Late-Holocene land-use history and environmental changes at the high altitudes of St Antoenien (Switzerland, Northern Alps): Combined evidence from pollen, soil and tree-ring analyses

In climatically sensitive regions such as the Northern Alps, changes in climate and land use have a strong impact on landscapes, vegetation, animals and humans. Multidisciplinary investigations in the high St Antoenien Valley (Switzerland) at 1400-3000 m a.s.l. have generated a reconstruction of land-use history. Humans began affecting the landscape of this high mountain region during the Bronze Age. Multiproxy palaeoenvironmental studies show that the present cultural landscape of the valley has been the result of long-term human environmental interactions. Pollen, soil and tree analyses were combined with archaeological and historical archives to provide strong evidence of the complexity of the high-mountain land-use system over the last 3500 years. Phases of agro-pastoral activity from Bronze Age (around 1300 BC), Iron Age (800-15 BC), Roman Period (15 BC-AD 450) and Middle Ages (AD 450-1500) are linked to climate and economic, social and cultural developments. Our results reveal that expansions of pasture land, in combination with climatic fluctuations, led to pronounced ecological changes in St Antoenien Valley. Humans adjusted land-use practices according to changing environmental conditions. In this context, the use of fire was an important factor in land management. Forest clearances reached maximum intensity during the late Middle Ages (AD 1300-1500) and triggered natural catastrophes that were amplified during the most severe environmental phase (AD 1600-1850) of the 'Little Ice Age' (LIA).