262 Forestry Quarterly 



during which the volume of the oldest size classes must last. If 

 this be forty-five (45) years then the cut for the next decade 

 would be from one-fifth to one-quarter of the volume of the 

 largest size classes. 



2. Hufnagl's method by volume based on diameter classes.^ 



3. Based on increment by Heyer's formula.* The period of dis- 

 tribution should be determined according to local conditions. 



Future revisions of the working plan and remeasurements of 

 the crop will serve to indicate what modifications must be made. 

 In any case the cut should be handled conservatively. After all, 

 an exact determination of the allowed annual cut is not essential. 

 What is wanted is a reliable guide thereto. As already stated, the 

 determination of the cut becomes more accurate with each revision 

 of the working plan. A. B. R. 



Die Betriebsordnung im Plenterwald. Schweizerische Zeitschrift fur Forst- 

 wesen, August to November incl., 1913, pp. 234-238, 265-272, 307-313, and 

 339-346. 



In a very clearly written essay Gascard 



New Light throws new light on some phases of budget 



on regulation by formula methods, with special 



Biidget reference to the most rational of aU methods. 



Regulation Heyer's. 



Fimdamental to determining a felling 



budget is the determination of the desirable average felling age 



(rotation). All other factors which influence the budget are 



fimctions of this factor and of the area of the forest. 



In the area allotment method the mere division of the total 



area by the rotation effected "in a brutal and radical manner" 



the normal ageclass distribution, sacrificing the interests of the 



present. With the formula methods came a realization that it 



may be desirable to cut over the area in a shorter time than the 



rotation, especially with abnormal ageclass conditions; instead of 



A A 



— the annual felling area would be — . If the ageclass conditions 



r e 



are normal, then e = r, and if a forest is composed of all mature or 



near mature stands, this e must be at least equal to the natural 



regeneration period (if managed under natural regeneration). 



»See Method 12, Var. II, pp. 75-78, "Theory and Practice of Working 

 Plans," John Wiley and Sons, N. Y., 1913. 

 * Ibid, pp. 63-65. 



