Fire ecology of a tree glacial refugium on a nunatak with a view on Alpine glaciers

Abstract : . In paleoecology, the function of biomass as a fire driver has become a focus of attention in cold ecosystems, and concerns have been raised about climate in this context. Little is known about the fire frequency and fire–plant relationships during glaciation when woodlands were limited and the climate was cold. . Fire history and tree biomass were reconstructed from sedimentary charcoal and macrore- mains, respectively, archived in lake sediments from the western Alps. Two nunataks were investigated, both with lacustrine sediments covering the last 21 000 yr at least. . During the Last Glacial Maximum (LGM) and the Lateglacial, fires occurred only on the nunatak sheltering woody plants. Cembra pine (Pinus cembra) and larch (Larix decidua) sur- vived above glaciers during the LGM, thus evidencing a biological refugium and supporting the nunatak theory. . We highlighted a long-term relationship between fires and dominant trees over the last 21000yr, where fire frequencies track the global climate and the local changes in tree biomass. Glacial climate (dry, cold) does not rule out fires. Fuel load and composition were sig- nificant fire drivers, with cembra pine dominating during colder periods with rare fires, and larch during the warmer Holocene with frequent fires. These findings increase knowledge of fire ecology in cold environments, and open perspectives in tree population genetics by con- sidering new areas of tree glacial refugia in Europe.
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Article dans une revue
New Phytologist, Wiley, 2017, 216 (4), pp.1281 - 1290. 〈10.1111/nph.14721〉
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Contributeur : Nathalie Lyvet <>
Soumis le : mardi 14 novembre 2017 - 10:39:18
Dernière modification le : jeudi 19 avril 2018 - 14:28:02

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Christopher Carcaillet, Olivier Blarquez. Fire ecology of a tree glacial refugium on a nunatak with a view on Alpine glaciers. New Phytologist, Wiley, 2017, 216 (4), pp.1281 - 1290. 〈10.1111/nph.14721〉. 〈hal-01634462〉

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