NATURAL REGENERATION. 143 



ones. Both circumstances must be considered in deter- 

 mining the number of trees to be left for the shelter- 

 wood, 



iii. DEGREE OF PREPARATION ARRIVED AT DURING THE PREPARATORY STAGE. 



The higher that degree, the lighter may be the shelter- 

 wood, other conditions being the same. Whenever 

 the preparation has been insufficient or faulty, it is 

 desirable to keep the sheltfcr-wood comparatively dark, 

 because the seeding may fail or be incomplete, so that 

 a second seed year must be awaited before the area 

 becomes completely stocked with a new crop. 



iv. SPECIES. 



Above all, the nature of the species determines the 

 density of the shelter-wood. Tender species, especially 

 those of slow growth during youth, require a dark 

 shelter-wood ; hardy, light-demanding, quick-growing 

 species a much lighter one. In the case of the latter, 

 the distance of the shelter trees may be only governed 

 by the distance to which the seed is naturally dissemi- 

 nated. 



v. GENERALLY. 



The cover of the shelter-wood should be as even as 

 possible throughout, whenever the conditions are uniform 

 over the whole regeneration area; if they differ from 

 place to place, the shelter-wood must be arranged so as 

 to suit the changes. Along the edges of the wood, 

 especially where exposed to dry, cold or strong air cur- 

 rents, the shelter-wood should be kept dark, and it may 

 even be necessary to provide beforehand a special shelter- 

 belt. 



