One of the fundamental and indeed basic objectives in attempting these primary -reconnaissance surveys of the Newton Stewart, Wanlockhead, and Peebles areas has been to assess how far the moorland vegetation of the Southern Uplands could, as far as available data allowed, be explained in terms of such purely physical factors as geology, landform, climate and soil - or, expressed in another manner, to what extent such physical factors might be considered to have determined or influenced the establishment and development of the character and distribution of the existing vegetation of the unimproved hill-grazings of this region ... and are continuing to do so. It must, however, always be borne in mind that natural and semi-natural vegetation represents a delicately balanced expression, not only of a complex of closely inter-related physical factors, any one of which may vary in its importance and in its effects from place to place and from time to time and none of which can be easily isolated or its Quantity and 'effectiveness' measured satisfactorily, but also, of a complex of biotic factors any of which may fluctuate in intensity even more drastically. In view of such facts it is not possible on the basis of a primary survey alone to hope to attempt more than assess, by a consideration of the nature, form, status, and distribution of the existing vegetation, where and in what respects physical factors appear to play a dominant or important role in determining the type of vegetation, and which of the many, and inter-related, of such factors can be regarded as the most important or effective in any one instance. On the basis of the work that has been undertaken here suggestions, and tentative conclusions, can be offered, but cannot be proved - their only substantiation lies in further corroboration (or invalidation) by more intensive and detailed observation, and finally, by controlled experiment which can aim at, but cannot always succeed in simulating exactly natural conditions. The results, the deductions - the writer hesitates to call them conclusions, as they cannot be regarded as conclusive - which have emerged from this particular study stem from two sources of slightly different 'status' or 'order'. The first are those presented by the actual study of the moorland vegetation in relation to its particular habitat, or habitats, within each of the individual sample areas surveyed. The second are those which can be deduced from a comparative appraisal of the three sample areas, taken, as they have been, as representative of the Southern Uplands as a whole. Most of these latter conclusions have been intimated, if not necessarily specifically stated, in the course of the preceding descriptions and discussions.