192 THE DEVELOPMENT OF BRITISH FORESTRY 



high price, and was extensively planted for shipbuilding. 

 Now it is impossible to grow it with any prospect of 

 profit on the majority of soils. 



It may be assumed that no tree can be called profitable 

 which is incapable of producing a volume of timber per 

 acre per annum which exceeds in value the interest on 

 the accumulated cost of production, allowing interest on 

 all outlay at a rate which compares favourably Avith that 

 yielded by any safe investment. Species requiring very 

 rich soils or favourable situations, or a heavy expenditure 

 to establish them on a sylvicultural scale, must be com- 

 paratively rapid growers in the first place, and command 

 a good price per cubic foot in the second, before a nett 

 return can be expected. With slow growers, or species 

 which can only produce a low yield per acre, the returns 

 are not merely small in volume, but the cost of handling 

 and marketing the timber is much heavier than in the 

 case of a dense and heavy crop. A self-sown crop scat- 

 tered over a wide area may be less profitable on this 

 account than a heavy crop produced at much greater 

 cost per acre, but commanding a still relatively higher 

 price on account of its heavy jdeld on a small area. This 

 fact is chiefly responsible for the sowing and planting of 

 Scots pine in Germany in place of the older method of 

 natural regeneration, which, while successful in a general 

 way, produced more patchy and irregular crops. 



While, therefore, the characteristics which render 

 timber species profitable in the British Isles are various, 

 they are in a general way associated with one or all of the 

 following features : — 



1. Plentiful seed production. 



2. Adaptability for transplanting, sowing in situ, or 

 natural regeneration. 



3. Power of resisting drought, early or late frost, wind, 

 insects, and fungi. 



