Saga - 1962, Blaðsíða 132

468
ÞORLEIFUR EINARSSON
SUMMARY
In this paper the author gives a brief review on pollen analysis
in Icelandic peat bogs, which have recently been started. The Ice-
landic flora consists of relatively few species, 440. The only forest
forming species is birch (Betula pubescens and B. tortuosa). The
climatic trends in postglacial times in Iceland seem to be similar to
those of the northwestern part of Europe. A) Late Glacial, birch
free in southern parts of the country and a small birch-maximum in
eastern N-Iceland; B) first birch period, followed by a birch-mini-
mum and a Sphagnum-maximum (9000—5000 before present, B. P.);
C) second birch period (5000 B. P.—870 A. D.); D) historical time
from 870 A. D.
The birch forest, which covered approximately 50 per cent of the
country 4000—2500 before present, declined from 2500 B.P. to the
onset of the settlement. In a short history of Iceland (íslendinga-
bók) written about 1120 Ari the Wise Thorgilsson (1068 — 1148) says
that Iceland was covered with wood between coast and mountain
when the landnám (settlement) began. Iceland was colonized mainly
from Norway in the years 870—930 A. D. After the beginning of the
landnám, the birch forest was devastated rapidly as can be seen from
the pollen diagrams. With the landnám the “wild” Gramineae in-
creased very rapidly and they are very characteristic for the in-
fluence of man in Iceland. Barley (Hordeum) was cultivated in Ice-
land during the first centuries of historical time. After the 15th or
16th century barley was not cultivated, perhaps for climatic, econo-
mical or other reasons. A small Cerealia-maximum in Skálholt in
the 17th century shows attempts to raise barley. The diagrams show
also some other cultural indicators (Artemisia, Myrica Gale, Linum
usitatissimum) and a sharp rise in weeds.
The inorganic constituents of Icelandic peat are much higher in
historical times than before, because of sedimentation of eolian dust
from soil deflation that began early in historical times. The pollen
analytical studies in Iceland are greatly faciliated by numerous,
partly dated, layers of volcanic ash in the bogs.