Publication Date:
2013-06-19
Description:
Lac Moras is a small lake located on a low-elevation plateau in the upper Rhône Valley (304 m a.s.l.). The upper 5 m of accumulated sediment in the lake span 7500 years and offer a detailed record of environmental perturbations and land-use history at a local scale. A multiproxy analysis (pollen, charcoal and geochemical parameters) led to the establishment of four periods of landscape dynamics. The first evidence of human impacts was recorded during the Neolithic and Bronze Age (6000–2700 cal. BP). These impacts were temporary and most likely affected small areas. The second period, in the Iron Age/classical antiquity (2200–1900 cal. BP), appears to be a key period in which the intensification of anthropogenic pressure (primarily grazing with localised areas of cultivation) caused high-intensity erosion events and deeply affected soil stability. During the Middle Ages, wheat, rye and hemp cultures as well as tree farming (walnut, chestnut) were intensively developed. From 50 cal. BP (the 19th century) onward, crop cultivation declined and was gradually replaced by meadows and pastures. According to these transformations in agro-pastoral practices, the associated use of fire changed. Whereas fire was used intensively to clear wild areas from the Neolithic to the early Middle Ages, its use was restricted to cleaning agro-pastoral areas during the second part of the Middle Ages. These periods correspond to the different reconstructed types of land use. These changes correspond to population growth, the evolution of settlement patterns and the increase in agrarian productivity by technological advances. The present landscape is a result of this coupled agrarian and environmental history. It is notable that the first permanent alteration occurred as early as classical antiquity.
Print ISSN:
0959-6836
Electronic ISSN:
1477-0911
Topics:
Geography
,
Geosciences
