The Botany of Iceland - 01.12.1942, Síða 30
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JOHS. GRONTVED
natural (non-cultivated) soils from other European cold and coldly
temperate zones which as a rule are decidedly acid. Uncultivated Danish
heath soils, for instance, show pj_j = 4—4.5 ; the soil in the spruce forests
of Scandinavia has practically the same pj_[ (between 4 and 5), with a
humus content corresponding to the Icelandic peat and heath soils.
Further, the cultivated mineral soils of Scandinavia gradually approach
Pfj about 5, if CaC03 is not applied in sufficient quantities.
Iceland does not possess deposits of lime or marl necessary for an
economic liming, and the soil of that island kingdom does not require
the liming and marling so necessary in other countries if agriculture and
horticulture are to yield their utmost.
Climate.
The Climate of Iceland may be characterized as intermediate be-
tween temperate and arctic; in its main features it is strongly influenced
by the surrounding ocean, and especially in the coastal parts it is of a
marked oceanic character. The summers are relatively cool (cp. tab. 3),
and the winters as a rule mild. Often, however, there occur great
anomalies, so great indeed that they are hardly reconcilable with the
conditions of an insular climate (cp. Iwan, 1935, p. 33). The explana-
tion will be found in the fact that Iceland is situated in the very region
where Polar and Atlantic water-volumes are mixing.
Under these circumstances the ocean will be able to increase the
differences in temperature from one year to another instead of reducing
them; this depends on how much the island comes under the influence
of long-lasting cold northern winds, or has its northern coasts blockaded
with icebergs from the Polar sea—or, on the other hand, is subj'ect to
the effect of the warmer Atlantic waters.
Days with fog and atmospheric precipitation, as well as with strong
winds, are frequent, but on the whole it holds good that there is a great
variation in the climatic conditions in the various localities along the
coasts, just as the climate of the interior is very different from that of
the coastal areas. The climate of Central Iceland has a far more
continental character, especially manifesting itself in the fact that the
winter and spring are considerably colder here than in the coastal
region. It may, however, be said that our knowledge of the climate in
the interior is on the whole very limited, inasmuch as there have not so
far been any meteorological stations established there.