756 Forestry Quarterly 



clearer: A spruce of 48 cm (19 inch) b.d.h. and 28-30 m (100 feet) 

 height is to be estimated. In the appropriate column the timber- 

 wood content is found to be 2.23 /m. If 32 cm (13 inch) is assumed 

 as the proper sawlog diameter, the content of the log is foimd to 

 be 1.56 fm and the length 13.3 m; the balance may be cut for 

 building timber or pole at 15 cm top diameter; by inspecting 

 proper colimms the contents are found to be .62 fm and the length 

 23.8— 13.3= 10.5 m. If, however, it is determined that it is more 

 advantageous to hold out the whole stem to a 18 cm top diameter, 

 it will be found to have a length of 22.4 m and furnish 2.14 fm. 



Test measurements in clear-cutting areas, in selection forest 

 fellings, and in areas thinned in different degrees are tabulated, 

 showing divergences between the tables and actual measurements. 



In the first case, for the grades of 12 to 32 cm results were 

 satisfactory, only the 42 cm assortment (butt log) showed more 

 frequent and greater differences. By using, however, the allow- 

 ances for unusual taper conditions errors could be reduced to 



-.6 to 4-1. 



No influence of thinnings could be determined, but the author 

 admits the basic material to be insufficient. The somewhat 

 scanty data from selection forest shows that the trees in the selec- 

 tion forest are stouter in their lower section. The assortment per 

 cents of the trees over 60 cm d.b.h. correspond to stems 2-4 cm 

 less in diameter of the tables; the 30-60 cm trees are more full- 

 bodied than the trees of the tables. 



The determination of assortment relations of entire stands, 

 also based on even-aged timber forest, reqmres the knowledge of 

 the total volume of the stand and the stem numbers in diameter and 

 height classes. It is well known that two or more stands of the 

 same total volume may differ considerably in assortments, due to 

 the distribution of stem classes or individual composition, es- 

 pecially as regards sawlog contents. For convenience the author 

 divides the stem ntimbers into larger (b.h.d.) size classes, each of 

 which furnishes a main assortment, thus: over 50 cm, stout wood; 

 37-50 cm, ordinary saw logs; 27-36 cm, building timber; 19-26 

 cm, telegraph poles; 13-18 cm, scaffolding, telephone poles; 7-12 

 cm, smaller poles of all kinds. Usually a stand furnishes only 

 three, sometimes only two, rarely four of these dimensions. The 

 volume of each size class and height class being known, the 

 question is what assortment volumes does a certain number of 

 stems of each of the size classes furnish. 



