148 rOEESTS, WOODS, AND TEEES 



produced being increased in quantity and improved in 

 quality by the admixture. Beech also resists wind well, 

 and when mixed with other trees renders the crop wind- 

 firm. It is also valuable in shelter belts. 



Masses of pure conifers, as of spruce, silver fir, larch, 

 Douglas fir, etc., are liable to be attacked by fungi and 

 insects ; and it is of great benefit to intersperse amidst these 

 uniform forests, bands and groups of beech and other broad- 

 leaved trees, which will intercept the spread of spores by 

 the foliage, and check insects by harbouring birds. In this 

 way, suitable spots for ash, oak, sycamore, and elm, mingled 

 with beech, may be found throughout the conifer planta- 

 tions. 



Natural woods of beech occur in the Chiltern Hills and 

 in the North and South Downs on the chalk, and in the 

 Cotswolds on oolitic limestone. Here beech is found 

 thriving on shallow soil, the rock below being often covered 

 with only a few inches of humus. The productivity of the 

 Chiltern beech woods is well known. These are worked on 

 the selection system, a section of a wood being taken in 

 hand each year, and from it the largest stems are extracted 

 by felling. On the spots from which the trees have been 

 removed, there springs up an abundance of seedling beech, 

 so that natural regeneration is readily effected, and no ex- 

 pense is incurred in the establishment of a young crop by 

 planting. Areas occur in which beech is pure, but it is 

 often mixed with scattered ash, whitebeam, and cherry, the 

 latter being often abundant, and occasionally large in size. 

 Beech, after it has passed the young pole stage, should not 

 be kept too dense upon the ground, as with complete canopy 

 the leaves are slow in decomposing, and produce, especially 

 on non-calcareous soil, an acid humus. The ground remains 

 bare of vegetation or else becomes covered with moss, Aira 

 flexuosa, and Melavipyrum, plants indicative of impoverished 

 soil ; and the beech ceases to grow vigorously, while natural 

 regeneration is impossible under these conditions. With a 

 slightly open canopy, the leaves decay quickly, producing 

 an alkaline or neutral humus ; and the soil is decked with 



