ON THE HISTORY AND AGE OF SOME ARCTIC 



PLANT SPECIES 



Emil Hadac 



Department of Botany, Czechoslovakian Academy of Sciences. Pruhonice, near Praha, 



Czechoslovakia 



The flora of the Arctic is very variable. We find there plant species which are 

 ,^_^ broadly Circumpolar and others which are confined to some part of the Arctic 

 ticrritory. There are also species of American, Asiatic, or European origin 

 — ^nixed with the Circumpolar High Arctic element. 



If we want to know how old the Arctic flora really is, we must first answer 

 several questions: How long have conditions favoring the tundra vegetation 

 existed in the Arctic? Was there any tundra vegetation during the Tertiary 

 epoch, or was it formed during the Ice Ages? If they already existed in 

 the Tertiary epoch, could they have survived all the glaciations? Is there 

 really any indigenous Arctic flora, or are plants now living in the Arctic all 

 immigrants from the mountains of the adjacent continents? 



Many questions and no easy answers! 



We have as far as I know no direct proof for a tundra vegetation earlier 

 than the Quaternary period. On the other hand, we know that the Taiga 

 formation (Piceetea) was already widely distributed in a large part of Siberia 

 in the second half of the Miocene and in the Pliocene. If Taiga existed as far 

 south as Baikal Lake, then there must have been conditions for a tundra 

 vegetation north of this vegetation type, if not in lowlands, then at least in the 

 Arctic mountains. 



If Lindquist's (1947) identification of Betula callosa in the Icelandic Miocene 

 is correct, we can expect true Arctic conditions not far to the north of the 

 Arctic Circle during that time. 



Now it is well known that in the Neogene the continents, at least in the 

 Northern Hemisphere, were raised perhaps several hundreds of meters 

 (cf., for example, Strachov, 1948). By this movement a land connection 

 between America, Iceland, and Scandinavia could be and most probably 

 was formed. Terrestrial sediments are found in this region originating mainly 

 from the Eocene (Kjartansson, 1940; cf. also Dahl, 1958), and the submarine 

 relief of the northern Atlantic shows us that there was a land connection not 

 only between Greenland and Scandinavia, but also between Northeast 

 Greenland and Spitsbergen (Fig. I). 



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