No Age Trends in Oak Stable Isotopes. Issue 4 (31st March 2020)

• Record Type: Journal Article
• Authors: Büntgen, Ulf; Kolář, Tomáš; Rybníček, Michal; Koňasová, Eva; Trnka, Mirek; Ač, Alexander; Krusic, Paul J.; Esper, Jan; Treydte, Kerstin; Reinig, Fredrick; Kirdyanov, Alexander; Herzig, Franz; Urban, Otmar
• Is Part Of: Paleoceanography and paleoclimatology. Volume 35:Issue 4(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-31
• Subjects: oaks, tree rings, stable isotopes, paleoclimate, climate reconstructions, Europe; Paleoceanography -- Periodicals; Paleoclimatology -- Periodicals; 551.46
• DOI: 10.1029/2019PA003831
• Languages: English
• ISSNs: 2572-4517

Abstract

Abstract: Although the importance of stable isotope ratios in tree rings is increasing for high‐resolution climate reconstructions, it is still unclear if such values exhibit age trends that require some form of standardization. Here we present 13, 496 and 13, 584 annually resolved and absolutely dated δ 18 O and δ 13 C measurements from 147 living and relict oaks ( Quercus spp.) that grew over the past 2, 000 years in the Czech Republic. In contrast to their heteroscedastic ring widths, the stable isotopes reveal constant spread versus level relationships over the trees' life span. Together with high signal strength, the absence of age‐related constraints makes δ 18 O and δ 13 C from oak latewood alpha cellulose a superior climate proxy in regions where traditional tree‐ring parameters are limited. Plain Language Summary: Tree‐ring stable isotopes are important paleoclimatic archives in regions where traditional dendrochronological parameters, such as ring width and wood density, perform poorly. However, it remains debatable if isotopic ratios contain nonclimatic age trends that require some initial statistical treatment. A well‐replicated compilation of annually resolved and absolutely dated stable oxygen and carbon isotope ratios in 21 living and 126 relict oaks from the Czech Republic provides unprecedented evidence to assess this biostatistical and tree physiological conundrum. Evenly distributed over the past 2, 000 years, neither the 13, 496 individual δ 18 O nor the 13, 584 individual δ 13 C measurement values exhibit any detectable trend during the life span of the oaks investigated. In rejecting age‐related limitations, and demonstrating strong temperature dependency, we conclude that nonpooled oak stable isotope ratios are possibly the best paleoclimatic archive for the central European lowlands and other areas where the species was most commonly used as construction timber, and where conventional tree‐ring parameters often fail. Key Points: We present and analyze 27, 080 annually resolved stable carbon and oxygen measurements from living and relict oaks Absence of age trends in stable carbon and oxygen measurements from Czech oaks over the past 2, 000 years Nonpooled oak stable isotope ratios are a superb paleoclimatic archive for central Europe where other tree‐ring parameters fail