78 MISC. PUBLICATION 9 0, U. S. DEPT. OF AGRICULTURE 



before the next cut. Protection of the forest against fire will go a 

 great way toward preventing loss from heart rots of the basal por- 

 tion of the tree, for the reason that these depend largely on fire 

 scars for their entrance. 



TREE SPECIES 



The distribution of individual tree species in Utah is very largely 

 determined by elevation and the consequent amount of moisture 

 available. (Fig. 43.) This emphasizes the great importance of for- 

 ests to the State, not only as sources of wood products, but as pro- 

 tectors and conservers of the water on which agricultural develop- 

 ments depend. 



SPRUCES AND TRUE FIRS OF UTAH 



ENGELMANN SPRUCE 



Engelmann spruce (Picea engelmannii) , with a stand of 1,436,743,- 

 000 board feet, ranks second among the timber trees of Utah in 

 quantity. This tree is distinguished by a dense long tapering crown 

 with rather erect upper branches and tassellike branchlets. The 

 foliage is generally a deep bluish green with a decidedly silvery or 

 whitish cast, especially on young trees. 



Occurrence. — Engelmann spruce grows in the higher mountains 

 throughout Utah. The most extensive stands in the State are found 

 in the Uinta Mountains, and on the Aquarius Plateau in Garfield 

 County. 



Requirements. — Engelmann spruce, especially when young, can 

 grow under heavy shade. It is a typical high-mountain species, 

 requiring considerable moisture and thriving where the growing 

 season is short and the soil cold. 



Reproduction. — The cones mature in one season and fall from the 

 trees in the late autumn or early winter. Well-developed Engel- 

 mann spruces produce abundant seed at intervals of three or four 

 years after attaining an age of about 30 years. The small winged 

 seeds are widely scattered by the wind and readily establish them- 

 selves. They reproduce especially well on fresh burns and raw wet 

 humus and in leaf litter, provided sufficient moisture is present. 

 Because of its ability to endure heavy shade, Engelmann spruce is 

 usually found in dense all-aged stands. 



Growth and yield. — Engelmann spruce is a slow-growing tree but 

 has remarkable ability to recover from prolonged crowding. Spruce 

 stands in Utah average 5,000 feet board measure per acre and rarely 

 exceed 20.000 feet per acre. 



Fire resistance. — Engelmann spruce has thin bark, a shallow root 

 system, a low dense branch habit, and very inflammable foliage. 

 Because of the high elevations and moisture on its range in Utah, 

 however, there is relatively little loss from fire. 



Characteristics of the wood. — The wood (locally called white pine) 

 is soft and fine-grained, practically colorless, and tasteless. It does 

 not split, nor warp, machines well, and when surfaced has a smooth 

 white appearance. The nail-holding ability is about the same as 

 that of western yellow pine. The wood takes and holds paint well. 

 Locally it is used for rough lumber and is manufactured into boxes 

 for butter, cheese, and candy. 



J 



