CHAMONIX WORKING PLAN 253 



Composition of the working groups as compared with former plan. 

 (Art. 2) ''Compartments." 



The feature of the working plan is the conciseness with which statistical 

 data are presented. Those who are familiar with the detailed compart- 

 ment descriptions given in German working plans will be particularly 

 interested in the graphic representation of the growing stock. This is 

 of great importance because in reality it is the key to the marking. 

 The weak link is the determination of the normal growing stock which 

 is taken to be the same for all situations and stands, but to be exact 

 would be practically impossible without undue expense. 



The stand descriptions are exact and are not by any means perfunc- 

 tory: For example, "Despite the avalanche of February 17, 1904, which 

 knocked down 3,116 trees and poles in the middle of the growing com- 

 partment, the stand has recovered and is approaching a normal growing 

 stock." As one glances through the pages care for exact details is 

 evident: "Avalanche area 3.91 hectares; numerous defective stands; 

 opening of 3.00 hectares; a number of trees dead topped; reproduction 

 sufficiently abundant " ; these are partial examples of the detail. Possibly 

 more care could have been taken in describing the reproduction, but I 

 rather surmise it is often lacking, so no mention is made. 



(Art. 3) Regulation of felling. Exact order left to local officers. 



(Art. 4) Determination of the yield. The yield is calculated under 

 the so-called method of 1883 where in the selection forest the volume 

 of the "old wood" is supposed to be five-eighths and the volume of the 

 "average wood" three-eighths of the total. If the minimum tree meas- 

 ured is 8 inches in diameter then the "average wood" includes trees 8 

 to 14 inches inclusive, the "old wood" all above 14 inches, and the 

 "young wood" the trees below 8 inches. 



In this case the actual total of the "average wood" amounted to 

 165,797.7 cubic meters and the "old wood" 126,979.3, a total of 292,777 

 cubic meters. The working plan says : 



292 777 X 5 



"The normal proportion should be: old wood, '—z = 182,986; average wood, 



s 

 292 777 X 3 

 '—^ = 109,791. It is far from being attained, but experience has shown that 



o 



it is necessary to convert it artificially. The principal yield would otherwise be lowered 

 by the normal volume of 'old wood.' It appears on the other hand from the descrip- 

 tive summary that a careful thinning is necessary in a large number of compartments; 

 there the average wood forms regular even-aged stands. It is then necessary to add 

 to the yield of the principal products an accessory yield comprising the loss which is 

 unavoidable because of the volume which does not enter into the calculation of the 

 yield, namely 109,791 cubic meters. We put this loss with great conservation at 0.25 



per cent per year, and we will then have for the actual yield (P), P = — -^-- \- 



