56 PRACTICAL FOREST MANAGEMENT. 



. quality (and especially the best and worst) is adequately 

 represented. When sufficient data are available, the 

 actual method and details of compiling the yield table 

 are described in the note by Smythies and Howard on 

 " Distribution and qualities of sal forests in the United 

 Provinces " and need not be repeated here. It is un- 

 necessary to emphasize to trained Forest Officers that 

 every species, every system of management (i.e. High 

 Forest, Coppice or Coppice-with-standards) and every 

 large variation in thinnings requires a separate yield 

 table. 



Up to the present, the only Yield Tables published in the 

 United Provinces are for sal, in 3 quality classes (by Smythies 

 and Howard), and for chir, in 4 quality classes (by Troup). The 

 chir yield table will shortly be revised, since in one or two points 

 (notably in basal area and number of trees per acre) it appears 

 slightly defective. Data are also being collected for deodar, and 

 sissoo. 



(b) Collection of data for single trees, or volume tables. 



The preparation of a volume table for any species is a much 

 simpler matter than the preparation of a yield table and where 

 data for the latter are available, the hundreds of sample trees that 

 must have been carefully measured up will usually afford ample 

 data for the compilation of a volume table. If any additional 

 statistics are necessary (e.g., volume of utilizable bole, or commer- 

 cial outturn of sawn timber under practical working conditions), 

 such additional data must be collected separately, and with 

 adequate staff, one year's measurements in the felling coupes 

 would supply all the necessary information. 



In addition to showing the outturn of timber, firewood, etc., 

 per tree, a satisfactory volume table should also show if possible the 

 C A. I. as in the calculation of the annual yield of a forest, such 

 information is often invaluable (examples are given below). 



