Periodical Literature 529 



nor the increment which accumulates until the final cut, but the 

 total increment of the whole working group is the basis and aim of 

 forest production. Only in this total increment, the possibility 

 of producing a certain yield comes to expression: the current 

 increment of all the stands. 



Normal yield tables may be used for this with discretion, for in 

 the broad practice stands are far from normal. In the yield 

 tables for oak, e. g., on II site at 140 years, the diameter is stated 

 as 18 inch; in the actual forest diameters may be 12 or 24 inch. 

 Similar variations will be found in pine, spruce, etc., from natiiral 

 regeneration, or sowing or planting in different spacing, 



Der Nachweis der Ertragsfdhigkeit des Waldes. Tharandter Forstliches 

 Jahrbuch, 1913, pp. 26. 



An important contribution to the discus- 

 Value sion of this difficult problem is furnished by 



Production Dr. Martin. Not the production of large 



quantities, but of high values should be the 

 aim of forest management, but, according to Dr. Martin, while 

 theoretically this is admitted, in practical application there is con- 

 siderable lack. Indeed, yield tables usually give only volumes, 

 and little has been done to secure data which must underlie value 

 production. This is due to the difficulties involved in establish- 

 ing values and value increments. Stand cost values should be 

 basic but for old stands especially are unknown; expectancy 

 values are liable to great variation; hence, in spite of their use- 

 lessness for young stands, use or sale values should be employed 

 as much as possible ; and this is officially recognized in the various 

 instructions for forest valuation and value increment calculations. 



There are two ways of ascertaining value increments, namely 

 by a statistical inquiry into the sale value of the average imit of 

 wood measure (Jestmeter) of stands of different age, or by investi- 

 gating of sample trees. 



Such statistical data have been collected for some time in 

 Bavaria and are being collected since 1912 in Prussia, by merely 

 tabulating classified sale results in typical districts. 



Upon the basis of some of these data the influences on value 

 production are briefly discussed: site conditions, location with 

 reference to market, method of establishing and treatment of the 

 crop. As regards site, on good soil not only is value production 



