PHYTOGEOGRAPHICAL PROBLEMS IN SVALBARD 



OlAF I. RONNING 

 The Royal Norwegian Society of Sciences, Botanical Department, Trondheim, Norway 



The Norwegian name Svalbard is a collective appelation given to all the 

 islands situated in the Arctic Ocean between 10° and 35° E. Long, and 

 between 74° and 81° N. Lat. It includes Bear Island in the south, the Spits- 

 bergen Archipelago, and several other smaller groups of islands around 

 Spitsbergen, i.e. King Charles Land, Hope Island, Northeast Land, etc., with 

 a total area of about 62,000 km'^. 



Svalbard belongs to the High Arctic region, but has a climate influenced 

 by the Gulf Stream. One of the branches flows along the western coast of 

 Spitsbergen and keeps the water open in summer farther north than anywhere 

 else on the Globe. Cold, Arctic streams run especially on the east, south and 

 north sides and on the west side between the Gulf Stream and the land. 



The mean temperature from 1912 to 1930 (Gronfjorden, 78° 30' N.) was 



— 7.6°C for the whole year, the average for July being +5.4°C and for March 



— 19.0°C. The precipitation is very low, with an average of 287 mm per 

 annum, but both temperature and precipitation vary greatly from one part of 

 the area to another. 



Looking at the Svalbard flora as a whole, we find between 155 and 160 

 indigenous vascular plants, according to the concept of species now most 

 commonly accepted. This means that in spite of the latitude and the severe 

 climatic conditions, the flora is rather rich. In the south it is related to that of 

 northern Scandinavia or the Scandinavian mountain areas, in the west to the 

 flora of east Greenland. To the east we find many plants common to Svalbard 

 and the Novaya Zemlya islands, but farther east the relationship is not so 

 pronounced. 



About 120 of the ca. 160 species reported from Svalbard are found also on 

 the neighbouring European mainland, i.e. northern Scandinavia. The rest, 

 about 35 species, have a pronounced High Arctic distribution and do not occur 

 in northern Scandinavia. Among them are: Alopecurus alpinus, Dupontia 

 fisheri, Festuca baffinensis, F. brachyphylla, Pleuropogon sabinei, Poa abbreviata, 

 PuccineUia angustata, Carex ursina, Cerastiwn regelii, Mimiartia rossii, 

 Draba sitbcapitata, Saxifraga flagellar is. Taraxacum arcticum, and others. 



A considerable number of the remaining species belong to the group of 

 plants with a centric distribution in Scandinavia, which means that they are 

 mainly within one limited area in southern or northern Scandinavia. In the 



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