The history and impacts of farming activities in south Greenland: an insight from lake deposits

Abstract

Agriculture in southern Greenland has a two-phase history: with the Norse, who first settled and farmed the region between 985AD and circa 1450AD, and with the recent reintroduction of sheep farming (1920AD to the present). The agricultural sector in Greenland is expected to grow over the next century as anticipated climate warming extends the length of the growing season and increases productivity. This article presents a synthesis of results from a well-dated 1500-year lake sediment record from Lake Igaliku, south Greenland (61 • 00 N, 45 • 26 W, 15m asl) that demonstrates the relative impacts of modern and Norse agricultural activities. Pollen, non-pollen palynomorphs (NPPs), sediment mass accumulation rates, diatoms and stable isotopes of nitrogen provide a comprehensive history of both phases of agriculture and their associated impacts on the landscape and adjacent lake. The initial colonisation of southern Greenland is marked by a loss of tree birch pollen, a rise in weed taxa, and an increase in coprophilous fungi and sediment accumulation rate consistent with land-use changes. The biological and chemical proxies within the lake, however, show only slight changes in diatom taxa, and a rise in δ 15 N. After the Norse demise and during the Little Ice Age, most of the markers return to pre-settlement conditions. However, the continuation of non-indigenous plant taxa suggests that the landscape did not completely return to a pre-disturbance state. After 1988, the character of the lake changed markedly: mesotrophic diatoms and N isotopes all reveal major shifts consistent with a trophic shift, together with a sharp rise in sediment accumulation rate. The post-1988 lake environment, affected by modern farming development, is unprecedented within the context of the last 1500 years. These results demonstrate the potential of lake sediment studies paired with archaeological investigations to reveal the relationship between climate, environment and human societies.

Bequest of the Norseman—The Potential for Agricultural Intensification and Expansion in Southern Greenland under Climate Change

“…Igaliku has long been recognized as the historic site of Gardar, the seat of the bishop of the Norse settlements in Greenland during the Middle Ages (986 to 1450) and has already experienced intensive agricultural use during this period [4,32,33]. The current settlement of Igaliku has been established in 1782 by the Norwegian colonist Anders Olsen, whose family subsisted on few domestic cattle and sheep [32].…”

“…The Danish Meteorological Institute (DMI) modeled a lengthening of the growing season of approximately two months until 2100 [2]. Despite the ecological restrictions, Greenlandic agriculture has already experienced an enormous intensification during the last decades, e.g., by tillage of fodder fields and application of industrial fertilizers [3,4]. This trend is expected to grow further over the next century as climate warming is anticipated to increase the length of the growing season and productivity [4].…”

“…Finally, agriculture in the pristine landscape of southern Greenland is not without consequences for ecosystem stability [4]. Unsustainable land use can affect ecosystem functions in several ways, as for example soil degradation by loss of organic matter, salinization, compaction, structural destruction, sealing, contamination or acidification [22].…”

First evidence of cryptotephra in palaeoenvironmental records associated with Norse occupation sites in Greenland

“…Pollen-analytical and other palaeoenvironmental approaches have been providing unprecedentedly detailed evidence for the nature and course of Norse settlement, particularly from organic deposits lying within or in close proximity to archaeological sites (cf. Edwards et al, 2008;Buckland et al, 2009;Golding et al, 2011;Bichet et al, 2013;Ledger et al, 2013). A recurrent issue, however, has been the availability M A N U S C R I P T…”

Uncertainties of Two Methods in Selecting Priority Areas for Protecting Soil Conservation Service at Regional Scale

“…Humans can never destroy natural erosion or tolerable soil erosion [51]. However, humans' significant contribution to accelerating and decelerating soil erosion is well documented at various spatiotemporal scales and in various geographical locations [52][53][54][55]. Consequently, one of the key tasks of soil conservation is to avoid human-accelerated erosion [53].…”