Náttúrufræðingurinn - 1964, Síða 42

88
NÁTTÚRU FRÆÐINGURINN
Þær jurtir og jurtahlutar, sem nú þegar hafa fundizt á Surtsey
vaxa í Vestmannaeyjum og hafa því borizt á sjó um 5 til 20 krn
langan veg. Fjarlægð þessi er að vísu svo lítil borið saman við
vegalengd milli íslands og meginlandins, að ekki verður unnt að
draga af því neinar stórvægilegar ályktanir um möguleika á flutn-
ingi plantna milli fjarlægra staða. Hins vegar er þetta órækur vott-
ur þess, að strandjurtir geta borizt lifandi í sjó, bæði sem fræ og
heilar plöntur um skemmri veg. Berizt hins vegar jurtir til Surts-
eyjar, sem ekki finnast í Vestmannaeyjum, fer málið að horfa
öðruvísi við. Iir því fróðlegt að fylgjast áfram með landnámi lífs-
ins á Surtsey.
S U M M A R Y
The Colonization of the Dryland Biota on the Island of Surtsey
off the Coast of Iceland
by Sturla Friðriksson,
The University Research Institute, Iieykjavík.
On thc I4th of November an eruption oecurred in the ocean south of West-
mann Islands off the coast of Iceland. A day later an island emerged and
has now grown to the height of 172 meters and over 1 ktn- in area. This new
island has been named Surtsey.
It is of great importance to record the colonization of the dryland hiota on
this island. This is valuahle in order to study thc successive order in whidi
living beings coloni/.e a virgin island in the North Atlantic and to study by
what means biota is transported to the island. This has not previously been
recorded on an island in the North Atlantic and could ejucidate facts about
the origin of the present biota of Iceland. There are contradictory views
among scientists on the origin of the present biota of Iceland. Most authors
hold the view that a great part of the dryland flora and lower fauna invaded
Iceland by a landbridge, connecting it with the continent of Europe during
an interglacial period and then survived the last glaciation as small refuges
on nunatacs and other icefree regions, while thc greater part of the country
was covered by glaciers. It is also generally argued by thc same authors that
thc dispersal of biota to Iceland is extremely difficult by other means than
migration across the dryland or by the aid of man. Other have argued that
the migration across the ocean by ways of ocean currents, winds or birds in
post glacial times Iias played a major part in the origin of the present biota.
Although the distance betwecn the island of Surtur and the nearest island
is short compared to the distance between Iceland and the continent of
Europe, the study of the colonization of the new island may give some indi-
cation to the way the biota does disperse in the North Atlantic and it may