344 SYLVICULTURAL NOTES ON TIMBER TREES 



thinly foliaged trees should be underplanted, except under 

 rare circumstances. 



Natural regeneration is very easy, provided the land be 

 clean and be not at all acid or sour, 1 and also that rabbits be 

 kept down. But the " seed " felling must be delayed until a 

 good seed year comes. 



Thinnings are usually necessary from about the 25th year 

 onwards. 



Rotation. 90 to 130 years for even-aged high forest. 

 But on poor land or under the selection system a rotation of 

 85 to 100 years will usually give the best result. 



Average Returns from pure crops in close-canopied high 

 forest should be per acre : 



Thinnings . . . 1660 cub. ft. to 2 in. q. g. 

 Final yield (at 1 20 years) 4800 6 

 Total production . . 7060 2 



Average annual increment, 58f cub. ft. 



Equivalent net rental 2 for land only | at 3%= is. id. 



(from date of planting) ) at 4% = minus 45. 8d. 



Of Fungi. Phytophthora omnivera often destroys beds 

 of seedlings in the nursery, causing the well-known "damping 

 off." It is somewhat similar to the potatoe disease. 



Nectria ditissima causes a canker on the stem. Beech 

 is also attacked by various species of Polyporus and Fomes 

 or Bracket fungi, e.g., Fomes fomentarius, Fomes igniarius, 

 Polyporus sulphur eus. Agaricus melleus is a very common 

 saprophyte on the decaying stumps of old Beech trees. 



Of Insects. The Felted Beech Scale Cryptococcus 

 fagi is very common, and often does great damage to trees. 

 It is recognised as a white felt-like substance on the bark of 

 the trees. 



The weevil (Orchestes fagi) attacks the leaves of trees. 



1 For this reason natural regeneration is far more common and far 

 easier to effect in cases where the soil contains much lime, than where 

 there is little or no lime in the soil. 



2 After deducting interest on ^8, the cost of planting and establishing 

 the crop. 



