Management of Lodgepole Pine 173 



tically over-dense stands do not decrease in numbers at a satis- 

 factory rate. It was formerly the opinion that about eight thou- 

 sand seedlings per acre were required for a well stocked stand. 

 It is now known, however, that under ordinary circumstances 

 such a stand is entirely too dense, for the mortality rate of the 

 species is too low, the persistence is too great ; a seedling stand 

 of such density will, without artificial thinning, remain over-dense 

 indefinitely. It is now considered that about one thousand seed- 

 lings per acre, well spaced, give a very desirable degree of stock- 

 ing. Of course, such a stand does not secure the pruning that 

 would take place in a more dense stand, but the production of 

 stems of large diameter is decidedly more important than clean 

 stems of very small diameter. 



Owing to its notable ability to retain good seed in sealed cones, 

 rather frequent fires in the past have enabled Lodgepole to 

 replace to a considerable extent all other species in its range. 

 Fires repeated at short intervals, however, eliminate even the 

 Lodgepole. Fire, an aid but not a necessity to reproduction, is 

 usually followed by over-dense seedling stands. On unburned 

 cut-over areas reproduction is usually much more satisfactory 

 than on burns because it is less dense. Plenty of reproduction is 

 usually secured without fire on areas cut absolutely clean. 



Lodgepole is a slow growing tree, particularly slow in its diam- 

 eter growth in dense stands. Even dominant trees grow com- 

 paratively slowly, reaching on the average in 140 years a diameter 

 of only 12 inches with a height of 75 feet. Individuals with 

 moderately good crowns respond well to thinnings made in the 

 stand. 



Fire easily kills Lodgepole, for the bark averages only about 

 two-tenths of an inch in thickness at the stump. 



Insects do considerable damage in a few localities. 



Fungous injury is usually slight, owing to the dry climate, 

 excepting in the case of decidedly old trees. 



Windthrow, even in stands heavily thinned, is not nearly so 

 common as is generally believed. Excepting on greatly exposed 

 situations such windfall as does occur is usually due to defective 

 root systems, a wet or shallow soil, or an unduly heavy cutting 

 in an over-dense stand. On fairly deep well-drained soil trees of 

 fair crown development are usually reasonably wind-firm. 



