may give 

 a small return from time to time. 



d. A(/e. 



The methods of determining the age of trees and woods 

 have been given in Forest Mensuration. 



An absolutely accurate determination of the age is neces- 

 sary on\j, when the data are required for the preparation of 



