THE MONTANE ZONE 145 



probably excels that of any other native species. Not only is the 

 annual crop abundant but the lodgepole begins early to bear 

 seeds, as early as the sixth year in some places. The lightness 

 of the seeds and their marked adaptability for wind dispersal, 

 their usual high rate of germination and long continued viability 

 are all points of marked importance. The ability of the lodge- 

 pole to grow in dense stands operates to exclude other species, 

 and its ability to recover from prolonged suppression further 

 makes for dominance. The lodgepole is also largely resistant to 

 disease. Against these points may be set off certain limiting 

 traits most of which arc, however, not very definite or pro- 

 nounced. There appear to be certain limitations in soil require- 

 ments, and light and a marked susceptibility to fire injury. 



It has been estimated that the average production of seed 

 per tree in Colorado varied from 20,000 to 50,000. Considering 

 the fact that the tree may begin as early as its 5th year to pro- 

 duce cones and that the cones remain closed for many years and 

 that when seeds are most needed, i. e., just after a fire there 

 is available for siowing not merely one season's crop but the 

 combined fruitage of several years, considering also the extended 

 viability of the seeds and their high germinative capacity it is 

 evident that the lodgepole pine is beyond all competitors in the 

 advantage derived from a reproductive capacity. The facility 

 with which it preempts and holds newly seeded, especially fire- 

 swept lands, is a fact related partly to its preference for bare 

 soil as a seed bed, but more decidedly to the large amount of 

 seed available for distribution at the opportune time. It is 

 found under recorded temperatures of -55 to 112 degrees F. in 

 the United States and doubtless has much wider range. In the 

 same locality (Anaconda) it may be subject to an annual varia- 

 tion of temperature through 165 degrees F. 



In the ability to recover after years of suppression is one of 

 the important factors in the persistence of the lodgepole. Un- 

 like many other species which would suffer permanent injury 

 from early shading, the lodgepole, after years of repression is 

 able to push forward rapidly to full vigor and reproductive 

 capacity as soon as the dominating individuals are removed. Es- 

 pecially may this be the case where the cutting or destruction of 



