Late Quaternary environmental changes in Yakutia (NE Siberia, Russia) - inferred from pollen and testate amoebae records
An increase of the global mean temperature during the last decades can already be recognised and will further continue over the future decades. It is stated that high latitudes warm more than the global mean, especially in winter. Here, effects of the current warming can obviously be seen from the p...
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| Other Authors: | , , , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2009
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| Subjects: | |
| Online Access: | https://refubium.fu-berlin.de/handle/fub188/8795 https://doi.org/10.17169/refubium-12994 https://nbn-resolving.org/urn:nbn:de:kobv:188-fudissthesis000000011674-8 |
| Summary: | An increase of the global mean temperature during the last decades can already be recognised and will further continue over the future decades. It is stated that high latitudes warm more than the global mean, especially in winter. Here, effects of the current warming can obviously be seen from the present destruction of terrestrial and marine permafrost as well as the reduction of sea–ice. Increasing temperatures in winter and changing precipitation patterns will significantly affect the vegetation zonation, particularly the treeline and northern limit of boreal forests, which is expected to move northwards. There has been an increase of studies dealing with the climate change reconstruction of the late Quaternary based on multi-proxy studies from sedimentary records of high latitude regions over the last decades. However, for most of the previous studies definite age control or detailed palaeoclimatic implications are lacking. Sedimentary studies from permafrost archives of NE Siberia allow obtaining essential data on the palaeoenvironmental history of this region. In this study the region of Yakutia is of particular interest. Within this thesis it is aspired (i) to refine and improve the indicator ability of testate amoebae from Holocene and late glacial deposits in northern Yakutia and (ii) to reconstruct late Quaternary palaeoenvironmental changes in NE Siberia based on pollen analysis. For the first aim an attempt was made to use testate amoebae from permafrost regions of NE Siberia (Mamontov Klyk, Laptev Sea coast) as indicators of palaeoenvironmental changes at local and regional scales. By comparison with other environmental indicators from this and adjacent arctic regions it is suggested that testate amoebae analysis can provide valuable information for a better understanding of late Quaternary environmental developments and climate fluctuations in arctic Siberia. For the second aim fossil pollen samples from two sediment cores from Lake Billyakh, situated in the western foreland of the Verkhoyansk ... |
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