THE THEORY AND PRACTICE OF WORKING PLANS 85 



With Judeich's suggested modification, the value of Karl's 

 formula is as a rough method in irregular stands or as a check 

 upon other methods of regulating the cut. For this purpose 

 either it or the just suggested modification of the Austrian 

 formula may be used according as the current or the mean 

 annual increment has been determined. 



7. BY VOLUME.— BASED ON GROWING STOCK AND INCREMENT. 

 HUNDESHAGEN'S METHOD. 



(a) Description of Method. — Hundeshagen conceives of the 

 increment or allowed cut as the interest on the growing stock 

 and assumes that the actual cut is to the actual growing stock 



as the normal cut is to the normal growing stock, or: =^ = -^ 



V nv 



transposed this is y = v— which is the Hundeshagen formula. 



nv 



Hundeshagen calls the factor — the " use per cent " (" Nutz- 



nv 



ungs prozent ")• If nv is calculated by means of the mean annual 



increment ( nv = — ) and 7iy is taken as = i, then — = - and 

 \ 2 / nv r 



y = vX- which is the same as Methods Nos. 2 and 3. Hun- 

 deshagen, however, calculates nv by means of yield tables. 

 V is the volume actually present in the forest. 



Hundeshagen suggests a short-cut method wherein for cal- 

 culating nv and v only those stands are to be considered whose 



age exceeds - and thereby a " partial use per cent " obtained. 



2 



(b) Example. — An uneven-aged forest of Western yellow 

 pine contains 3,500,000 feet board measure of timber 12 inches 

 and over diameter breast high, on 1000 acres. The mean 

 annual increment (/) is assumed at .7 per cent, the rotation at 

 200 years. Disregarding Hundeshagen's method of deter- 

 mining 7iv by means of yield tables and taking ^-^ = - = — = .01, 



nv r 200 

 the formula gives: 



