390 SYLVICULTURAL NOTES ON TIMBER TREES 



circumstances, and a short rotation of about forty to fifty 

 years will usually then be indicated. 



Chalky soils or those containing an excess of lime, seem 

 very inimical to it in most cases. It should never be planted 

 on such soils unless there be abundant proof that it is likely 

 to succeed. It should be avoided on very dry soils. 



It prefers a damp atmosphere, and will succeed better in 

 the west than in the east of England. 



It is tender as to spring and autumn frosts, and on 

 exposed localities the trees are apt to lose their leaders ; 

 though, in crowded pure plantations, this latter danger is 

 minimised to the greatest extent. 



Cultivation, etc. The tree is thickly foliaged, and a 

 moderate shade bearer, and its side branches require a close 

 canopy in order to prevent their development. It bears 

 pruning very well indeed. 



It is a very rapid-growing tree, and soon surpasses 

 practically all other trees which may happen to be planted 

 with it. In its native country it often attains the enormous 

 height of 300 feet and over. 



It may be used for underplanting thin-foliaged trees, 

 provided the canopy be not thick. In this respect it is 

 necessary to take into consideration its rapid height growth, 

 as the over crop would have to be cut directly it is caught up. 



It may well be grown in even-aged high forest, but 

 must, usually, be grown quite pure, or else mixed by patches, 

 on account of its very rapid growth. 



Possibly an even-aged mixture of Douglas Fir and 

 Corsican Pine, planted 3 feet 6 inches apart, would give good 

 results ; but the pines should all be removed as thinnings. 



Douglas Fir and Thuya gigantea occur naturally together, 

 but the Douglas Fir usually soon outgrow the Thuya. 



Japanese Larch will sometimes keep pace for a time with 

 Douglas Fir, but finally they will have to be removed ; and 

 they will not have exerted any pruning effect on the 

 Douglas Firs. 



Douglas Fir and Sitka Spruce is a very good mixture. 



Douglas Fir can also be grown upon the selection 



