498 Forestry Quarterly. 



by one and one-half, even on best sites, while the height growth 

 corresponds here to that of the poorest sites. 



Calling the relation of height to diameter the relative height, he 

 finds this relation to be dependent on the light enjoyment, and it 

 is largest in dense cover. In the average of a large number of 

 stems, if grown under persistent thinning practice this relative 

 height was found for pine 24.9, spruce 39.8, beech 38.4 ; if grown 

 in densest cover for pine 126, spruce 130, beech 157.6. The rela- 

 tive height sinks with age and rises with decrease in soil quality. 



To classify densities, the author proposes to use the relative 

 height and the sum of the cross-section areas on a given area unit. 

 The higher the former the smaller the crown and the denser the 

 cover; also the older the stand the lower the relative height and 

 the larger the total of cross-section areas. Multiplying the latter 

 per acre with the relative height for a given age and soil class, a 

 tolerably constant result is found for each species, which may be 

 used as density factor. 



The author constructs a table for pine under given conditions 

 from 60 to 140 years old, and by using this multiplication of rela- 

 tive height and cross section area, he finds at all ages the density 

 factor to be 343 for I site class, 326 for II site, 304 for III site. 

 Hence the procedure: Determine on sample areas (average 

 trees) age n, diameter d, absolute height h, cubic contents per acre, 



hXc 

 relative height and sum of cross section areas c, then gives 



hXc 



the site class, the density factor (supposedly to be compared 



d 



with normal figures for these). 



From Lesnoj Journal, 1910. Allgemeine Forst- u. Jagdzeitung. April, 

 191 1, pp. 135-136. 



Hufnagl makes a very interesting contri- 

 Value bution to forest valuation. He points out, 



of that it is necessary to distinguish between 



Increment value of increment and quality or value in- 



ane? crement. While in a sustained yield man- 



Quality agement it is usual to assume correctly that 



Increment. in a normal management class the sum of 



the current increment on all age classes is 

 equal to the volume of the oldest age class, this is not true for the 



