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Stable carbon isotope analysis of subfossil wood from Austrian Alps

Kłusek M., Pawełczyk S.

Geochronometria

2014

Vol. 41, no. 4

400--408

The presented studies were carried out in order to check the usefulness of subfossil wood for stable isotope analysis. The aim of research was also to define the optimal method of subfossil samples preparation. Subfossil samples used during the presented studies are a part of the multicentury dendrochronological scale. This chronology originates in an area situated around a small mountain lake — Schwarzersee, in Austria. The obtained results of stable carbon isotope measurements confirmed that the method of α-cellulose extraction by the application of acidic sodium chlorite and sodium hydroxide solutions removes resins and other mobile compounds from wood. Therefore, in the case of the analysed samples, the additional chemical process of extractives removing was found to be unnecessary. Studied wood samples contained an adequate proportion of α-cellulose similar to the values characteristic for the contemporary trees. This proved an adequate wood preservation which is essential for the conduction of isotopic research.

Influence of climate change on carbon and oxygen isotope fractionation factors between glucose and α-cellulose of pine wood

Sensuła B., Pazdur A.

Geochronometria

2013

Vol. 40, no. 2

145--152

We present the first analysis of the influence of climate change on carbon and oxygen isotope fractionation factors for two saccharides (glucose and α-cellulose ) of pine wood. The conifers grew in the Niepołomice Forest in Poland and the annual rings covered a time span from 1935 to 2000 AD. Glucose samples from acid hydrolysis of α-cellulose were extracted from annual tree rings. The carbon and oxygen isotope fractionation factors between glucose and α-cellulose were not stable over time. The mean value for the carbon isotope fractionation factors between glucose and α-cellulose was greater than unity. The mean value for the oxygen isotope fractionation factors be-tween glucose and α-cellulose was lower than unity. We established, with respect to climate change, the significance of the interannual and intraannual variation in the carbon and oxygen isotope frac-tionation factors between both saccharides. We used moving interval correlation results for May of the previous year through September of the current year using a base length of 48 years. The relation-ship with summer temperature is the main climate signal in the carbon isotope fractionation factor be-tween glucose and α-cellulose. The relationship with autumn sunshine is the main climate signal in the oxygen isotope fractionation factor between glucose and α-cellulose for the tree ring chronology.