An example of the consequences of human activities on the evolution of subalpine landscapes

A pollen study at Survilly (2235m asl, 06° 49′ 12″ E, 45° 59′ 24″ N), a small peatbog located on the Anterne mountain (Upper-Arve Valley, French north-western Alps) highlights the local role of human activities in Holocene vegetation dynamics of the currently treeless subalpine belt and the consecutive resumption of erosion. As early as 8890 cal. years BP (± 122), Pinus cembra grew close to the site. Grasslands without shrubs were established at around 4624 ± 86 cal. years BP. Due to human activities, spruces extended little after 3600 cal. BP. The intense grazing that resulted in the current alpine meadows goes back to 1436 cal. years BP (± 81). After 4624 cal. BP three clay layers show that from this period, the erosion became as active as during the first steps of the colonization of the vegetation prior to 10,050 cal. BP. During peat growth only a millimetre of clay at the end of the 9400–9050 cal. BP climatic event was recorded.