The climate of the Alps of the last 65,000 years. Climate reconstruction according to fossil vertebrate remains.
- Author(s)
- Doris Nagel, Michael Hofreiter, Federica Alberti, Susanne Lindauer, Nadja Kavcik-Graumann, Gernot Rabeder
- Abstract
Fossil mammals and birds from caves are the only biological tools for the reconstruction of the Alpine climate before the last great glaciation, since all other archives such as lake sediments or bogs were destroyed by the glacial advance about 20,000 years ago. There are some species that are adapted to a certain climate and tolerate only very small environmental fluctuations and these are of particular interest for reconstructing the former climate. It can be assumed that fossil representatives of these species have lived under the same environmental conditions and thus they can be used as climatic indicators. The diet of pure fossil representatives (e.g. cave bear) can be reconstructed based on tooth morphology and/or stable isotopes (nitrogen ratio). The ratio of carbon isotopes (C13/C12), the jaw morphology as well as the chewing patterns on molars give further information about the specialization within the herbivores. Browsers live from soft herbs and leaves, as they grow in forests, while grazers mainly feed on grass typically found in steppes and alpine pastures outside forests and above the tree line. The following criteria must be met by a taxon to be considered a climatic indicator: 1) Taxonomic classification: The assignment to an extant or fossil species (teeth and bones) must be unambiguous, if necessary with the help of DNA analysis. 2) Altitude of the site: The altitude of the cave is important because the average temperatures in the caves are closely linked to the altitude. The altitudinal gradient of the temperature is on average 0.65° C per 100 m, therefore the mean temperature values decrease by about 0.65° C per 100 m increase 3) Age determination: For a climate reconstruction, the assignment of the species to a certain age must be unambiguous. In addition to the radiocarbon method, which allows absolute ages only up to 50,000 years before present, for some taxa with sufficient DNA sequence information, such as cave bears, age determination by ancient-DNA is now also possible and even back much further in time. 4) Size of habitat: Animals have different habitat requirements; therefore, some migrate while others stay in close proximity. Migratory animals are for example reindeer, mammoths or rhinoceroses, which migrate long distances and thus cross climatically different areas. The climatological importance of migratory animals is much lower than that of non-migrating animals which do not leave an ecologically limited area throughout the year. Non-migrators are for example lemmings, marmots, ptarmigans, hamsters or jerboas but also cave bears.
- Organisation(s)
- Department of Palaeontology
- External organisation(s)
- Universität Potsdam, Curt-Engelhorn-Center Archaeometry gGmbH
- Publication date
- 2023
- Austrian Fields of Science 2012
- 105118 Palaeontology
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/beac0912-410a-45e5-8775-4d3ba74dd523