Periodical Literature. 541 



classes, and only three site classes are required : good, medium, 

 poor. 



Special investigations are to be made on nichtstandortsge- 

 masse Bestockungsteilc — stands which are not stocked in adap- 

 tation to the site — and on health conditions, so that in the felling 

 plans these can be specially considered. The graphical represen- 

 tations of these conditions help to bring to recognition the amount 

 of these anticipated fellings. Altogether every flaw in the whole 

 sustained yield plans must be laid open. The present condition 

 of a polewood, e. g., allows us now to recognize whether the 

 decade to which it is assigned or in which it becomes mature will 

 be favored in the budget or curtailed. 



The volume detenninatioiis are as a rule confined to the stands 

 which are to be cut in the next decade. In evenaged close stands 

 mere ocular estimate, using experienced felling yields or yield 

 tables as a check ; otherwise a sample area method is to be used, 

 or in very uneven stands calipering all trees. For determining the 

 rotation special measurements by the Urich method are to be 

 made. 



The increment is to be taken either from suitable normal yield 

 tables or the current increment is to be measured by the use of 



Schneider's formula I — \ either on sample trees measured in 



{nd J 



middle of tree length or on standing trees breasthigh. This actual 



increment is compared with what it should be by division with the 



factor of density. Similarly the normal use per cent, secured by 



comparison of normal stock and normal increment from normal 



yield tables is placed in comparison with the actual. 



Value increment is based on diameter increment, distribution of 

 assortments and quality number. These data are to be graphi- 

 cally shown : progress with age or average diameters of stands for 

 each species and site class ; workwood per cents, and other assort- 

 ments; from the latter and the wood prices of the current year, 

 the quality number is figured. It is interesting to note under the 

 question of system of silviculture that the selection forest is sug- 

 gested only for small forests near cities and health resorts ; not 

 even for the mountain forests ! 



Rotation is to correspond to the aim of the management which 

 is stated to be "the largest production of the most marketable 



