Warm season precipitation signal in [delta]2H values of wood lignin methoxyl groups from high elevation larch trees in Switzerland
Rationale In this study, we tested stable hydrogen isotope ratios of wood lignin methoxyl groups ([delta]2Hmethoxyl values) as a palaeoclimate proxy in dendrochronology. This is a quite new method in the field of dendrochronology and the sample preparation is much simpler than the methods used befor...
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Published in | Rapid communications in mass spectrometry Vol. 31; no. 19; p. 1589 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Bognor Regis
Wiley Subscription Services, Inc
15.10.2017
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Subjects | |
Online Access | Get full text |
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Summary: | Rationale In this study, we tested stable hydrogen isotope ratios of wood lignin methoxyl groups ([delta]2Hmethoxyl values) as a palaeoclimate proxy in dendrochronology. This is a quite new method in the field of dendrochronology and the sample preparation is much simpler than the methods used before to measure [delta]2H values from wood. Methods We measured [delta]2Hmethoxyl values in high elevation larch trees (Larix decidua Mill.) from Simplon Valley (southern Switzerland). Thirty-seven larch trees were sampled and five individuals analysed for their [delta]2Hmethoxyl values at annual (1971-2009) and pentadal resolution (1746-2009). The [delta]2Hmethoxyl values were measured as CH3I released upon treatment of the dried wood samples with hydroiodic acid. 10-90 µL from the head-space were injected into the gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/HTC-IRMS) system. Results Testing the climate response of the [delta]2Hmethoxyl values, the annually resolved series show a positive correlation of r = 0.60 with June/July precipitation. The pentadally resolved [delta]2Hmethoxyl series do not show any significant correlation to climate parameters. Conclusions Increased precipitation during June and July, which are on average warm and relatively dry months, results in higher [delta]2H values of the xylem water and, therefore, higher [delta]2H values in the lignin methoxyl groups. Therefore, we suggest that [delta]2Hmethoxyl values of high elevation larch trees might serve as a summer precipitation proxy. |
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ISSN: | 0951-4198 1097-0231 |
DOI: | 10.1002/rcm.7938 |