CHOICE OF SYSTEM 195 



it is not storm proof, though it might be naturally regenerated 

 in a mixture along with other shade-bearing conifers whose 

 height growth is somewhat similar. It is sometimes thus 

 regenerated along with Silver Fir on the Continent. 



The group system is peculiarly suited to the regeneration 

 of these conifers, for their seed is light and easily carried by 

 the wind, and as long as the felled patches remain free from 

 grass, the young crop gets a maximum amount of moisture ; 

 and the older trees give protection on all sides from cold 

 winds, and thus lessen surface evaporation. If the soil be dry, 

 the patches or groups must be larger than would otherwise be 

 admissible ; though the danger from windfall will be increased. 



When the compartment system of regeneration under a 

 shelter wood is resorted to, the procedure will be much the 

 same as in the case of Beech. But Douglas Fir and Wey- 

 mouth Pine will not bear so much shade, and the canopy 

 must be thinner, and the mother trees removed earlier. 



In the case of Douglas Fir it is very essential to gradually 

 accustom the future mother trees to isolation, otherwise 

 they are rather liable to have their tops broken off by gales. 

 For this reason the group system will usually be preferable. 



THE COMPARATIVE MERITS AND DEMERITS OP 

 THE SYSTEMS. 



Compartment System : 

 Merits 



(1) Operations are concentrated ; therefore supervision is 



easier ; and damage caused by the removal of timber 

 is more cheaply repaired e.g., roads. 



(2) Side shade is avoided ; therefore it is not so detrimental 



to light-demanding seedlings. 



(3) The greatest proportion of good timber is produced. 

 Demerits 



(1) Soil deterioration is quicker, both on account of side 



light and of dry winds. 



(2) In exposed places, windfall is to be feared. 



(3) If a seed year fails, a greater loss is incurred ; therefore 



the risks are greater. 



