Jökull - 01.01.2004, Page 10

Hafdís Hanna Ægisdóttir and Þóra Ellen Þórhallsdóttir
Figure 2. Distribution of Campanula uniflora in Iceland. Figure/Mynd: Kristinsson, 2003. – Útbreiðsla fjalla-
bláklukku (Campanula uniflora) á Íslandi.
incompatable genus, as consistent with the theory of
glacial survival.
Tabula Rasa or Glacial Survival?
Where should one look for glacial relicts? A high arc-
tic species with disjunct and isolated populations that
are restricted to high mountain habitats is a likely sur-
vival candidate. High arctic species are most likely
better adapted to in situ survival than species of low-
arctic or boreal origin. In terms of environment, high
coastal mountains situated close to deep ocean waters
are more likely to have been ice-free (Dahl, 1946).
Campanula uniflora is a mostly high arctic species
with an amphi-Atlantic distribution (Brochmann and
Steen, 1999) and can be found as far north as 80◦N in
Greenland (Böcher et al., 1978) and Svalbard (data
provided by Herb. Univers. Osloensis). In Iceland,
C. uniflora is rare and its populations are restricted
to a few isolated populations in the coastal moun-
tains of the north and northwest (Figure 2) (Kristins-
son, 1986), which probably were ice-free during the
last glacial period (about 115,000 yrs ago until 10,000
yrs ago) (e.g. Hjort et al., 1985; Einarsson, 1991 and
Norðdahl, 1991) (Figure 1). Accordingly, C. uni-
flora is one of the most likely glacial survival candi-
dates in the Icelandic flora (Steindórsson, 1963). A
study on the genetic diversity of Campanula uniflora
in Iceland has recently been completed (Ægisdóttir,
2003). Results from an isozyme study on five dif-
ferent populations in Iceland show no molecular evi-
dence for glacial survival as there was no genetic di-
versity between geographically isolated populations
(Ægisdóttir, 2003).
10 JÖKULL No. 54