Náttúrufræðingurinn - 1969, Blaðsíða 37

NÁTTÚRUFRÆÐI NGURINN
31
HEIMILDARIT
Godslte, C. L. 1944: Tlie Geographical Distribution in Norway of certain
Indices of Humidity and Oceanity. — Bergens Museums Árbok 1944.
Naturvidensk. rekke nr. 8.
Gröntved, Joh. 1942: Tlie Pteridophyta and Spermatophyta of Iceland. —
Botany of Iceland, Vol. IV, p. I.
Kotilainen, M. J. 1933: Zur Frage der Verbreitung des atlantischen Floren-
elements Fennoskandias. — Ann. Bot. soc. zool. bot. fenn. Vanamo. Flel-
sinki.
Löve, A. og D. 1956: Cytotaxonomical Conspectus of the Icelandic Flora. —
Acta horti Gothoburgensis, Vol. XX, 4.
Steindór Steindórsson. 1962: On the Age and Immigration of the Icelandic
Flora. Rit Vísindafél. fsl. XXXV.
Flóra íslands, 3. útg. Akureyri 1948.
Flóra. Tímarit um íslenzka grasafræði. Akureyri 1963—68.
Náttúrufræðingurinn. Reykjavík 1931—1968.
Veðráttan. Reykjavík 1924—1968.
S U M M A R Y
The distribution of plants in Iceland in relation to climate
Part I
by Helgi Hallgrimsson
Museum of Natural 1-listory, Akureyri.
The Icelandic climate has often been considered a higlily oceanic one, and
lor the south-east coastland, with annual precipitation 1500—2000 mm, this is
really the case. Also the peninsulas and the lowland in south-west is rather
oceanic. North of the great glaciers, however, one will lind a rather con-
tinental climate, with annual precipitation lower than 500 mm.
Using the formula of oceanic index, given by Kotilainen (1933) and modified
to take only the number of days with mean temperatures 0°—5° C, the author
has computed relative numbers for the principial weathcr stations in Iceland.
(Fig. I.) Then these numbers have been used to divide the country into five
climatic zones or areas (Fig. 3), oí which the zones I—111 may be termed
continental relative to the mean Icelandic climate.
The remaining maps (Fisg. 4—10) give the distribution limits of 32 vascular
plants, grouped according to their habitats and areals.
As may clearly be seen the distribution of these plants fits well in the region
(I—III, and IV, 1) of continental climate.
Some of the species in question will show a distinct continental distribution
in other countries too, and many are truly arctic.