ORIGIN AND DEVELOPMENT OP HEATHER MOORLAND. 117 



XIV. The Origin and Development of Heather Moorland. 

 By Dr W. G. Smith. 



(Extract reprinted from The Scottish Geographical Magazine for 

 November 1902.) 



Development of Heather Vegetation from Forest. — The develop- 

 ment of heath on bare sand is probably the more primitive mode, 

 yet Graebner ^ considers that the majority of the existing heath areas 

 in North-West Germany have been developed on the sites of 

 former forests. This is admitted by most observers, and although 

 the German plain is an area of low altitude, the results are worth 

 considering in regard to the origin of British heather moorlands. 

 R. Smith- decided to adopt 2000 feet (608 metres) as the approxi- 

 mate upper limit of the heather moor; above this limit the heather 

 either ceases or becomes a subordinate element in the blaeberry 

 {Vaccinium myrtillus) type of vegetation. The birch wood or 

 thicket also ceases about this altitude, and is the highest of our 

 forest zones. Woods of larch and Scots pine occur in Northern 

 Perthshire up to 1800 feet, but White's Flora of Perthshire gives 

 isolated pines up to 1900 feet altitude. In Aberdeenshire, Dickie's 

 Flora gives 2200 feet, and quotes from Watson's Cyhele the find- 

 ing of a pine trunk, 8 feet girth, in peat at 1650 feet. Geikie ^ 

 says that pine trunks in peat are not uncommon from 1800 to 

 2500 feet altitude. The agreement between the upper limit of the 

 principal heather area and the higher forest zones in Scotland is 

 suggestive of a possible origin of the heaths from forests ; in many 

 cases this was doubtless so, but more evidence is required before 

 this course of development can be admitted as universal. In North 

 Germany the conversion of forests of a high national value into 

 heather wastes of little value is an important economic question. 

 The problem has naturally attracted much attention, and Graebner 

 had it before him as one of his chief objects. The explanation 

 most widely accepted is that of Krause and Borgreve ; the forests 

 have been exploited by man for the timber, and the failure to 



^ Die Vegetation der Erde, edited by Engler and Drude: vol. v. Die Heide 

 Norddeutschlands, by Dr Paul Graebner. 



-Smith, Robert, Botanical Survey of Scotland : i. Edinburgh district; 

 II. Northern Perthshire. John Bartholomew & Co., Edinburgh, 1900. — Also 

 Scot. Oeog. Mag., July and August 1900. 



3 Geikie, J., Trans. Roy. Soc. Edin., xxiv. pp. 363-384, 1865-66. 



