BARK-SCORCHING. 525 



(c/) Age of Tree. — The trees mentioned above are exposed to 

 injuries by bark-scorching from the age of poles upwards, but 

 large trees suffer more than smaller ones ; the latter, owing to 

 the greater curvature of their stems, do not receive so much 

 direct heat as the former, and they radiate heat more freely 

 than large trees. In beech woods, where bark-scorching is 

 frequent, 60- to 70- year-old beech trees suffer most. 



(e) Position of Trees. — Bark-scorching attacks trees standing 

 in the open only, and especially those which have been 

 recently exposed, after standing in a dense wood ; also trees 

 along the westerly and south-westerly boundaries of a forest. 

 Trees forming a dense leaf -canopy are never attacked, as 

 their bark cannot become heated like that of exposed trees. 

 Exposed trees do not always suffer in the first year after 

 exposure ; sometimes four years pass before bark-scorching 

 occurs, but this depends on the state of the weather. 



(/) Locality. — The locality and its surroundings, and the 

 nature of the soil-covering, may be here considered. As 

 westerly and south-westerly aspects are most exposed to 

 danger, any woods forming protective zones in these direc- 

 tions prevent or reduce the effects of insolation. JCrndergrowth 

 and soil-covering of dead leaves and humus are also Ui-:eful, as 

 the reflection of the sun's heat from the ground is much 

 greater when the soil, and especially calcareous or sandy soil, 

 is fully exposed. The malady is most frequent during the hot 

 months in beech forests. 



4. Protective Rules. 



(a) Avoid fellings by which beech- or spruce- woods may 

 become exposed to the west, south-west, or south. 



(h) Do not leave beech-standards near the threatened 

 boundaries of a wood. In France it has been usual to lop the 

 side branches of trees in woods bordering on roads, in order 

 to prevent injury to the roads by drip and shade. This pre- 

 disposes beech and other smooth-barked trees to scorching. 

 It is better to fell such trees and encourage advance growth, 

 which shelters the wood, without endangering the roads. 



(c) Mix oak, elm, birch or conifers with beech. 



((/) Allow the trees on the western and south-western 



