MIXED WOODS: ADVANTAGES 99 



(3) Where the soil varies in particular spots, the trees 



best suited to such places can be planted, thus 

 utilising the ground to the fullest advantage. 



(4) Where thinly foliaged trees, which alone cannot pre- 



serve the fertility of the soil, are mixed with shade- 

 bearing trees, whose rate of growth must be slower, 

 the latter, by their soil-improving qualities, cause a 

 more vigorous and more prolonged growth of the 

 thinly foliaged trees. For instance, Oak l or Larch, 

 when mixed with Beech or Hornbeam or Spanish 

 Chestnut, will grow far finer timber than were the 

 Oak or Larch grown alone. 



(5) Mixtures of thinly foliaged trees with shade-bearing 



trees will, provided the latter never outgrow the 

 former, yield a greater out-turn of timber per acre 

 than pure crops of thinly foliaged trees, as a greater 

 number of stems per acre is admissible and the thinly 

 foliaged trees will have relatively a greater growing 

 space. 



(6) A given soil can often supply sufficient plant food and 



water for a mixture of trees, whereas it might not be 

 able to do so for an exacting pure crop. For different 

 trees make different demands on the soil for plant 

 food and water ; and as their root systems differ, 

 some being deep-rooted and some shallow, the 

 supplies can be drawn from a larger area. 



(7) More valuable thinnings will be realised by introducing 



species such as Larch, Ash, and Spanish Chestnut, than 

 were a pure crop of Oak, Beech, or Silver Fir grown. 



(8) The original cost of forming a plantation can often be 



reduced by planting a proportion of cheap plants, 

 which can be removed as thinnings. 



Whereas, the chief disadvantages of mixed woods in- 

 clude the following : 



(i) They are difficult to manage, and require great skill. 



1 Oak must be given a start when grown with Beech, or it will be out- 

 grown and suppressed in most cases. 



