THE SYSTEMATIC AFFORESTATION OF GREAT BRITAIN. 281 



present, they will be found detrimental to the growth of the young 

 trees if left untouched. Burning is the simplest, least expensive, 

 and most expeditious method of checking the growth of heath, 

 bramble, and wiry grasses, while in the case of shrubby growth, such 

 as gorse and broom, uprooting the plants and reducing them to ashes 

 on the ground is often a necessity, particularly where the growth is 

 old. On high-lying and exposed ground the surface growth is usually 

 dwarf, and can readily be dealt with by burning during dry, windy 

 weather. Burning will not eradicate heath, but will so check its 

 growth that, by the time it recovers, the young trees will be able to 

 hold their own and be beyond all danger of injury. Advantage has 

 been taken of existing shrub growth, in the way of shelter to the 

 newly planted trees, on both the Snowdon and the Lothian hills, 

 in the formation of young plantations. Usually, however, all surface 

 vegetation of rough growth is disposed of. 



Drainage. — The amount of drainage necessary will vary greatly, 

 according to the nature of the soil and subsoil and general lie of the 

 ground. Some portions of the land may require little or no drainage, 

 while in low-lying and boggy situations the removal of stagnant 

 water is probably the most important operation in connexion with 

 the formation of a plantation. It is well known that stagnant water 

 has a most injurious effect when present in the soil, and causes the 

 young trees to have a stunted, sickly appearance, to make little 

 progress, and often die out altogether. As before said, there may, 

 however, be many acres where not a single drain will be required, 

 and the evil of over-drainage must also be carefully guarded against. 

 On the other hand, when the soil is in a sour, unhealthy condition 

 because of excessive moisture, the vegetation invariably indicates 

 it. Patches of heather and other native plants on a wet moorland, 

 particularly where the underlying stratum is moor pan, are usually 

 stunted in growth, sickly in appearance, and covered with lichens. 

 In proceeding with drainage operations, the general He or inclination 

 of the ground must first be taken into account, in order that both the 

 main and minor drains may have full advantage of the greatest fall 

 possible. Straightening and cleaning existing water-courses will 

 also be found of the greatest value in removing surplus moisture 

 from the soil. 



The main drains should be carried along the lowest part of the 

 ground, or in a natural hollow, to which point the water from the 

 minor drains may be readily conveyed. For main drains the usual 

 size is 3 feet wide at top, 3 feet deep, and from 1 to 2 feet wide at 

 bottom, the minor drains being less in proportion, or 2 feet deep, 

 2 J feet wide at surface, and about the width of the draining spade 

 at bottom. According to the amount of moisture in the ground, so 

 will the distances at which the drains should be cut vary; but in 

 ordinary cases these should not exceed 30 feet, or be less than 10 feet 

 apart. The minor drains must never run at right angles to the main 

 so as to cause obstructions, and in all cases the sides of the ditches 



