CHAP. XL] Effects of Underplanting 231 



shade-bearing ; and, if measures are not taken to counteract 

 the consequences of the gradual interruption which takes 

 place in the leaf-canopy, the effects of insolation and of 

 exposure to the freer action of wind and rain on the soil, 

 tend to diminish its productive power, and must ultimately 

 lead to its deterioration. 



To obviate the consequences of this natural tendency on 

 the part of the lightly-foliaged species, which is not reconcil- 

 able with the conservation of the productive energy of the 

 soil, the best plan capable of adoption is to underplant them 

 with shade-bearing species for the purpose of maintaining the 

 soil cool and moist, and of improving it through the larger 

 quantities of mould formed by their dead foliage. 



In most of the open forests of Oak, Larch, or Pine, for 

 example, there will usually be some sort of natural undergrowth 

 .found under the comparatively light shade of these forest trees ; 

 but the practical influence exerted by an underwood of brush- 

 wood, scrub, or berries, is by no means so beneficial as that of 

 undergrowth formed either naturally or artificially by Beech, 

 Hornbeam, Sweet Chestnut, or Sycamore or by evergreens 

 like Spruce, and Silver, Douglas, or Nordmann's Firs *. 



The first occasion on which underplanting is known to 

 have been carried out under Oak, with the express intention of 



' giving a covering of dead foliage to a soil already overgrown with 

 whortleberry, and thus strengthening its productive capacity, and stimu- 

 lating the diminished increment of the Oaks,' 



took place in the Spessart forest in central Germany about 



1 Under Firs are included only the genera Picea, Abies, 7"suga, and 

 Pseudotsuga, including Spruce, Silver Fir, Hemlock, Nordmann's, Menzies, 

 and Douglas Firs, but not the Pines (Pinus) incorrectly though perhaps 

 more commonly called Firs, e. g. Scots Fir for Scots Pine. Etymologically, 

 Fir is properly the name of the Scots Pine, from the old Anglo-Saxon/r/z ; 

 but if we retain it, then we must coin distinctive names for Spruce and Silver 

 Fir, which are distinctly different genera not indigenous to Britain, and only 

 introduced during the seventeenth century. For these trees we have never 

 adopted any generic names such as are current in France and Germany, 

 whence they were brought over. 



