32 BULLETIN 327, U. S. DEPARTMENT OF AGRICULTURE. 



yellowish-brown to very light brown. The wood of this fir is little 

 known in the Iiocky Mountains and is only occasionally cut for lum- 

 ber in the Pacific slope region, though its good quality entitles it to 

 be better known and more widely used. The ease with which the 

 wood can be worked, and other good physical qualities, render it the 

 equal, if not the superior, of the softer fir woods now cut for lumber. 



OCCURRENCE AND HABITS. 



Grand fir is essentially a tree of moist situations. It grows most 

 commonly on alluvial stream bottoms and adjacent higher ground, 

 lower gentle mountain slopes, depressions, and gulches, at elevations 

 between about 2,000 and 7,000 feet (Map No. 8). The best and most 

 abundant growth occurs on stream bottoms at the lower levels, much 

 smaller trees being found at high elevations. Its deep root system 

 demands permeable, preferably moist, porous, well-drained soils. 

 With favorable moisture and climatic conditions grand fir grows 

 well on rather poor, thin soils, but better quality is necessary in soils 

 deficient in moisture and subject to rapid evaporation. 



Grand fir rarely occurs in pure stands, except of limited extent. 

 Usually it is mixed with western white pine, lodgepole pine, western 

 larch, Engelmann spruce, mountain red cedar, western yew, Douglas 

 fir, black cottonwood, balm of Gilead, and sometimes with western 

 yellow pine. The number of species and the percentages of the stand 

 they represent in this - association vary greatly in different localities 

 within the general range of grand fir. It is always dominant when 

 associated with mountain red cedar. 



Grand fir is the least tolerant of shade, with one or two exceptions, 

 of all of our fir trees, growing only moderately well under such condi- 

 tions. It is much less able to live under the shade of other trees than 

 the mountain red cedar, western hemlock, and western yew, but much 

 more tolerant than Douglas fir, western white pine, western larch, 

 and western yellow pine. Seedlings endure considerable shade for 

 several years, but unless they are given full overhead light, such 

 growths become dwarfed and die within a few years. With overhead 

 light, the height growth of this fir is rapid, and under side shade the 

 trunks are readily cleared of branches, forming the characteristic 

 long, clean stems. Endurance of shade, however, varies in general 

 with age, exposure, moisture of the soil and air, quality and quantity 

 of available soil, altitude, and latitude. The largest trees are prod- 

 ucts of sufficient moisture, soil, heat, and full sunlight. Under these 

 conditions it will also endure considerable shade. On poor, dry 

 soils and in warm exposed places, shelter from cold winds and some 

 shade are beneficial in reducing soil evaporation and transpiration; 



