72 The Care of Ornamental Timber 



the main point is to encourage every tree to develop a well-developed 

 root-system and a well-balanced crown. 



General. It will, of course, be understood that these remarks 

 apply only to the fringe of a wood exposed to the prevailing 

 winds, and to those situations especially liable to damage from 

 this cause. 



The Care of Ornamental Timber. 



The decay of ornamental timber is such an insidious process 

 that the owner is often unaware of the existence of the disease 

 before the damage is irretrievable. To the casual observer, it happens, 

 very frequently, that an avenue of elms has a very presentable 

 appearance in summer, because the foliage covers the defects ; but an 

 examination often shows that there, is hardly a single specimen that 

 is sound, nearly every tree possessing more or less large cavities in 

 which water is standing. Gradually the heart-wood of the tree 

 disappears, until a mere shell is left of the trunk, with perhaps the 

 alburnum, or sap-wood, of only sufficient thickness to fulfil its 

 function. The limbs usually continue to be sound, and their weight 

 increases, while their supporting trunk is diminished in strength. 

 This condition of affairs continues until a storm occurs, and then the 

 limbs fall off. The whole symmetry of the crown is destroyed, and, 

 at the same time, the fall of the limbs is a serious danger to men and 

 animals. 



The reason why one species of tree is so long-lived and others 

 comparatively short-lived seems to depend largely on the density of 

 their timber and on the resistance to the attacks of bacteria and 

 fungi ; so that if these attacks can be prevented, the life of a 

 tree ought, theoretically, to be indefinitely prolonged. 



The origin of decay, in the majority of cases, is due to one of three 

 causes : — {a), the lodging of water in some depression formed by the 

 conformation of the outline of the trunk ; or (6), to faulty lopping or 

 pruning ; or (c), to a limb being broken off by wind, leaving a 

 stump projecting from the trunk. 



