De la déglaciation à l’agriculture moderne :histoire environnementale du sud du Groenland

• Published in: Les Nouvelles de l'archéologie
• Main Authors: Gauthier, Emilie, Bichet, Vincent, Massa, Charly, Guillemot, Typhaine, Millet, Laurent, Petit, Christophe, Richard, Hervé
• Format: Article in Journal/Newspaper
• Language: French
• Published: Editions de la maison des sciences de l'homme 2015
• Subjects: analyse multi-proxy; lac; Vikings; archeo; hist; Garðar; Greenland; Igaliku; Dwarf birch; Groenland
• Online Access: http://journals.openedition.org/nda/3135

Palaeoenvironmentalists from the Chrono-environment laboratory in Besançon have been working in Greenland since 2006. The Study area is located in southern Greenland, within the Norse Eastern settlement occupied from 986 to 1450 cal. BC. The study aims at characterizing the impact of this first colonization on a pristine environment. The lacustrine sequence was studied with the help of different proxies (palynology, Non Pollen Palynomorph, Diatoms, sedimentology, geochemical and isotope analyses) and, in some site, the Norse settlement was integrated in the Holocene context. About 20 sediment cores were collected during 5 fieldtrips from 2006 to 2013. The Holocene sequence from Igaliku, the medieval Garðar, starts at 8000 cal. AD and the record of pollen rain start at about 6100 cal. AD it is one of the best radiocarbon dated sequence of this area. From 6100 to 2500 cal. AD, pollen diagram from Lake Igaliku shows that vegetation is dominated by juniper and willow. Starting in 2500 cal. AD, with the beginning of the neoglacial period, Juniper pollen decreases while dwarf birch and white birch become the dominant tree taxa. Decrease in birch and juniper and the rise in coprophilous fungi are the first evidences of the Norse settlement. The presence of settlers and livestock is clearly recorded: increasing soil erosion frequencies Norse apophytes (sheep sorrel, dandelion, buttercup) and coprophilous fungi. This colonization phase is followed by a period of decreasing human impact at the beginning of the 14th century, with a decrease in coprophilous fungi suggesting a reduced grazing pressure. The regrowth of willow and birch and the disappearance of anthropogenic indicators except sheep sorrel type between the 15th and 18th century demonstrate the abandonment of the settlement, until the development of contemporary agriculture in the 20th century. Impact of modern agriculture on vegetation is comparable to the Norse impact. However, mechanization and fertilization have heavily increased soil erosion and ...