PICEA ENGELMANNI, Eng. 

 Engelmann Spruce. 



Size Average 80 to 100 ft. by 1J to 3 ft. Maximum 150 ft. by 

 3 to 4 ft. 



Growth. Rate moderate but persistent. Its most rapid height 

 growth occurs between the 20th and 40th years. Its diameter growth 

 is most rapid about the 50th year. Life up to 500 years or more. 



Root System. Horizontal; somewhat deeper than that of lodge- 

 pole pine, but still quite shallow, seldom reaching a depth of more than 

 two feet. 



Bole. Moderate taper; straight and clear in dense stands. 



Crown. On its best sites Engelmann spruce is a tall symmetrical 

 tree. Its crown is narrow, compact, and spire-like, and except in the 

 closest stands, reaches almost to the ground. 



Tolerance. Very tolerant of shade, and will exceed alpine fir and 

 most of its other associates in this respect. Great powers of reviving 

 after suppression. It usually forms close, dense stands in which all ages 

 are present. Rather more tolerant in youth than later on in old age. 



Wood. Light, soft, not strong, straight grained; 22 pounds. 



Reproduction. A prolific seed producer after the 25th year, 

 with heavy seed years every three years. Cones mature in the latter 

 part of August, and shed seed by October. Seed, small, light, and 

 winged ; germination percent high ; vitality persistent. Germinates best 

 in moist mineral soil; rarely in humus. 



Range. It extends from Yukon and British Columbia to southern 

 Oregon and through the Rockies of British Columbia and Alberta to 

 New Mexico and Arizona. It is also found in Montana, Idaho, and 

 Washington. Essentially a tree of high altitudes; in Canada running 

 from 2500 to 6000 feet, and farther south is found as high as 12,000 feet. 



Climate. Wide range. Temperatures from 95 to -40 Fahr. 

 Annual average precipitation of over 25 inches largely in the form of 

 snow. Daily range of temperature is also high, especially in its upper 

 altitudinal range. 



Soil. Not very exacting as to soil provided there is sufficient 

 moisture. Does not require such a degree of drainage as other species. 

 Attains its best development on the deep rich soils of gulches and river 

 valleys. With its shallow root system it can grow in wet soils. 



Association. Forms large pure stands and also grows in mixture 

 with other species. Pure stands are more frequent in the south. Its 

 most common associates are alpine fir and Douglas fir. This is especially 

 true for Montana and northern Idaho. 



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