31 DETERMINATION AND REGULATION OF THE YIELD. 



(2.) The treatment of 600 acres as coppice with standards ; 



(3.) Thinnings in the oldest coniferous woods. 

 And so on. 



It is evident, therefore, that the returns fall oft' from period 

 to period, in so far as the reduction is not made good by 

 thinnings in the young coniferous woods. This can to some 

 extent be modified, by not making any cuttings in the 200 

 acres of coppice with standards, which will come under con- 

 version during the next period of 10 3'ears ; in other words, 

 to let the material get 10 years older, than it otherwise would. 



The expected yield is determined by estimating the returns 

 from the 200 acres to be converted and adding thereto the 

 necessary cuttings on the rest of the area ; the latter should 

 be sparingly done, so as to equalise the cuttings as much as 

 possible. 



Section II. — Other Methods of Determining and Regu- 

 lating THE Yield of Forests. 

 The number of other methods is so large, that it is not 

 possible, or necessary, to describe them all in this place. 

 The most important ones may, according to their principal 

 characteristics, be grouped in the following manner: — 



A. Division of the forest into fixed annual coupes. 



B. Allotment of woods to the periods of a rotation. 



1. According to area. 



2. ,, ,, volume. 



3. ,, ,, area and volume combined. 



C. Regulation of the yield according to increment and 



growing stock. 



1. The Austrian method. 



2. Hundeshagen's ,, 



3. Von Mantel's ,, 



4. Brandis' ,, 



D. Regulation of the yield according to increment and 



growing stock, combined with the allotment of areas to 

 the several periods of a rotation (Heyer's method). 



