BIOLOGICAL UTILISATION OF SOIL. 1X5 



and Picea excelsa. Still higher we find a zone in which the 

 birch predominates, extending from 900 to 1100 ^ m., traces of 

 which are still found on the high plateau of Finmark. 



Within the Polar Circle 6 per cent, of the surface is wooded. 

 There also the birch dominates, the pine is secondary, Picea does 

 not exist. 



Why should it not be the same, and with still more reason, in 

 the Scottish Highlands'? They were formerly covered with 

 f oi-ests : the most positive natural and historical evidence places 

 this point beyond dispute. 



According to Dion Cassius and Herodian, the Roman legions 

 and the auxiliary troops were employed by the emperor Severus, in 

 the year 207 of our era, in cutting down the forests : 50,000 men 

 they say, perished in this enterprise. The ancient forest, Sylva 

 Caledonia, which had originally an area of 20 miles, is now 

 represented by a few small forests such as that of Coille-More, or 

 Great Wood, and that of Marr in Aberdeenshire. According to 

 old maps, forests surrounded Stirling, Elgin, Banff, Aberdeen, 

 Kintore, and Paisley. The great wood of Drumselch partly 

 covered the neighbourhood of Edinburgh. Selkirkshire, formerly 

 called Selkirk Forest, must have been very well wooded. Vast 

 stretches of heatber, peat-bogs, and marshes have replaced these 

 old forests. Amongst the causes of destruction, particular to 

 Scotland, we must mention the attempt of the Government to take 

 away from the Highlanders the refuge which they found in the 

 depths of the forests. John of Lancaster employed 2400 work- 

 men to cut down the forests of Scotland. Robert Bruce destroyed 

 a great number of them in his expedition to Inveraray against 

 Comyn. In the northern part of the kingdom the Danes burned 

 extensive wooded areas. We find an order of General Monck, 

 dated 1654, which commands the destruction of the forest of 

 Aberfoyle. 



Tradition and the ruins which each step in the glens compels 

 us to observe, witness that the soil formerly supported and fed 

 a much denser population. 



Beside the documents afforded by the local archives and folk- 

 lore, we find in the soil itself certain proofs of this former state of 

 things. For, in many places, and in different parts of the country, 

 we come across entire forests still apparent by the stumps buried 

 in the bogs or in the water. 



This is convincing evidence that the limits of tree-vegetation, 

 1 3000 to 3600 feet. 



