CONIFEROUS FOREST TREES IN GREAT BRITAIN. 77 



The requirements of this species in this country have yet to 

 be fully determined. Until that is done, they may be safely 

 taken as similar to those of Norway spruce. 



We have practically everything to learn regarding the 

 rate of growth and production in this country. There are 

 several plantations over 20 years old under different conditions 

 available for study. These indicate faster height-growth and 

 heavier volume-production than Norway spruce. 



As regards timber, from American experience and our own, 

 limited though it is, it is fairly certain that Sitka spruce is 

 considerably superior to the other spruces. Unlike other 

 species of Picea it has a visible heartwood. 



It has not been sufficiently extensively planted to enable its 

 silvicultural problems to be determined. It grows faster than 

 Norway spruce in early life, there being a shorter check period, 

 and it probably should be planted at a minimum distance 

 of 5-6 feet. There is a very satisfactory plantation in the 

 south-west borders of Scotland, now about 20 years old, which 

 was planted at 9 feet apart. It will very probably respond 

 to heavy thinnings, but that is still to be investigated. Like 

 other spruces it is difficult to establish on pure heather land, 

 but probably less so than common spruce. 



The author knows no species, not even Douglas fir, which 

 gives greater promise than Sitka spruce. Its various problems 

 should be investigated without delay, both by experimental 

 work in this country and by a study of its growth in western 

 North America. 



White Spruce. 



This species is a native of the north and north-east of 

 North America. Its soil requirements are less exacting 

 than those of the other two spruces discussed, and the 

 tree has been used with other conifers for the fixation of 

 sand dunes. Its place would probably be on the dry, poorer 

 soils. It is more frost-hardy than the other spruces, and 

 owing to its dense branching it has been used as a shelter 

 tree in margins. 



Under average conditions its rate of growth and production is 

 considerably less than that of common spruce and Sitka spruce. 

 It may, however, be of value under the less favourable 

 conditions. 



