28t TENDING OF CROWItKl) \V(i(H»S \ l-'l'Kl; KARLY VOnil. 



tliese advantages [)iiiniiig may he extended to the removal of 

 dead hranches, or to tlial of green ones as well. Pruning 

 maj' exercise an additional advantage in causing the hole to 

 grow more cylindrical, instead of approaching the shape of a 

 cone ; in other words it maj' render holes less tapcrlufi. 



The second of the ahove- mentioned cases occurs wliere a 

 wood consists of two or more generations of different ages, as 

 in coppice with standards, the selection system, two-storied 

 high forest, etc. It may also cccur in young woods, wliere a 

 slow growing valuahle 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, fretjuenlly show signs 

 of failing strength in the upper part of the crown. ]>y lemoving 

 the lower branches the vigoui- in tlie upper part may l>e 

 restored. This case applies specially to oak standards, the 

 boles of which, exposed to light after a prolonged crowded 

 position, have developed epicormic l)ranclies. 



2. Daiiticra cimncricd icitli Pnnniui. 



The removal of dry branches or remnants of hranches is 

 not, as a rule, conducive to any danger to the life or heallh 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 brandies. Here the 

 wound caused by the removal of the branch frequently causes 

 rot, because the unprotected open wound offers a tit germinat- 

 ing bed for the spores (jf fungi ; 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. 



