RECENT DISCOVERIES IN THE SOUTH NORWEGIAN 



FLORA AND THEIR SIGNIFICANCE FOR THE 



UNDERSTANDING OF THE HISTORY OF THE 



SCANDINAVIAN MOUNTAIN FLORA 



DURING AND AFTER THE 



LAST GLACIATION 



Rolf Nordhagen 



Botanical Museum, University of Oslo, Oslo, Norway 



The mountain flora of Scandinavia, and particularly that of Norway, contains 

 types of plant distribution which by no means can be explained according to 

 the theory that the Scandinavian Peninsula was completely buried under the 

 ice during the Last Glaciation. This idea has received the epithet of tabula 

 rasa theory because according to it all life existing in this part of Europe 

 during the Last Interglacial was completely eradicated during the Last 

 Ice Age. After this calamity all the present flora and fauna of Scandinavia had 

 to immigrate anew, preferably from south, east and northeast. 



One of the first Scandinavian botanists to oppose the tabula rasa theory was 

 the Norwegian Axel Blytt (1881, 1882). Judging from his papers in the 

 1880's he evidently realized that a number of hardy species in the Norwegian 

 flora had survived the Last Glaciation inside Norway. In 1882 he wrote: 

 "Es ist moghch, jawohl sogar warscheinlich dass jene gronlandischen Ele- 

 mente in unserer Flora Reste aus den interglazialen Zeiten sind" (It is possible, 

 yes, even probable that this Greenlandic element in our flora is a remnant 

 from the Interglacial times). Other statements by Blytt in his papers from the 

 1880's are, however, on the whole rather haltering. 



However, in a later paper Blytt (1893) contested the idea put forward by the 

 Swedish botanist F, W. C. Areschoug (1869) that the so-called "Arctic flora" 

 n Scandinavia should have a north Siberian origin. Regarding the Norwegian 

 mountain flora, Blytt states that it has rather a Greenlandic or Greenlandic- 

 American origin. Here he points his finger to something of utmost importance, 

 to stiU actual problems of a historical-phytogeographical nature that Nordic 

 natural science will never be able to by-pass. 



Whereas most of the present plant species on the Scandinavian Peninsula 

 are to be found in Europe — though in many cases in distinctly disjunct areas — 



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