246 SYLVICULTURE IN THE TROPICS n . m 



their crown the lower branches of the crow 7 n die down. 

 The depth to which the crown remains green will 

 depend on the species and also on the denseness of the 

 neighbouring crowns. In many species, after the lower 

 branches have died they drop off, breaking off close to 

 the stem, and the w T ounds made are quickly occluded, 

 the bark closing over them. In others they take long 

 to drop off, or only portions break off, leaving snags w r ith 

 a rough uneven end through w 7 hich fungi find an inlet 

 into the tree and lead to unsoundness. It is ahvays 

 advantageous to prune such branches and all dead 

 branches, and this should be done close to the stem, 

 care being taken not to injure the bark of the tree. 



Green branches are also pruned sometimes in order 

 to lengthen the bole ; the operation at the same time 

 leading to the formation of more cylindrical timber. 

 This might be done, for example, in trees w T hich are 

 isolated and whose lower branches have not died down, 

 or where there are trees of different ages, if some are 

 exposed to direct sunlight on one side on w r hich their 

 lower branches have not died down. This is, however, 

 an operation which should only be made with care. 

 As cracks are liable to appear on the exposed surface, 

 they offer a ready access to fungoid diseases. As a rule, 

 therefore, large branches should not be lopped. The 

 size up to which they may be lopped w T ill vary accord- 

 ing to the quickness with which the wound can be 

 occluded. Schlich 1 states that it is dangerous and 

 objectionable to prune branches of a diameter greater 

 than 3 inches (7 '5 cm.). 



When trees which have been growing under 

 complete leaf-canopy are suddenly isolated, as e.g. 

 when after -fellings are being made, their boles, on 

 being exposed to direct sunlight, give out a number of 

 shoots, known as epicorms or as epicormic branches. 

 These, if they are allowed to remain, will divert the sap 

 from the crown and will cause its branches to die from 

 the top; the tree will become "stag-headed." It is 



1 Manual of Forestry, vol. ii. ]>. 2S">. 



