Náttúrufræðingurinn - 1971, Qupperneq 53

NÁTTÚRUFRÆÐI NGURINN
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Ingólfur Daviðsson. 1969. Gróðurathuganir 1966. Náttúruír. 38. árg. Reykja-
vík.
Kolilainen, M. ./. 1933. Zur Frage der Verbreitung des atlantischen Floren-
elementes Fennoskandias. Ann. Bot. soc. zool. bot. fenn. Vanamo. Hel-
sinki.
Stefán Stefánsson. 1948. F'lóra íslands, 3. útg. Akureyri.
Steindór Steindórsson. 1962. On the Age and Immigration of the Icelandic
Flora. Rit Vfsindafél. ísl. XXXV. Reykjavík.
— 1964. Gróður á íslandi. Reykjavík.
— 1964. Um ísaldarplöntur. Náttúrul'r. 34. árg. Reykjavík.
— 1968. Flóra Snæfellsness, Viðaukar. Flóra, 6. árg. Akureyri.
Sturla Friðriksson. 1963. Unt aðflutning íslenzku flórunnar. Náttúrufr. 32. árg.
Reykjavík.
S U M M A R Y
The Distribution of Vascular Plants in Iceland in Relation to Climate
Part II: Oceanic Distribulion
by
Helgi Hallgrimssoyi,
Museum of Natural History, Akureyri, Iceland.
In part I of this article (Náttúrufrædingurinn, Vol. 39, pp. 17—31, 1969),
a division of Iceland into climatic zones was suggested, by using the formula
of oceanic index by Iíotilainen (1933).
The formula is modified to fit the Icelandic conditions in the following
way: the íigure dt is here taken as an average number ol days witlt mean
temperature betweeu 0 and 5 centigrades. This number is not available in
the Icelandic weathertables, and therefore the method of Godske (1945) is
used to determine it. The numbers of this modified oceanic index are shown
on tlie map p. 20 in part I and the resulting division in Fig. 1 in this part.
Areas of plant species with similar distribution are drawn on the same
distribution maps, witli different lines.
The maps were produced as follows: first the distribution of each species
was plotted on a dot map. Of various reference-works with distribution maps,
used in the compilation, those of Steindórsson (1962), Löve & Löve (1956)
and Gröntved (1942) were the most important ones. Then lines were drawn
on the maps encircling all the dots, and at last these lines were copied on a
transparent paper to produce the final maps. The original maps are kept in
the Museum of Natural History in Akureyri, with references to the literature
used for making them.
The nomenclature follows that of Stefánsson (1948) with the exception of
Galium brevipes.
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