SYLVICULTURAL NOTES ON CONIFERS 165 



exposed situations, being storm-firm, though it does best in 

 sheltered places, especially on northern aspects. It will stand 

 a good deal of shade. It is accommodating as to soil, but 

 prefers a deep fresh one, and likes some lime. It is a rapid 

 grower, but not so fast as Douglas fir or larch. This tree may 

 prove useful for underplanting on moist soils in the place of 

 spruce as it bears more shade than the latter. It could also 

 be grown as a mixture in lines with Douglas fir, but as its 

 timber has not yet been proved to be valuable when grown in 

 Great Britain, it should only be planted on an experimental 

 scale at present. Its timber will probably prove to be excel- 

 lent for gate-posts and for fencing purposes. 



It suffers but little from insects and fungi, but rodents arc 

 fond of gnawing the bark of young trees. 



THE FIRS 

 Douglas fir (Pseudotsnga Doug las ii). 



There are two distinct varieties of this important species : 

 the Pacific or Green Douglas fir and the Colorado or Blue 

 Douglas fir. 



The Colorado variety has shorter and bluer needles, which 

 are stiffer than those of the Pacific Douglas fir. If the needles 

 of the two species are rubbed they have a distinctive scent, 

 and it will be found that the Colorado has a much coarser 

 smell than the Pacific. It is of the greatest importance in 

 sylviculture to distinguish between these two varieties, as the 

 Colorado is not nearly so useful a tree as the Pacific. 



The Pacific Douglas fir is a native of the Rocky Mountains 

 and Vancouver Island ; it was introduced into Great Britain 

 in 1828. It is a fairly hardy tree, but requires sheltered 

 situations as its long leading shoot gets easily broken off, 

 or bent, by wind. It also requires a damp atmosphere. It 

 suffers from autumn frost in low-lying situations, but does not 

 get much injured by spring frosts. Northern aspects are best. 

 It bears a fair amount of shade. It is a very rapid grower, 

 and in favourable situations will outgrow larch. It is fairly 



