REDUCED AREAS. 



135 



not nece3sarily of equal area, so that if the average quality class 

 of the crops contained in the various periods is approximately the 

 same and th_ area of the several periodic blocks approximately 

 equal, no great necessity for a system of reduced araas arises. In 

 other cases steps must be taken to reduce every compartment to 

 the same standard of productivity. This may be done in a 

 comparatively small working circle such as Chuka by the working 

 plan officer taking the best areas as =1 and the other compart- 

 ments as = '8 or "6, as the case may be. The reduced area of 

 every compartment is then calculated and equal reduced areas 

 allotted to each period. 



This will usually be made by the method of volume and area 

 based on periods, vide Chapter VI. Either special volume tables 

 must be prepared from the provincial tables showing the figures 

 for the average quality of the locality, or the figures for the quality 

 class corresponding most nearly to the average of the working 

 circle may be adopted. Alternately where each compartment has 

 been allotted to a definite quality class as in Dehra Dun division, 

 the figures for that quality class will be used both in calculating 

 the yield and in felling against it. 



Under certain circumstances where the yield in volume for the 

 whole working circle is required, Heyer's or Blanford's modifica- 

 tion of Von Mantel's formula may be adopted, although the latter 

 is more suited to selection forests. 



Extracts from working plans for the different species are given 

 below : 



" No sequence of fellings is laid down ; it is only prescribed 

 that in the regeneration area periodic blocks I and VI, the 

 Divisional Forest Officer will carry out fellings when and where 

 he considers them most desirable, subject to the prescribed annual 

 yield. He is permitted to depart from this in any year up to a limit 

 of plus or minus 10 per cent, without further sanction, the excess 

 or deficit being brought forward in the control form. 



' There is no hard and fast rule regarding what is overwood 

 and what regeneration. Complete uniformity is not aimed at ; 



Calcula- 

 tion of the 

 yield. 



Methods of 



executing 



the 



fellings. 



Sal in 



Dehra 



Dun. 



