112 OUR FORESTS AND WOODLANDS 
requirements of this tree for a large growing-space 
during the second half of its life-period, renders 
artificial assistance of some sort necessary. This 
can best and most effectually be given by 
means of providing an underwood for the pro- 
tection and improvement of the soil. Where the 
oak is grown scattered among a matrix of beech, 
special measures of this sort are usually unneces- 
sary ; but otherwise they must be undertaken, else 
loss of capital will occur through deterioration 
of the soil, which will affect both the future rate 
of growth of the present still immature crop of 
trees, and the whole well-being of the next crop 
of timber that may be grown. 
The best kind of underwood is beech, so far as 
the protection and improvement of the soil is 
concerned; but in most parts of Britain local 
conditions will usually indicate ash, sycamore, 
maple, hazel, and perhaps elm here and there, as 
more likely to be profitable; for in our humid 
climate these, and particularly the sycamore, will 
often bear so considerable an amount of shade 
as to make it very suitable for such an under- 
wood. Many of these will no doubt spring from 
the stool when their stems are removed during 
