202 A MANUAL OF FORESTRY. 



young woods, where a slow- growing valuable species 

 is threatened by a faster-growing one. In such a case 

 it may be preferable to prune the latter instead of 

 removing it altogether. 



Trees with many side branches, which have been 

 subjected to unfavourable conditions of growth, 

 frequently show signs of failing strength in the upper 

 part of the crown. By removing the lower branches, 

 the vigour in the upper part may be restored. This 

 case applies specially to Oak standards, the boles of 

 which, exposed to light after a prolonged crowded 

 growth, have developed epicormic branches. 



2. Dangers connected with Pruning. 



The removal of dry branches or remnants of branches 

 is not, as a rule, conducive to any danger to the life or 

 health of the tree, provided the operation be carried out 

 in a careful way. On the contrary, it often reduces the 

 danger from rot, because it facilitates the process of 

 occlusion, or covering over of the wound by layers of new 

 wood. 



Matters are different in the case of green branches. 

 Here the wound caused by the removal of the branch 

 frequently causes rot, because the unprotected open 

 wound offers a fit germinating bed for the spores of 

 fungi ; or the wound, on drying, opens out in rents and 

 cracks, into which rain-water may carry the spores ; the 

 latter germinate and cause decomposition, which spreads 

 and reduces the value of the stem or may entirely 

 destroy it. Several dangerous parasitic and saprophitic 

 species of fungi thus enter trees. 



It is essential, therefore, that the wound should be 



