182 BRITISH FOREST TREES 



confine the reproductive operations to the latter alone, 

 subordinate species being best introduced later on. The 

 soil-covering in mature forests in close canopy is seldom of 

 such nature that it can at once offer a good germinating- 

 bed for the seed ; hence a certain deliberate interruption of 

 canopy is necessary in order to allow rain, light, and warmth 

 to accomplish the decomposition of the dead foliage cover- 

 ing the ground, except on the fresher and more fertile soils 

 where the greater moisture has all along been more favourable 

 to the formation of humus. Under ordinary circumstances, 

 with a moderate preparatory felling, the decomposition of 

 the soil-covering of dead foliage is accomplished in about 

 four to five years. This takes place quickest on limy soils, 

 where felling is sometimes hardly necessary at all, owing to 

 the danger of the soil becoming overrun with weeds, but 

 proceeds more slowly on the sandy varieties of soil. 



In addition to the subordinate species, only the smaller 

 dominated stems are removed, so that about 1 2 per cent, of the 

 cubic contents are harvested, which would include about every 

 fifth to seventh tree of the smaller classes. The fall can 

 always be greater on the cooler northern and eastern aspects, 

 and in localities where the foliage lies thick ; where the soil 

 already shows tendency towards growth of grass or weeds it 

 is unnecessary, and would be out of place. Young self-sown 

 growth should only be allowed to remain if of good develop- 

 ment and not over six to eight years old, as beech differs 

 greatly from silver fir in respect to the recuperative power of 

 seedlings that have stood long under dense shade, and such 

 badly grown patches only interfere with a free circulation of 

 the air, thus increasing danger from frost. By driving 

 in cattle for grazing, or swine for pannage, the work of 

 breaking up the soil, and rendering it receptive for the seed, 

 is greatly furthered. 



The reproductive or seed-felling takes place when a good 



