88 Forestry Quarterly. 



are not on hand from former estimates of stock and increment, 

 which can be proved, the stock of older stands is ascertained by 

 sample area method, in the younger stands it is estimated, basing 

 the estimate on yield tables or otherwise. The period of equal- 

 ization may be less, but not more than the rotation. 



if 

 While theoretically the normal stock ns = — ■, it was found that, 



if i was determined according to Heyer upon the basis of the 

 highest average increment at felling age, measurements of normal 

 stands develop only .45W. It was also found that the normal 

 increment is not an unattainable ideal but could be determined as 

 the average increment at felling age of well stocked and well 

 managed stands. For the communal fuelwood forests, the rota- 

 tion was established on Heyer's basis, but in the timber forest 

 size of the material desirable to be grown (a diameter control) 

 is determinative. 



The mathematically determined felling budget is however only 

 used as a guide, just as Heyer had intended. Silvicultural con- 

 siderations are primary, and especially when a comparison of 

 actual and normal age classes shows that the older age classes are 

 deficient, the establishment of these in normal quantity is a su- 

 perior requirement, unless it can be shown that younger age 

 classes could be without damage utilized in shorter rotation to 

 eke out the felling budget. That is to say, a summary compari- 

 son of actual and normal stock is not sufficient, the comparison 

 must be made by age classes. 



There is then a careful selection made of stands to be cut 

 within the next decade ; in this selection there are chosen first 

 old stands, then poor growing, damaged or unsuitably composed 

 stands, and lastly stands below the normal felling age are con- 

 sidered, if necessary to approach the calculated permissible 

 budget. 



Since every ten years the whole working plan is again revised, 

 any miscalculations or mis judgments are soon corrected. 



Die Forsfeinrichttmgsfrage, etc. Allgemeine Forst- und Jagdzeitung, 

 1908, pp. 363-371- 



