14 



BULLETIN 1060, U. S. DEPARTMENT OF AGRICULTURE. 



The composition of a typical piece of what is distinguished as the 

 " western hemlock-Sitka spruce type " in British Columbia is as 

 follows : 8 



Per cent. 



Western hemlock 3S 



Sitka spruce 27 



Western red cedar 15 



Balsam (silver) fir 15 



Others (Alaska cedar and Cottonwood) 5 



100 



A summary of cruises made in 1918 in spruce stands on the west 

 side of the Olympic National Forest in Washington shows the fol- 

 lowing average composition of the forest : 9 



Per cent. 



Western hemlock >. 37 



Douglas fir 26 



Sitka spruce 21 



Silver fir 7 



Western red cedar 6 



Others 3 



100 



The mixed forest is usually of even age ; infrequently it is of two 

 age classes, and then the hemlock trees are the smaller and younger 

 ones, of the stand. An all-aged forest occurs but rarely, and then 

 'as an open stand on swampy soils. 



An idea of the composition of the stand and the representation 

 of small-sized trees of other species (in the older stands) may be 

 gained from Table 4. This table shows the results of measurements 

 on 12 sample plots in typical stands in Oregon and Washington 

 in which Sitka spruce comprised from 50 to 100 per cent of the 

 volume of the stand. 



Table 4. — 'Number of trees of Sitka spruce and other species per acre for typical 



stands of various ages. 



Plots. 



Living trees per acre. 



Designation and locality. 



Newport III. 

 Blodgettl... 

 Raymond I.. 

 Newport I. . . 

 Tsiltcoos II. . 

 Raymond II. 

 Hoquiam I . . 



Beaver I 



Tsiltcoos I... 



Clatsop I 



Newport II.. 

 Hoquiam II . 



Area. 



Acres. 

 0.4 

 .2 

 4.0 

 2.0 

 2.0 

 4.0 

 4.0 

 4.0 

 4.0 

 5.2 

 2.0 

 2.0 



Sitka spruce. 



Age. 



Under 12 Over 12 

 inches, inches. 



Years. 

 27 

 60 

 70 

 130 

 175 

 175 

 240 

 260 

 290 

 310 

 320 

 340 



448.0 

 104.0 

 1.5 

 2.5 

 1.5 

 3.5 

 .0 

 .2 

 .5 

 .0 

 3.0 

 .0 



122.0 

 112.0 

 27.7 

 61.0 

 49.5 

 13.2 

 18.0 

 18.2 

 21.5 

 10.1 

 7.0 

 7.0 



Other species. 



Under 12 Over 12 

 inches. inches. 



30.0 



24.0 



25.2 



3.0 



10.0 



13.8 



28.2 



5.3 



8.0 



.0 



43.5 



40.0 



0.0 

 32.0 

 98.0 



8.0 

 13.5 

 41.2 

 18.8 



9.6 



8.0 

 10.3 

 54.0 

 34.0 



Total. 



600.0 

 272.0 

 152. 4 

 74.5 

 74.5 

 71.7 

 65.0 

 33.3 

 38.0 

 20.4 

 107.1 

 81.0 



8 " Forests of British Columbia," by H. N. Whitford and R. D. Craig, p. 61, 1918. 

 • " Descriptive Report of Olympic West Side Spruce," by C. J. Conover. Forest Service 

 manuscript report, p. 13, 1918. 



