THE SILVICULTURAL TREATMENT OF THE DOUGLAS FIR. 249 



I have two small plantations here which I am taking into 

 account in making these notes. In one, the Douglas was mixed 

 with spruce and planted in about equal numbers at 6 feet apart ; 

 in the other, pure Douglas was planted at 3^^ feet. Both these 

 plantations are too young — 14 and 18 years old respectively — 

 to give very definite results, but they are old enough to be 

 instructive. In the first, the result has been the practical 

 suppression of the spruce but a great growth of Douglas of a 

 rather branchy nature, the lower branches have been killed off 

 but should have been killed off sooner ; in the other, the trees 

 have been too much drawn up, and a considerable thinning has 

 had to be undertaken, and the thinnings are of no value. 



After considering the above, I have come to the conclusion 

 that the Douglas will produce the best results when planted in 

 a pure plantation. The light-demanding larch appears to be 

 killed out by want of light before it is of any value, and the 

 shade-bearing spruce does not start into height-growth soon 

 enough to hold its own. The Douglas in a suitable locality 

 grows so fast that nothing can live with it. 



The conditions suitable to the growth of the Douglas fir are 

 well known to most foresters — there must be sufficient depth of 

 soil and permeable subsoil to admit of a good root-formation 

 or else the tree develops a root-system similar to that of the 

 spruce, all on the surface, and is then easily blown down. The 

 leading shoot is apt to be soft and easily broken by the wind. 

 The tree will bear a considerable amount of shade, especially 

 side shade. When the soil and subsoil admit of the formation 

 of a good root-system the tree is not easily blown down, and 

 when the height-growth is not too rapid the leading shoot is not 

 so easily broken. 



Having found a situation that is sheltered from the strongest 

 winds, which are not necessarily the prevalent winds, and with 

 a sufficient depth of soil, the next question that arises is at what 

 distance to plant the trees, and all the other questions that arise in 

 economic forestry are involved. The labour and cost of plants 

 increase with the density of the plantations, and the value of the 

 thinnings and the cost of thinning have to be taken into 

 account. If too many trees are planted the cost of making the 

 plantation is increased, the thinnings have to be made earlier, 

 and they are probably of no value ; if too few trees are planted 

 the result is branchy timber and no thinnings, but expense in 



VOL. XXVIII. PART II. R 



