SYLVICULTURE 33 



the method of procedure must be very carefully considered. 

 It is not sufficient to have regard only to the initial cost, 

 but the sureness and permanence of the result must also be 

 thought of. False economy frequently leads to very defec- 

 tive work in planting. This, by necessitating the repeated 

 and extensive filling in of blanks, makes what appeared at 

 first to be a cheap method of regeneration actually more 

 costly than had a greater sum been originally spent and an 

 immediately successful result obtained. 



Reclamation 



It may happen that before planting operations can be taken 

 in hand the land requires to be specially treated because of 

 peculiarly unfavourable conditions. Draining may be neces- 

 sary ; an impermeable substratum may be met with near the 

 surface of the soil ; shifting sands may have to be fixed, or 

 thick masses of vegetable matter treated. 



Of the many methods of draining land, that by means of 

 open ditches is the only one generally applicable within the 

 woods. Pipe drainage is frequently made use of in forest 

 nurseries. The drainage of woodland is an expensive opera- 

 tion, and if not very cautiously carried out, much harm may 

 be done by it, particularly to adjoining lands. It therefore 

 behoves the forester to proceed with it only after very careful 

 consideration. 



As regards an impermeable substratum, the common form 

 is known by the term moor-pan. It consists of a layer of 

 sandy material cemented by organic acids into a yellow or 

 brown stone-like mass of varying hardness. On exposure to 

 the influences of air and frost, it becomes pulverised and loses 

 its injurious properties. Frequent in land bearing a growth of 

 heather, moor-pan is found chiefly in poor sandy districts. It 

 occurs at various depths, and in quite thin sheets, as well as 

 layers as much as one foot thick. The ill effects of moor- 

 pan consist in preventing the roots of trees from reaching the 

 deeper soil, and in hindering the percolation of water into the 



