UTILIZATION AND MANAGEMENT OF LODGEPOLE PINE. 



37 



Table 19. — Volume regulation for the next 140 years on the Bernice division, Deerlodge 



National Forest, Mont. 



Period. 



Stand 

 matur- 

 ing. 



Cutting 



each 

 decade. 



Balance 

 at end of 

 decade. 



Present (1910) 



1,000 b. ft. 

 92,831 



1,000 I. ft. 

 20, 000 



20,000 

 20, 000 

 20, 000 

 20, 000 

 20, 000 

 20, 000 

 20, 000 

 20, 000 

 20, 000 

 70, 000 

 70, 000 

 70, 000 

 70, 000 



1,000 b. ft. 

 72, 831 



52, 831 



Decade beginning— 



1920 



1930 



1 28, 770 



1,254 



9,631 



6,628 



11,633 



12,215 



38, 090 



15, 058 



78, 920 



63, 448 



106, 730 



16, 678 



61 601 



1940 



42, 855 



1950 



32, 486 



1960 



19,114 



1970 



10, 747 

 2,962 



1980 



1990 



21,052 



2000... 



16,110 



2010 



25, 030 



2020 



18, 478 



2030 



55, 208 



2040 



1,886 







Total 



481,886 



480,000 



1,886 







Average annual yield for rotation, 3,442 thousand board feet for the division, or 55 board feet per acre 

 of productive timberland. 



1 Increment taking place on stands now merchantable, but which will not all be cut for about 50 years 

 (65 board feet per acre added annually on 17,761 acres for 25 years). Sixty-five board feet per acre per 

 annum is approximately the average increment in a stand 0.6 normal on an average site between the age 

 of 120 and 160 years. 



It will be observed (Table 17) that a large proportion of the area 

 is taken up with the younger age classes, due partly to heavy cuttings 

 in the last 30 years. On the whole, however, the age classes are 

 fairly well distributed for an unmanaged forest. It will also be seen 

 (Table 18) that none of the older age classes have a high normality. 

 This is because when such stands include over 2,000 board feet per 

 acre they are classed with the merchantable timber, although they 

 may be actually less than 120 years old. The method of volume 

 regulation (Table 19) calls for a moderate cut on the division for 100 

 years and a much heavier one for the last 40 years of the rotation, 

 without reducing the annual cut at any time. Such a regulation is 

 made necessary by the irregularity in the distribution of age classes. 

 Other divisions of the Forest have a surplus of their area in the older 

 age classes, so that the annual cut for the entire Forest and for the 

 whole rotation can be given the proper degree of uniformity only by 

 applying the regulation to groups of such divisions rather than to 

 each division separately. The figures showing the stand maturing 

 for each 10-year period are taken directly from Table 18, except the 

 figures for 1930, which represent the approximate growth on the 

 mature timber originally on the area. The figures for the real 

 growing stock (present total stand) in Table 18 were obtained by 

 multiplying the normal stand per acre for each age class, as given in 

 Table 9, United States Department of Agriculture Bulletin 154, 

 "The Life History of Lodgepole Pine in the Rocky Mountains," by 

 the average normality (which gave the present stand per acre) and 

 multiplying this result by the actual area occupied by each age class. 

 For example, the normal yield on average sites at 10 years of age is 



