Human impact on the Holocene forest line in the Central Alps

Abstract

Palaeoecological investigations of a small mire in Ötztal, Tyrol, Austria, situated about 50 m above the potential tree-line, indicates that human impact on the landscape started with burning of heath at approximately 5300 B.P. At about 4800 B.P. a weak increase in important apophytes may reflect the local presence of domestic animals. Between 4000 and 3500 B.P. a clear decline in pastoral activity occurred. From 3000 B.P. a strong increase in the representation of apophytes suggests local summer settlement, while in the interval 2600–2200 B.P. anthropogenic activity declined. After 2150 B.P. there was a marked increase in summer farm activity. Fresh information is presented on tree-line fluctuations during the Holocene: Pinus cembra forest ascended above the present potential tree-line by more than 50–100 m between 9000–8000 B.P., 6000–5500 B.P., and 3800–3000 B.P. A Betula maximum between 7000 and 5500 B.P. is probably due to succession in nearby avalanche tracks, as well as to a higher tree-line. Low humification and low loss-on-ignition values around 6000 B.P. may reflect the Frosnitz stadial (6900–6000 B.P.). The Rootmoos I stadial (5400 B.P.) and probably the early Sub-Atlantic stadial maximum (3000–2300) are also reflected in the physical properties of the peat profile.