480 



A HANDBOOK OF CONIFERiE 



as 76,000,000,0001 board ft. and in the United States in 1919 

 as 525 billion board ft.^ 



Whitf ord and Craig ^ give some interesting figures of yield in 

 the forests of British Columbia. The ordinary yield is from 

 20,000 — 50,000 board ft. per acre, but frequently on the better 

 sites the jdeld is 100,000 board ft. per acre, and an instance is 

 recorded where 5,000,000 board ft. was cut from 10 acres. Single 

 mature trees ordinarily contain 2,000-5,000 board ft., but some- 

 times exceed 10,000 board ft. In the mountains the yield is 

 usually less than in the coast forests. In this country small areas 

 have produced a very heavy volume of timber, as the following 

 quarter-girth measurements indicate.^ 



The "milder" and more easily worked timber is usually 

 obtained from trees growing in particularly favourable positions, 

 and constitutes the " yellow fir " of commerce, the coarser and 

 deeper-coloured wood being known as " red fir." Timber can 

 be procured from British Columbia in spars 90 ft. long by 17 

 in. side ; selected slabbed spars up to 80 ft. long by 20 in. side ; 

 square timber 70 ft. long by 14 in. side, and 20 ft. long by 24 

 in. side; deals, planks, etc., to 40 ft. long; clear and select 

 deals up to 32 ft. long. Three qualities are exported, clear, select 

 and merchantable. 



Oregon Douglas fir grows under a wide range of soil and 

 climatic conditions, attaining its most luxuriant growth in deep, 

 moist, well-drained, sandy loam, where the annual precipitation 

 is high (40-60 in. in America). It, however, succeeds in light, 

 gravelly loam, heavy loam and peat, provided the ground is not 

 water-logged. The tree is well adapted for sandstone formations, 

 but is not suitable for limy soils. 



iWTiitford and Craig: For. of Brit. Columh., 192 (1918). 



^ N. C. Brown, For. Prods., their Manufacture and Use (1919). 



^ Loc. cit. 



*Journ. Board of Agric. xx, 1087 (1914). 



