PLANTING DISTANCE FOR DOUGLAS FIR. II 



It is interesting to see what the lumber-men of the Pacific 

 Coast have to say as to the quality of naturally-grown Douglas 

 fir timber. Mr Elwes, in Elwes and Henry's Trees of Great 

 Britain, tells us that a distinction is drawn in the saw-mill trade 

 between two qualities of Douglas fir timber, known respectively 

 as red and yellow fir. He tells us that the yellow fir is of much 

 better quality than the red, and the difference is due entirely 

 to the conditions under which the timber is grown. He quotes 

 from Professor Sheldon as follows:— "The rapid growth of 

 Oregon fir in the open produces red fir, and the subsequent 

 growth when the trees begin to crowd each other produces 

 yellow fir. Trees grown in dense clumps, crowded all their 

 life, produce solid yellow fir." Mr Elwes tells us further that 

 in examining the stumps of mature trees having a diameter 

 of 6 to 8 feet, he found that the annual rings in the earlier 

 period of growth numbered five or six to the inch of radius, 

 and as many as twenty to the inch in the later stages. 



Now to compare this information with our own experience 

 in Scotland, it is not uncommon to find trees standing singly 

 on good soil making much more rapid increase in diameter, 

 so that only two or three rings and sometimes less than two 

 will cover an inch of radius. But when we come to examine 

 plantations made at 3 feet apart, we shall not find anything 

 like such a rapid increase in diameter : at 12 years planted the 

 average diameter ^ including bark at \h feet from the ground 

 is 4;^ inches, giving about 5I rings to the inch of radius. 

 So far as it is possible to judge at such an early age, this 

 result seems to come near to the rate of growth in the natural 

 forest described by Mr Elwes. 



At twelve years after planting the plantation is well into the 

 thicket stage of growth, the height-growth of the thicket is 

 rapid, and probably quite equal to that of trees of the same 

 age standing singly. But it is evident that the diameter 

 increment is already affected by the density of the crop, and 

 from what we know of the tree in its native country it is 

 probable that the quality of the timber in process of formation 

 is already better than that of trees grown in the open. 



Some support for this conjecture is to be found in Bulletin 



1 These figures are taken from a plantation made in 1909. Suppressed 

 stems and those which must soon become suppresse4 are excluded in 

 calculating the average diameter. 



