CHAPTER XI 

 LODGEPOLE PINE TYPE 



General Conditions. — This typ>e occurs in the higher mountains 

 — at least 4000 feet above sea level — of Colorado, Utah, 

 Wyoming, Idaho and Montana. Altitudinally it is the next 

 important timber type above the western yellow pine and reaches 

 nearly to tree line on some of the lower and more protected 

 mountains. CJenerally, however, it gives place to Engelmann 

 spruce and alpine fir before tree line is reached. 



Since it occurs at a relatively high altitude the precipitation 

 is naturally greater than in the yellow pine type. Exact figures 

 are not available but it seems safe to estimate that the annual 

 precipitation averages between 25 and 35 inches. The mean 

 annual temperature is low, 40 degrees to 45 degrees, as might be 

 surmised from the altitude. Likewise a high percentage of the 

 year has temperatures below freezing. In fact the growing 

 season does not exceed five months. 



From the previous description it follows that the topography 

 is generally steep and rough. Lodgepole pine does, however, 

 need a fair degree of soil depth so that it is never found in abund- 

 ance on ledges or rock cliffs. 



Usually no other species is vigorous enough to contest success- 

 fully with lodgepole pine for the possession of soil adapted to the 

 latter. It is a prolific seeder, a thrifty grower and has few 

 enemies. Hence it usually occurs in pure stands over large areas. 

 Only occasionally are there small groups of aspen, Douglas fir, 

 alpine fir, white bark pine or western larch mixed with it. 



While there is great range in the growth conditions the follow- 

 ing figures give a fair notion of what lodgepole pine can do under 

 good conditions in 50 and 100 years. 



^ SO years loo years 



Diameter 7.5 inches 9 inches 



Height 46 feet 68 feet 



Density per acre 1250 600 



Yidd per acre 2250 cubic feet 10,800 board feet 



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