LIFE HISTORY OF LODGEPOLE PINE IN" ROCKY MOUNTAINS. 13 



should be reduced to about 500 at the end of 30 years, to about 300 

 at the end of 90 years, and to about 250 by the one hundred and 

 fortieth year, when the stand may be considered mature. Unfortu- 

 nately, owing to the low mortality rate of lodgepole pine, a stand of 

 1,000 evenly distributed seedlings 10 years old will not, by natural 

 means, be reduced to 500 at 30 years, 300 at 90 years, and 250 at 

 140 years. Ordinarily this could be brought about only by thinning. 

 If, however, the stand is sufficiently open to arrive at maturity with 

 250 stems per acre without thinning, decidedly limby trees will be 

 the result. On the other hand, a stand of 1,000 well-spaced seed- 

 lings 10 years old, at which age a stand may be considered as 

 established, probably will have about half that number of trees 

 at maturity. In such a case those of fairly good form and diameter 

 may be cut and the others left to grow for an additional period. 

 Seedling stands of from 300 to 500 plants per acre are preferable 

 to those of 8,000 or more, even when thinning is possible, since for 

 many years the latter will not produce material which can be taken 

 out with profit in the course of thinning. Thinnings, moreover, 

 will probably be impracticable, except in a few localities, and for 

 this reason from 300 to 500 seedlings may generally be considered 

 preferable to 2,000 or more. A good volume of limby timber is 

 better than a large number of poles; besides, the spaces in an open 

 stand will gradually fill in with individuals of a more satisfactory 

 form. Where thinnings are practicable a density of about 2,000 

 plants at the start is best. Plate III, figure 2, shows a well- developed 

 60-year-old stand of lodgepole of something less than normal density. 



It should be borne in mind that the figures for density given in 

 the preceding paragraph are more or less arbitrary, and in deter- 

 mining the normality of a stand as much attention should be given 

 to the spacing and height growth as to the number of stems. A 

 relatively large number of trees per acre is not undesirable, provided 

 there is enough variation in the height of individual trees to pre- 

 vent stagnation of growth. 



The production of clean stems is of comparatively little im- 

 portance, since lodgepole is used mainly for mine timbers and rail- 

 way ties, and in the future is not likely to have additional uses other 

 than for telephone poles, pulp, and common lumber. Of far greater 

 importance than clean stems are rapid growth and the production 

 of large-sized timber. Lodgepole is slow-growing, and there is 

 always an abundance of trees of small size. Ordinarily there is 

 far greater danger of overstocking than of understocking. Ob- 

 servations on 40,58*5 acres of young growth on the Deerlodge 

 National Forest show 78.7 per cent of the entire area to be over- 

 stocked, 20.5 per cent understocked, and only 0.8 per cent normally 

 stocked. 



