14 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



larch together on account of the supposed danger of spreading 

 larch disease, through the medium of the spruce gall aphis, 

 would not in this case at any rate hold good, as the Sitka spruce 

 is singularly free from attack by that pest. When planted on 

 dry, gravelly soil, the Sitka spruce has here proved its aversion to 

 such conditions by early becoming stunted in growth, losing most 

 of its foliage, and by the stem, thus exposed to too much light, 

 frequently exhibiting a growth of epicormic shoots, a feature also 

 noticeable in older woods, where the stems have been suddenly 

 exposed to light through thinning operations or otherwise. 



What the most profitable rotation period for Sitka spruce 

 may be has yet to be ascertained, but, so far as can at present 

 be judged, a long rotation will probably yield the highest 

 financial results ; for, as the timber is specially suited for struc- 

 tural purposes, a sufficiently long period must be allowed for 

 its maturation, and any rotation less than loo to 120 years 

 need not, I believe, be calculated upon as being likely to 

 produce the quality of timber desirable for these purposes. In 

 this country, the tree has all the appearence of being very long 

 lived, and a large annual increment may be expected up to a 

 great age. With the extension of forestry, it will be necessary, 

 in order to develop the market for home-grown timber, to 

 provide a higher-grade timber than has hitherto been produced 

 under cultivation, and thus to comply with builders' specifica- 

 tions ; and this can only be accomplished by the adoption of a 

 rotation period of sufficient length to enable the timber to mature 

 thoroughly. Should a home demand for pulpwood arise, as it 

 seems certain to do in course of time, a period of 40 years would 

 be sufficient to produce the class of material required for the 

 purpose ] and as a pulpwood tree the Sitka spruce has, I 

 believe, a great future in store. Norway spruce is the 

 principal species for pulp at present, but Sitka spruce can be 

 produced on a shorter rotation, and is also much freer from 

 knots than that species. 



As a pitwood tree it is not likely to compete seriously with 

 larch or Douglas fir : it does not mature its timber so early, and 

 in a young state it breaks under strain with a short fracture. 



In the north of Scotland, one of the principal drawbacks to 

 forestry has been the difficulty of finding a remunerative market 

 for small thinnings, as the excessive haulage rates have pre- 

 cluded the possibility of sending pitwood, other than larch, to 



