422 SYLVICULTURAL NOTES ON TIMBER TREES 



humous soil resting upon a cool stiffish bottom. Shallow soils, 

 or very dry soils are quite unsuited to it. But it will succeed 

 on deep, somewhat dry soils, especially if the aspects be north. 

 It has a deep root system and is a storm-proof tree. 



Cultivation, etc. It is capable of bearing considerable 

 shade if the soil be moist enough ; and it may be used for 

 underplanting, where the overhead canopy is light. 



It transplants readily, and is a very quick growing tree ; 

 and, in some cases, it will practically keep pace with Douglas 

 Fir. 



Its side branches are vigorous, and a close canopy is 

 necessary in order to effect natural pruning. 



It may be grown in even-aged high forest, when it is 

 best grown pure. 



Mixtures by alternate rows or single trees are difficult to 

 arrange. 



Sitka Spruce and Douglas Fir, or Sitka Spruce and 

 Weymouth Pine will grow excellent timber ; but, both these 

 mixtures are very expensive. 



Sitka Spruce and Thuya gigantea should give very good 

 results. 



In order to lessen the expense, a mixture of Sitka Spruce 

 and Corsican Pine may be planted, all the latter being removed 

 as thinnings. 



Sitka Spruce will also, in all probability, succeed well 

 under the group or selection systems. 



It is very suitable for underplanting, if the overhead 

 canopy be light. 



Like all thickly foliaged trees, it is quite unsuited for 

 standards over coppice. 



Rotation. The best rotation is from 70 to 75 years. 



Average returns from crops grown in this country have 

 yet to be proved. But it will, in all probability, prove rather 

 more profitable than Weymouth Pine. 



Of Fungi and Insects which will attack it in this country, 

 it is somewhat premature to treat of; but, many of those 

 enumerated when treating of Norway Spruce and Scots 

 Pine have already attacked the Sitka Spruce. 



