164 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



of these modifying influences may be seen in the small " out- 

 liers " and isolated clumps of Scots pine which stand out in 

 relief on the birch-clad mountain sides. After the clearing of 

 these areas birch has often taken possession of them, although 

 in some cases, as at Gusach, and especially in Rothiemurchus, 

 Abernethy and Ballochbuie, Scots pine is again establishing itself. 

 Juniper is apparently the only undergrowth obtained in these 

 forests, and in parts of Abernethy and Rothiemurchus it shows 

 a very vigorous development. 



The ground-vegetation of this Scots pine " Urwald " is unique, 

 in that it consists mainly of plants which one does not usually 

 associate with woodland, but rather with moorland. In Locheil 

 Forest the dominants may be taken as ling [Calluna), bell- 

 heather (Erica tetralix) and blaeberry ( Vaccinium myrtillus), 

 while bracken {Pteris aqiiilina) fringes the forest and also appears 

 in the " opens." W. G. Smith describes a similar ground flora 

 for this type of primitive woodland in the Rannoch and Speyside 

 districts, and, in addition, other small plants which are pecuhar 

 to this class of forest. These are wintergreens {Pyrola), chickweed 

 wintergreen {Trie 11 talis), and several small orchids {Goodyera 

 repens, Listera cordata, etc.).^ Possibly the fact of Scots pine 

 yielding a comparatively acid humus, might tend to the develop- 

 ment of the more or less xerophilous heath plants in association 

 with it. 



Oak "Urwald." 



This type again finds a more extensive and better development 

 in the Highland part of the area under consideration. Within this 

 area natural oak-woods occur at elevations varying from 50 feet 

 to 650 feet above sea-level, while in other parts of Scotland oak 

 is reported to ascend to over 1000 feet. These woods mainly 

 occupy the lower hill slopes, and occur typically skirting the 

 shores of lochs, or following the course of some river in a narrow 

 strip along either bank. Thus, as regards altitudinal distribution, 

 natural oak-woods seem to be much more restricted than either 

 birch or Scots pine ; while the actual area covered by oak-woods 

 is distinctly less than that covered by birch woodlands. The 

 position and shape of many of these natural oak forests would 

 seem to indicate that soil conditions play an important part 



'See "The Vegetation of Woodlands," Transactions of the Jioyol Scottish 

 Arboricultural Society, vol. xxiv., part i, pp, 20 and 21. 



