RED ROT. 677 



or snowbreak, hail, etc. Wherever the living tissues of the 

 wood are exposed, especially where the wounds are not clean- 

 cut, moisture penetrates into them, unless they are protected 

 by antiseptic substances, such as a natural flow of turpentine, 

 or by tar. With the entrance of water into the tissues, certain 

 chemical changes take place in their contents, and local disease 

 may arise. Spores of fungi also penetrate the tissues, such as 

 the spores of species of PolyjJoms in the upper parts of the 

 tree, or of Armillarea mellea, etc., in its roots. 



4. Damage done. 



Red rot affects the technical value of wood in proportion to 

 its extent and degree of development, and to the innate value 

 of the tree which is attacked. Wood affected by red rot cannot 

 be used as timber, and is only of slight value as fuel. The 

 worst form of this disease is when it attacks a tree's roots, as 

 it then generally affects the whole stem ; the least dangerous 

 form is in the branches. 



It is not rare in spruce woods 60 — 70 years old to find that 

 10 per cent, of the trees are rotten, whilst the liability of rotten 

 trees to windbreak and snowbreak is another cause of disaster. 



5. Treatment of the Disease. 



The rules for combating red rot depend on the cause of the 

 disease. 



a. Wltoi due to Unstu/able >Sy/7.s\ 



Great care should be taken in planting to allot the species 

 of trees to soils suitable for their welfare. 



Remove densely growing mosses and other unfavourable 

 vegetation from damp mountain soils. 



Drain and work up the superficial layers of compact soils. 



In wet soils which cannot be drained, plantations should be 

 made on mounds or ridges. 



On calcareous soils broadleaved species should be intermixed 

 with Scots pine and spruce ; low rotations of 60 — 70 years 

 should be adopted for spruce. 



