BRITISH FOREST TREES 211 



situations where it is necessary to give the oak a good 

 advantage over the beech, and in localities where it is 

 exposed to danger from cattle or deer. 



Wherever coppice woods are to be formed in localities 

 prone to rank growth of grass, planting has undoubted 

 advantages over sowing, and in order to stimulate to quicker 

 growth of shoots, the transplants used should be at 

 least three years old. As soon as the roots seem to have 

 established themselves the ascending axis may be removed 

 close to the ground. A preference is, however, given to the 

 use of four-year-old transplants whose leading shoots are 

 removed close to the roots, which are then planted out 

 rather deep in the soil. Transplants thus cut back yield a 

 thicker growth of shoots. 



. Softwoods. 



i. BIRCH (Betula alba, L. = B. VERRUCOSA and 

 B. PUBESCENS, Ehrh.) 



Distribution. The original Betula alba of Linneus was 

 found by Ehrhart to comprise two distinct varieties, 

 B. verrucosa and B. pubescens, whose indigenous zones seem 

 to overlap and merge into each other, so that hard and fast 

 lines of identification and distribution can hardly be 

 drawn. The southern limit of the birch, with in which 

 B. verrucosa is chiefly found, extends from north-west Spain, 

 across the Pyrenees, and along the southern slopes of the 

 Alps to Croatia, Servia, and Thrace ; this is the chief variety 

 occurring on dry soils throughout northern Germany and 

 Britain, but on moist and wet soils it often passes from the 

 warty into the soft-haired form, B. pubescens. In the birch 

 forests of the far north, which extend from Scandinavia 



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