ON PLANTING DISTANCES FOR CONIFERS. 1 7 



The planting distance has a direct effect on the develop- 

 ment of the wood during the period of formation, and, to a 

 less extent, during the period of competition, after the canopy 

 has closed. It should be clearly understood that the period 

 of competition is the most important time in the life-history of 

 the plantation, and it is during this period that the wood is 

 either made, by careful attention, or marred, by neglect and 

 bad forestry. It is during this period that the forester has it 

 in his power to mould the growth of the trees to his will by 

 judicious thinning and care. 



There is need for careful discrimination between the effects 

 of bad tending of a wood after the canopy has closed, and the 

 effects of the original planting distance. It is very doubtful, 

 for example, if the planting distance, unless it be so excessive 

 that the canopy does not close for a long period of years, has 

 any direct effect on the ultimate form of the stems. 



With spruce on good soil, Schiffel gives the following results : — 

 Planted at 3 feet by 3 feet, the canopy closed in the ninth year ; 

 planted at 6 feet by 6 feet, the canopy closed in the twelfth 

 year, and at 6^ feet by 6^ feet, it closed in the fourteenth year. 

 No figures are given for wider distances, but we can assume, 

 in view of the increasing rapidity of growth, that, planted at 

 8 feet by 8 feet, the canopy would close in the twentieth year. 

 On poorer soils, a longer period would be necessary. It is not 

 claimed that all species would close so rapidly, but it is claimed 

 that the much faster-growing species, like Douglas fir, Sitka 

 spruce, and Japanese larch, would close at least as rapidly and 

 probably much more so. 



What are the direct effects of planting distance on the woods 

 up to the closing of the canopy? (i) The shorter the planting 

 distance the sooner does the canopy close, but for most species, 

 at any distance up to 8 feet, closing has taken place before the 

 twenty-fifth year, making allowance for poorer sites. (2) As a 

 result of this, the closer the canopy the sooner does humus 

 accumulate and improve the soil conditions. (3) Also, the 

 exclusion of light by the branches kills off the ground vegetation. 

 (4) The ground is more rapidly protected from drying out in 

 dry and exposed localities. (5) A few failures in the original 

 planting can be ignored if the distance has been close. A 

 gap is more serious in the widely-spaced plantation. (6) The 

 closer the planting the smaller the development of side branches. 



VOL. XXXV. PART I. B 



