Árbók Hins íslenzka fornleifafélags - 01.01.2010, Blaðsíða 56

GRÓÐURFARSBREYTINGAR Á ÍSLANDI VIÐ LANDNÁM 55
Summary
The principal aims of our study were to investigate the f loristic landscapes in
existence at the time of settlement and the impact that Norse colonisation had upon
the vegetation. The focal period is AD 500-1500, which allows for the circum-settle-
ment investigation of the environmental response to the colonisation. Three main
study areas were selected, Ketilsstaðir in Mýrdalur and Stóra-Mörk in Eyjafjöll, both
in southern Iceland, and Reykholtsdalur in western Iceland.
The main study tool employed is high-resolution pollen analysis. This is
supplemented by stratigraphic analysis consisting especially of organic content
measurement and magnetic susceptibility. The determination of chronologies has been
greatly facilitated by tephrochronology. This provides both the Ketilsstaðir and Stóra-
Mörk study sites with robust and reliable temporal frameworks. In Reykholtsdalur,
more distant from much volcanic activity, a combination of tephrochronology and
radiocarbon dating had to be applied.
This study has revealed that the landscapes at the time of settlement were perhaps
more varied than commonly perceived. The areas in which the Ketilsstaðir farm was
established were without woodlands before AD 870 and remained so. In these open
landscapes, the impact of settlement on vegetation was minimal, and major changes
in the development of vegetation were driven by volcanic activity as much as land-
use. The wooded landscapes in which the farms at Stóra-Mörk and Reykholt in
Reykholtsdalur were established reacted differently to the arrival of humans. Around
the farms, the woodland soon retreated as landscapes became increasingly open,
and taxa common in meadows and pastures became increasingly dominant. Further
away from farms, woodland lingered into late medieval times. The pollen analysis of
lake sediments from Breiðavatn, ca. 2 km from Reykholt, has revealed that despite
a minimal decrease in the pollen of Betula pubescens soon after settlement, woodland
was able to thrive until between AD 1150-1300, during which time it was probably
permanently removed from the pollen catchment area. The consequence of woodland
removal and the subsequent exposure of soils was catastrophic soil erosion, which is
well recorded at both Stóra-Mörk and Breiðavatn.
Egill Erlendsson starfar við Líf- og umhverfisvísindadeild Háskóla Íslands.
Kevin J. Edwards starfar við Departments of Geography & Environment
and Archaeology við háskólann í Aberdeen.