SYLVICULTURAL NOTES ON ALDER. 268 



Pruning should be avoided. 



Thinnings. The Maple should be given an ample 

 growing space when the height-growth begins to fall 

 off. 



8. COMMON ALDER = Ahius glutinosa (Geertn.). 

 a. Utility. 



The specific gravity of air-dried wood is, on an 

 average, '53. The timber is soft, splits easily, does 

 not last in the open, but well under water, and is used 

 accordingly ; it is also used for herring-barrel staves, for 

 cigar boxes, and cooperage. It yields an inferior fuel, 

 but a charcoal well adapted for the manufacture of 

 gunpowder. For Schulze's powder the wood is used 

 without first converting it into charcoal. The bark is 

 used for tanning. 



&. Distribution. 



It is found in most parts of Europe, almost up to 

 62 of latitude, in Northern Africa, and in Western and 

 Northern Asia. It is indigenous in Great Britain and 

 Ireland. It goes up to 1600 feet in the Scotch High- 

 lands, and to about 4000 in the Alps. 



c. Locality. 



Climate. Alder requires little warmth, is fairly hardy 

 against frost, but very sensitive to drought. It is a 

 light-demanding tree, standing about on a par with 

 Elm, but somewhat below Oak. It requires moist 

 air, and suffers from snow and rime, which break the 

 branches. 



