Evaluation of Different Pooling Methods to Establish a Multi-Century delta O-18 Chronology for Paleoclimate Reconstruction

Foroozan Z, Grießinger J, Pourtahmasi K, Bräuning A (2019)

Publication Type: Journal article

Publication year: 2019

Journal

Geosciences MDPI

Book Volume: 9

Journal Issue: 6

DOI: 10.3390/geosciences9060270

Abstract

To develop multi-century stable isotope chronologies from tree rings, pooling techniques are applied to reduce laboratory costs and time. However, pooling of wood samples from different trees may have adverse effects on the signal amplitude in the final isotope chronology. We tested different pooling approaches to identify the method that is most cost-efficient, without compromising the ability of the final chronology to reflect long-term climate variability as well as climatic extreme years. As test material, we used delta O-18 data from juniper trees (Juniperus polycarpus) from Northern Iran. We compared inter-tree and shifted 5-year blocks serial pooling of stable isotope series from 5 individual trees and addition of one single series to a shifted serial pooled chronology. The inter-tree pooled chronology showed the strongest climate sensitivity and most synchronous delta O-18 variations with the individual tree ring analyses, while the shifted block chronologies showed a marked decline in high-frequency signals and no correlations with climate variables of the growth year. Combinations of block-pooled and single isotope series compensated the high-frequency decline but added tree-individual climatic signals. Therefore, we recommend pooling calendar synchronous tree rings from individual trees as a viable alternative to individual-tree isotope measurements for robust paleoclimate reconstructions.

Authors with CRIS profile

Zeynab Foroozan Lehrstuhl für Geographie (Physische Geographie) Jussi Grießinger Institut für Geographie Achim Bräuning Lehrstuhl für Geographie (Physische Geographie)

Involved external institutions

University of Tehran IR Iran, Islamic Republic of (IR)

How to cite

APA:

Foroozan, Z., Grießinger, J., Pourtahmasi, K., & Bräuning, A. (2019). Evaluation of Different Pooling Methods to Establish a Multi-Century delta O-18 Chronology for Paleoclimate Reconstruction. Geosciences, 9(6). https://doi.org/10.3390/geosciences9060270

MLA:

Foroozan, Zeynab, et al. "Evaluation of Different Pooling Methods to Establish a Multi-Century delta O-18 Chronology for Paleoclimate Reconstruction." Geosciences 9.6 (2019).

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