NATURAL REGENERATION. 137 



i. FllKI'AUATION OF A SUITABLE SEED-BED. 



The soil must be brought into a condition which 

 ensures a proper germination of the seed, and enables 

 the seedlings to reach the mineral soil with their rootlets 

 within a reasonable period ; it must be suitably porous 

 and moist. The necessary measures to ensure this 

 depend on the previous condition of the soil and wood, 

 and on the nature of the locality. 



In the course of a rotation crowded woods produce 

 considerable quantities of humus, which decomposes 

 at a quicker or slower rate according to species and 

 other circumstances. Where, on approaching the period 

 of regeneration, the layer of humus and leaves is so 

 large that seedlings cannot reach the mineral soil within 

 a few weeks after germination, it must be reduced 

 before regeneration is attempted. This is done by 

 removing some of the trees, and thus admitting the 

 sun's rays and a more active circulation of air, which 

 cause an accelerated decomposition of the humus. The 

 severity of the cutting depends on the original density 

 of the leaf-canopy; dark cover overhead demands a 

 heavy cutting ; a thin cover, a light cutting or none at 

 all. It also depends on the nature of the soil; over 

 limestone the humus decomposes rapidly, on cold heavy 

 soil slowly. Again, the leaves of some trees decompose 

 more rapidly than those of others.* 



Situation and the local climate must also be con- 

 sidered. Where the degree of moisture in the soil and 

 the air is high, decomposition proceeds at a slow rate ; 

 such localities are high situations, northern aspects, moist 



* See page 148 of Volume I. 



