32 



Conditio7is affecting Growth 



Dry Soils 

 Corsican Pine Birch 



Scotch Pine Acacia 



Austrian Pine Aspen 



Speaking generally, pine, birch, poplar, and rowan are probably 

 the least dependent on good soils ; whereas oak, ash, elm, and 

 sycamore require them. 



Trees remove an almost insignificant amount of mineral matter 

 from the ground compared with the ordinary agricultural crop. 

 This is shown by the following extracts from a table as given by 

 Ebermayer (p. 8). 



The above results are taken from calculations based on the 

 timber only ; the leaves use a larger quantity of minerals. 



Further details of the requirements of different species of trees 

 are given in Chapter VII. 



