28 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



The planting density must be arranged according to the 

 productive factors of the locality. It would be folly to attempt 

 to crowd more trees in per acre than are reasonably likely to be 

 able to maintain a fair rate of growth and volume production at 

 all stages of development. 



Taking different soils, sites, and exposures along with light- 

 demanding and shade-tolerating species, fast and slow growers, 

 the time taken for a plantation to become established, i e. to 

 establish canopy, may vary from 6 to lo years on the average. 

 There should be time and room for root development as well as 

 for that of stem and branch, and too close crowding, especially 

 with transplants which have all received the same nursery 

 treatment, and which are all equally strong and well matched in 

 the struggle for existence, is simply a method of reducing 

 the all-round subsequent vitality of the plantation. It further 

 leads to the cutting of early and valueless thinnings, which 

 means more expense. The aim should be to plant in such a 

 way that merely ordinary cleaning operations will suffice, until 

 the first thinnings which will yield marketable material fall due. 

 This aims at effecting economy in plants and labour at the 

 commencement of operations, and this leads to further economy 

 or saving in the avoidance of early thinning out of useless 

 material. The maximum use is thus made of the young trees 

 which have cost money to rear in the nursery and to plant in 

 the forest, or, put the other way, too close planting means a 

 waste of plants and extra cost in tending and thinning in the 

 earliest stages of over-crowded plantations. 



Early close crowding and suppression means greater risk of 

 damage by insect and fungus attack, and a greater subsequent 

 danger from snow-break and wind, unless thinnings are begun 

 early and carried out carefully at frequent intervals. Close 

 planting will not completely solve the problem of stem cleaning 

 in the case of spruce and Douglas fir in this climate. 



Experience and investigation have shown that the growth ot 

 conifers is quicker in our insular climate, at least up to the 

 pole stage, than on the Continent. This has an important 

 bearing on the time taken to form canopy after planting, and 

 the quicker the growth the less the need for close planting. 

 Hence under the conditions of growth in this country even wider 

 spacing than that practised on the Continent is indicated. 



