24o TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



23. The Silvicultural Treatment of the Douglas Fir. 



By W. Stki-art Fothrixgham. 



I am led to make the following notes by the perusal of 

 some accounts of Douglas fir plantations which have appeared 

 in t\\Q Journal of the Board of Agriculture during 191 3. 



Five plantations are very carefully described, and the 

 conditions under which they have been raised are given in 

 great detail, also the measurements of the selected areas and 

 volumes of timber. In all these accounts great volumes of 

 timber per tree and per acre are recorded, but unfortunately 

 nothing is said about the quality of the timber, I do not mean 

 the strength or durability, but the presence or absence of side 

 branches and consequently of knots. 



All the plantations described appear to have been planted at 

 wide intervals, which would seem to suggest a lack of sufficient 

 plants at the time of their formation, a consideration that need 

 not now be taken into account, as there is plenty of seed 

 to be got in all parts of the country, and it is no more 

 expensive to raise than any other seed. Where the plantations 

 were not of pure Douglas that tree seems to have suppressed its 

 nurses at an early age. 



In describing the Taymount plantation, the writer says that 

 303 Douglas firs were planted to the acre with about three 

 times as many larch, but the larch soon fell victims to disease ; 

 and at Llandinam the system of mixing the Douglas with the 

 larch seems to have been followed with the same result, for the 

 writer records that the larch all disappeared at an early age. 

 In both cases the larch was of probably no value. 



At Cochwillan the selected area contained, at the age of 

 fifty-eight, only a little more than 100 trees to the acre, which 

 cannot be looked upon as a full crop, and no history is given of 

 any previous thinnings or of any mixture. 



At Tortworth the trees are reported to have been planted 

 at 10 to 15 feet apart, and at Dunster at 10 feet apart. 



All these plantations give somewhat similar results, viz., large 

 volume of timber per tree and per acre, but nothing is reported 

 about the quality of the timber, and the question arises whether 

 the best silvicultural methods have been adopted and the best 

 financial results secured. 



