THE BROAD-LEAVED TREES 151 



age, but usually only at intervals of from five to nine years. It 

 coppices badly, and the stools only last three or four rotations. 

 Beech is best grown as high forest in pure woods on rota- 

 tions from 80 to 1 20 years, but first-class timber of ash, oak, 

 larch, &c., can be produced by introducing these trees into the 

 beech woods, either singly or in small groups, and it is chiefly 

 as a nurse to the valuable light-demand ers that beech will be 

 grown in Great Britain. It is the best tree for underplanting 

 open woods of light-demanding species. It is unsuitable for 

 standards- over-coppice, and is not very good as coppice except 

 as a soil improver. It must be grown densely, or the stems 

 will not get naturally pruned ; thinnings must be lightly con- 

 ducted. It is a slow grower at first, but after twenty to thirty 

 years the rate of growth increases. Beech woods are very 

 suited to natural regeneration, especially when the soil con- 

 tains lime. An aphis (Coccus fagi) does considerable damage, 

 otherwise it does not suffer much from insects or fungi, though 

 it is attacked by a good many species. The bark of trees 

 suddenly exposed to the sun is very often blistered. 



Birch (Be tula alba). 



A native of Great Britain and Europe, and is found up to 

 an elevation of 2,500 feet in Scotland. It is very hardy 

 and does not suffer from frost. It does well on any aspect. 

 It is highly light-demanding. It is very accommodating 

 as to soil, and can be grown on almost any kind of soil 

 and situation. It produces large quantities of seed, is easily 

 regenerated naturally, and is apt to come up wherever there 

 is clear ground, and is often a troublesome weed in plan- 

 tations. Coppice shoots are usually weak, and the stools die 

 after two or three rotations. It is not a good tree for pure 

 woods as the soil deteriorates under it, but it is found growing 

 alone where the soil is too poor for other species. It should be 

 grown singly or in groups in woods of other broad- leaved species. 

 It should not be mixed with conifers as it injures them by the 



