BRITISH FOREST TREES 



According to Hartig : l 



" The quantity of nutriment taken up from the soil depends 

 chiefly on the species, for some plants extract greater supplies than 

 others. Thus the spruce, for example, when growing along with the 

 beech in forests forming close canopy, extracts more raw mineral 

 substance for ashes than the latter. At fifty years of age the relative 

 proportion of productions between the spruce and the beech is : 



As regards cubic contents 2*78 to I 



,, ,, dry woody substance I'Sotoi 



,, ., ashes (mineral substance). 1*28 to I 



" These figures prove that spruce not only withdraws more nutri- 

 ment from the soil than beech, but that it also produces more timber 

 than the beech with any given quantity of mineral substance. For 

 the production of any given cubic quantity of beech timber more 

 mineral matter is requisite than for the production of the same volume 

 of spruce.'' 



Experience however here again shows that the forest trees 

 may be classified as follows in regard to the demands made 

 on the general fertility and mineral strength of the soil : 



Heyer (for Central Germany). 



Greatest demands. I Elm, sycamore, ash. 



High demands. 



Oak, beech, maple, 

 sweet chestnut, silver 

 fir. 



Lime, larch, horn- 

 beam, alders, 



chestnut, spruce, 

 Cembran pine. 



Lower demands. 



Poplars and tree 

 willows. 



Gayer (for Southern Germany). 

 Most exacting. 



j Elm, maple and 

 sycamore, ash. 



Exacting. 



Little exacting. 



' Oak, beech, lime, 

 j silver fir, aspen, 

 willow. 



Sweet chestnut, larch 



hornbeam, birch, 



alder, spruce. 



i Scots, Wey mouth 

 Least demands. and Austrian pines, 

 birch, acacia. 



Least exacting. 



Scots an . d Austrian 

 pines 



1 Anatomic umi Physiologic der Pflanzen, 1891, p. 227. 



