Interactions between climate and vegetation during the Lateglacial period as recorded by lake and mire sediment archives in Northern Italy and Southern Switzerland

• Published in: Quaternary Science Reviews
• Main Authors: Vescovi, Elisa, Ravazzi, Cesare, Arpenti, Enrico, Finsinger, Walter, Pini, Roberta, Valsecchi, Verushka, Wick, Lucia, Ammann, Brigitta, Tinner, Willy
• Other Authors: Institute of Plant Sciences, University of Bern, Institute for the Dynamics of Environmental Processes-CNR, CNR-IDPA, Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano-Bicocca Milano (UNIMIB), Utrecht University Utrecht, Consiglio Nazionale delle Ricerche Milano (CNR), University of Milan, Institute of Prehistory and Archaeological Science (IPAS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: [SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture; forestry; [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics; [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM]; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDE.MCG]Environmental Sciences/Global Changes; [SDE.ES]Environmental Sciences/Environmental and Society; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Greenland
• Online Access: https://hal.archives-ouvertes.fr/hal-01845686; https://doi.org/10.1016/j.quascirev.2007.03.005

International audience We reconstruct the vegetational history of the southern side of the Alps at 18,000–10,000 cal yr BP using previous and new AMS-dated stratigraphic records of pollen, stomata, and macrofossils. To address potential effects of climatic change on vegetation, we compare our results with independent paleoclimatic series (e.g. isotope and chironomid records from the Alps and the Alpine forelands). The period before 16,000 cal yr BP is documented only at the lowland sites. The previous studies used for comparison with our new Palughetto record, however, shows that Alpine deglaciation must have started before 18,000–17,500 cal yr BP south of the Alps and that deglaciated sites were colonized by open woods and shrublands (Juniperus, tree Betula, Larix, Pinus cembra) at ca 17,500 cal yr BP. The vegetational history of a new site (Palughetto, 1040 m a.s.l.) is consistent with that of previous investigations in the study region. Our results show three conspicuous vegetational shifts delimited by statistically significant pollen zones, at ca 14,800–14,400, 13,300–12,800 and 11,600–11,200 cal yr BP. At sites situated above 1000 m a.s.l. (e.g. Palughetto, Pian di Gembro) forests expanded in alpine environments at ca 14,500 cal yr BP (onset of Bølling period, GI-1 in the Greenland ice record). At the same time, rather closed treeline communities of the lowlands were replaced by dense stands of Pinus sylvestris and Betula. These early forests and shrublands consisted of Larix, P. cembra, Juniperus, P. sylvestris, Pinus mugo, and Betula, and had become established at ca 16,000 cal yr BP, probably in response to a temperature increase. If combined with other records from the Southern Alps, our data suggest that treeline ascended by ca 800–1000 m in a few centuries at most, probably as a consequence of climatic warming at the beginning of the Bølling period. At 13,100–12,800 cal yr BP the onset of a long-lasting decline of P. sylvestris was accompanied by the expansion of Quercus and other thermophilous ...