This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Gobet, E. Articles by Ammann, B. Search for Related Content GeoRef GeoRef Citation Social Bookmarking                         What's this?

Early-Holocene afforestation processes in the lower subalpine belt of the Central Swiss Alps as inferred from macrofossil and pollen records

Institute of Plant Sciences, Section Palaeoecology, University of Bern, Altenbergrain 21 CH-3013 Bern, Switzerland erika.gobet{at}ips.unibe.ch

Willy Tinner

Institute of Plant Sciences, Section Palaeoecology, University of Bern, Altenbergrain 21 CH-3013 Bern, Switzerland

Christian Bigler

Ecology and Environmental Science, Umea University, SE-90187 Umea, Sweden

Peter A. Hochuli

Paldontologisches Institut, University of Zurich, Karl Schmid-Strasse 4, CH-8006 Zurich, Switzerland

Brigitta Ammann

Institute of Plant Sciences, Section Palaeoecology, University of Bern, Altenbergrain 21 CH-3013 Bern, Switzerland

To reconstruct the vegetation history of the Upper Engadine, continuous sediment cores covering the past 11 800 years from Lej da Champfer and Lej da San Murezzan (Upper Engadine Valley, c. 1800 m a.s.l., southeastern Switzerland) have been analysed for pollen and plant macrofossils. The chronologies of the cores are based on 16 and 22 radiocarbon dates, respectively. The palaeobotanical records of both lakes are in agreement for the Holocene, but remarkable differences exist between the sites during the period 11 100 to 10 500 cal. BP, when Lej da Champfer was affected by re-sedimentation processes. Macrofossil data suggest that Holocene afforestation began at around 11400 cal. BP. A climatic deterioration, the Preboreal Oscillation, stopped and subsequently delayed the establishment of trees until c. 11000 cal. BP, when first Betula, then Pinus sylvestrislmugo, then Larix 300 years later, and finally Pinus cembra expanded within the lake catchment. Treeline was at c. 1500 m during the Younger Dryas (12 542- 11 550 cal. BP) in the Central Alps. Our results, along with other macrofossil studies from the Alps, suggest a nearly simultaneous afforestation (e.g., by Pinus sylvestris in the lower subalpine belt) between 1500 and 2340 m a.s.l. at around 11 400 to 11 300 cal. BP. We suggest that forest-limit species (e.g., Pinus cembra, Larix decidua) could expand faster at today's treeline (c. 2350 m a.s.l.), than 550 m lower. Earlier expansions at higher altitudes probably resulted from reduced competition with low-altitude trees (e.g. Pinus sylvestris) and herbaceous species. Comparison with other proxies such as oxygen isotopes, residual A1⁴C, glacier fluctuations, and alpine climatic cooling phases suggests climatic sensitivity of vegetation during the early Holocene.

Key Words: Palynology • vegetation history • timberline • succession • afforestation • Preboreal Oscillation • numerical methods • early Holocene • Swiss Alps

The Holocene, Vol. 15, No. 5, 672-686 (2005)
DOI: 10.1191/0959683605hl843rp


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				M. Wehrli, W. Tinner, and B. Ammann 16 000 years of vegetation and settlement history from Egelsee (Menzingen, central Switzerland) The Holocene, September 1, 2007; 17(6): 747 - 761. [Abstract] [PDF]