Rit Landbúnaðardeildar : B-flokkur - 01.05.1947, Blaðsíða 17

15
transport seeds to Iceland from other countries. The observations given
by Guðmundsson (1940, 1942, 1945) on wind-driven birds in autumn and
winter from Scandinavia, and even from Siberia, show, however, that
birds may be able to cross the ocean from these countries to Iceland at
such time when fresh seeds may be available in nature. But no observation
on seeds transported by such wind-driven birds has been made at present
in our country, and the present writers are not inclined to believe that
they are able to carry living and germinable seeds to Southeast-Iceland
from Scandinavia (cf. Winge, 1. cit.). Similarly the distribution of
practically all the rare plant species of Iceland does not seem to
indicate a transport by aid of birds in recent times. The writers are at
least not inclined to suggest that many of the Icelandic species have been
imported by birds after the last glaciation.
As concerns the possibility of dispersion of species by sea currents,
different parts of plants have been borne every year to the coasts of
Iceland by the Gulf Stream and the Polar Current. The latter
is found to carry different arctic trees from the Siberian coasts
to the northern and western coasts of Iceland, and although the present
writers have not heard of seeds found driving towards the country at
places with a large amount of drift-wood from Siberia, it is not excluded
that seeds may be borne by the current from Siberia and Northern-
Norway to the Icelandic north-coast (cf. e.g. Norman, 1895). Closer studies
of the phytogeography of the northern coast in relation to the possible
dispersion of plant species by the Polar Current would eventually reveal
how many species might have invaded Iceland in that way after the
glaciations.
For a long time, however, it has been known that fruits and seeds of
tropical and subtropical plants may be borne by the Gulf Stream to the
south- and west-coasts of Iceland. Seeds of Caesalpinia, Dioclea, Entada,
Mucuna and even coconuts have frequently been collected on these
beaches. The same seeds have been observed several times on the beaches
of Northern and Western Europe (cf. Heintze, 1932—1936; Hemsley,
1885; Ridley, 1930). Most of the seeds, however, are not germinable
(cf. Hemsley, 1. cit.), although germinable seeds of Caesalpinia, Entada
and Mucuna have sometimes been found in Norway and Ireland (Heintze,
1932—1936; Ridley, 1930; Lindman, cited from Rommell, 1938, p.
360).
Of course seeds have been observed drifting in other parts of Europe,
e.g. in the Black Sea (cf. Borza and Bujorean, 1927), at Florida (Simpson,
1932), in the West-Indies and Azores (Guppy, 1917), and in different
places in East-Asia (cf. Kerr, 1930), but it is only of a theoretical interest