528 Forestry Quarterly 



It should, however, be recognized that the yield data of the tables 

 must be used with discretion. The tables cannot be generally- 

 applied for the east and the west, for mountain and plain; the 

 conception of normality is not fixed and remaining the same, being 

 variable like all economic factors. Stands with varying stem 

 nimibers, varying diameters and volumes may be considered 

 normal. 



It must, also, be kept in mind that silvicultural problems influ- 

 ence the method of organization. In the uniform, planted spruce 

 or pine forest, imder a clearing system an area method may siifhce. 

 On the other hand, natural regeneration, if correctly managed, is 

 opposed to the schematic area allotment ; here nature rules and the 

 cutting must take into consideration the condition of soil, the 

 occurrence of seed years, the requirements of the young growth. 

 Hence, in Baden, in the territory of the naturally regenerated fir 

 the area method has long been abandoned, for natural regeneration 

 cannot be forced into a fixed time scheme ; if the annual or period'c 

 area is fixed, natural regeneration is hampered; larger areas than 

 the so-called normal periodic area must be at the disposal of the 

 manager. 



In such modern silvicultural methods as interlucation in pine and 

 oak, which consist in a severe, but gradual opening up, the area 

 is also not entirely cut; similarly, thinning practice in older 

 stands and salvage fellings, which furnish considerable material in 

 pine and spruce forest, are in antagonism to the determmation of 

 yield by area, especially as it is difficult clearly to differentiate final 

 yield and intermediate yield. The instructions, to be sure, require 

 such differentiation, but in practice this is frequently not possible: 

 whether, e. g., the resiilts of a preparatory regeneration cut or a 

 severe thinning are to be cotmted one way or the other. 



The author insists that in a properly organized forest it must 

 be shown that the sustained yield is being maintained, and this can 

 be done only by increment determination. This is done in the 

 southern State departments much more fully than in Prussia. In 

 Baden, for instance, for every stand the average total increment, 

 i. e., the total average production in final and intermediate yield 

 for the rotation and given species and management is to be ascer- 

 tained, as well as the current (periodic) total increment to be 

 expected for the next decade. Not the voltmie of the stands, 

 artificially ranged into the I period, is a proper measure of the cut ; 



