SURVIVAL OF PLANTS ON NUNATAKS IN NORWAY 

 DURING THE PLEISTOCENE GLACIATION 



O. GjiEREVOLL 



Royal Norwegian Society of Sciences^ Trondheim, Norway 



During the 80 years that have passed since Axel Blytt (1876) set up his 

 theory about an Interglacial element in the mountain flora of Scandinavia, a 

 very comprehensive record of supporting biological arguments has been ac- 

 quired. From the point of view of a botanist, the distribution of numerous 

 species cannot be satisfactorily explained without assuming their survival 

 during at least the Last Glaciation on refugia along the west coast of southern 

 as well as of northern Norway. I will not here resume the arguments, nor the 

 discussion, that are still going on between biologists and disbelieving geologists. 

 I take it for granted that a great part of our alpine vegetation is of an Inter- 

 glacial age. 



The question of where the plants might have survived has been subject to 

 much discussion. The main view has been that the plants persisted on refugia 

 close to the coast, partly outside the present coast Hne on the continental 

 shelf not submerged during the Ice Age. The shelf is narrowest outside More 

 in southern Norway and Troms-Finnmark in northern Norway. From Green- 

 land and other Arctic areas we know that the alpine plants are descending 

 toward sea level. 



At the same time it is evident — to judge from the present situation in 

 Greenland — that if coastal refugia have existed in areas adjacent to high 

 mountains in the neighborhood, these mountains must have protruded from 

 the ice-shield as nunataks. Would it have been possible for alpine plants to 

 persist in the nunatak areas? 



In his epoch-making paper "Essay on the immigration of the Norwegian 

 flora during alternating rainy and dry periods", Blytt (1876) pointed out a 

 group which he called "Arctic plants" occurring in northern as well as in 

 southern Norway, particularly in the continental mountains. 



From the work of Th. C. E. Fries (1913), "Botanische Untersuchungen in 

 nordlichsten Schweden", the theory of survival got its cartographical founda- 

 tion. He showed that many important species in the Scandinavian alpine 

 flora have a centric distribution (Fig. 1). About 25 species display a biceutric 

 distribution occupying one area in southern Norway and one in northern 

 Scandinavia. The unicentric ones are found only in one of these areas, about 



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