ORIGINAL WORKING PLAN DATA 



521 



PART III 

 Special Study op the Working Group 



Art. 1. — Compartments. — It has been laid out according to natural boundaries 

 such as roads or ravines following current usage. Each compartment has been marked 

 and designated with capital letters. Their area varies from 2.11 hectares to 8.46 

 hectares, an average of 5.28; this is in keeping with the size of the forest. 



The forest description follows: (Sample given on pages 532 and 633). 



Art. 2. — Exploitability, rotation, periods. — A tree 0.60 meter (23.6 inches d.b.h.) 

 in diameter is best suited to the sale requirements. A smaller size would not be adapted 

 to all uses, while a large size would make lumbering too diflScult. We shall therefore 

 adopt 0.60 meter as the exploitable size. 



To reach this size a tree requires at least 140 years. If you glance over the curves 

 inserted in the Appendix (page 528) it is evident that the spruce and fir take on an 

 average 16 years to pass from one diameter class (2 inches) to another; it follows that 

 to pass through the diameter classes from 6 inches to 24 inches takes 144 years. In 

 fixing the rotation at this figure we are overlooking the length of time that a tree takes 

 to pass from the understory, and recent studies have shown that this method of pro- 

 cedure is legitimate. It seems logical to choose 16 years as the period since it takes 

 that length of time to pass from one diameter class to another. 



Art. 3. — Regulation of felling. — The compartments A, B, C, D, E, F, G, I, L, 

 and M only carry a growing stock which can be inventoried. These are the only com- 

 partments to be cut over by selection cuttings based on volume. The compartments 

 H and K, stocked solely with young growth, wiU be run over by improvement cuttings 

 based on area. On the formal request of the commune (which, while wishing to sell 

 the principal cuttings, desires to provide for the residents a small right to gather hard- 

 wood fuel) these shall be filled by improvement cuttings in the compartments C, D, 

 E, F, G, I, L, and M. The table below gives a r6sum6 of these plans: 



A. — FELLINGS BY VOLUME 



Art. 4. — Determination of the yield. — The yield wiU be calculated in accord- 

 ance with the method given in the circular of July 17, 1883, which consists in dividing 

 the wood in three groups in accordance with their size: (1) The young wood whose 

 diameter is less than one-third the exploitable size. (2) The average wood whose 

 diameter is included between one-third and two-thirds this size. (3) The old wood 

 whose diameter is more than two-thirds this size. 



