NOTES ON THE DOUGLAS FIR. 29 



Standing to the acre is pertiaps greater in Pacific Coast woods 

 than in British Douglas fir plantations, although the aggregate 

 volume of wood may not be very different and the timber is 

 rarely so wide ringed as in British-grown trees. ^ In the Forestry 

 Museum of the University of Aberdeen there are three specimens 

 of Douglas fir timber : one slowly-grown yellow high-grade 

 Douglas fir from the Pacific Coast; the second, red fir with 

 narrow rings, also from the western American forests; and a 

 third, a sample of rapidly-grown Douglas fir from the Durris 

 woods in Aberdeenshire. In the latter there are twenty-nine 

 annual rings in the section, the diameter of which is 15 inches, 

 the proportionate width of the heartwood, composed of alternate 

 bands of yellow spring wood and dark-red summer wood of 

 nearly equal breadth, to the yellow sapwood being approximately 

 as 2 to I. Apart from having wider annual rings and con- 

 sequently being coarser-grained timber, the Durris specimen 

 bears a considerable family likeness to the high-grade Pacific 

 Coast Douglas fir, and is very unlike the hard flinty red fir. 

 In the Pacific Coast forests, the bark of the Douglas fir is of a 

 light greyish-brown colour, very much lighter in colour than the 

 bark of British-grown Douglas fir, and remains unbroken until 

 the tree is at least 40-50 years of age. But in Britain it 

 usually becomes cracked and furrowed before the twenty-fifth 

 year. In the forests of the Rocky Mountains the branches 

 seem to be more persistent than in the Coast forests. 



The natural regeneration of the Douglas fir in the Pacific 

 Coast forests is exceedingly good. In his paper on "The 

 Reproduction of Commercial Species in the Southern Coastal 

 Forests of British Columbia," Dr Howe says that he has some- 

 times counted as many as 322,000 seedling Douglas firs upon 

 an acre of ground in British Columbia forests. The reproduction 

 is greatly facilitated by the light burning of the slash and other 

 debris after logging operations. When this is done favourable 

 conditions are created for the germination of Douglas fir seed, 

 and at the same time the Tsiiga heterophylla trees, which are 

 always present as an understory in Douglas fir forests, are 

 destroyed and prevented from taking possession of the area to 

 the exclusion of the more valuable Douglas fir. After the 



1 Dr Howe states that the height-growth of the Douglas fir in the Coast 

 forests averages about 6 inches per annum during the first ten years of the 

 life of the tree. On the hest class of sites the growth may be i foot. 



