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| Titel |
δ¹³C and δ¹⁸O in Siberian tree rings as indicators of environmental changes in the Eurasian north |
| VerfasserIn |
O. V. Sidorova, R. T. W. Siegwolf, M. Saurer, T. Boettger, E. A. Vaganov |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019170
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| Zusammenfassung |
| According to the Intergovernmental Panel on Climate Change report (IPCC 2007) some aspects of the currentclimate change are not unusual, but others are. Therefore we need to look into the past for revealing “unusual”(extremely warm or cold) climatic changes. The application of long-term tree-ring chronologies in paleoclimatereconstructions helps us to evaluate climatic and environmental changes in the past and to estimate the magnitudeof the recent warming.The application of the stable isotope analysis to classical dendrochronology is steadily increasing because sta-ble isotopes provide complementary information about climatic variabilities, which is not available with tree ringwidth alone. In northern latitude forests, stable isotopes may yield insight into precipitation variability, while tree-ring width and density are more sensitive to temperature changes. Using stable isotopes is therefore very helpfulin improving our understanding of the forest response to environmental changes.The tree-ring width and stable isotope (δ13C,δ18O) analyses were carried out for Siberian tree ring chronologiesfrom northeastern Yakutia (70N-148E) and eastern Taimyr (71N-102E). The results showed extremely warm AD900-1100, AD 1950-2006 and extremely cold AD 516-560, AD 1600-1650, AD 1800-1850 periods during thelate Holocene. Isotope analyses reveal new supplementary signals about the moisture regime, in particular a cor-relation to July precipitation was found for the calibration period. We detected a strong relationship between theoxygen isotope ratio of tree rings and Greenland ice core chronologies [Meese et al. 1994] for the Medieval andrecent periods, which indicate similarities in the nature of low-frequency temperature variability in these two re-gions. Further, we found that trees from the vast Subarctic Eurasia zone (eastern Taimyr and northeastern Yakutia)showed a decrease in the tree radial growth,δ13C,δ18O in whole wood and cellulose after major volcanic eruptions(stratovolcano), that indicate a temperature decrease (up to 4◦C) due reduced incoming solar radiation, which isthought to be due to higher stomatal conductance caused by a decrease in VPD but lower photosynthetic capacity,due to significantly lower temperatures. |
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