CHAP. V.] 



Soil and Situation 



9 1 



abnormal development of the root-system takes place relatively 

 to the ascending axis, and to the crown of foliage charged 

 with the duties of transpiration and assimilation. The chief 

 signs of depth of soil are length of bole, fuller coronal develop- 

 ment, and richer soil-covering of underwood, brushwood, and 

 weeds. A tolerably correct estimate may, in fact, be obtained 

 concerning the depth and the general quality of the soil from 

 the mean average height of the timber crops on such soils as 

 are usually to be found under woods. Thus Grebe gives the 

 following averages for the Thiiringer Wald in the middle Saxon 

 states J : 



AGE OF FOREST IN YEARS, AND AVERAGE HEIGHT IN FEET. 



How the general quality of the soil affects the outturn in 

 timber from the different kinds of woodland crops may be seen 



1 Die Betriebs- und Ertragsregelung der Forste, 2nd edit. 1879. These 

 heights are of course only rough approximations so far as growth of these 

 trees in Britain is concerned. But there is no climatic reason why they 

 should not be equalled, or even excelled, in properly managed woods. 



