Simulating oxygen isotope ratios in tree ring cellulose using a dynamic global vegetation model

Keel, Sonja Gisela Yin; Joos, Fortunat; Spahni, Renato; Saurer, Matthias; Weigt, Rosemarie B.; Klesse, Stefan (2016). Simulating oxygen isotope ratios in tree ring cellulose using a dynamic global vegetation model. Biogeosciences, 13(13), pp. 3869-3886. Copernicus Publications 10.5194/bg-13-3869-2016

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Records of stable oxygen isotope ratios in tree rings are valuable tools to reconstruct past climatic conditions and investigate the response of trees to those conditions. So far the use of stable oxygen isotope signatures of tree rings has not been systematically evaluated in dynamic global vegetation models (DGVMs). DGVMs integrate many hydrological and physiological processes and their application could improve proxy-model comparisons and the interpretation of oxygen isotope records. Here we present an approach to simulate leaf water and stem cellulose δ18O of trees using the LPX-Bern DGVM (LPX-Bern). Our results lie within a few per mil of measured tree ring δ18O of 31 different forest stands mainly located in Europe. Temporal means over the last 5 decades as well as interannual variations for a subset of sites in Switzerland are captured. A sensitivity analysis reveals that relative humidity, temperature, and the water isotope boundary conditions have the largest influence on simulated stem cellulose δ18O, followed by all climatic factors combined, whereas increasing atmospheric CO2 and nitrogen deposition exert no impact. We conclude that simulations with LPX-Bern are useful for investigating large-scale oxygen isotope patterns of tree ring cellulose to elucidate the importance of different environmental factors on isotope variations and therefore help to reduce uncertainties in the interpretation of δ18O of tree rings.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)

UniBE Contributor:

Keel, Sonja Gisela Yin; Joos, Fortunat and Spahni, Renato

Subjects:

500 Science > 530 Physics
500 Science > 550 Earth sciences & geology

ISSN:

1726-4170

Publisher:

Copernicus Publications

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

31 Oct 2016 09:00

Last Modified:

31 Oct 2016 09:00

Publisher DOI:

10.5194/bg-13-3869-2016

BORIS DOI:

10.7892/boris.89292

URI:

https://boris.unibe.ch/id/eprint/89292

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