150 THE DEVELOPMENT OF BHITISH FORESTRY 



such. But the universal condition of British woods 

 cannot be altogether attributed to these causes, for unless 

 the crop consists of a shallow-rooting species easily over- 

 turned by wind, or the woods are entirely given up to 

 ground game from the first, it is seldom that the bulk of 

 timber produced at the final felling is necessarily affected, 

 although its quality may be, and its intermediate yields 

 reduced. With a thin stock on the ground during 

 the first ten to twenty years, as usually happens when 

 plantations have suffered from early deaths, wind damage, 

 or rabbits, the yield of timber from them is chiefly 

 reduced during the period between the twentieth and 

 fiftieth years, or the period during which, in properly 

 managed woods, the heaviest and most profitable thin- 

 nings are made for the benefit of the maturing crop. 

 The great difference in the number of stems per acre 

 in British and continental woods is thus found in the 

 early stages, and this difference is usually increased 

 with the shade-bearing qualities of the species composing 

 the crops. 



The following table shows the number of stems at 

 different ages usually found in German woods in first- 

 class localities, as given in yield tables by Schwappach 

 and others : — 



