The Rotation 



Equally as important as the calculations are the assump- 

 tions upon which they are based. Of these assumptions 

 the rotation has the greatest influence on the allowable cut. 

 The proper rotation is a matter of considerable debate, 

 ^ome feel that a 100-year-old or younger crop will be readily 

 marketable, and others believe that a rotation period up- 

 ward ot 120 years must be adopted. For the purpose ot 

 calculation in this report, a 120-year rotation is arbitrarily 

 chosen. The determining factor will, in the end, be the 

 nature ot the markets for the northern Idaho timber 

 products. At present the principal outlet is tor lumber, 

 sold as boards or match blocks and other remanutactured 

 products in the eastern and middlewestern States. Com- 

 peting as it is with other producers more favorably situated, 

 the northern Idaho industry has been able to continue 

 largely because ot a superior product. For the most part, 

 it seems that this quality product cannot be raised in any 

 shorter period than 120 years. 



.At an age ot 120 years about the best that can be 

 expected trom reasonably well-managed young white pine 

 stands over an extensive area is thought to be 12 M board 

 feet per acre ot western white pine, but this may be low. 

 The average for northern Idaho as a whole — old and 

 voung saw-timber stands combined — is 9.3 M board teet. 

 This includes many poorer stands, however, the best 

 having been logged first. In the Clearwater district, where 

 a large part of the original timber is uncut, western white 

 pine stands average approximately 12 M board teet ot 

 western white pine per acre. 



Sawlog-size trees begin to appear in western white pine 

 stands at 60 to 80 years. Some ot these voimg stands are 

 being logged at the present time. Apart trom the tact that 

 the market probably could not absorb much ot such timber, 

 the liquidation ot these younger stands is untortunate and 

 not evidence ot the desirability ot a short rotation. To 

 have them cut just as they enter the period ot heavy volume 

 growth constitutes a real loss to the commimity. On the 

 other hand, partial logging, which would leave a portion of 

 the marketable timber in these stands to reach greater size 

 and improve in quality, would be a very desirable 

 management practice. 



Method oj Management 



The utilization ot any stand may properly be carried out 

 in several difl^erent ways. One operator might cut every- 

 thing, leaving a relatively clean area behind him. Another, 

 to take ad\antage ot growing conditions, might prefer to 

 liquiilate the stand in several cuts over a period ot years 

 and i)btain greater yields. Reproduction may be present 

 in some stands at the time ot logging, but in nianv inst.mces 

 a period of years must elapse before ailequate restockuig is 

 obtained. Not all of the pt)ssibilities and conditions can be 

 fitted into a single pattern, but, as a rather extensive 



opening up ot stands is necessary to msure the establish- 

 ment ot western white pine reproduction, the calculations 

 here are based on one major harvest cut per rotation which 

 would bring about even-aged reproduction. This method 

 involves logging each acre only once in a rotation. In 

 actual practice, it is desirable to vary the number of cuts 

 and the kind of cutting to suit local conditions and thereby 

 enhance the yields. 



The Allowable Cut in Northern Idaho 



If it were not for the fire losses, the total cut of all sf)ecies 

 (excluding cedar poles) could be permanently maintained 

 at 689 million board feet per year or almost 20 percent more 

 than the present cut (see appendix). But because of fire, 

 the allowable annual cut is only 518 million board teet 

 (fig. 38), or considerably less than is now being produced. 

 While fire damage in young stands is often passed off as 

 something of minor importance, it is noteworthy that 39 

 percent ot the reduction from 689 million to 518 million 

 board feet is because of fires in seedling, sapling, and 

 pole stands. 



The lopsided utilization under which western white pme 

 bears the brunt ot the logging has been pointed out in 

 preceding chapters. As a group, the species other than 

 western white pine are not being used to the extent they 

 should be. The cut ot these could be increased by 149 

 million board feet yearly without taxing forest productive 

 capacity. With western white pine, the story is entirely 

 different. The allowable annual cut is 140 million board 

 feet and the actual log cut 351 million board feet — 2S 

 times as great. It a start at sustained yield had been 

 made some years ago, the allowable production would 

 have been higher. It present fire losses were eliminated. 





pnnuRL c 



UTTI 



no DRRin 







560 MILLION 

 BOARD FEET 







^ 



518 MILLION 

 BOARD FEET 



vLOC SCALE ' 



PRESENT DESIRABLE 

 CUT MAXIMUM 



FloiRt" .'t'. The .I'lnii.i/ cut of ttJl sptciti iV somtfrK*: frrutrr .'ijK .a: 

 jujtmiMtJ trili ftrritnljin iusMi. 



41 



