990 



Mclereological statislics for the mountain-climale have, unfor- 

 tunately, never been oblained, but it may be assumed that it is 

 more rigorous Ihaii in the lower regions. The temperature being 

 lower, the cold period is thus prolonged, and the summer is less 

 warm. Fog is more frequent, so that among other things, Hght is 

 considerably reduced. Finally the effect of storms will be much 

 increased on the broad expanses of the plateaux. The conditions 

 of plant-hfe are in every way barder, and it follows that the species 

 which can thrive are fewer in number than in the lowlands; Ihe 

 species are also to some extent different. 



The phmt-formation with the greatest distribution on the table- 

 lands of the Færoese mountains is that of the rocky-flats, the »Fjæld- 

 mark«, in the form first characterised by Warming {1888, p. 68), 

 and generally adopted by later authors dealing with the vegetation 

 of norlhern countries. Proceeding from this formation, one can 

 trace the development of two other formations relatively more 

 luxuriant in character — the alpine-bog formation and the Grimmia- 

 heath. It is thcrefore more natural to deal with the drier rocky- 

 fiat formation first, rather than to begin with the formations having 

 a higher water-content, as was done with the sub-alpine formations. 



a. The rocky-flat formation (Fjældmark). 



The plateaux of the Færoese mountains are gravelly or stony 

 and have a barren greyish-brown appearance. The rocks generally 

 stand out like islets in a sea of gravel, the product of a rapid ero- 

 sion of the easily weathered basalt. But in some piaces there is 

 hardly any loose material of erosion, nothing but solid rock form- 

 ing a rugged surface. 



This wilderness is relievcd here and there by a few piants, 

 which contrive to grow in small depressions amongst the rocks or 

 under shelter of boulders and slones, anywhere, in short, away 

 from the violent winds. 



That the winds are the chief cause of the barrenness of the 

 mountain-plateaux is everywhere evident. Let the vegetation be 

 sheltered from the blast, even to a slight degree, then it becomes 

 richer and more continuous. Mosses in particular appear in in- 

 creasing number. Amongst these Griinmia hypnoides and G. eri- 

 coides are always abundant species, and in this way the Grim mia- 

 heath begins to be developed. One can trace in many piaces how 

 the plant-covering advances step by step over the treacherous loose 



