Rit Landbúnaðardeildar : B-flokkur - 01.05.1947, Blaðsíða 19

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time of the first dispersion of different plant species to Iceland by sea
currents, hut in the case of Cnkile edentula the present writers are inclined
to suggest that this species has not survived the last g'laciation on the
island. If the species had survived in Iceland during the last glaciation and
since been dispersed by sea currents, it can be assumed that it would have
survived either in some places in West-Iceland or in the eastern parts of
South-Iceland. But, then, the sea currents would nol have been able to plant
the seeds to the beaches of Revkjanes in the South-West of Iceland, where it
is especially common at present (cf. Iwan, 1935). If, however, it has
survived on the unglaciated coasts in different parts of the island, its
present occurrence wrould scarcely be connected only to the present
coast line. Wide areas in the lowland in the southern and western parts
of the island were covered Avith sea just after the glaciations (cf. Iwan,
1935t, and the coast line Avas 100 km or more further inland than it is
at the present. If the species were found in the island at that time, it
might at least be assumed that it would appear at present not only at the
coasts hut also at lakes and along rivers in Ihe lowland in Borgarfjörður
and Suðurland. Its persistence in such localities is known in America,
e.g. at the Great Lakes. The present writers, however, have not been able
to find any locality far from Ihe present coast line, and they feel strongly
that the species Cakile edentula has been transported to the Icelandic
coasts after the end of the last glaciation and after the coast line took
on its present form.
Although some other species have certainly dispersed to Iceland by
means of sea currents after the last glaciation, the present writers are not
inclined to assume that more than 15% of the present flora elements
have dispersed to the island after the Ice Age. As mentioned above, up to
30% of the flora might have been transported bjr the aid of man during
the last 1100—'1200 years. But the remaining 55% (at least) are sug-
gested to have survived the latest glaciation and possibly the whole Ice
Age in Iceland.
As regards the possibilities of Ihe survival of plants during the last
glaciation in Iceland, Hansen (1904, 1930) was the first to point out that
at Ieast a part of the flora of Iceland must have dispersed to the island
before the glaciation took place. Lindhoth (1931), who studied the Ice-
landic insects and demonstrated that a relatively hig'h percentage of the
insect fauna must have survived the Ice Age in some places, also gave
some accounts of possible hibernators among the plants. Gplting (1934)
concluded that at least Primula stricta and Carex glacialis might have
survived in Iceland as well as in Greenland, and also that Arenaria
norvegica must have immigrated to Iceland prior to the latest glaciation
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