PRIMITIVE WOODLAND AND PLANTATION TYPES IN SCOTLAND. l6l 



The wider distribution of the birch impHes that it is the less ex- 

 acting of the two species, and therefore is found forming the lowest 

 stratum on the gravel ; with soil improvement Scots pine would 

 probably encroach and finally oust the birch ; on the advent of some 

 catastrophe, perhaps, or possibly in the natural rotation of species, 

 Scots pine was effaced, and birch established itself to again repeat 

 the cycle. So that, as regards their occurrence on the same area in 

 the past, Scots pine is seen to have been intercalated between birch. 



On the area under consideration, Scots pine " Urwald " was 

 observed at elevations varying from about 200 feet at Achnacarry 

 to 1500 feet at Ardverikie, although at this latter altitude the 

 trees were quite isolated. In Rothiemurchus and Ballochbuie, 

 however, Scots pine ascends to an elevation of over 2000 feet, 

 and in Strathspey and Deeside this tree reaches a higher altitude 

 than birch. Thus, while sufficient statistics are not at present 

 available to determine definitely the relative altitudinal zones of 

 Scots pine and birch, it may be taken that in the past these species 

 have been in competition for the middle and upper zones of tree- 

 growth. It was observed that in the eastern part of the area, in 

 Strathspey and Deeside, Scots pine occupied the upper limits of 

 tree-growth ; while in the western part, from Loch Long to Fort 

 William, birch took up this position. In this connection, the fact 

 that the rainfall in the eastern part is roughly only one-third of 

 that in the western, may not be without significance. 



The Black Wood of Rannoch in Perthshire, Rothiemurchus, 

 Glenaffric, Glenmoriston, Glenmore and Abernethy in Inverness- 

 shire, Ballochbuie and Glen Lui in Aberdeenshire, and GlentuUa 

 in Argyllshire, form extensive and typical examples of Scots pine 

 " Urwald," but probably one of the best examples of its kind is 

 Locheil Old Forest in Inverness-shire, which will now be described 

 as the type. It lies considerably to the west of the Cairngorm 

 district, but probably belongs to the same primeval forest which 

 extended right across that part of Scotland. The forest forms a 

 strip of some six miles in length along the southern shore of 

 Loch Arkaig, and occupies therefore a northern aspect. It takes 

 U[) a position on the middle hill slope, and is fringed above and 

 below by birch. At Gusach, farther up Loch Arkaig side, there 

 still exists an " outlier " of this forest, which was practically clear 

 felled about a hundred years ago, and it is of interest to note that 

 the few trees left are regenerating the area naturally. Locheil 

 forest covers an area of about 1500 acres, and lies approximately 



