DETER:\riNATION OF THE QUALITY OF WOODS. 259 



fir will be found in Appendix III. In these tables only 

 three quality classes have been distinguished, I. representing 

 the best, III. the least favourable, and II. the average, or 

 middling, quality. 



The quality of young woods cannot be judged by their 

 volume, since the factors of the locality may not yet have 

 found full expression in it ; here the quality must be estimated 

 by the general condition of the crop and especially its height 

 growth. Indeed, the latter may be used even in older woods, 

 especially as long as it has not ceased. 



The determination of the quality from yield tables, in the 

 case of clear cutting in high forest and in coppice, is a simple 

 matter, as previously shown. The regeneration area under 

 the shelter-wood system gives some trouble, because it is no 

 longer fully stocked, so that the volume does not represent 

 the quality ; here the determination must be based upon an 

 investigation of the quality of the locality combined with the 

 condition of the shelter- wood and young growth. A similar 

 procedure is followed in the case of coppice with standards 

 and in selection forests. The quality of blanks is estimated 

 from the soil and climate, or from that of adjoining woods, 

 which have been produced on soil of a similar description. 



b. Reduction to One QuaUtij. 



Several methods of regulating the yield demand a reduction 

 of the areas of the several woods, or working sections, to one 

 quality, so as to enter into the account only areas of equal 

 yield capacity. Such a reduction to one quality may be made 

 as regards the locality, or the growing wood ; in each case as 

 regards the normal or real quality. The method of procedure 

 is the same in each case. 



The reduction is made by means of the final mean annual 

 increment, or yield. It can be made under one of the two 

 following conditions : — Eitlier the total of the several reduced 

 areas shall be equal to the actual area of the working section ; 

 in other words, the calculation is made with the mean quality 



s2 



