1000 years of environmental change and human impact at Stora-Mork,southern Iceland: A multiproxy study of a dynamic and vulnerable landscape

摘要

Multiproxy pollen, sediment, plant macrofossil and subfossil insect analyses are used to explore environmental change at Stora-Mork in southern Iceland between ad 500 and 1500. Previous palaeoecological studies in Iceland have indicated that vegetation and landscape change rapidly succeeded the initial settlement of the island around ad 871, with strong environmental consequences. However, recent high-resolution studies in western and northern Iceland suggest that the timing and amplitude of these changes may be less uniform than previously assumed. The palaeoecological evidence from Stora-Mork shows an initially muted anthropogenic signal. Before the early tenth century, the area was characterized by damp birch and willow woodland. Large-scale human impact did not begin until after ad 920 when a change in land use to grazing and crop production is observed in the pollen, insect and plant macrofossil records. Shifts in vegetation and insect taxa and in aeolian deposition indicate that this activity resulted in woodland reduction, increased soil instability, eutrophication and land surface drying. The relatively late appearance of large-scale human impact at Stora-Mork is consistent with the tenth-century farm establishment suggested by the historical record, and the delay in settlement at the location may relate to an initial avoidance of labour-intensive woodland clearance and/or management of woodland resources. This paper adds to the emerging body of evidence that suggests that the scale and timing of the initial effect of the human presence on Icelandic environments was influenced by complex and varied climatic, landscape, vegetational and cultural factors.